Author: "Perotti F" - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"Perotti F"' showing total 1,014 results

Start Over Author "Perotti F"

1,014 results on '"Perotti F"'

1. Benchmarking the design of the cryogenics system for the underground argon in DarkSide-20k

Author: Collaboration, DarkSide-20k, Acerbi, F., Adhikari, P., Agnes, P., Ahmad, I., Albergo, S., Albuquerque, I. F. M., Alexander, T., Alton, A. K., Amaudruz, P., Angiolilli, M., Aprile, E., Ardito, R., Corona, M. Atzori, Auty, D. J., Ave, M., Avetisov, I. C., Azzolini, O., Back, H. O., Balmforth, Z., Olmedo, A. Barrado, Barrillon, P., Batignani, G., Bhowmick, P., Blua, S., Bocci, V., Bonivento, W., Bottino, B., Boulay, M. G., Buchowicz, A., Bussino, S., Busto, J., Cadeddu, M., Cadoni, M., Calabrese, R., Camillo, V., Caminata, A., Canci, N., Capra, A., Caravati, M., Cárdenas-Montes, M., Cargioli, N., Carlini, M., Castellani, A., Castello, P., Cavalcante, P., Cebrian, S., Ruiz, J. Cela, Chashin, S., Chepurnov, A., Cifarelli, L., Cintas, D., Citterio, M., Cleveland, B., Coadou, Y., Cocco, V., Colaiuda, D., Vilda, E. Conde, Consiglio, L., Costa, B. S., Czubak, M., D'Aniello, M., D'Auria, S., Rolo, M. D. Da Rocha, Darbo, G., Davini, S., De Cecco, S., De Guido, G., Dellacasa, G., Derbin, A. V., Devoto, A., Di Capua, F., Di Ludovico, A., Di Noto, L., Di Stefano, P., Dias, L. K., Mairena, D. Díaz, Ding, X., Dionisi, C., Dolganov, G., Dordei, F., Dronik, V., Elersich, A., Ellingwood, E., Erjavec, T., Diaz, M. Fernandez, Ficorella, A., Fiorillo, G., Franchini, P., Franco, D., Gatti, H. Frandini, Frolov, E., Gabriele, F., Gahan, D., Galbiati, C., Galiński, G., Gallina, G., Gallus, G., Garbini, M., Abia, P. Garcia, Gawdzik, A., Gendotti, A., Ghisi, A., Giovanetti, G. K., Casanueva, V. Goicoechea, Gola, A., Grandi, L., Grauso, G., di Cortona, G. Grilli, Grobov, A., Gromov, M., Guerzoni, M., Gulino, M., Guo, C., Hackett, B. R., Hallin, A., Hamer, A., Haranczyk, M., Harrop, B., Hessel, T., Hill, S., Horikawa, S., Hu, J., Hubaut, F., Hucker, J., Hugues, T., Hungerford, E. V., Ianni, A., Ippolito, V., Jamil, A., Jillings, C., Jois, S., Kachru, P., Keloth, R., Kemmerich, N., Kemp, A., Kendziora, C. L., Kimura, M., Kish, A., Kondo, K., Korga, G., Kotsiopoulou, L., Koulosousas, S., Kubankin, A., Kunzé, P., Kuss, M., Kuźniak, M., Kuzwa, M., La Commara, M., Lai, M., Guirriec, E. Le, Leason, E., Leoni, A., Lidey, L., Lissia, M., Luzzi, L., Lychagina, O., Macfadyen, O., Machulin, I. N., Manecki, S., Manthos, I., Mapelli, L., Marasciulli, A., Mari, S. M., Mariani, C., Maricic, J., Martinez, M., Martoff, C. J., Matteucci, G., Mavrokoridis, K., McDonald, A. B., Mclaughlin, J., Merzi, S., Messina, A., Milincic, R., Minutoli, S., Mitra, A., Moharana, A., Moioli, S., Monroe, J., Moretti, E., Morrocchi, M., Mroz, T., Muratova, V. N., Murphy, M., Murra, M., Muscas, C., Musico, P., Nania, R., Nessi, M., Nieradka, G., Nikolopoulos, K., Nikoloudaki, E., Nowak, J., Olchanski, K., Oleinik, A., Oleynikov, V., Organtini, P., de Solórzano, A. Ortiz, Pallavicini, M., Pandola, L., Pantic, E., Paoloni, E., Papi, D., Pastuszak, G., Paternoster, G., Peck, A., Pegoraro, P. A., Pelczar, K., Pellegrini, L. A., Perez, R., Perotti, F., Pesudo, V., Piacentini, S. I., Pino, N., Plante, G., Pocar, A., Poehlmann, M., Pordes, S., Pralavorio, P., Price, D., Puglia, S., Bazetto, M. Queiroga, Ragusa, F., Ramachers, Y., Ramirez, A., Ravinthiran, S., Razeti, M., Renshaw, A. L., Rescigno, M., Retiere, F., Rignanese, L. P., Rivetti, A., Roberts, A., Roberts, C., Rogers, G., Romero, L., Rossi, M., Rubbia, A., Rudik, D., Sabia, M., Salomone, P., Samoylov, O., Sandford, E., Sanfilippo, S., Santone, D., Santorelli, R., Santos, E. M., Savarese, C., Scapparone, E., Schillaci, G., Schuckman II, F. G., Scioli, G., Semenov, D. A., Shalamova, V., Sheshukov, A., Simeone, M., Skensved, P., Skorokhvatov, M. D., Smirnov, O., Smirnova, T., Smith, B., Sotnikov, A., Spadoni, F., Spangenberg, M., Stefanizzi, R., Steri, A., Stornelli, V., Stracka, S., Sulis, S., Sung, A., Sunny, C., Suvorov, Y., Szelc, A. M., Taborda, O., Tartaglia, R., Taylor, A., Taylor, J., Tedesco, S., Testera, G., Thieme, K., Thompson, A., Thorpe, T. N., Tonazzo, A., Torres-Lara, S., Tricomi, A., Unzhakov, E. V., Vallivilayil, T. J., Van Uffelen, M., Velazquez-Fernandez, L., Viant, T., Viel, S., Vishneva, A., Vogelaar, R. B., Vossebeld, J., Vyas, B., Wada, M., Walczak, M. B., Wang, H., Wang, Y., Westerdale, S., Williams, L., Wojaczyński, R., Wojcik, M., Wojcik, M. M., Wright, T., Xiao, X., Xie, Y., Yang, C., Yin, J., Zabihi, A., Zakhary, P., Zani, A., Zhang, Y., Zhu, T., Zichichi, A., Zuzel, G., and Zykova, M. P.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: DarkSide-20k (DS-20k) is a dark matter detection experiment under construction at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. It utilises ~100 t of low radioactivity argon from an underground source (UAr) in its inner detector, with half serving as target in a dual-phase time projection chamber (TPC). The UAr cryogenics system must maintain stable thermodynamic conditions throughout the experiment's lifetime of >10 years. Continuous removal of impurities and radon from the UAr is essential for maximising signal yield and mitigating background. We are developing an efficient and powerful cryogenics system with a gas purification loop with a target circulation rate of 1000 slpm. Central to its design is a condenser operated with liquid nitrogen which is paired with a gas heat exchanger cascade, delivering a combined cooling power of >8 kW. Here we present the design choices in view of the DS-20k requirements, in particular the condenser's working principle and the cooling control, and we show test results obtained with a dedicated benchmarking platform at CERN and LNGS. We find that the thermal efficiency of the recirculation loop, defined in terms of nitrogen consumption per argon flow rate, is 95 % and the pressure in the test cryostat can be maintained within $\pm$(0.1-0.2) mbar. We further detail a 5-day cool-down procedure of the test cryostat, maintaining a cooling rate typically within -2 K/h, as required for the DS-20k inner detector. Additionally, we assess the circuit's flow resistance, and the heat transfer capabilities of two heat exchanger geometries for argon phase change, used to provide gas for recirculation. We conclude by discussing how our findings influence the finalisation of the system design, including necessary modifications to meet requirements and ongoing testing activities., Comment: 45 pages, 24 figures
Published: 2024

2. DarkSide-20k sensitivity to light dark matter particles

Author: Collaboration, DarkSide-20k, Acerbi, F., Adhikari, P., Agnes, P., Ahmad, I., Albergo, S., Albuquerque, I. F. M., Alexander, T., Alton, A. K., Amaudruz, P., Angiolilli, M., Aprile, E., Ardito, R., Corona, M. Atzori, Auty, D. J., Ave, M., Avetisov, I. C., Azzolini, O., Back, H. O., Balmforth, Z., Olmedo, A. Barrado, Barrillon, P., Batignani, G., Bhowmick, P., Blua, S., Bocci, V., Bonivento, W., Bottino, B., Boulay, M. G., Buchowicz, A., Bussino, S., Busto, J., Cadeddu, M., Cadoni, M., Calabrese, R., Camillo, V., Caminata, A., Canci, N., Capra, A., Caravati, M., Cárdenas-Montes, M., Cargioli, N., Carlini, M., Castellani, A., Castello, P., Cavalcante, P., Cebrian, S., Ruiz, J. M. Cela, Chashin, S., Chepurnov, A., Cifarelli, L., Cintas, D., Citterio, M., Cleveland, B., Coadou, Y., Cocco, V., Colaiuda, D., Vilda, E. Conde, Consiglio, L., Costa, B. S., Czubak, M., D'Aniello, M., D'Auria, S., Rolo, M. D. Da Rocha, Darbo, G., Davini, S., De Cecco, S., De Guido, G., Dellacasa, G., Derbin, A. V., Devoto, A., Di Capua, F., Di Ludovico, A., Di Noto, L., Di Stefano, P., Dias, L. K., Mairena, D. Díaz, Ding, X., Dionisi, C., Dolganov, G., Dordei, F., Dronik, V., Elersich, A., Ellingwood, E., Erjavec, T., Diaz, M. Fernandez, Ficorella, A., Fiorillo, G., Franchini, P., Franco, D., Gatti, H. Frandini, Frolov, E., Gabriele, F., Gahan, D., Galbiati, C., Galiński, G., Gallina, G., Gallus, G., Garbini, M., Abia, P. Garcia, Gawdzik, A., Gendotti, A., Ghisi, A., Giovanetti, G. K., Casanueva, V. Goicoechea, Gola, A., Grandi, L., Grauso, G., di Cortona, G. Grilli, Grobov, A., Gromov, M., Guerzoni, M., Gulino, M., Guo, C., Hackett, B. R., Hallin, A., Hamer, A., Haranczyk, M., Harrop, B., Hessel, T., Hill, S., Horikawa, S., Hu, J., Hubaut, F., Hucker, J., Hugues, T., Hungerford, E. V., Ianni, A., Ippolito, V., Jamil, A., Jillings, C., Jois, S., Kachru, P., Keloth, R., Kemmerich, N., Kemp, A., Kendziora, C. L., Kimura, M., Kondo, K., Korga, G., Kotsiopoulou, L., Koulosousas, S., Kubankin, A., Kunzé, P., Kuss, M., Kuźniak, M., Kuzwa, M., La Commara, M., Lai, M., Guirriec, E. Le, Leason, E., Leoni, A., Lidey, L., Lissia, M., Luzzi, L., Lychagina, O., Macfadyen, O., Machulin, I. N., Manecki, S., Manthos, I., Mapelli, L., Marasciulli, A., Mari, S. M., Mariani, C., Maricic, J., Martinez, M., Martoff, C. J., Matteucci, G., Mavrokoridis, K., McDonald, A. B., Mclaughlin, J., Merzi, S., Messina, A., Milincic, R., Minutoli, S., Mitra, A., Moioli, S., Monroe, J., Moretti, E., Morrocchi, M., Mroz, T., Muratova, V. N., Murphy, M., Murra, M., Muscas, C., Musico, P., Nania, R., Nessi, M., Nieradka, G., Nikolopoulos, K., Nikoloudaki, E., Nowak, J., Olchanski, K., Oleinik, A., Oleynikov, V., Organtini, P., de Solórzano, A. Ortiz, Pallavicini, M., Pandola, L., Pantic, E., Paoloni, E., Papi, D., Pastuszak, G., Paternoster, G., Peck, A., Pegoraro, P. A., Pelczar, K., Pellegrini, L. A., Perez, R., Perotti, F., Pesudo, V., Piacentini, S., Pino, N., Plante, G., Pocar, A., Poehlmann, M., Pordes, S., Pralavorio, P., Price, D., Puglia, S., Bazetto, M. Queiroga, Ragusa, F., Ramachers, Y., Ramirez, A., Ravinthiran, S., Razeti, M., Renshaw, A. L., Rescigno, M., Retiere, F., Rignanese, L. P., Rivetti, A., Roberts, A., Roberts, C., Rogers, G., Romero, L., Rossi, M., Rubbia, A., Rudik, D., Sabia, M., Salomone, P., Samoylov, O., Sandford, E., Sanfilippo, S., Santone, D., Santorelli, R., Santos, E. M., Savarese, C., Scapparone, E., Schillaci, G., Schuckman II, F. G., Scioli, G., Semenov, D. A., Shalamova, V., Sheshukov, A., Simeone, M., Skensved, P., Skorokhvatov, M. D., Smirnov, O., Smirnova, T., Smith, B., Sotnikov, A., Spadoni, F., Spangenberg, M., Stefanizzi, R., Steri, A., Stornelli, V., Stracka, S., Sulis, S., Sung, A., Sunny, C., Suvorov, Y., Szelc, A. M., Taborda, O., Tartaglia, R., Taylor, A., Taylor, J., Tedesco, S., Testera, G., Thieme, K., Thompson, A., Tonazzo, A., Torres-Lara, S., Tricomi, A., Unzhakov, E. V., Vallivilayil, T. J., Van Uffelen, M., Velazquez-Fernandez, L., Viant, T., Viel, S., Vishneva, A., Vogelaar, R. B., Vossebeld, J., Vyas, B., Walczak, M. B., Wang, Y., Wang, H., Westerdale, S., Williams, L., Wojaczyński, R., Wojcik, M., Wojcik, M. M., Wright, T., Xie, Y., Yang, C., Yin, J., Zabihi, A., Zakhary, P., Zani, A., Zhang, Y., Zhu, T., Zichichi, A., Zuzel, G., and Zykova, M. P.
Subjects: High Energy Physics - Experiment, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The dual-phase liquid argon time projection chamber is presently one of the leading technologies to search for dark matter particles with masses below 10 GeV/c$^2$. This was demonstrated by the DarkSide-50 experiment with approximately 50 kg of low-radioactivity liquid argon as target material. The next generation experiment DarkSide-20k, currently under construction, will use 1,000 times more argon and is expected to start operation in 2027. Based on the DarkSide-50 experience, here we assess the DarkSide-20k sensitivity to models predicting light dark matter particles, including Weakly Interacting Massive Particles (WIMPs) and sub-GeV/c$^2$ particles interacting with electrons in argon atoms. With one year of data, a sensitivity improvement to dark matter interaction cross-sections by at least one order of magnitude with respect to DarkSide-50 is expected for all these models. A sensitivity to WIMP--nucleon interaction cross-sections below $1\times10^{-42}$ cm$^2$ is achievable for WIMP masses above 800 MeV/c$^2$. With 10 years exposure, the neutrino fog can be reached for WIMP masses around 5 GeV/c$^2$., Comment: 13 pages, 4 figures, supplementary material (4 figures)
Published: 2024
Full Text: View/download PDF

3. A new hybrid gadolinium nanoparticles-loaded polymeric material for neutron detection in rare event searches

Author: Collaboration, DarkSide-20k, Acerbi, F., Adhikari, P., Agnes, P., Ahmad, I., Albergo, S., Albuquerque, I. F., Alexander, T., Alton, A. K., Amaudruz, P., Angiolilli, M., Aprile, E., Ardito, R., Corona, M. Atzori, Auty, D. J., Ave, M., Avetisov, I. C., Azzolini, O., Back, H. O., Balmforth, Z., Olmedo, A. Barrado, Barrillon, P., Batignani, G., Bhowmick, P., Bocci, V., Bonivento, W., Bottino, B., Boulay, M. G., Buchowicz, A., Bussino, S., Busto, J., Cadeddu, M., Cadoni, M., Calabrese, R., Camillo, V., Caminata, A., Canci, N., Capra, A., Caravati, M., Cárdenas-Montes, M., Cargioli, N., Carlini, M., Castellani, A., Castello, P., Cavalcante, P., Cavallo, D., Cebrian, S., Ruiz, J. Cela, Chashin, S., Chepurnov, A., Cifarelli, L., Cintas, D., Citterio, M., Cleveland, B., Coadou, Y., Cocco, V., Colaiuda, D., Vilda, E. Conde, Consiglio, L., Costa, B. S., Czubak, M., D'Auria, S., Rolo, M. D. Da Rocha, Darbo, G., Davini, S., De Cecco, S., De Guido, G., Dellacasa, G., Derbin, A. V., Devoto, A., Di Capua, F., Di Ludovico, A., Di Noto, L., Di Stefano, P., Dias, L. K., Mairena, D. Díaz, Ding, X., Dionisi, C., Dolganov, G., Dordei, F., Dronik, V., Elersich, A., Ellingwood, E., Erjavec, T., Diaz, M. Fernandez, Ficorella, A., Fiorillo, G., Franchini, P., Franco, D., Gatti, H. Frandini, Frolov, E., Gabriele, F., Gahan, D., Galbiati, C., Galinski, G., Gallina, G., Garbini, M., Abia, P. Garcia, Gawdzik, A., Gendotti, A., Ghisi, A., Giovanetti, G. K., Casanueva, V. Goicoechea, Gola, A., Grandi, L., Grauso, G., di Cortona, G. Grilli, Grobov, A., Gromov, M., Guerzoni, M., Gulino, M., Guo, C., Hackett, B. R., Hallin, A., Hamer, A., Haranczyk, M., Harrop, B., Hessel, T., Hill, S., Horikawa, S., Hu, J., Hubaut, F., Hucker, J., Hugues, T., Hungerford, E. V., Ianni, A., Ippolito, V., Jamil, A., Jillings, C., Keloth, R., Kemmerich, N., Kemp, A., Kendziora, C. L., Kimura, M., Kondo, K., Korga, G., Kotsiopoulou, L., Koulosousas, S., Kubankin, A., Kuss, M., Kuzniak, M., Kuzwa, M., La Commara, M., Lai, M., Guirriec, E. Le, Leason, E., Leoni, A., Lidey, L., Lissia, M., Luzzi, L., Lychagina, O., Macfadyen, O., Machulin, I. N., Manecki, S., Manthos, I., Mapelli, L., Marasciulli, A., Mari, S. M., Mariani, C., Maricic, J., Marini, A., Martinez, M., Martoff, C. J., Matteucci, G., Mavrokoridis, K., McDonald, A. B., Mclaughlin, J., Merzi, S., Messina, A., Milincic, R., Minutoli, S., Mitra, A., Moharana, A., Moioli, S., Monroe, J., Moretti, E., Morrocchi, M., Mroz, T., Muratova, V. N., Murphy, M., Murra, M., Muscas, C., Musico, P., Nania, R., Nessi, M., Nieradka, G., Nikolopoulos, K., Nikoloudaki, E., Nowak, J., Olchanski, K., Oleinik, A., Oleynikov, V., Organtini, P., de Solórzano, A. Ortiz, Pallavicini, M., Pandola, L., Pantic, E., Paoloni, E., Papi, D., Pastuszak, G., Paternoster, G., Peddis, D., Pegoraro, P. A., Pelczar, K., Pellegrini, L. A., Perez, R., Perotti, F., Pesudo, V., Piacentini, S. I., Pino, N., Plante, G., Pocar, A., Poehlmann, M., Pordes, S., Pralavorio, P., Price, D., Puglia, S., Bazetto, M. Queiroga, Ragusa, F., Ramachers, Y., Ramirez, A., Ravinthiran, S., Razeti, M., Renshaw, A. L., Rescigno, M., Retiere, F., Rignanese, L. P., Rivetti, A., Roberts, A., Roberts, C., Rogers, G., Romero, L., Rossi, M., Rubbia, A., Rudik, D., Sabia, M., Sadashivajois, S., Salomone, P., Samoylov, O., Sandford, E., Sanfilippo, S., Santone, D., Santorelli, R., Santos, E. M., Savarese, C., Scapparone, E., Schillaci, G., Schuckman II, F. G., Scioli, G., Semenov, D. A., Sheshukov, A., Simeone, M., Skensved, P., Skorokhvatov, M. D., Slimani, S., Smirnov, O., Smirnova, T., Smith, B., Sotnikov, A., Spadoni, F., Spangenberg, M., Stefanizzi, R., Steri, A., Stornelli, V., Stracka, S., Sulis, S., Sung, A., Sunny, C., Suvorov, Y., Szelc, A. M., Taborda, O., Tartaglia, R., Taylor, A., Taylor, J., Tedesco, S., Testera, G., Thieme, K., Thompson, A., Tonazzo, A., Torres-Lara, S., Tosi, S., Tricomi, A., Unzhakov, E. V., Vallivilayil, T. J., Van Uffelen, M., Velazquez-Fernandez, L., Viant, T., Vicini, S., Viel, S., Vishneva, A., Vogelaar, R. B., Vossebeld, J., Vyas, B., Wada, M., Walczak, M. B., Wang, H., Wang, Y., Westerdale, S., Williams, L., Wojaczynski, R., Wojcik, M. M., Wojcik, M., Wright, T., Xie, Y., Yang, C., Yin, J., Zabihi, A., Zakhary, P., Zani, A., Zhang, Y., Zhu, T., Zichichi, A., Zuzel, G., and Zykova, M. P.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: Experiments aimed at direct searches for WIMP dark matter require highly effective reduction of backgrounds and control of any residual radioactive contamination. In particular, neutrons interacting with atomic nuclei represent an important class of backgrounds due to the expected similarity of a WIMP-nucleon interaction, so that such experiments often feature a dedicated neutron detector surrounding the active target volume. In the context of the development of DarkSide-20k detector at INFN Gran Sasso National Laboratory (LNGS), several R&D projects were conceived and developed for the creation of a new hybrid material rich in both hydrogen and gadolinium nuclei to be employed as an essential element of the neutron detector. Thanks to its very high cross-section for neutron capture, gadolinium is one of the most widely used elements in neutron detectors, while the hydrogen-rich material is instrumental in efficiently moderating the neutrons. In this paper results from one of the R&Ds are presented. In this effort the new hybrid material was obtained as a poly(methyl methacrylate) (PMMA) matrix, loaded with gadolinium oxide in the form of nanoparticles. We describe its realization, including all phases of design, purification, construction, characterization, and determination of mechanical properties of the new material.
Published: 2024
Full Text: View/download PDF

4. AGILE gamma-ray detection of the exceptional GRB 221009A

Author: Tavani, M., Piano, G., Bulgarelli, A., Foffano, L., Ursi, A., Verrecchia, F., Pittori, C., Casentini, C., Giuliani, A., Longo, F., Panebianco, G., Di Piano, A., Baroncelli, L., Fioretti, V., Parmiggiani, N., Argan, A., Trois, A., Vercellone, S., Cardillo, M., Antonelli, L. A., Barbiellini, G., Caraveo, P., Cattaneo, P. W., Chen, A. W., Costa, E., Del Monte, E., Di Cocco, G., Donnarumma, I., Evangelista, Y., Feroci, M., Gianotti, F., Labanti, C., Lazzarotto, F., Lipari, P., Lucarelli, F., Marisaldi, M., Mereghetti, S., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Picozza, P., Pilia, M., Rapisarda, M., Rappoldi, A., Rubini, A., Soffitta, P., Trifoglio, M., Vittorini, V., and D'Amico, F.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Gamma-ray emission in the MeV-GeV range from explosive cosmic events is of invaluable relevance to understanding physical processes related to the formation of neutron stars and black holes. Here we report on the detection by the AGILE satellite in the MeV-GeV energy range of the remarkable long-duration gamma-ray burst GRB 221009A. The AGILE onboard detectors have good exposure to GRB 221009A during its initial crucial phases. Hard X-ray/MeV emission in the prompt phase lasted hundreds of seconds, with the brightest radiation being emitted between 200 and 300 seconds after the initial trigger. Very intense GeV gamma-ray emission is detected by AGILE in the prompt and early afterglow phase up to 10,000 seconds. Time-resolved spectral analysis shows time-variable MeV-peaked emission simultaneous with intense power-law GeV radiation that persists in the afterglow phase. The coexistence during the prompt phase of very intense MeV emission together with highly nonthermal and hardening GeV radiation is a remarkable feature of GRB 221009A. During the prompt phase, the event shows spectrally different MeV and GeV emissions that are most likely generated by physical mechanisms occurring in different locations. AGILE observations provide crucial flux and spectral gamma-ray information regarding the early phases of GRB 221009A during which emission in the TeV range was reported., Comment: Accepted for publication in ApJL on September 19, 2023. Published online on October 17, 2023. Revised Figure 5 (June 13, 2024)
Published: 2023
Full Text: View/download PDF

5. Sensitivity projections for a dual-phase argon TPC optimized for light dark matter searches through the ionization channel

Author: Agnes, P., Ahmad, I., Albergo, S., Albuquerque, I. F. M., Alexander, T., Alton, A. K., Amaudruz, P., Corona, M. Atzori, Auty, D. J., Ave, M., Avetisov, I. Ch., Avetisov, R. I., Azzolini, O., Back, H. O., Balmforth, Z., Barbarian, V., Olmedo, A. Barrado, Barrillon, P., Basco, A., Batignani, G., Berzin, E., Bondar, A., Bonivento, W. M., Borisova, E., Bottino, B., Boulay, M. G., Buccino, G., Bussino, S., Busto, J., Buzulutskov, A., Cadeddu, M., Cadoni, M., Caminata, A., Canci, N., Capra, A., Caprioli, S., Caravati, M., Cárdenas-Montes, M., Cargioli, N., Carlini, M., Castello, P., Cataudella, V., Cavalcante, P., Cavuoti, S., Cebrian, S., Ruiz, J. M. Cela, Chashin, S., Chepurnov, A., Chyhyrynets, E, Cicalò, C., Cifarelli, L., Cintas, D., Cocco, V., Vilda, E. Conde, Consiglio, L., Copello, S., Covone, G., Cross, S., Czudak, P., D'Aniello, M., D'Auria, S., Rolo, M. D. Da Rocha, Dadoun, O., Daniel, M., Davini, S., De Candia, A., De Cecco, S., De Falco, A., De Filippis, G., De Gruttola, D., De Pasquale, S., De Rosa, G., Dellacasa, G., Derbin, A. V., Devoto, A., Di Capua, F., Di Noto, L., Di Stefano, P., Dionisi, C., Dolganov, G., Dordei, F., Doria, L., Erjavec, T., Diaz, M. Fernandez, Fiorillo, G., Franceschi, A., Franchini, P., Franco, D., Frolov, E., Funicello, N., Gabriele, F., Gahan, D., Galbiati, C., Gallina, G., Gallus, G., Garbini, M., Abia, P. Garcia, Gendotti, A., Ghiano, C., Giampaolo, R. A., Giganti, C., Giorgi, M. A., Giovanetti, G. K., Casanueva, V. Goicoechea, Gola, A., Gorman, D., Diaz, R. Graciani, Grauso, G., di Cortona, G. Grilli, Grobov, A., Gromov, M., Guan, M., Guerzoni, M., Gulino, M., Guo, C., Hackett, B. R., Hall, J. B., Hallin, A. L., Hamer, A., Helton, H., Haranczyk, M., Hessel, T., Hill, S., Horikawa, S., Hubaut, F., Hugues, T., Hungerford, E. V., Ianni, An., Ippolito, V., Jillings, C., Kachru, P., Kemp, A. A., Kendziora, C. L., Keppel, G., Khomyakov, A. V., Kimura, M., Kochanek, I., Kondo, K., Korga, G., Koulosousas, S., Kubankin, A., Kuss, M., Kuźniak, M., La Commara, M., Lai, M., Guirriec, E. Le, Leason, E., Li, X., Lidey, L., Lipp, J., Lissia, M., Longo, G., Luzzi, L., Macfadyen, O., Machulin, I. N., Manthos, I., Mapelli, L., Margotti, A., Mari, S. M., Mariani, C., Maricic, J., Marini, A., Martínez, M., Martoff, C. J., Masoni, A., Mavrokoridis, K., Mazzi, A., McDonald, A. B., Messina, A., Milincic, R., Moggi, A., Moharana, A., Monroe, J., Morrocchi, M., Mozhevitina, E. N., Mróz, T., Muratova, V. N., Muscas, C., Musico, P., Nania, R., Napolitano, T., Nessi, M., Nieradka, G., Nikolopoulos, K., Nikulin, I., Nowak, J., Olchansky, K., Oleinik, A., Oleynikov, V., Organtini, P., de Solórzano, A. Ortiz, Pagani, L., Pallavicini, M., Pandola, L., Pantic, E., Paoloni, E., Paternoster, G., Pegoraro, P. A., Pelczar, K., Pellegrino, C., Perotti, F., Pesudo, V., Piacentini, S., Pietropaolo, F., Pino, N., Pira, C., Pocar, A., Poehlmann, D. M., Pordes, S., Pralavorio, P., Price, D., Raffaelli, F., Ragusa, F., Ramachers, Y., Ramirez, A., Razeti, M., Razeto, A., Renshaw, A. L., Rescigno, M., Resnati, F., Retiere, F., Rignanese, L. P., Ripoli, C., Rivetti, A., Roberts, A., Roberts, C., Rode, J., Rogers, G., Romero, L., Rossi, M., Rubbia, A., Sadashivajois, S., Saffold, T. R., Samoylov, O., Sandford, E., Sanfilippo, S., Santone, D., Santorelli, R., Savarese, C., Scapparone, E., Scioli, G., Semenov, D. A., Shchagin, A., Sheshukov, A., Simeone, M., Skensved, P., Skorokhvatov, M. D., Smirnov, O., Smirnova, T., Smith, B., Sokolov, A., Spangenberg, M., Stefanizzi, R., Steri, A., Stracka, S., Strickland, V., Stringer, M., Sulis, S., Sung, A., Suvorov, Y., Szelc, A. M., Türkoğ, C., Tartaglia, R., Taylor, A., Taylor, J., Tedesco, S., Testera, G., Thieme, K., Thorpe, T. N., Tonazzo, A., Torres-Lara, S., Tricomi, A., Unzhakov, E. V., John, T. Vallivilayil, Van Uffelen, M., Viant, T., Viel, S., Vishneva, A., Vogelaar, R. B., Vossebeld, J., Wada, M., Walczak, M. B., Wang, Y., Westerdale, S., Wheadon, R. J., Williams, L., Wingerter-Seez, I., Wojaczyński, R., Wojcik, Ma. M., Wojcik, Ma., Wright, T., Xie, Y., Yang, C., Zabihi, A., Zakhary, P., Zani, A., Zichichi, A., Zuzel, G., and Zykova, M. P.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: Dark matter lighter than 10 GeV/c$^2$ encompasses a promising range of candidates. A conceptual design for a new detector, DarkSide-LowMass, is presented, based on the DarkSide-50 detector and progress toward DarkSide-20k, optimized for a low-threshold electron-counting measurement. Sensitivity to light dark matter is explored for various potential energy thresholds and background rates. These studies show that DarkSide-LowMass can achieve sensitivity to light dark matter down to the solar neutrino floor for GeV-scale masses and significant sensitivity down to 10 MeV/c$^2$ considering the Migdal effect or interactions with electrons. Requirements for optimizing the detector's sensitivity are explored, as are potential sensitivity gains from modeling and mitigating spurious electron backgrounds that may dominate the signal at the lowest energies.
Published: 2022
Full Text: View/download PDF

6. Separating $^{39}$Ar from $^{40}$Ar by cryogenic distillation with Aria for dark matter searches

Author: DarkSide Collaboration, Agnes, P., Albergo, S., Albuquerque, I. F. M., Alexander, T., Alici, A., Alton, A. K., Amaudruz, P., Arba, M., Arpaia, P., Arcelli, S., Ave, M., Avetissov, I. Ch., Avetisov, R. I., Azzolini, O., Back, H. O., Balmforth, Z., Barbarian, V., Olmedo, A. Barrado, Barrillon, P., Basco, A., Batignani, G., Bondar, A., Bonivento, W. M., Borisova, E., Bottino, B., Boulay, M. G., Buccino, G., Bussino, S., Busto, J., Buzulutskov, A., Cadeddu, M., Cadoni, M., Caminata, A., Canesi, E. V., Canci, N., Cappello, G., Caravati, M., C, M., Cargioli, N., Carlini, M., Carnesecchi, F., Castello, P., Castellani, A., Catalanotti, S., Cataudella, V., Cavalcante, P., Cavuoti, S., Cebrian, S., Ruiz, J. M. Cela, Celano, B., Chashin, S., Chepurnov, A., Cical, C., Cifarelli, L., Cintas, D., Coccetti, F., Cocco, V., Colocci, M., Vilda, E. Conde, Consiglio, L., Copello, S., Corning, J., Covone, G., Czudak, P., D'Aniello, M., D'Auria, S., Rolo, M. D. Da Rocha, Dadoun, O., Daniel, M., Davini, S., De Candia, A., De Cecco, S., De Falco, A., De Filippis, G., De Gruttola, D., De Guido, G., De Rosa, G., Della Valle, M., Dellacasa, G., De Pasquale, S., Derbin, A. V., Devoto, A., Di Noto, L., Di Eusanio, F., Dionisi, C., Di Stefano, P., Dolganov, G., Dongiovanni, D., Dordei, F., Downing, M., Erjavec, T., Falciano, S., Farenzena, S., Diaz, M. Fernandez, Filip, C., Fiorillo, G., Franceschi, A., Franco, D., Frolov, E., Funicello, N., Gabriele, F., Galbiati, C., Garbini, M., Abia, P. Garcia, Gendotti, A., Ghiano, C., Giampaolo, R. A., Giganti, C., Giorgi, M. A., Giovanetti, G. K., Gligan, M. L., Casanueva, V. Goicoechea, Gola, A., Goretti, A. M., Diaz, R. Graciani, Grigoriev, G. Y., Grobov, A., Gromov, M., Guan, M., Guerzoni, M., Guetti, M., Gulino, M., Guo, C., Hackett, B. R., Hallin, A., Haranczyk, M., Hill, S., Horikawa, S., Hubaut, F., Hugues, T., Hungerford, E. V., Ianni, An., Ippolito, V., James, C. C., Jillings, C., Kachru, P., Kemp, A. A., Kendziora, C. L., Keppel, G., Khomyakov, A. V., Kim, S., Kish, A., Kochanek, I., Kondo, K., Korga, G., Kubankin, A., Kugathasan, R., Kuss, M., Kuźniak, M., La Commara, M., La Delfa, L., La Grasta, D., Lai, M., Lami, N., Langrock, S., Leyton, M., Li, X., Lidey, L., Lippi, F., Lissia, M., Longo, G., Maccioni, N., Machulin, I. N., Mapelli, L., Marasciulli, A., Margotti, A., Mari, S. M., Maricic, J., Marinelli, M., Mart, M., Rojas, A. D. Martinez, Martini, A., Martoff, C. J., Mascia, M., Masetto, M., Masoni, A., Mazzi, A., McDonald, A. B., Mclaughlin, J., Messina, A., Meyers, P. D., Miletic, T., Milincic, R., Miola, R., Moggi, A., Moharana, A., Moioli, S., Monroe, J., Morisi, S., Morrocchi, M., Mozhevitina, E. N., Mr, T., Muratova, V. N., Murenu, A., Muscas, C., Musenich, L., Musico, P., Nania, R., Napolitano, T., Agasson, A. Navrer, Nessi, M., Nikulin, I., Nowak, J., Oleinik, A., Oleynikov, V., Pagani, L., Pallavicini, M., Palmas, S., Pandola, L., Pantic, E., Paoloni, E., Paternoster, G., Pegoraro, P. A., Pellegrini, L. A., Pellegrino, C., Pelczar, K., Perotti, F., Pesudo, V., Picciau, E., Pietropaolo, F., Pinna, T., Pocar, A., Podda, P., Poehlmann, D. M., Pordes, S., Poudel, S. S., Pralavorio, P., Price, D., Raffaelli, F., Ragusa, F., Ramirez, A., Razeti, M., Razeto, A., Renshaw, A. L., Rescia, S., Rescigno, M., Resnati, F., Retiere, F., Rignanese, L. P., Ripoli, C., Rivetti, A., Rode, J., Romero, L., Rossi, M., Rubbia, A., Rucaj, M., Sabiu, G. M., Salatino, P., Samoylov, O., S, E., Sandford, E., Sanfilippo, S., Sangiorgio, V. A., Santacroce, V., Santone, D., Santorelli, R., Santucci, A., Savarese, C., Scapparone, E., Schlitzer, B., Scioli, G., Semenov, D. A., Shaw, B., Shchagin, A., Sheshukov, A., Simeone, M., Skensved, P., Skorokhvatov, M. D., Smirnov, O., Smith, B., Sokolov, A., Stefanizzi, R., Steri, A., Stracka, S., Strickland, V., Stringer, M., Sulis, S., Suvorov, Y., Szelc, A. M., Zsücs-Balázs, J. Z., Tartaglia, R., Testera, G., Thorpe, T. N., Tonazzo, A., Torres-Lara, S., Tosti, S., Tricomi, A., Tuveri, M., Unzhakov, E. V., Usai, G., John, T. Vallivilayil, Vescovi, S., Viant, T., Viel, S., Vishneva, A., Vogelaar, R. B., Wada, M., Wang, H., Wang, Y., Westerdale, S., Wheadon, R. J., Williams, L., Wojcik, Ma. M., Wojcik, Ma., Xiao, X., Yang, C., Zani, A., Zenobio, F., Zichichi, A., Zuzel, G., and Zykova, M. P.
Subjects: Physics - Instrumentation and Detectors, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The Aria project consists of a plant, hosting a 350 m cryogenic isotopic distillation column, the tallest ever built, which is currently in the installation phase in a mine shaft at Carbosulcis S.p.A., Nuraxi-Figus (SU), Italy. Aria is one of the pillars of the argon dark-matter search experimental program, lead by the Global Argon Dark Matter Collaboration. Aria was designed to reduce the isotopic abundance of $^{39}$Ar, a $\beta$-emitter of cosmogenic origin, whose activity poses background and pile-up concerns in the detectors, in the argon used for the dark-matter searches, the so-called Underground Argon (UAr). In this paper, we discuss the requirements, design, construction, tests, and projected performance of the plant for the isotopic cryogenic distillation of argon. We also present the successful results of isotopic cryogenic distillation of nitrogen with a prototype plant, operating the column at total reflux.
Published: 2021
Full Text: View/download PDF

7. Sensitivity of future liquid argon dark matter search experiments to core-collapse supernova neutrinos

Author: Agnes, P., Albergo, S., Albuquerque, I. F. M., Alexander, T., Alici, A., Alton, A. K., Amaudruz, P., Arcelli, S., Ave, M., Avetissov, I. Ch., Avetisov, R. I., Azzolini, O., Back, H. O., Balmforth, Z., Barbarian, V., Olmedo, A. Barrado, Barrillon, P., Basco, A., Batignani, G., Bondar, A., Bonivento, W. M., Borisova, E., Bottino, B., Boulay, M. G., Buccino, G., Bussino, S., Busto, J., Buzulutskov, A., Cadeddu, M., Cadoni, M., Caminata, A., Canci, N., Cappello, G., Caravati, M., Cárdenas-Montes, M., Carlini, M., Carnesecchi, F., Castello, P., Catalanotti, S., Cataudella, V., Cavalcante, P., Cavuoti, S., Cebrian, S., Ruiz, J. M. Cela, Celano, B., Chashin, S., Chepurnov, A., Chyhyrynets, E, Cicalò, C., Cifarelli, L., Cintas, D., Coccetti, F., Cocco, V., Colocci, M., Vilda, E. Conde, Consiglio, L., Copello, S., Corning, J., Covone, G., Czudak, P., D'Auria, S., Rolo, M. D. Da Rocha, Dadoun, O., Daniel, M., Davini, S., De Candia, A., De Cecco, S., De Falco, A., De Filippis, G., De Gruttola, D., De Guido, G., De Rosa, G., Della Valle, M., Dellacasa, G., De Pasquale, S., Derbin, A. V., Devoto, A., Di Noto, L., Dionisi, C., Di Stefano, P., Dolganov, G., Dordei, F., Doria, L., Downing, M., Erjavec, T., Diaz, M. Fernandez, Fiorillo, G., Franceschi, A., Franco, D., Frolov, E., Funicello, N., Gabriele, F., Galbiati, C., Garbini, M., Abia, P. Garcia, Gendotti, A., Ghiano, C., Giampaolo, R. A., Giganti, C., Giorgi, M. A., Giovanetti, G. K., Casanueva, V. Goicoechea, Gola, A., Diaz, R. Graciani, Grigoriev, G. Y., Grobov, A., Gromov, M., Guan, M., Guerzoni, M., Gulino, M., Guo, C., Hackett, B. R., Hallin, A., Haranczyk, M., Hill, S., Horikawa, S., Hubaut, F., Hugues, T., Hungerford, E. V., Ianni, An., Ippolito, V., James, C. C., Jillings, C., Kachru, P., Kemp, A. A., Kendziora, C. L., Keppel, G., Khomyakov, A. V., Kim, S., Kish, A., Kochanek, I., Kondo, K., Korga, G., Kubankin, A., Kugathasan, R., Kuss, M., Kuźniak, M., La Commara, M., Lai, M., Langrock, S., Leyton, M., Li, X., Lidey, L., Lissia, M., Longo, G., Machulin, I. N., Mapelli, L., Marasciulli, A., Margotti, A., Mari, S. M., Maricic, J., Martínez, M., Rojas, A. D. Martinez, Martoff, C. J., Masoni, A., Mazzi, A., McDonald, A. B., Mclaughlin, J., Messina, A., Meyers, P. D., Miletic, T., Milincic, R., Moggi, A., Moharana, A., Moioli, S., Monroe, J., Morisi, S., Morrocchi, M., Mozhevitina, E. N., Mróz, T., Muratova, V. N., Muscas, C., Musenich, L., Musico, P., Nania, R., Napolitano, T., Agasson, A. Navrer, Nessi, M., Nikulin, I., Nowak, J., Oleinik, A., Oleynikov, V., Pagani, L., Pallavicini, M., Pandola, L., Pantic, E., Paoloni, E., Paternoster, G., Pegoraro, P. A., Pelczar, K., Pellegrini, L. A., Pellegrino, C., Perotti, F., Pesudo, V., Picciau, E., Pietropaolo, F., Pira, C., Pocar, A., Poehlmann, D. M., Pordes, S., Poudel, S. S., Pralavorio, P., Price, D., Raffaelli, F., Ragusa, F., Ramirez, A., Razeti, M., Razeto, A., Renshaw, A. L., Rescia, S., Rescigno, M., Resnati, F., Retiere, F., Rignanese, L. P., Ripoli, C., Rivetti, A., Rode, J., Romero, L., Rossi, M., Rubbia, A., Salatino, P., Samoylov, O., García, E. Sánchez, Sandford, E., Sanfilippo, S., Santone, D., Santorelli, R., Savarese, C., Scapparone, E., Schlitzer, B., Scioli, G., Semenov, D. A., Shaw, B., Shchagin, A., Sheshukov, A., Simeone, M., Skensved, P., Skorokhvatov, M. D., Smirnov, O., Smith, B., Sokolov, A., Steri, A., Stracka, S., Strickland, V., Stringer, M., Sulis, S., Suvorov, Y., Szelc, A. M., Tartaglia, R., Testera, G., Thorpe, T. N., Tonazzo, A., Torres-Lara, S., Tricomi, A., Unzhakov, E. V., Usai, G., John, T. Vallivilayil, Viant, T., Viel, S., Vishneva, A., Vogelaar, R. B., Wada, M., Wang, H., Wang, Y., Westerdale, S., Wheadon, R. J., Williams, L., Wojcik, Ma. M., Wojcik, Ma., Xiao, X., Yang, C., Ye, Z., Zani, A., Zichichi, A., Zuzel, G., and Zykova, M. P.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract: Future liquid-argon DarkSide-20k and ARGO detectors, designed for direct dark matter search, will be sensitive also to core-collapse supernova neutrinos, via coherent elastic neutrino-nucleus scattering. This interaction channel is flavor-insensitive with a high-cross section, enabling for a high-statistics neutrino detection with target masses of $\sim$50~t and $\sim$360~t for DarkSide-20k and ARGO, respectively. Thanks to the low-energy threshold of $\sim$0.5~keV$_{nr}$ achievable by exploiting the ionization channel, DarkSide-20k and ARGO have the potential to discover supernova bursts throughout our galaxy and up to the Small Magellanic Cloud, respectively, assuming a 11-M$_{\odot}$ progenitor star. We report also on the sensitivity to the neutronization burst, whose electron neutrino flux is suppressed by oscillations when detected via charged current and elastic scattering. Finally, the accuracies in the reconstruction of the average and total neutrino energy in the different phases of the supernova burst, as well as its time profile, are also discussed, taking into account the expected background and the detector response., Comment: 21 pages, 8 figures
Published: 2020
Full Text: View/download PDF

8. An X-Ray Burst from a Magnetar Enlightening the Mechanism of Fast Radio Bursts

Author: Tavani, M., Casentini, C., Ursi, A., Verrecchia, F., Addis, A., Antonelli, L. A., Argan, A., Barbiellini, G., Baroncelli, L., Bernardi, G., Bianchi, G., Bulgarelli, A., Caraveo, P., Cardillo, M., Cattaneo, P. W., Chen, A. W., Costa, E., Del Monte, E., Di Cocco, G., Di Persio, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fioretti, V., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Labanti, C., Lazzarotto, F., Lipari, P., Longo, F., Lucarelli, F., Magro, A., Marisaldi, M., Mereghetti, S., Morelli, E., Morselli, A., Naldi, G., Pacciani, L., Parmiggiani, N., Paoletti, F., Pellizzoni, A., Perri, M., Perotti, F., Piano, G., Picozza, P., Pilia, M., Pittori, C., Puccetti, S., Pupillo, G., Rapisarda, M., Rappoldi, A., Rubini, A., Setti, G., Soffitta, P., Trifoglio, M., Trois, A., Vercellone, S., Vittorini, V., Giommi, P., and Amico, F. D'
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Fast radio bursts (FRBs) are short (millisecond) radio pulses originating from enigmatic sources at extragalactic distances so far lacking a detection in other energy bands. Magnetized neutron stars (magnetars) have been considered as the sources powering the FRBs, but the connection is controversial because of differing energetics and the lack of radio and X-ray detections with similar characteristics in the two classes. We report here the detection by the AGILE satellite on April 28, 2020 of an X-ray burst in coincidence with the very bright radio burst from the Galactic magnetar SGR 1935+2154. The burst detected by AGILE in the hard X-ray band (18-60 keV) lasts about 0.5 seconds, it is spectrally cutoff above 80 keV, and implies an isotropically emitted energy ~ $10^{40}$ erg. This event is remarkable in many ways: it shows for the first time that a magnetar can produce X-ray bursts in coincidence with FRB-like radio bursts; it also suggests that FRBs associated with magnetars may emit X-ray bursts of both magnetospheric and radio-pulse types that may be discovered in nearby sources. Guided by this detection, we discuss SGR 1935+2154 in the context of FRBs, and especially focus on the class of repeating-FRBs. Based on energetics, magnetars with fields B ~ $10^{15}$ G may power the majority of repeating-FRBs. Nearby repeating-FRBs offer a unique occasion to consolidate the FRB-magnetar connection, and we present new data on the X-ray monitoring of nearby FRBs. Our detection enlightens and constrains the physical process leading to FRBs: contrary to previous expectations, high-brightness temperature radio emission coexists with spectrally-cutoff X-ray radiation., Comment: Submitted to Nature Astronomy, May 18, 2020
Published: 2020

9. SiPM-matrix readout of two-phase argon detectors using electroluminescence in the visible and near infrared range

Author: The DarkSide collaboration, Aalseth, C. E., Abdelhakim, S., Agnes, P., Ajaj, R., Albuquerque, I. F. M., Alexander, T., Alici, A., Alton, A. K., Amaudruz, P., Ameli, F., Anstey, J., Antonioli, P., Arba, M., Arcelli, S., Ardito, R., Arnquist, I. J., Arpaia, P., Asner, D. M., Asunskis, A., Ave, M., Back, H. O., Barbaryan, V., Olmedo, A. Barrado, Batignani, G., Bisogni, M. G., Bocci, V., Bondar, A., Bonfini, G., Bonivento, W., Borisova, E., Bottino, B., Boulay, M. G., Bunker, R., Bussino, S., Buzulutskov, A., Cadeddu, M., Cadoni, M., Caminata, A., Canci, N., Candela, A., Cantini, C., Caravati, M., Cariello, M., Carnesecchi, F., Castellani, A., Castello, P., Cavalcante, P., Cavazza, D., Cavuoti, S., Cebrian, S., Ruiz, J. M. Cela, Celano, B., Cereseto, R., Chashin, S., Cheng, W., Chepurnov, A., Cicalò, C., Cifarelli, L., Citterio, M., Coccetti, F., Cocco, V., Colocci, M., Vilda, E. Conde, Consiglio, L., Cossio, F., Covone, G., Crivelli, P., D'Antone, I., D'Incecco, M., Rolo, M. D. Da Rocha, Dadoun, O., Daniel, M., Davini, S., De Cecco, S., De Deo, M., De Falco, A., De Gruttola, D., De Guido, G., De Rosa, G., Dellacasa, G., Demontis, P., De Pasquale, S., Derbin, A. V., Devoto, A., Di Eusanio, F., Di Noto, L., Di Pietro, G., Di Stefano, P., Dionisi, C., Dolganov, G., Dordei, F., Downing, M., Edalatfar, F., Empl, A., Diaz, M. Fernandez, Filip, C., Fiorillo, G., Fomenko, K., Franceschi, A., Franco, D., Frolov, E., Froudakis, G. E., Funicello, N., Gabriele, F., Gabrieli, A., Galbiati, C., Garbini, M., Abia, P. Garcia, Fora, D. Gascón, Gendotti, A., Ghiano, C., Ghisi, A., Giampa, P., Giampaolo, R. A., Giganti, C., Giorgi, M. A., Giovanetti, G. K., Gligan, M. L., Gorchakov, O., Grab, M., Diaz, R. Graciani, Grassi, M., Grate, J. W., Grobov, A., Gromov, M., Guan, M., Guerra, M. B. B., Guerzoni, M., Gulino, M., Haaland, R. K., Hackett, B. R., Hallin, A., Haranczyk, M., Harrop, B., Hoppe, E. W., Horikawa, S., Hosseini, B., Hubaut, F., Humble, P., Hungerford, E. V., Ianni, An., Ilyasov, A., Ippolito, V., Jillings, C., Keeter, K., Kendziora, C. L., Kochanek, I., Kondo, K., Kopp, G., Korablev, D., Korga, G., Kubankin, A., Kugathasan, R., Kuss, M., La Commara, M., La Delfa, L., Lai, M., Lebois, M., Lehnert, B., Levashko, N., Li, X., Liqiang, Q., Lissia, M., Lodi, G. U., Longo, G., Lussana, R., Luzzi, L., Machado, A. A., Machulin, I. N., Mandarano, A., Manecki, S., Mapelli, L., Margotti, A., Mari, S. M., Mariani, M., Maricic, J., Marinelli, M., Marras, D., Martínez, M., Rojas, A. D. Martinez, Mascia, M., Mason, J., Masoni, A., McDonald, A. B., Messina, A., Miletic, T., Milincic, R., Moggi, A., Moioli, S., Monroe, J., Morrocchi, M., Mroz, T., Mu, W., Muratova, V. N., Murphy, S., Muscas, C., Musico, P., Nania, R., Napolitano, T., Agasson, A. Navrer, Nessi, M., Nikulin, I., Nosov, V., Nowak, J. A., Oleinik, A., Oleynikov, V., Orsini, M., Ortica, F., Pagani, L., Pallavicini, M., Palmas, S., Pandola, L., Pantic, E., Paoloni, E., Pazzona, F., Peeters, S., Pegoraro, P. A., Pelczar, K., Pellegrini, L. A., Pellegrino, C., Pelliccia, N., Perotti, F., Pesudo, V., Picciau, E., Pietropaolo, F., Pocar, A., Pollmann, T. R., Portaluppi, D., Poudel, S. S., Pralavorio, P., Price, D., Radics, B., Raffaelli, F., Ragusa, F., Razeti, M., Regenfus, C., Renshaw, A. L., Rescia, S., Rescigno, M., Retiere, F., Rignanese, L. P., Ripoli, C., Rivetti, A., Rode, J., Romani, A., Romero, L., Rossi, N., Rubbia, A., Sala, P., Salatino, P., Samoylov, O., García, E. Sánchez, Sandford, E., Sanfilippo, S., Sant, M., Santone, D., Santorelli, R., Savarese, C., Scapparone, E., Schlitzer, B., Scioli, G., Segreto, E., Seifert, A., Semenov, D. A., Shchagin, A., Sheshukov, A., Siddhanta, S., Simeone, M., Singh, P. N., Skensved, P., Skorokhvatov, M. D., Smirnov, O., Sobrero, G., Sokolov, A., Sotnikov, A., Stainforth, R., Steri, A., Stracka, S., Strickland, V., Suffritti, G. B., Sulis, S., Suvorov, Y., Szelc, A. M., Tartaglia, R., Testera, G., Thorpe, T., Tonazzo, A., Tosi, A., Tuveri, M., Unzhakov, E. V., Usai, G., Vacca, A., Vázquez-Jáuregui, E., Viant, T., Viel, S., Villa, F., Vishneva, A., Vogelaar, R. B., Wahl, J., Walding, J. J., Wang, H., Wang, Y., Westerdale, S., Wheadon, R. J., Williams, R., Wilson, J., Wojcik, Ma. M., Wojcik, Ma., Wu, S., Xiao, X., Yang, C., Ye, Z., Zuffa, M., and Zuzel, G.
Subjects: Physics - Instrumentation and Detectors, Astrophysics - Instrumentation and Methods for Astrophysics, High Energy Physics - Experiment
Abstract: Proportional electroluminescence (EL) in noble gases is used in two-phase detectors for dark matter searches to record (in the gas phase) the ionization signal induced by particle scattering in the liquid phase. The "standard" EL mechanism is considered to be due to noble gas excimer emission in the vacuum ultraviolet (VUV). In addition, there are two alternative mechanisms, producing light in the visible and near infrared (NIR) ranges. The first is due to bremsstrahlung of electrons scattered on neutral atoms ("neutral bremsstrahlung", NBrS). The second, responsible for electron avalanche scintillation in the NIR at higher electric fields, is due to transitions between excited atomic states. In this work, we have for the first time demonstrated two alternative techniques of the optical readout of two-phase argon detectors, in the visible and NIR range, using a silicon photomultiplier matrix and electroluminescence due to either neutral bremsstrahlung or avalanche scintillation. The amplitude yield and position resolution were measured for these readout techniques, which allowed to assess the detection threshold for electron and nuclear recoils in two-phase argon detectors for dark matter searches. To the best of our knowledge, this is the first practical application of the NBrS effect in detection science., Comment: 26 pages, 22 figures, 3 tables
Published: 2020
Full Text: View/download PDF

10. Design and construction of a new detector to measure ultra-low radioactive-isotope contamination of argon

Author: The DarkSide Collaboration, Aalseth, C. E., Abdelhakim, S., Acerbi, F., Agnes, P., Ajaj, R., Albuquerque, I. F. M., Alexander, T., Alici, A., Alton, A. K., Amaudruz, P., Ameli, F., Anstey, J., Antonioli, P., Arba, M., Arcelli, S., Ardito, R., Arnquist, I. J., Arpaia, P., Asner, D. M., Asunskis, A., Ave, M., Back, H. O., Olmedo, A. Barrado, Batignani, G., Bisogni, M. G., Bocci, V., Bondar, A., Bonfini, G., Bonivento, W., Borisova, E., Bottino, B., Boulay, M. G., Bunker, R., Bussino, S., Buzulutskov, A., Cadeddu, M., Cadoni, M., Caminata, A., Canci, N., Candela, A., Cantini, C., Caravati, M., Cariello, M., Carnesecchi, F., Carpinelli, M., Castellani, A., Castello, P., Catalanotti, S., Cataudella, V., Cavalcante, P., Cavazza, D., Cavuoti, S., Cebrian, S., Ruiz, J. M. Cela, Celano, B., Cereseto, R., Cheng, W., Chepurnov, A., Cicalò, C., Cifarelli, L., Citterio, M., Cocco, A. G., Cocco, V., Colocci, M., Consiglio, L., Cossio, F., Covone, G., Crivelli, P., D'Antone, I., D'Incecco, M., D'Urso, D., Rolo, M. D. Da Rocha, Dadoun, O., Daniel, M., Davini, S., De Candia, A., De Cecco, S., De Deo, M., De Falco, A., De Filippis, G., De Gruttola, D., De Guido, G., De Rosa, G., Dellacasa, G., Demontis, P., DePaquale, S., Derbin, A. V., Devoto, A., Di Eusanio, F., Di Noto, L., Di Pietro, G., Di Stefano, P., Dionisi, C., Dolganov, G., Dordei, F., Downing, M., Edalatfar, F., Empl, A., Diaz, M. Fernandez, Ferri, A., Filip, C., Fiorillo, G., Fomenko, K., Franceschi, A., Franco, D., Froudakis, G. E., Gabriele, F., Gabrieli, A., Galbiati, C., Abia, P. Garcia, Fora, D. Gascón, Gendotti, A., Ghiano, C., Ghisi, A., Giagu, S., Giampa, P., Giampaolo, R. A., Giganti, C., Giorgi, M. A., Giovanetti, G. K., Gligan, M. L., Gola, A., Gorchakov, O., Grab, M., Diaz, R. Graciani, Granato, F., Grassi, M., Grate, J. W., Grigoriev, G. Y., Grobov, A., Gromov, M., Guan, M., Guerra, M. B. B., Guerzoni, M., Gulino, M., Haaland, R. K., Hackett, B. R., Hallin, A., Harrop, B., Hoppe, E. W., Horikawa, S., Hosseini, B., Hubaut, F., Humble, P., Hungerford, E. V., Ianni, An., Ilyasov, A., Ippolito, V., Jillings, C., Keeter, K., Kendziora, C. L., Kim, S., Kochanek, I., Kondo, K., Kopp, G., Korablev, D., Korga, G., Kubankin, A., Kugathasan, R., Kuss, M., Kuźniak, M., La Commara, M., La Delfa, L., Lai, M., Langrock, S., Lebois, M., Lehnert, B., Levashko, N., Li, X., Liqiang, Q., Lissia, M., Lodi, G. U., Longo, G., Manzano, R. López, Lussana, R., Luzzi, L., Machado, A. A., Machulin, I. N., Mandarano, A., Mapelli, L., Marcante, M., Margotti, A., Mari, S. M., Mariani, M., Maricic, J., Marinelli, M., Marras, D., Martínez, M., Morales, J. J. Martínez, Rojas, A. D. Martinez, Martoff, C. J., Mascia, M., Mason, J., Masoni, A., Mazzi, A., McDonald, A. B., Messina, A., Meyers, P. D., Miletic, T., Milincic, R., Moggi, A., Moioli, S., Monroe, J., Morrocchi, M., Mroz, T., Mu, W., Muratova, V. N., Murphy, S., Muscas, C., Musico, P., Nania, R., Napolitano, T., Agasson, A. Navrer, Nessi, M., Nikulin, I., Oleinik, A., Oleynikov, V., Orsini, M., Ortica, F., Pagani, L., Pallavicini, M., Palmas, S., Pandola, L., Pantic, E., Paoloni, E., Paternoster, G., Pavletcov, V., Pazzona, F., Peeters, S., Pegoraro, P. A., Pelczar, K., Pellegrini, L. A., Pellegrino, C., Pelliccia, N., Perotti, F., Pesudo, V., Picciau, E., Piemonte, C., Pietropaolo, F., Pocar, A., Pollman, T., Portaluppi, D., Poudel, S. S., Pralavorio, P., Price, D., Radics, B., Raffaelli, F., Ragusa, F., Razeti, M., Razeto, A., Regazzoni, V., Regenfus, C., Renshaw, A. L., Rescia, S., Rescigno, M., Retiere, F., Rignanese, L. P., Rivetti, A., Romani, A., Romero, L., Rossi, N., Rubbia, A., Sablone, D., Sala, P., Salatino, P., Samoylov, O., García, E. Sánchez, Sanfilippo, S., Sant, M., Santone, D., Santorelli, R., Savarese, C., Scapparone, E., Schlitzer, B., Scioli, G., Segreto, E., Seifert, A., Semenov, D. A., Shchagin, A., Sheshukov, A., Siddhanta, S., Simeone, M., Singh, P. N., Skensved, P., Skorokhvatov, M. D., Smirnov, O., Sobrero, G., Sokolov, A., Sotnikov, A., Stainforth, R., Steri, A., Stracka, S., Strickland, V., Suffritti, G. B., Sulis, S., Suvorov, Y., Szelc, A. M., Tartaglia, R., Testera, G., Thorpe, T., Tonazzo, A., Tosi, A., Tuveri, M., Unzhakov, E. V., Usai, G., Vacca, A., Vázquez-Jáuregui, E., Verducci, M., Viant, T., Viel, S., Villa, F., Vishneva, A., Vogelaar, R. B., Wada, M., Wahl, J., Walding, J. J., Wang, H., Wang, Y., Westerdale, S., Wheadon, R. J., Williams, R., Wilson, J., Wojcik, Marcin, Wojcik, Mariusz, Wu, S., Xiao, X., Yang, C., Ye, Z., Zuffa, M., and Zuzel, G.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract: Large liquid argon detectors offer one of the best avenues for the detection of galactic weakly interacting massive particles (WIMPs) via their scattering on atomic nuclei. The liquid argon target allows exquisite discrimination between nuclear and electron recoil signals via pulse-shape discrimination of the scintillation signals. Atmospheric argon (AAr), however, has a naturally occurring radioactive isotope, $^{39}$Ar, a $\beta$ emitter of cosmogenic origin. For large detectors, the atmospheric $^{39}$Ar activity poses pile-up concerns. The use of argon extracted from underground wells, deprived of $^{39}$Ar, is key to the physics potential of these experiments. The DarkSide-20k dark matter search experiment will operate a dual-phase time projection chamber with 50 tonnes of radio-pure underground argon (UAr), that was shown to be depleted of $^{39}$Ar with respect to AAr by a factor larger than 1400. Assessing the $^{39}$Ar content of the UAr during extraction is crucial for the success of DarkSide-20k, as well as for future experiments of the Global Argon Dark Matter Collaboration (GADMC). This will be carried out by the DArT in ArDM experiment, a small chamber made with extremely radio-pure materials that will be placed at the centre of the ArDM detector, in the Canfranc Underground Laboratory (LSC) in Spain. The ArDM LAr volume acts as an active veto for background radioactivity, mostly $\gamma$-rays from the ArDM detector materials and the surrounding rock. This article describes the DArT in ArDM project, including the chamber design and construction, and reviews the background required to achieve the expected performance of the detector., Comment: 13 pages, 8 figures. Corresponding author: E. S\'anchez Garc\'ia
Published: 2020
Full Text: View/download PDF

11. Different approaches for stress index calculation in elbows of a fusion plant piping system

Author: Lo Conte, A., Perotti, F., Conti, D., Baldisserri, B., and La Salandra, V.
Published: 2023
Full Text: View/download PDF

12. Research advancement on Submerged Floating Tunnels: Recent activity at DICA-Politecnico di Milano

Author: Foti, F., primary, Martinelli, L., additional, Mulas, M.G., additional, and Perotti, F., additional
Published: 2022
Full Text: View/download PDF

13. DarkSide-20k: A 20 Tonne Two-Phase LAr TPC for Direct Dark Matter Detection at LNGS

Author: Aalseth, C. E., Acerbi, F., Agnes, P., Albuquerque, I. F. M., Alexander, T., Alici, A., Alton, A. K., Antonioli, P., Arcelli, S., Ardito, R., Arnquist, I. J., Asner, D. M., Ave, M., Back, H. O., Olmedo, A. I. Barrado, Batignani, G., Bertoldo, E., Bettarini, S., Bisogni, M. G., Bocci, V., Bondar, A., Bonfini, G., Bonivento, W., Bossa, M., Bottino, B., Boulay, M., Bunker, R., Bussino, S., Buzulutskov, A., Cadeddu, M., Cadoni, M., Caminata, A., Canci, N., Candela, A., Cantini, C., Caravati, M., Cariello, M., Carlini, M., Carpinelli, M., Castellani, A., Catalanotti, S., Cataudella, V., Cavalcante, P., Cavuoti, S., Cereseto, R., Chepurnov, A., Cicalò, C., Cifarelli, L., Citterio, M., Cocco, A. G., Colocci, M., Corgiolu, S., Covone, G., Crivelli, P., D'Antone, I., D'Incecco, M., D'Urso, D., Rolo, M. D. Da Rocha, Daniel, M., Davini, S., de Candia, A., De Cecco, S., De Deo, M., De Filippis, G., De Guido, G., De Rosa, G., Dellacasa, G., Della Valle, M., Demontis, P., Derbin, A., Devoto, A., Di Eusanio, F., Di Pietro, G., Dionisi, C., Dolgov, A., Dormia, I., Dussoni, S., Empl, A., Diaz, M. Fernandez, Ferri, A., Filip, C., Fiorillo, G., Fomenko, K., Franco, D., Froudakis, G. E., Gabriele, F., Gabrieli, A., Galbiati, C., Abia, P. Garcia, Gendotti, A., Ghisi, A., Giagu, S., Giampa, P., Gibertoni, G., Giganti, C., Giorgi, M. A., Giovanetti, G. K., Gligan, M. L., Gola, A., Gorchakov, O., Goretti, A. M., Granato, F., Grassi, M., Grate, J. W., Grigoriev, G. Y., Gromov, M., Guan, M., Guerra, M. B. B., Guerzoni, M., Gulino, M., Haaland, R. K., Hallin, A., Harrop, B., Hoppe, E. W., Horikawa, S., Hosseini, B., Hughes, D., Humble, P., Hungerford, E. V., Ianni, An., Jillings, C., Johnson, T. N., Keeter, K., Kendziora, C. L., Kim, S., Koh, G., Korablev, D., Korga, G., Kubankin, A., Kuss, M., Kuźniak, M., Lehnert, B., Li, X., Lissia, M., Lodi, G. U., Loer, B., Longo, G., Loverre, P., Lussana, R., Luzzi, L., Ma, Y., Machado, A. A., Machulin, I. N., Mandarano, A., Mapelli, L., Marcante, M., Margotti, A., Mari, S. M., Mariani, M., Maricic, J., Martoff, C. J., Mascia, M., Mayer, M., McDonald, A. B., Messina, A., Meyers, P. D., Milincic, R., Moggi, A., Moioli, S., Monroe, J., Monte, A., Morrocchi, M., Mount, B. J., Mu, W., Muratova, V. N., Murphy, S., Musico, P., Nania, R., Agasson, A. Navrer, Nikulin, I., Nosov, V., Nozdrina, A. O., Nurakhov, N. N., Oleinik, A., Oleynikov, V., Orsini, M., Ortica, F., Pagani, L., Pallavicini, M., Palmas, S., Pandola, L., Pantic, E., Paoloni, E., Paternoster, G., Pavletcov, V., Pazzona, F., Peeters, S., Pelczar, K., Pellegrini, L. A., Pelliccia, N., Perotti, F., Perruzza, R., Fortes, V. Pesudo, Piemonte, C., Pilo, F., Pocar, A., Pollmann, T., Portaluppi, D., Pugachev, D. A., Qian, H., Radics, B., Raffaelli, F., Ragusa, F., Razeti, M., Razeto, A., Regazzoni, V., Regenfus, C., Reinhold, B., Renshaw, A. L., Rescigno, M., Retière, F., Riffard, Q., Rivetti, A., Rizzardini, S., Romani, A., Romero, L., Rossi, B., Rossi, N., Rubbia, A., Sablone, D., Salatino, P., Samoylov, O., García, E. Sánchez, Sands, W., Sant, M., Santorelli, R., Savarese, C., Scapparone, E., Schlitzer, B., Scioli, G., Segreto, E., Seifert, A., Semenov, D. A., Shchagin, A., Shekhtman, L., Shemyakina, E., Sheshukov, A., Simeone, M., Singh, P. N., Skensved, P., Skorokhvatov, M. D., Smirnov, O., Sobrero, G., Sokolov, A., Sotnikov, A., Speziale, F., Stainforth, R., Stanford, C., Suffritti, G. B., Suvorov, Y., Tartaglia, R., Testera, G., Tonazzo, A., Tosi, A., Trinchese, P., Unzhakov, E. V., Vacca, A., Vázquez-Jáuregui, E., Verducci, M., Viant, T., Villa, F., Vishneva, A., Vogelaar, B., Wada, M., Wahl, J., Walding, J., Walker, S., Wang, H., Wang, Y., Watson, A. W., Westerdale, S., Williams, R., Wojcik, M. M., Wu, S., Xiang, X., Xiao, X., Yang, C., Ye, Z., de Llano, A. Yllera, Zappa, F., Zappalà, G., Zhu, C., Zichichi, A., Zullo, M., and Zullo, A.
Subjects: Physics - Instrumentation and Detectors
Abstract: Building on the successful experience in operating the DarkSide-50 detector, the DarkSide Collaboration is going to construct DarkSide-20k, a direct WIMP search detector using a two-phase Liquid Argon Time Projection Chamber (LArTPC) with an active (fiducial) mass of 23 t (20 t). The DarkSide-20k LArTPC will be deployed within a shield/veto with a spherical Liquid Scintillator Veto (LSV) inside a cylindrical Water Cherenkov Veto (WCV). Operation of DarkSide-50 demonstrated a major reduction in the dominant $^{39}$Ar background when using argon extracted from an underground source, before applying pulse shape analysis. Data from DarkSide-50, in combination with MC simulation and analytical modeling, shows that a rejection factor for discrimination between electron and nuclear recoils of $\gt3\times10^9$ is achievable. This, along with the use of the veto system, is the key to unlocking the path to large LArTPC detector masses, while maintaining an "instrumental background-free" experiment, an experiment in which less than 0.1 events (other than $\nu$-induced nuclear recoils) is expected to occur within the WIMP search region during the planned exposure. DarkSide-20k will have ultra-low backgrounds than can be measured in situ. This will give sensitivity to WIMP-nucleon cross sections of $1.2\times10^{-47}$ cm$^2$ ($1.1\times10^{-46}$ cm$^2$) for WIMPs of $1$ TeV$/c^2$ ($10$ TeV$/c^2$) mass, to be achieved during a 5 yr run producing an exposure of 100 t yr free from any instrumental background. DarkSide-20k could then extend its operation to a decade, increasing the exposure to 200 t yr, reaching a sensitivity of $7.4\times10^{-48}$ cm$^2$ ($6.9\times10^{-47}$ cm$^2$) for WIMPs of $1$ TeV$/c^2$ ($10$ TeV$/c^2$) mass.
Published: 2017
Full Text: View/download PDF

14. Cryogenic Characterization of FBK RGB-HD SiPMs

Author: Aalseth, C. E., Acerbi, F., Agnes, P., Albuquerque, I. F. M., Alexander, T., Alici, A., Alton, A. K., Ampudia, P., Antonioli, P., Arcelli, S., Ardito, R., Arnquist, I. J., Asner, D. M., Back, H. O., Batignani, G., Bertoldo, E., Bettarini, S., Bisogni, M. G., Bocci, V., Bondar, A., Bonfini, G., Bonivento, W., Bossa, M., Bottino, B., Bunker, R., Bussino, S., Buzulutskov, A., Cadeddu, M., Cadoni, M., Caminata, A., Canci, N., Candela, A., Cantini, C., Caravati, M., Cariello, M., Carlini, M., Carpinelli, M., Castellani, A., Catalanotti, S., Cataudella, V., Cavalcante, P., Cereseto, R., Chen, Y., Chepurnov, A., Chiavassa, A., Cicalò, C., Cifarelli, L., Citterio, M., Cocco, A. G., Colocci, M., Corgiolu, S., Covone, G., Crivelli, P., D'Antone, I., D'Incecco, M., Rolo, M. D. Da Rocha, Daniel, M., Davini, S., De Candia, A., De Cecco, S., De Deo, M., De Filippis, G., De Guido, G., De Rosa, G., Dellacasa, G., Demontis, P., Derbin, A. V., Devoto, A., Di Eusanio, F., Di Pietro, G., Dionisi, C., Dolgov, A., Dormia, I., Dussoni, S., Empl, A., Ferri, A., Filip, C., Fiorillo, G., Fomenko, K., Franco, D., Froudakis, G. E., Gabriele, F., Gabrieli, A., Galbiati, C., Abia, P. Garcia, Gendotti, A., Ghisi, A., Giagu, S., Gibertoni, G., Giganti, C., Giorgi, M., Giovanetti, G. K., Gligan, M. L., Gola, A., Gorchakov, O., Goretti, A. M., Granato, F., Grassi, M., Grate, J. W., Grigoriev, G. Y., Gromov, M., Guan, M., Guerra, M. B. B., Guerzoni, M., Gulino, M., Haaland, R. K., Harrop, B., Hoppe, E. W., Horikawa, S., Hosseini, B., Hughes, D., Humble, P., Hungerford, E. V., Ianni, An., Cabre, S. Jimenez, Johnson, T. N., Keeter, K., Kendziora, C. L., Kim, S., Koh, G., Korablev, D., Korga, G., Kubankin, A., Kugathasan, R., Kuss, M., Li, X., Lissia, M., Lodi, G. U., Loer, B., Longo, G., Lussana, R., Luzzi, L., Ma, Y., Machado, A. A., Machulin, I. N., Mais, L., Mandarano, A., Mapelli, L., Marcante, M., Margotti, A., Mari, S. M., Mariani, M., Maricic, J., Marinelli, M., Marras, D., Martoff, C. J., Mascia, M., Messina, A., Meyers, P. D., Milincic, R., Moggi, A., Moioli, S., Monasterio, S., Monroe, J., Monte, A., Morrocchi, M., Mu, W., Muratova, V. N., Murphy, S., Musico, P., Nania, R., Napolitano, J., Agasson, A. Navrer, Nikulin, I., Nosov, V., Nozdrina, A. O., Nurakhov, N. N., Oleinik, A., Oleynikov, V., Orsini, M., Ortica, F., Pagani, L., Pallavicini, M., Palmas, S., Pandola, L., Pantic, E., Paoloni, E., Paternoster, G., Pavletcov, V., Pazzona, F., Pelczar, K., Pellegrini, L. A., Pelliccia, N., Perotti, F., Perruzza, R., Piemonte, C., Pilo, F., Pocar, A., Portaluppi, D., Poudel, S. S., Pugachev, D. A., Qian, H., Radics, B., Raffaelli, F., Ragusa, F., Randle, K., Razeti, M., Razeto, A., Regazzoni, V., Regenfus, C., Reinhold, B., Renshaw, A. L., Rescigno, M., Riffard, Q., Rivetti, A., Romani, A., Romero, L., Rossi, B., Rossi, N., Rubbia, A., Sablone, D., Salatino, P., Samoylov, O., Sands, W., Sant, M., Santorelli, R., Savarese, C., Scapparone, E., Schlitzer, B., Scioli, G., Sechi, E., Segreto, E., Seifert, A., Semenov, D. A., Serci, S., Shchagin, A., Shekhtman, L., Shemyakina, E., Sheshukov, A., Simeone, M., Singh, P. N., Skorokhvatov, M. D., Smirnov, O., Sobrero, G., Sokolov, A., Sotnikov, A., Stanford, C., Suffritti, G. B., Suvorov, Y., Tartaglia, R., Testera, G., Tonazzo, A., Tosi, A., Trinchese, P., Unzhakov, E. V., Vacca, A., Verducci, M., Viant, T., Villa, F., Vishneva, A., Vogelaar, B., Wada, M., Wahl, J., Walker, S., Wang, H., Wang, Y., Watson, A. W., Westerdale, S., Wilhelmi, J., Williams, R., Wojcik, M. M., Wu, S., Xiang, X., Xiao, X., Yang, C., Ye, Z., Zappa, F., Zappalà, G., Zhu, C., Zichichi, A., and Zuzel, G.
Subjects: Physics - Instrumentation and Detectors
Abstract: We report on the cryogenic characterization of Red Green Blue - High Density (RGB-HD) SiPMs developed at Fondazione Bruno Kessler (FBK) as part of the DarkSide program of dark matter searches with liquid argon time projection chambers. A dedicated setup was used to measure the primary dark noise, the correlated noise, and the gain of the SiPMs at varying temperatures. A custom-made data acquisition system and analysis software were used to precisely characterize these parameters. We demonstrate that FBK RGB-HD SiPMs with low quenching resistance (RGB-HD-LR$_q$) can be operated from 40 K to 300 K with gains in the range $10^5$ to $10^6$ and noise rates on the order of a few Hz/mm$^2$.
Published: 2017
Full Text: View/download PDF

15. Saipem's submerged floating tunnel concept – an industry and University cooperation to drive innovation in civil infrastructures

Author: Chiesa, G., primary, Faggiano, B., additional, Landolfo, R., additional, Mazzolani, F.M., additional, Martinelli, L., additional, Mulas, M.G., additional, and Perotti, F., additional
Published: 2022
Full Text: View/download PDF

16. A semi-analytical model for the design and optimization of SFTs under seismic loading

Author: Foti, F., primary, Martinelli, L., additional, and Perotti, F., additional
Published: 2022
Full Text: View/download PDF

17. An X-ray burst from a magnetar enlightening the mechanism of fast radio bursts

Author: Tavani, M., Casentini, C., Ursi, A., Verrecchia, F., Addis, A., Antonelli, L. A., Argan, A., Barbiellini, G., Baroncelli, L., Bernardi, G., Bianchi, G., Bulgarelli, A., Caraveo, P., Cardillo, M., Cattaneo, P. W., Chen, A. W., Costa, E., Del Monte, E., Di Cocco, G., Di Persio, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fioretti, V., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Labanti, C., Lazzarotto, F., Lipari, P., Longo, F., Lucarelli, F., Magro, A., Marisaldi, M., Mereghetti, S., Morelli, E., Morselli, A., Naldi, G., Pacciani, L., Parmiggiani, N., Paoletti, F., Pellizzoni, A., Perri, M., Perotti, F., Piano, G., Picozza, P., Pilia, M., Pittori, C., Puccetti, S., Pupillo, G., Rapisarda, M., Rappoldi, A., Rubini, A., Setti, G., Soffitta, P., Trifoglio, M., Trois, A., Vercellone, S., Vittorini, V., Giommi, P., and D’Amico, F.
Published: 2021
Full Text: View/download PDF

18. Seismic design and response of a 14-story concentrically braced steel building

Author: Martinelli, L., primary, Perotti, F., additional, and Bozzi, A., additional
Published: 2021
Full Text: View/download PDF

19. Wind Pressure Distribution on a Porous Double Skin Façade System

Author: Zasso, A., Perotti, F., Rosa, L., Schito, P., Pomaranzi, G., Daniotti, N., di Prisco, Marco, Series Editor, Chen, Sheng-Hong, Series Editor, Vayas, Ioannis, Series Editor, Kumar Shukla, Sanjay, Series Editor, Sharma, Anuj, Series Editor, Kumar, Nagesh, Series Editor, Wang, Chien Ming, Series Editor, Ricciardelli, Francesco, editor, and Avossa, Alberto Maria, editor
Published: 2019
Full Text: View/download PDF

20. An updated list of AGILE bright gamma-ray sources and their variability in pointing mode

Author: Verrecchia, F., Pittori, C., Chen, A. W., Bulgarelli, A., Tavani, M., Lucarelli, F., Giommi, P., Vercellone, S., Pellizzoni, A., Giuliani, A., Longo, F., Barbiellini, G., Trifoglio, M., Gianotti, F., Argan, A., Antonelli, L. A., Caraveo, P., Cardillo, M., Cattaneo, P. W., Cocco, V., Colafrancesco, S., Contessi, T., Costa, E., Del Monte, E., De Paris, G., Di Cocco, G., Di Persio, G., Donnarumma, I., Evangelista, Y., Fanari, G., Feroci, M., Ferrari, A., Fiorini, M., Fornari, F., Fuschino, F., Froysland, T., Frutti, M., Galli, M., Labanti, C., Lapshov, I., Lazzarotto, F., Liello, F., Lipari, P., Mattaini, E., Marisaldi, M., Mastropietro, M., Mauri, A., Mauri, F., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Perotti, F., Piano, G., Picozza, P., Pilia, M., Pontoni, C., Porrovecchio, G., Prest, M., Primavera, R., Pucella, G., Rapisarda, M., Rappoldi, A., Rossi, E., Rubini, A., Sabatini, S., Santolamazza, P., Soffitta, P., Stellato, S., Striani, E., Tamburelli, F., Traci, A., Trois, A., Vallazza, E., Vittorini, V., Zanello, D., Salotti, L., and Valentini, G.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present a variability study of a sample of bright gamma-ray (30 MeV -- 50 GeV) sources. This sample is an extension of the first AGILE catalogue of gamma-ray sources (1AGL), obtained using the complete set of AGILE observations in pointing mode performed during a 2.3 year period from July 9, 2007 until October 30, 2009. The dataset of AGILE pointed observations covers a long time interval and its gamma-ray data archive is useful for monitoring studies of medium-to-high brightness gamma-ray sources. In the analysis reported here, we used data obtained with an improved event filter that covers a wider field of view, on a much larger (about 27.5 months) dataset, integrating data on observation block time scales, which mostly range from a few days to thirty days. The data processing resulted in a better characterized source list than 1AGL was, and includes 54 sources, 7 of which are new high galactic latitude (|BII| >= 5) sources, 8 are new sources on the galactic plane, and 20 sources from the previous catalogue with revised positions. Eight 1AGL sources (2 high-latitude and 6 on the galactic plane) were not detected in the final processing either because of low OB exposure and/or due to their position in complex galactic regions. We report the results in a catalogue of all the detections obtained in each single OB, including the variability results for each of these sources. In particular, we found that 12 sources out of 42 or 11 out of 53 are variable, depending on the variability index used, where 42 and 53 are the number of sources for which these indices could be calculated. Seven of the 11 variable sources are blazars, the others are Crab pulsar+nebula, LS I +61{\deg}303, Cyg X-3, and 1AGLR J2021+4030., Comment: 30 pages, 12 figures
Published: 2013
Full Text: View/download PDF

21. Calibration of AGILE-GRID with In-Flight Data and Monte Carlo Simulations

Author: Chen, Andrew W., Argan, A., Bulgarelli, A., Cattaneo, P. W., Contessi, T., Giuliani, A., Pittori, C., Pucella, G., Tavani, M., Trois, A., Verrecchia, F., Barbiellini, G., Caraveo, P., Colafrancesco, S., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Donnarumma, I., Evangelista, Y., Ferrari, A., Feroci, M., Fioretti, V., Fiorini, M., Fuschino, F., Galli, M., Gianotti, F., Giommi, P., Giusti, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Lucarelli, F., Marisaldi, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Sabatini, S., Santolamazza, P., Soffitta, P., Striani, E., Trifoglio, M., Valentini, G., Vallazza, E., Vercellone, S., Vittorini, V., and Zanello, D.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: Context: AGILE is a gamma-ray astrophysics mission which has been in orbit since 23 April 2007 and continues to operate reliably. The gamma-ray detector, AGILE-GRID, has observed Galactic and extragalactic sources, many of which were collected in the first AGILE Catalog. Aims: We present the calibration of the AGILE-GRID using in-flight data and Monte Carlo simulations, producing Instrument Response Functions (IRFs) for the effective area A_eff), Energy Dispersion Probability (EDP), and Point Spread Function (PSF), each as a function of incident direction in instrument coordinates and energy. Methods: We performed Monte Carlo simulations at different gamma-ray energies and incident angles, including background rejection filters and Kalman filter-based gamma-ray reconstruction. Long integrations of in-flight observations of the Vela, Crab and Geminga sources in broad and narrow energy bands were used to validate and improve the accuracy of the instrument response functions. Results: The weighted average PSFs as a function of spectra correspond well to the data for all sources and energy bands. Conclusions: Changes in the interpolation of the PSF from Monte Carlo data and in the procedure for construction of the energy-weighted effective areas have improved the correspondence between predicted and observed fluxes and spectra of celestial calibration sources, reducing false positives and obviating the need for post-hoc energy-dependent scaling factors. The new IRFs have been publicly available from the Agile Science Data Centre since November 25, 2011, while the changes in the analysis software will be distributed in an upcoming release.
Published: 2013
Full Text: View/download PDF

22. SFTs under seismic loading: Conceptual design and optimization tools

Author: Foti, F., primary, Martinelli, L., additional, and Perotti, F., additional
Published: 2021
Full Text: View/download PDF

23. The characterization of the distant blazar GB6 J1239+0443 from flaring and low activity periods

Author: Pacciani, L., Donnarumma, I., Denney, K. D., Assef, R. J., Ikejiri, Y., Yamanaka, M., Uemura, M., Domingo, A., Giommi, P., Tarchi, A., Verrecchia, F., Longo, F., Rainó, S., Giusti, M., Vercellone, S., Chen, A. W., Striani, E., Vittorini, V., Tavani, M., Bulgarelli, A., Giuliani, A., Pucella, G., Argan, A., Barbiellini, G., Caraveo, P., Cattaneo, P. W., Colafrancesco, S., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Evangelista, Y., Ferrari, A., Feroci, M., Fiorini, M., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Marisaldi, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Sabatini, S., Soffitta, P., Trifoglio, M., Trois, A., Vallazza, E., Zanello, D., Pittori, C., Santolamazza, P., Lucarelli, F., Salotti, L., and Valentini, G.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: In 2008 AGILE and Fermi detected gamma-ray flaring activity from the unidentified EGRET source 3EG J1236+0457, recently associated with a flat spectrum radio quasar GB6 J1239+0443 at z=1.762. The optical counterpart of the gamma-ray source underwent a flux enhancement of a factor 15-30 in 6 years, and of ~10 in six months. We interpret this flare-up in terms of a transition from an accretion-disk dominated emission to a synchrotron-jet dominated one. We analysed a Sloan Digital Sky Survey (SDSS) archival optical spectrum taken during a period of low radio and optical activity of the source. We estimated the mass of the central black hole using the width of the CIV emission line. In our work, we have also investigated SDSS archival optical photometric data and UV GALEX observations to estimate the thermal-disk emission contribution of GB6 J1239+0443. Our analysis of the gamma-ray data taken during the flaring episodes indicates a flat gamma-ray spectrum, with an extension of up to 15 GeV, with no statistically-relevant sign of absorption from the broad line region, suggesting that the blazar-zone is located beyond the broad line region. This result is confirmed by the modeling of the broad-band spectral energy distribution (well constrained by the available multiwavelength data) of the flaring activity periods and by the accretion disk luminosity and black hole mass estimated by us using archival data., Comment: 30 pages, 7 figures, 4 tables MNRAS Accepted on 2012 June 18
Published: 2012
Full Text: View/download PDF

24. Galactic Sources Science With Agile: The Case Of The Carina Region

Author: Sabatini, S., Tavani, M., Pian, E., Bulgarelli, A., Caraveo, P., Viotti, R., Corcoran, M. F., Giuliani, A., Pittori, C., Verrecchia, F., Vercellone, S., Mereghetti, S., Argan, A., Barbiellini, G., Boffelli, F., Cattaneo, P. W., Chen, A. W., Cocco, V., D'Ammando, F., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Donnarumma, I., Evangelista, Y., Ferrari, A., Feroci, M., Fiorini, M., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Marisaldi, M., Mastropietro, M., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Pucella, G., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Soffitta, P., Trifoglio, M., Trois, A., Vallazza, E., Vittorini, V., Zambra, A., Zanello, D., Santolamazza, P., Giommi, P., Colafrancesco, S., Antonelli, L. A., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: During its first 2 years of operation, the gamma-ray AGILE satellite accumulated an extensive dataset for the Galactic plane. The data have been monitored for transient sources and several gamma-ray sources were detected. Their variability and possible association were studied. In this talk we will focus on the results of extensive observations of the Carina Region during the time period 2007 July - 2009 January, for a total livetime of ~130 days. The region is extremely complex, hosting massive star formation, with the remarkable colliding wind binary Eta Carinae, massive star clusters and HII regions (e.g. NGC 3324, RCW49, Westerlund II) and a giant molecular cloud extending over 150 pc (between l=284.7 and l=289). The Carina Nebula itself is the largest and IR highest surface brightness nebula of the Southern emisphere. We monitored several gamma ray sources in the Carina Region. In particular we detect a gamma ray source (1AGL J1043-5931) consistent with the position of Eta Carinae and report a remarkable 2-days gamma-ray flaring episode from this source on 2008 Oct 11-13. If 1AGL J1043-5931 is associated with the Eta Car system, our data provides the long sought first detection above 100 MeV of a colliding wind binary., Comment: 5 pages, 5 figures, proceedings of RICAP 2009
Published: 2012
Full Text: View/download PDF

25. The flaring blazars of the first 1.5 years of the AGILE mission

Author: Pacciani, L., Bulgarelli, A., Chen, A. W., D'Ammando, F., Donnarumma, I., Giuliani, A., Longo, F., Pucella, G., Tavani, M., Vercellone, S., Vittorini, V., Argan, A., Barbiellini, G., Boffelli, F., Caraveo, P., Cattaneo, P. W., Cocco, V., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Evangelista, Y., Ferrari, A., Feroci, M., Fiorini, M., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Marisaldi, M., Mastropietro, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Sabatini, S., Soffitta, P., Trifoglio, M., Trois, A., Vallazza, E., Zambra, A., Zanello, D., Antonelli, L. A., Colafrancesco, S., Giommi, P., Pittori, C., Verrecchia, F., Santolamazza, P., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report the AGILE gamma-ray observations and the results of the multiwavelength campaigns on seven flaring blazars detected by the mission: During two multiwavelength campaigns, we observed gamma-ray activity from two Flat Spectrum Radio Quasars of the Virgo region, e.g. 3C 279 and 3C 273 (the latter being the first extragalactic source simultaneously observed with the gamma-ray telescope and the hard X ray imager of the mission). Due to the large FOV of the AGILE/GRID instrument, we achieved an almost continuous coverage of the FSRQ 3C 454.3. The source showed flux above 10E-6 photons/cm2/s (E > 100 MeV) and showed day by day variability during all the AGILE observing periods. In the EGRET era, the source was found in high gamma-ray activity only once. An other blazar, PKS 1510-089 was frequently found in high gamma-ray activity. S5 0716+71, an intermediate BL Lac object, exhibited a very high gamma-ray activity and fast gamma-ray variability during a period of intense optical activity. We observed high gamma-ray activity from W Comae, a BL Lac object, and Mrk 421, an high energy peaked BL Lac object. For this source, a multiwavelength campaign from optical to TeV has been performed.
Published: 2011
Full Text: View/download PDF

26. The observation of Gamma Ray Bursts and Terrestrial Gamma-ray Flashes with AGILE

Author: Del Monte, E., Barbiellini, G., Fuschino, F., Giuliani, A., Longo, F., Marisaldi, M., Mereghetti, S., Moretti, E., Trifoglio, M., Vianello, G., Costa, E., Donnarumma, I., Evangelista, Y., Feroci, M., Galli, M., Lapshov, I., Lazzarotto, F., Lipari, P., Pacciani, L., Rapisarda, M., Soffitta, P., Tavani, M., Vercellone, S., Cutini, S., Boffelli, F., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Chen, A., Di Cocco, G., Gianotti, F., Labanti, C., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Prest, M., Pucella, G., Rappoldi, A., Sabatini, S., Striani, E., Trois, A., Vallazza, E., Vittorini, V., Antonelli, L. A., Pittori, C., Preger, B., Santolamazza, P., Verrecchia, F., Giommi, P., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Since its early phases of operation, the AGILE mission is successfully observing Gamma Ray Bursts (GRBs) in the hard X-ray band with the SuperAGILE imager and in the MeV range with the Mini-Calorimeter. Up to now, three firm GRB detections were obtained above 25 MeV and some bursts were detected with lower statistical confidence in the same energy band. When a GRB is localized, either by SuperAGILE or Swift/BAT or INTEGRAL/IBIS or Fermi/GBM or IPN, inside the field of view of the Gamma Ray Imager of AGILE, a detection is searched for in the gamma ray band or an upper limit is provided. A promising result of AGILE is the detection of very short gamma ray transients, a few ms in duration and possibly identified with Terrestrial Gamma-ray Flashes. In this paper we show the current status of the observation of Gamma Ray Bursts and Terrestrial Gamma-ray Flashes with AGILE., Comment: Four pages and four figures
Published: 2011
Full Text: View/download PDF

27. First results about on-ground calibration of the Silicon Tracker for the AGILE satellite

Author: AGILE Collaboration, Cattaneo, P. W., Argan, A., Boffelli, F., Bulgarelli, A., Buonomo, B., Chen, A. W., D'Ammando, F., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Longo, F., Marisaldi, M., Mazzitelli, G., Pellizzoni, A., Prest, M., Pucella, G., Quintieri, L., Rappoldi, A., Tavani, M., Trifoglio, M., Trois, A., Valente, P., Vallazza, E., Vercellone, S., Zambra, A., Barbiellini, G., Caraveo, P., Cocco, V., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Mastropietro, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Rapisarda, M., Rubini, A., Sabatini, S., Soffitta, P., Striani, E., Vittorini, V., Zanello, D., Colafrancesco, S., Giommi, P., Pittori, C., Santolamazza, P., Verrecchia, F., and Salotti, L.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Instrumentation and Detectors
Abstract: The AGILE scientific instrument has been calibrated with a tagged $\gamma$-ray beam at the Beam Test Facility (BTF) of the INFN Laboratori Nazionali di Frascati (LNF). The goal of the calibration was the measure of the Point Spread Function (PSF) as a function of the photon energy and incident angle and the validation of the Monte Carlo (MC) simulation of the silicon tracker operation. The calibration setup is described and some preliminary results are presented., Comment: Presented at the 2nd Roma International Conference on Astroparticle Physics 2009, Villa Mondragone, Rome, Italy, May 13-15 2009. Pages 6, Figures 10
Published: 2011
Full Text: View/download PDF

28. Characterization of a tagged $\gamma$-ray beam line at the DA$\Phi$NE Beam Test Facility

Author: Cattaneo, P. W., Argan, A., Boffelli, F., Bulgarelli, A., Buonomo, B., Chen, A. W., D'Ammando, F., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Longo, F., Marisaldi, M., Mazzitelli, G., Pellizzoni, A., Prest, M., Pucella, G., Quintieri, L., Rappoldi, A., Tavani, M., Trifoglio, M., Trois, A., Valente, P., Vallazza, E., Vercellone, S., Zambra, A., Barbiellini, G., Caraveo, P., Cocco, V., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Mastropietro, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Rapisarda, M., Rubini, A., Sabatini, S., Soffitta, P., Striani, E., Vittorini, V., Zanello, D., Colafrancesco, S., Giommi, P., Pittori, C., Santolamazza, P., Verrecchia, F., and Salotti, L.
Subjects: Physics - Instrumentation and Detectors, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: At the core of the AGILE scientific instrument, designed to operate on a satellite, there is the Gamma Ray Imaging Detector (GRID) consisting of a Silicon Tracker (ST), a Cesium Iodide Mini-Calorimeter and an Anti-Coincidence system of plastic scintillator bars. The ST needs an on-ground calibration with a $\gamma$-ray beam to validate the simulation used to calculate the energy response function and the effective area versus the energy and the direction of the $\gamma$ rays. A tagged $\gamma$-ray beam line was designed at the Beam Test Facility (BTF) of the INFN Laboratori Nazionali of Frascati (LNF), based on an electron beam generating $\gamma$ rays through bremsstrahlung in a position-sensitive target. The $\gamma$-ray energy is deduced by difference with the post-bremsstrahlung electron energy \cite{prest}-\cite{hasan}. The electron energy is measured by a spectrometer consisting of a dipole magnet and an array of position sensitive silicon strip detectors, the Photon Tagging System (PTS). The use of the combined BTF-PTS system as tagged photon beam requires understanding the efficiency of $\gamma$-ray tagging, the probability of fake tagging, the energy resolution and the relation of the PTS hit position versus the $\gamma$-ray energy. This paper describes this study comparing data taken during the AGILE calibration occurred in 2005 with simulation., Comment: 23 pages; 17 figures. Second and final version accepted by Nucl. Instr. & Meth. A
Published: 2011
Full Text: View/download PDF

29. AGILE detection of Cygnus X-3 {\gamma}-ray active states during the period mid-2009/mid-2010

Author: Bulgarelli, A., Tavani, M., Chen, A. W., Evangelista, Y., Trifoglio, M., Gianotti, F., Piano, G., Sabatini, S., Striani, E., Pooley, G., Trushkin, S., Nizhelskij, N. A., McCollough, M., Koljonen, K. I. I., Hannikainen, D., Lähteenmäki, A., Tammi, J., Lavonen, N., Steeghs, D., Aboudan, A., Argan, A., Barbiellini, G., Campana, R., Caraveo, P., Cattaneo, P. W., Cocco, V., Contessi, T., Costa, E., D'Ammando, F., Del Monte, E., De Paris, G., Di Cocco, G., Donnarumma, I., Feroci, M., Fiorini, M., Fuschino, F., Galli, M., Giuliani, A., Giusti, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Marisaldi, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Picozza, P., Pilia, M., Prest, M., Pucella, G., Rapisarda, M., Rappoldi, A., Rubini, A., Soffitta, P., Trois, A., Vallazza, E., Vercellone, S., Vittorini, V., Zambra, A., Zanello, D., Giommi, P., Pittori, C., Verrecchia, F., Santolamazza, P., Lucarelli, F., Colafrancesco, S., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Cygnus X-3 (Cyg X-3) is a well-known microquasar producing variable emission at all wavelengths. Cyg X-3 is a prominent X-ray binary producing relativistic jets, and studying its high energy emission is crucial for the understanding of the fundamental acceleration processes in accreting compact objects. Aims. Our goal is to study extreme particle acceleration and {\gamma}-ray production above 100 MeV during special spectral states of Cyg X- 3 usually characterized by a low hard X-ray flux and enhanced soft X-ray states. We observed Cyg X-3 with the AGILE satellite in extended time intervals from 2009 Jun.-Jul., and 2009 Nov.-2010 Jul. We report here the results of the AGILE {\gamma}-ray monitoring of Cyg X-3 as well as the results from extensive multiwavelength campaigns involving radio (RATAN-600, AMI-LA and Mets\"{a}hovi Radio Observatories) and X-ray monitoring data (XTE and Swift). We detect a series of repeated {\gamma}-ray flaring activity from Cyg X-3 that correlate with the soft X-ray states and episodes of decreasing or non-detectable hard X-ray emission. Furthermore, we detect {\gamma}-ray enhanced emission that tends to be associated with radio flares greater than 1 Jy at 15 GHz, confirming a trend already detected in previous observations. The source remained active above 100 MeV for an extended period of time (almost 1.5 months in 2009 Jun.-Jul. and 1 month in 2010 May). We study in detail the short timescale {\gamma}-ray flares that occurred before or near the radio peaks. Our results confirm the transient nature of the extreme particle acceleration from the microquasar Cyg X-3. A series of repeated {\gamma}-ray flares shows correlations with radio and X-ray emission confirming a well established trend of emission. We compare our results with Fermi-LAT and MAGIC TeV observations of Cyg X-3., Comment: 16 pages, 8 figures, 7 tables; A&A (2011)
Published: 2011
Full Text: View/download PDF

30. The AGILE observations of the hard and bright GRB 100724B

Author: Del Monte, E., Barbiellini, G., Donnarumma, I., Fuschino, F., Giuliani, A., Longo, F., Marisaldi, M., Pucella, G., Tavani, M., Trifoglio, M., Trois, A., Argan, A., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Chen, A., Costa, E., D'Ammando, F., Di Cocco, G., Evangelista, Y., Feroci, M., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Mereghetti, S., Moretti, E., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Prest, M., Rapisarda, M., Rappoldi, A., Sabatini, S., Soffitta, P., Striani, E., Vallazza, E., Vercellone, S., Vittorini, V., Antonelli, L. A., Cutini, S., Pittori, C., Santolamazza, P., Verrecchia, F., Giommi, P., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The observation of Gamma Ray Bursts (GRBs) in the gamma-ray band has been advanced by the AGILE and Fermi satellites after the era of the Compton Gamma-Ray Observatory. AGILE and Fermi are showing that the GeV-bright GRBs share a set of common features, particularly the high fluence from the keV up to the GeV energy bands, the high value of the minimum Lorentz factor, the presence of an extended emission of gamma-rays, often delayed with respect to lower energies, and finally the possible presence of multiple spectral components. GRB 100724B, localised in a joint effort by Fermi and the InterPlanetary Newtork, is the brightest burst detected in gamma-rays so far by AGILE. Characteristic features of GRB 100724B are the simultaneous emissions at MeV and GeV, without delayed onset nor time lag as shown by the analysis of the cross correlation function, and the significant spectral evolution in hard X-rays over the event duration. In this paper we show the analysis of the AGILE data of GRB 100724B and we discuss its features in the context of the bursts observed so far in gamma-rays and the recently proposed models., Comment: 8 pages, 5 figures. Accepted for publication by A&A. Final version after the correction by the language editor
Published: 2011
Full Text: View/download PDF

31. The Crab Nebula super-flare in April 2011: extremely fast particle acceleration and gamma-ray emission

Author: Striani, E., Tavani, M., Piano, G., Donnarumma, I., Pucella, G., Vittorini, V., Bulgarelli, A., Trois, A., Pittori, C., Verrecchia, F., Costa, E., Weisskopf, M., Tennant, A., Argan, A., Barbiellini, G., Caraveo, P., Cardillo, M, Cattaneo, P. W., Chen, A. W., De Paris, G., Del Monte, E., Di Cocco, G., Evangelista, Y., Ferrari, A., Feroci, M., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Labanti, C., Lapshov, I., Lazzarotto, F., Longo, F., Marisaldi, M., Mereghetti, S., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Picozza, P., Pilia, M., Rapisarda, M., Rappoldi, A., Sabatini, S., Soffitta, P., Trifoglio, M., Vercellone, S., Lucarelli, F., Santolamazza, P., and Giommi, P.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report on the extremely intense and fast gamma-ray are above 100 MeV detected by AGILE from the Crab Nebula in mid-April 2011. This event is the fourth of a sequence of reported major gamma-ray flares produced by the Crab Nebula in the period 2007/mid-2011. These events are attributed to strong radiative and plasma instabilities in the inner Crab Nebula, and their properties are crucial for theoretical studies of fast and efficient particle acceleration up to 10^15 eV. Here we study the very rapid flux and spectral evolution of the event that reached on April 16, 2011 the record-high peak flux of F = (26 +/- 5) x 10^-6 ph cm^-2 s^-1 with a risetime timescale that we determine to be in the range 6-10 hrs. The peak flaring gamma-ray spectrum reaches a distinct maximum near 500 MeV with no substantial emission above 1 GeV. The very rapid risetime and overall evolution of the Crab Nebula are strongly constrain the acceleration mechanisms and challenge MHD models. We briefly discuss the theoretical implications of our observations., Comment: 4 pages, 2 figures. Accepted for pubblication in ApJL
Published: 2011
Full Text: View/download PDF

32. AGILE detection of extreme gamma-ray activity from the blazar PKS 1510-089 during March 2009. Multifrequency analysis

Author: D'Ammando, F., Raiteri, C. M., Villata, M., Romano, P., Pucella, G., Krimm, H. A., Covino, S., Orienti, M., Giovannini, G., Vercellone, S., Pian, E., Donnarumma, I., Vittorini, V., Tavani, M., Argan, A., Barbiellini, G., Boffelli, F., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Chen, A. W., Cocco, V., Costa, E., Del Monte, E., De Paris, G., Di Cocco, G., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Froysland, T., Frutti, M., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Marisaldi, M., Mereghetti, S., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Sabatini, S., Soffitta, P., Striani, E., Trifoglio, M., Trois, A., Vallazza, E., Zambra, A., Zanello, D., Agudo, I., Aller, H. D., Aller, M. F., Arkharov, A. A., Bach, U., Benitez, E., Berdyugin, A., Blinov, D. A., Buemi, C. S., Chen, W. P., Di Paola, A., Dolci, M., Forne, E., Fuhrmann, L., Gomez, J. L., Gurwell, M. A., Jordan, B., Jorstad, S. G., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H. Y., Kimeridze, G., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Kurtanidze, O. M., Kurtanidze, S. O., Larionov, V. M., Lahteenmaki, A., Leto, P., Lindfors, E., Marscher, A. P., McBreen, B., McHardy, I. M., Morozova, D. A., Nilsson, K., Pasanen, M., Roca-Sogorb, M., Sillanpaa, A., Takalo, L. O., Tornikoski, M., Trigilio, C., Troitsky, I. S., Umana, G., Antonelli, L. A., Colafrancesco, S., Pittori, C., Santolamazza, P., Verrecchia, F., Giommi, P., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report on the extreme gamma-ray activity from the FSRQ PKS 1510-089 observed by AGILE in March 2009. In the same period a radio-to-optical monitoring of the source was provided by the GASP-WEBT and REM. Moreover, several Swift ToO observations were triggered, adding important information on the source behaviour from optical/UV to hard X-rays. We paid particular attention to the calibration of the Swift/UVOT data to make it suitable to the blazars spectra. Simultaneous observations from radio to gamma rays allowed us to study in detail the correlation among the emission variability at different frequencies and to investigate the mechanisms at work. In the period 9-30 March 2009, AGILE detected an average gamma-ray flux of (311+/-21)x10^-8 ph cm^-2 s^-1 for E>100 MeV, and a peak level of (702+/-131)x10^-8 ph cm^-2 s^-1 on daily integration. The gamma-ray activity occurred during a period of increasing activity from near-IR to UV, with a flaring episode detected on 26-27 March 2009, suggesting that a single mechanism is responsible for the flux enhancement observed from near-IR to UV. By contrast, Swift/XRT observations seem to show no clear correlation of the X-ray fluxes with the optical and gamma-ray ones. However, the X-ray observations show a harder photon index (1.3-1.6) with respect to most FSRQs and a hint of harder-when-brighter behaviour, indicating the possible presence of a second emission component at soft X-ray energies. Moreover, the broad band spectrum from radio-to-UV confirmed the evidence of thermal features in the optical/UV spectrum of PKS 1510-089 also during high gamma-ray state. On the other hand, during 25-26 March 2009 a flat spectrum in the optical/UV energy band was observed, suggesting an important contribution of the synchrotron emission in this part of the spectrum during the brightest gamma-ray flare, therefore a significant shift of the synchrotron peak., Comment: 13 pages, 7 figures, 3 tables. Accepted for publication in Astronomy and Astrophysics
Published: 2011
Full Text: View/download PDF

33. Discovery of Powerful Gamma-Ray Flares from the Crab Nebula

Author: Tavani, M., Bulgarelli, A., Vittorini, V., Pellizzoni, A., Striani, E., Caraveo, P., Weisskopf, M. C., Tennant, A., Pucella, G., Trois, A., Costa, E., Evangelista, Y., Pittori, C., Verrecchia, F., Del Monte, E., Campana, R., Pilia, M., De Luca, A., Donnarumma, I., Horns, D., Ferrigno, C., Heinke, C. O., Trifoglio, M., Gianotti, F., Vercellone, S., Argan, A., Barbiellini, G., Cattaneo, P. W., Chen, A. W., Contessi, T., D'Ammando, F., DeParis, G., Di Cocco, G., Di Persio, G., Feroci, M., Ferrari, A., Galli, M., Giuliani, A., Giusti, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Fuschino, F., Marisaldi, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Perotti, F., Piano, G., Picozza, P., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Sabatini, S., Soffitta, P., Vallazza, E., Zambra, A., Zanello, D., Lucarelli, F., Santolamazza, P., Giommi, P., Salotti, L., and Bignami, G. F.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The well known Crab Nebula is at the center of the SN1054 supernova remnant. It consists of a rotationally-powered pulsar interacting with a surrounding nebula through a relativistic particle wind. The emissions originating from the pulsar and nebula have been considered to be essentially stable. Here we report the detection of strong gamma-ray (100 MeV-10 GeV) flares observed by the AGILE satellite in September, 2010 and October, 2007. In both cases, the unpulsed flux increased by a factor of 3 compared to the non-flaring flux. The flare luminosity and short timescale favor an origin near the pulsar, and we discuss Chandra Observatory X-ray and HST optical follow-up observations of the nebula. Our observations challenge standard models of nebular emission and require power-law acceleration by shock-driven plasma wave turbulence within a ~1-day timescale., Comment: 23 pages (including Supporting On-line Material), 8 figures, 1 table. Version published in Science Express on January 6, 2011 (available at http://www.sciencemag.org/content/early/2011/01/05/science.1200083)
Published: 2011
Full Text: View/download PDF

34. Gamma-Ray Localization of Terrestrial Gamma-Ray Flashes

Author: Marisaldi, M., Argan, A., Trois, A., Giuliani, A., Tavani, M., Labanti, C., Fuschino, F., Bulgarelli, A., Longo, F., Barbiellini, G., Del Monte, E., Moretti, E., Trifoglio, M., Costa, E., Caraveo, P., Cattaneo, P. W., Chen, A., D'Ammando, F., De Paris, G., Di Cocco, G., Di Persio, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Froysland, T., Galli, M., Gianotti, F., Lapshov, I., Lazzarotto, F., Lipari, P., Mereghetti, S., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Picozza, P., Piano, G., Pilia, M., Prest, M., Pucella, G., Rapisarda, M., Rappoldi, A., Rubini, A., Sabatini, S., Soffitta, P., Striani, E., Vallazza, E., Vercellone, S., Vittorini, V., Zambra, A., Zanello, D., Antonelli, L. A., Colafrancesco, S., Cutini, S., Giommi, P., Lucarelli, F., Pittori, C., Santolamazza, P., Verrecchia, F., and Salotti, L.
Subjects: Physics - Atmospheric and Oceanic Physics, Astrophysics - Earth and Planetary Astrophysics
Abstract: Terrestrial Gamma-Ray Flashes (TGFs) are very short bursts of high energy photons and electrons originating in Earth's atmosphere. We present here a localization study of TGFs carried out at gamma-ray energies above 20 MeV based on an innovative event selection method. We use the AGILE satellite Silicon Tracker data that for the first time have been correlated with TGFs detected by the AGILE Mini-Calorimeter. We detect 8 TGFs with gamma-ray photons of energies above 20 MeV localized by the AGILE gamma-ray imager with an accuracy of 5-10 degrees at 50 MeV. Remarkably, all TGF-associated gamma rays are compatible with a terrestrial production site closer to the sub-satellite point than 400 km. Considering that our gamma rays reach the AGILE satellite at 540 km altitude with limited scattering or attenuation, our measurements provide the first precise direct localization of TGFs from space., Comment: 5 pages, 4 figures, 1 table, available at http://prl.aps.org/abstract/PRL/v105/i12/e128501
Published: 2010
Full Text: View/download PDF

35. Study of the gamma-ray source 1AGL J2022+4032 in the Cygnus Region

Author: Chen, A. W., Piano, G., Tavani, M., Trois, A., Dubner, G., Giacani, E., Argan, A., Barbiellini, G., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Costa, E., D'Ammando, F., De Paris, G., Del Monte, E., Di Cocco, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Giusti, M., Labanti, C., Lazzarotto, F., Lipari, P., Longo, F., Marisaldi, M., Mereghetti, S., Moretti, E., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Picozza, P., Pilia, M., Prest, M., Pucella, G., Rapisarda, M., Rappoldi, A., Sabatini, S., Scalise, E., Soffitta, P., Striani, E., Trifoglio, M., Vallazza, E., Vercellone, S., Vittorini, V., Zambra, A., Zanello, D., Pittori, C., Giommi, P., Verrecchia, F., Lucarelli, F., Santolamazza, P., Colafrancesco, S., Antonelli, L. A., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Identification of gamma-ray-emitting Galactic sources is a long-standing problem in astrophysics. One such source, 1AGL J2022+4032, coincident with the interior of the radio shell of the supernova remnant Gamma Cygni (SNR G78.2+2.1) in the Cygnus Region, has recently been identified by Fermi as a gamma-ray pulsar, LAT PSR J2021+4026. We present long-term observations of 1AGL J2022+4032 with the AGILE gamma-ray telescope, measuring its flux and light curve. We compare the light curve of 1AGL J2022+4032 with that of 1AGL J2021+3652 (PSR J2021+3651), showing that the flux variability of 1AGL J2022+4032 appears to be greater than the level predicted from statistical and systematic effects and producing detailed simulations to estimate the probability of the apparent observed variability. We evaluate the possibility that the gamma-ray emission may be due to the superposition of two or more point sources, some of which may be variable, considering a number of possible counterparts. We consider the possibility of a nearby X-ray quiet microquasar contributing to the flux of 1AGL J2022+4032 to be more likely than the hypotheses of a background blazar or intrinsic gamma-ray variabilty of LAT PSR J2021+4026., Comment: 7 pages, 7 figures, accepted for publication in Astronomy & Astrophysics
Published: 2010
Full Text: View/download PDF

36. Agile Observations of the 'Soft' Gamma-Ray Pulsar PSR B1509-58

Author: Pilia, M., Pellizzoni, A., Trois, A., Verrecchia, F., Esposito, P., Weltevrede, P., Johnston, S., Burgay, M., Possenti, A., Del Monte, E., Fuschino, F., Santolamazza, P., Chen, A., Giuliani, A., Caraveo, P., Mereghetti, S., Tavani, M., Argan, A., Costa, E., D'Amico, N., De Luca, A., Evangelista, Y., Feroci, M., Longo, F., Marisaldi, M., Barbiellini, G., Bulgarelli, A., Cattaneo, P. W., Cocco, V., D'Ammando, F., De Paris, G., Di Cocco, G., Donnarumma, I., Fiorini, M., Froysland, T., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Morselli, A., Pacciani, L., Perotti, F., Piano, G., Picozza, P., Prest, M., Pucella, G., Rapisarda, M., Rappoldi, A., Sabatini, S., Soffitta, P., Trifoglio, M., Vallazza, E., Vercellone, S., Vittorini, V., Zambra, A., Zanello, D., Pittori, C., Lucarelli, F., Giommi, P., Salotti, L., and Bignami, G. F.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present the results of new Agile observations of PSR B1509-58 performed over a period of 2.5 years following the detection obtained with a subset of the present data. The modulation significance of the lightcurve above 30 MeV is at a 5$\sigma$ confidence level and the lightcurve is similar to those found earlier by Comptel up to 30 MeV: a broad asymmetric first peak reaching its maximum 0.39 +/- 0.02 cycles after the radio peak plus a second peak at 0.94 +/- 0.03. The gamma-ray spectral energy distribution of the pulsed flux detected by Comptel and Agile is well described by a power-law (photon index alpha=1.87+/-0.09) with a remarkable cutoff at E_c=81 +/- 20 MeV, representing the softest spectrum observed among gamma-ray pulsars so far. The pulsar luminosity at E > 1 MeV is $L_{\gamma}=4.2^{+0.5}_{-0.2} \times10^{35}$ erg/s, assuming a distance of 5.2 kpc, which implies a spin-down conversion efficiency to gamma-rays of $\sim 0.03$. The unusual soft break in the spectrum of PSR B1509-58 has been interpreted in the framework of polar cap models as a signature of the exotic photon splitting process in the strong magnetic field of this pulsar. In this interpretation our spectrum constrains the magnetic altitude of the emission point(s) at 3 km above the neutron star surface, implying that the attenuation may not be as strong as formerly suggested because pair production can substitute photon splitting in regions of the magnetosphere where the magnetic field becomes too low to sustain photon splitting. In the case of an outer-gap scenario, or the two pole caustic model, better constraints on the geometry of the emission would be needed from the radio band in order to establish whether the conditions required by the models to reproduce Agile lightcurves and spectra match the polarization measurements., Comment: 17 pages, 2 figures, accepted for publication in ApJ
Published: 2010
Full Text: View/download PDF

37. The extraordinary gamma-ray flare of the blazar 3C 454.3

Author: Striani, E., Vercellone, S., Tavani, M., Vittorini, V., D'Ammando, F., Donnarumma, I., Pacciani, L., Pucella, G., Bulgarelli, A., Trifoglio, M., Gianotti, F., Giommi, P., Argan, A., Barbiellini, G., Caraveo, P., Cattaneo, P. W., Chen, A. W., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Fuschino, F., Galli, M., Giuliani, A., Giusti, M., Labanti, C., Lazzarotto, F., Lipari, P., Longo, F., Marisaldi, M., Mereghetti, S., Moretti, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Prest, M., Rapisarda, M., Rappoldi, A., Sabatini, S., Scalise, E., Soffitta, P., Trois, A., Vallazza, E., Zambra, A., Zanello, D., Pittori, C., Verrecchia, F., Santolamazza, P., Lucarelli, F., Colafrancesco, S., Antonelli, L. A., and Salotti, L.
Subjects: Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We present the gamma-ray data of the extraordinary flaring activity above 100 MeV from the flat spectrum radio quasar 3C 454.3 detected by AGILE during the month of December 2009. 3C 454.3, that has been among the most active blazars of the FSRQ type since 2007, was detected in the gamma-ray range with a progressively rising flux since November 10, 2009. The gamma-ray flux reached a value comparable with that of the Vela pulsar on December 2, 2009. Remarkably, between December 2 and 3, 2009 the source more than doubled its gamma-ray emission and became the brightest gamma-ray source in the sky with a peak flux of F_{\gamma,p} = (2000 \pm 400) x 10^-8 ph cm^-2 s^-1 for a 1-day integration above 100 MeV. The gamma-ray intensity decreased in the following days with the source flux remaining at large values near F \simeq (1000 \pm 200) x 10^-8 ph cm^-2 s^-1 for more than a week. This exceptional gamma-ray flare dissipated among the largest ever detected intrinsic radiated power in gamma-rays above 100 MeV (L_{\gamma, source, peak} \simeq 3 x 10^46 erg s^-1, for a relativistic Doppler factor of {\delta} \simeq 30). The total isotropic irradiated energy of the month-long episode in the range 100 MeV - 3 GeV is E_{\gamma,iso} \simeq 10^56 erg. We report the intensity and spectral evolution of the gamma-ray emission across the flaring episode. We briefly discuss the important theoretical implications of our detection., Comment: 17 pages, 3 figures, ApJ accepted
Published: 2010
Full Text: View/download PDF

38. The December 2009 gamma-ray flare of 3C 454.3: the multifrequency campaign

Author: Pacciani, L., Vittorini, V., Tavani, M., Fiocchi, M. T., Vercellone, S., D'Ammando, F., Sakamoto, T., Pian, E., Raiteri, C. M., Villata, M., Sasada, M., Itoh, R., Yamanaka, M., Uemura, M., Striani, E., Fugazza, D., Tiengo, A., Krimm, H. A., Stroh, M. C., Falcone, A. D., Curran, P. A., Sadun, A. C., Lahteenmaki, A., Tornikoski, M., Aller, H. D., Aller, M. F., Lin, C. S., Larionov, V. M., Leto, P., Takalo, L. O., Berdyugin, A., Gurwell, M. A., Bulgarelli, A., Chen, A. W., Donnarumma, I., Giuliani, A., Longo, F., Pucella, G., Argan, A., Caraveo, G. Barbiellini P., Cattaneo, P. W., Cocco, V., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Evangelista, Y., Ferrari, A., Feroci, M., Fiorini, M., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Marisaldi, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Sabatini, S., Soffitta, P., Trifoglio, M., Trois, A., Vallazza, E., Zanello, D., Colafrancesco, S., Pittori, C., Verrecchia, F., Santolamazza, P., Lucarelli, F., Giommi, P., and Salotti, L.
Subjects: Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: During the month of December, 2009 the blazar 3C 454.3 became the brightest gamma-ray source in the sky, reaching a peak flux F ~2000E-8 ph/cm2/s for E > 100 MeV. Starting in November, 2009 intensive multifrequency campaigns monitored the 3C 454 gamma-ray outburst. Here we report the results of a 2-month campaign involving AGILE, INTEGRAL, Swift/XRT, Swift/BAT, RossiXTE for the high-energy observations, and Swift/UVOT, KANATA, GRT, REM for the near-IR/optical/UV data. The GASP/WEBT provided radio and additional optical data. We detected a long-term active emission phase lasting ~1 month at all wavelengths: in the gamma-ray band, peak emission was reached on December 2-3, 2009. Remarkably, this gamma-ray super-flare was not accompanied by correspondingly intense emission in the optical/UV band that reached a level substantially lower than the previous observations in 2007-2008. The lack of strong simultaneous optical brightening during the super-flare and the determination of the broad-band spectral evolution severely constrain the theoretical modelling. We find that the pre- and post-flare broad-band behavior can be explained by a one-zone model involving SSC plus external Compton emission from an accretion disk and a broad-line region. However, the spectra of the Dec. 2-3, 2009 super-flare and of the secondary peak emission on Dec. 9, 2009 cannot be satisfactorily modelled by a simple one-zone model. An additional particle component is most likely active during these states., Comment: 21 pages, 2 figures, ApJL accepted
Published: 2010
Full Text: View/download PDF

39. AGILE detection of GeV gamma-ray emission from the SNR W28

Author: Giuliani, A., Tavani, M., Bulgarelli, A., Striani, E., Sabatini, S., Cardillo, M., Fukui, Y., Kawamura, A., Ohama, A., Furukawa, N., Torii, K., Aharonian, F. A., Verrecchia, F., Argan, A., Barbiellini, G., Caraveo, P. A., Cattaneo, P. W., Chen, A. W., Cocco, V., Costa, E., D'Ammando, F., Del Monte, E., De Paris, G., Di Cocco, G., Donnarumma, I., Evangelista, Y., Feroci, M., Fiorini, M., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, Y., Lazzarotto, F., Lipari, P., Longo, F., Mereghetti, M. Marisaldi., Morselli, A., Moretti, E., Pacciani, L., Pellizzoni, A., Perotti, F., Picozza, P., Pilia, M., Prest, M., Pucella, G., Rapisarda, M., Rappoldi, A., Soffitta, P., Trifoglio, M., Trois, A., Vallazza, E., Vercellone, S., Vittorini, V., Zambra, A., Zanello, D., Pittori, C., Santolamazza, P., Giommi, P., Colafrancesco, S., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Supernova remnants (SNRs) are believed to be the main sources of Galactic cosmic rays. Molecular clouds associated with SNRs can produce gamma-ray emission through the interaction of accelerated particles with the concentrated gas. The middle aged SNR W28, for its associated system of dense molecular clouds, provides an excellent opportunity to test this hypothesis. We present the AGILE/GRID observations of SNR W28, and compare them with observations at other wavelengths (TeV and 12CO J=1-->0 molecular line emission). The gamma-ray flux detected by AGILE from the dominant source associated with W28 is (14 +- 5) 10^-8 ph cm^-2 s^-1 for E > 400 MeV. This source is positionally well correlated with the TeV emission observed by the HESS telescope. The local variations of the GeV to TeV flux ratio suggest a difference between the CR spectra of the north-west and south molecular cloud complexes. A model based on a hadronic-induced interaction and diffusion with two molecular clouds at different distances from the W28 shell can explain both the morphological and spectral features observed by AGILE in the MeV-GeV energy range and by the HESS telescope in the TeV energy range. The combined set of AGILE and H.E.S.S. data strongly support a hadronic model for the gamma-ray production in W28., Comment: Accepted for publication in Astronomy & Astrophysics Letters
Published: 2010
Full Text: View/download PDF

40. A year-long AGILE observation of Cygnus X-1 in hard spectral state

Author: Del Monte, E., Feroci, M., Evangelista, Y., Costa, E., Donnarumma, I., Lapshov, I., Lazzarotto, F., Pacciani, L., Rapisarda, M., Soffitta, P., Argan, A., Barbiellini, G., Boffelli, F., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Chen, A., D'Ammando, F., Di Cocco, G., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Labanti, C., Lipari, P., Longo, F., Marisaldi, M., Mereghetti, S., Moretti, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Prest, M., Pucella, G., Rappoldi, A., Sabatini, S., Striani, E., Tavani, M., Trifoglio, M., Trois, A., Vallazza, E., Vercellone, S., Vittorini, V., Zambra, A., Antonelli, L. A., Cutini, S., Pittori, C., Preger, B., Santolamazza, P., Verrecchia, F., Giommi, P., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present the observation of Cyg X-1 in hard spectral state performed during the AGILE Science Verification Phase and Observing Cycle 1 in hard X-rays (with SuperAGILE) and gamma rays (with the GRID) and lasting for about 160 days with a live time of $\sim 6$ Ms. We investigate the variability of Cyg X-1 in hard X-rays at different timescales, from $\sim 300$ s up to one day, and we apply different tools of timing analysis, such as the autocorrelation function, the first order structure function and the Lomb-Scargle periodogram, to our data (from SuperAGILE) and to the simultaneous data in soft X-rays (from RXTE/ASM). We conclude our investigation with a search for emission in the energy range above 100 MeV with the maximum likelihood technique. In the hard X-ray band the flux of Cyg X-1 shows its typical erratic fluctuations at all timescales with variations of about a factor of two that do not affect significantly the shape of the energy spectrum. From the first order structure function we find that the X-ray emission of Cyg X-1 is characterized by \textit{antipersistence}, indication of a negative feedback mechanism at work. In the gamma ray data a statistically significant point-like source at the position of Cyg X-1 is not found and the upper limit on the flux is $\mathrm{5 \times 10^{-8} \; ph \; cm^{-2} \; s^{-1}}$, over the whole observation (160 days). Finally we compare our upper limit in gamma rays with the expectation of various models of the Cyg X-1 emission, of both hadronic and leptonic origin, in the GeV -- TeV band. The time history of Cyg X-1 in the hard X-ray band over 13 months (not continuous) is shown. Different tools of analysis do not provide fully converging results of the characteristic timescales in the system, suggesting that the timescales found in the structure function are not intrinsic to the physics of the source., Comment: 15 pages and 11 figures (with subfigures). Accepted for publication by A&A.
Published: 2010
Full Text: View/download PDF

41. Episodic Transient Gamma-Ray Emission from the Microquasar Cygnus X-1

Author: Sabatini, S., Tavani, M., Striani, E., Bulgarelli, A., Vittorini, V., Piano, G., Del Monte, E., Feroci, M., de Pasquale, F., Trifoglio, M., Gianotti, F., Argan, A., Barbiellini, G., Caraveo, P., Cattaneo, P. W., Chen, A. W., D'Ammando, F., Costa, E., De Paris, G., Di Cocco, G., Donnarumma, I., Evangelista, Y., Ferrari, A., Fiorini, M., Fuschino, F., Galli, M., Giuliani, A., Giusti, M., Labanti, C., Lazzarotto, F., Lipari, P., Longo, F., Marisaldi, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Picozza, P., Pilia, M., Pucella, G., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Scalise, E., Soffitta, P., Trois, A., Vallazza, E., Vercellone, S., Zambra, A., Zanello, D., Pittori, C., Verrecchia, F., Santolamazza, P., Giommi, P., Colafrancesco, S., Antonelli, L. A., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Cygnus X-1 is the archetypal black hole (BH) binary system in our Galaxy. We report the main results of an extensive search for transient gamma-ray emission from Cygnus X-1 carried out in the energy range 100 MeV - 3 GeV by the AGILE satellite, during the period 2007 July - 2009 October. The total exposure time is about 300 days, during which the source was in the "hard" X-ray spectral state. We divided the observing intervals in 2 or 4 week periods, and searched for transient and persistent emission. We report an episode of significant transient gamma-ray emission detected on 2009, October 16 in a position compatible with Cygnus X-1 optical position. This episode, occurred during a hard spectral state of Cygnus X-1, shows that a 1-2 day time variable emission above 100 MeV can be produced during hard spectral states, having important theoretical implications for current Comptonization models for Cygnus X-1 and other microquasars. Except for this one short timescale episode, no significant gamma-ray emission was detected by AGILE. By integrating all available data we obtain a 2$\sigma$ upper limit for the total integrated flux of $F_{\gamma,U.L.} = 3 \times 10^{-8} \rm ph cm^{-2} s^{-1}$ in the energy range 100 MeV - 3 GeV. We then clearly establish the existence of a spectral cutoff in the energy range 1-100 MeV that applies to the typical hard state outside the flaring period and that confirms the historically known spectral cutoff above 1 MeV., Comment: Accepted for publication by ApJ on the 9th of Feb 2010, 5 pages, 3 figures
Published: 2010
Full Text: View/download PDF

42. Multiwavelength observations of 3C 454.3. III. Eighteen months of AGILE monitoring of the 'Crazy Diamond'

Author: Vercellone, S., D'Ammando, F., Vittorini, V., Donnarumma, I., Pucella, G., Tavani, M., Ferrari, A., Raiteri, C. M., Villata, M., Romano, P., Krimm, H., Tiengo, A., Chen, A. W., Giovannini, G., Venturi, T., Giroletti, M., Kovalev, Y. Y., Sokolovsky, K., Pushkarev, A. B., Lister, M. L., Argan, A., Barbiellini, G., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Cocco, V., Costa, E., Del Monte, E., De Paris, G., Di Cocco, G., Evangelista, Y., Feroci, M., Fiorini, M., Fornari, F., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Giuliani, A., Marisaldi, M., Mereghetti, S., Morselli, A., Pellizzoni, A., Pacciani, L., Perotti, F., Piano, G., Picozza, P., Pilia, M., Prest, M., Rapisarda, M., Rappoldi, A., Sabatini, S., Soffitta, P., Striani, E., Trifoglio, M., Trois, A., Vallazza, E., Zambra, A., Zanello, D., Pittori, C., Verrecchia, F., Santolamazza, P., Giommi, P., Colafrancesco, S., Salotti, L., Agudo, I., Aller, H. D., Aller, M. F., Arkharov, A. A., Bach, U., Bachev, R., Beltrame, P., Benitez, E., Boettcher, M., Buemi, C. S., Calcidese, P., Capezzali, D., Carosati, D., Chen, W. P., Da Rio, D., Di Paola, A., Dolci, M., Dultzin, D., Forne, E., Gomez, J. L., Gurwell, M. A., Hagen-Thorn, V. A., Halkola, A., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H. Y., Jorstad, S. G., Kimeridze, G., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Kurtanidze, O., Lahteenmaki, A., Larionov, V. M., Leto, P., Ligustri, R., Lindfors, E., Lopez, J. M., Marscher, A. P., Mujica, R., Nikolashvili, M., and Nilsson, K.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report on 18 months of multiwavelength observations of the blazar 3C 454.3 (Crazy Diamond) carried out in July 2007-January 2009. We show the results of the AGILE campaigns which took place on May-June 2008, July-August 2008, and October 2008-January 2009. During the May 2008-January 2009 period, the source average flux was highly variable, from an average gamma-ray flux F(E>100MeV) > 200E-8 ph/cm2/s in May-June 2008, to F(E>100MeV)~80E-8 ph/cm2/s in October 2008-January 2009. The average gamma-ray spectrum between 100 MeV and 1 GeV can be fit by a simple power law (Gamma_GRID ~ 2.0 to 2.2). Only 3-sigma upper limits can be derived in the 20-60 keV energy band with Super-AGILE. During July-August 2007 and May-June 2008, RXTE measured a flux of F(3-20 keV)= 8.4E-11 erg/cm2/s, and F(3-20 keV)=4.5E-11 erg/cm2/s, respectively and a constant photon index Gamma_PCA=1.65. Swift/XRT observations were carried out during all AGILE campaigns, obtaining a F(2-10 keV)=(0.9-7.5)E-11 erg/cm2/s and a photon index Gamma_XRT=1.33-2.04. BAT measured an average flux of ~5 mCrab. GASP-WEBT monitored 3C 454.3 during the whole 2007-2008 period from the radio to the optical. A correlation analysis between the optical and the gamma-ray fluxes shows a time lag of tau=-0.4 days. An analysis of 15 GHz and 43 GHz VLBI core radio flux observations shows an increasing trend of the core radio flux, anti- correlated with the higher frequency data. The modeling SEDs, and the behavior of the long-term light curves in different energy bands, allow us to compare the jet properties during different emission states, and to study the geometrical properties of the jet on a time-span longer than one year., Comment: Accepted for publication in ApJ. Adapted Abstract. 17 pages, 19 Figures, 5 Tables
Published: 2010
Full Text: View/download PDF

43. Direct Evidence for Hadronic Cosmic-Ray Acceleration in the Supernova Renmant IC 443

Author: Tavani, M., Giuliani, A., Chen, A. W., Argan, A., Barbiellini, G., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Cocco, V., Contessi, T., D'Ammando, F., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Donnarumma, I., Evangelista, Y., Ferrari, A., Feroci, M., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Marisaldi, M., Mastropietro, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Pucella, G., Prest, M., Rapisarda, M., Rappoldi, A., Scalise, E., Rubini, A., Sabatini, S., Striani, E., Soffitta, P., Trifoglio, M., Trois, A., Vallazza, E., Vercellone, S., Vittorini, V., Zambra, A., Zanello, D., Pittori, C., Verrecchia, F., Santolamazza, P., Giommi, P., Colafrancesco, S., Antonelli, L. A., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: The Supernova Remnant (SNR) IC 443 is an intermediate-age remnant well known for its radio, optical, X-ray and gamma-ray energy emissions. In this Letter we study the gamma-ray emission above 100 MeV from IC 443 as obtained by the AGILE satellite. A distinct pattern of diffuse emission in the energy range 100 MeV-3 GeV is detected across the SNR with its prominent maximum (source "A") localized in the Northeastern shell with a flux F = (47 \pm 10) 10^{-8} photons cm^{-2} s^{-1} above 100 MeV. This location is the site of the strongest shock interaction between the SNR blast wave and the dense circumstellar medium. Source "A" is not coincident with the TeV source located 0.4 degree away and associated with a dense molecular cloud complex in the SNR central region. From our observations, and from the lack of detectable diffuse TeV emission from its Northeastern rim, we demonstrate that electrons cannot be the main emitters of gamma-rays in the range 0.1-10 GeV at the site of the strongest SNR shock. The intensity, spectral characteristics, and location of the most prominent gamma-ray emission together with the absence of co-spatial detectable TeV emission are consistent only with a hadronic model of cosmic-ray acceleration in the SNR. A high-density molecular cloud (cloud "E") provides a remarkable "target" for nucleonic interactions of accelerated hadrons: our results show enhanced gamma-ray production near the molecular cloud/shocked shell interaction site. IC 443 provides the first unambiguous evidence of cosmic-ray acceleration by SNRs., Comment: 5 pages, 2 figures; accepted by ApJLetters on Jan 21, 2010
Published: 2010
Full Text: View/download PDF

44. Detection of Gamma-Ray Emission from the Vela Pulsar Wind Nebula with AGILE

Author: Pellizzoni, A., Trois, A., Tavani, M., Pilia, M., Giuliani, A., Pucella, G., Esposito, P., Sabatini, S., Piano, G., Argan, A., Barbiellini, G., Bulgarelli, A., Burgay, M., Caraveo, P., Cattaneo, P. W., Chen, A. W., Cocco, V., Contessi, T., Costa, E., D'Ammando, F., Del Monte, E., De Paris, G., Di Cocco, G., Di Persio, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Fuschino, F., Galli, M., Gianotti, F., Hotan, A., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Marisaldi, M., Mastropietro, M., Mereghetti, S., Moretti, E., Morselli, A., Pacciani, L., Palfreyman, J., Perotti, F., Picozza, P., Pittori, C., Possenti, A., Prest, M., Rapisarda, M., Rappoldi, A., Rossi, E., Rubini, A., Santolamazza, P., Scalise, E., Soffitta, P., Striani, E., Trifoglio, M., Vallazza, E., Vercellone, S., Verrecchia, F., Vittorini, V., Zambra, A., Zanello, D., Giommi, P., Colafrancesco, S., Antonelli, A., Salotti, L., D'Amico, N., and Bignami, G. F.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Pulsars are known to power winds of relativistic particles that can produce bright nebulae by interacting with the surrounding medium. These pulsar wind nebulae (PWNe) are observed in the radio, optical, x-rays and, in some cases, also at TeV energies, but the lack of information in the gamma-ray band prevents from drawing a comprehensive multiwavelength picture of their phenomenology and emission mechanisms. Using data from the AGILE satellite, we detected the Vela pulsar wind nebula in the energy range from 100 MeV to 3 GeV. This result constrains the particle population responsible for the GeV emission, probing multivavelength PWN models, and establishes a class of gamma-ray emitters that could account for a fraction of the unidentified Galactic gamma-ray sources., Comment: Accepted by Science; first published online on December 31, 2009 in Science Express. Science article and Supporting Online Material are available at http://www.sciencemag.org
Published: 2009
Full Text: View/download PDF

45. Temporal properties of GX 301-2 over a year-long observation with SuperAGILE

Author: Evangelista, Y., Feroci, M., Costa, E., Del Monte, E., Donnarumma, I., Lapshov, I., Lazzarotto, F., Pacciani, L., Rapisarda, M., Soffitta, P., Argan, A., Barbiellini, G., Boffelli, F., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Chen, A., D'Ammando, F., Di Cocco, G., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Labanti, C., Lipari, P., Longo, F., Marisaldi, M., Mereghetti, S., Moretti, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Prest, M., Pucella, G., Rappoldi, A., Sabatini, S., Striani, E., Tavani, M., Trifoglio, M., Trois, A., Vallazza, E., Vercellone, S., Vittorini, V., Zambra, A., Antonelli, L. A., Cutini, S., Pittori, C., Preger, B., Santolamazza, P., Verrecchia, F., Giommi, P., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present the long-term monitoring of the High Mass X-ray Binary GX 301-2 performed with the SuperAGILE instrument on-board the AGILE mission. The source was monitored in the 20-60 keV energy band during the first year of the mission from 2007 July 17 to 2008 August 31, covering about one whole orbital period and three more pre-periastron passages for a total net observation time of about 3.7 Ms. The SuperAGILE dataset represents one of the most continuous and complete monitoring at hard X-ray energies of the 41.5 day long binary period available to date. The source behavior was characterized at all orbital phases in terms of hard X-ray flux, spectral hardness, spin period history, pulsed fraction and pulse shape profile. We also complemented the SuperAGILE observations with the soft X-ray data of the RossiXTE/ASM. Our analysis shows a clear orbital modulation of the spectral hardness, with peaks in correspondence with the pre-periastron flare and near phase 0.25. The hardness peaks we found could be related with the wind-plus-stream accretion model proposed in order to explain the orbital light curve modulation of GX 301-2. Timing analysis of the pulsar spin period shows that the secular trend of the about 680 s pulse period is consistent with the previous observations, although there is evidence of a slight decrease in the spin-down rate. The analysis of the hard X-ray pulsed emission also showed a variable pulse shape profile as a function of the orbital phase, with substructures detected near the passage at the periastron, and a clear modulation of the pulsed fraction, which appears in turn strongly anti-correlated with the source intensity., Comment: 10 pages, 7 figures, 3 tables, accepted for publication in ApJ
Published: 2009
Full Text: View/download PDF

46. Discovery of extreme particle acceleration in the microquasar Cygnus X-3

Author: Tavani, M., Bulgarelli, A., Piano, G., Sabatini, S., Striani, E., Evangelista, Y., Trois, A., Pooley, G., Trushkin, S., Nizhelskij, N. A., McCollough, M., Koljonen, K. I. I., Pucella, G., Giuliani, A., Chen, A. W., Costa, E., Vittorini, V., Trifoglio, M., Gianotti, F., Argan, A., Barbiellini, G., Caraveo, P., Cattaneo, P. W., Cocco, V., Contessi, T., D'Ammando, F., Del Monte, E., De Paris, G., Di Cocco, G., Di Persio, G., Donnarumma, I., Feroci, M., Ferrari, A., Fuschino, F., Galli, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Mattaini, E., Marisaldi, M., Mastropietro, M., Mauri, A., Mereghetti, S., Morelli, E., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Picozza, P., Pilia, M., Prest, M., Rapisarda, M., Rappoldi, A., Rossi, E., Rubini, A., Scalise, E., Soffitta, P., Vallazza, E., Vercellone, S., Zambra, A., Zanello, D., Pittori, C., Verrecchia, F., Giommi, P., Colafrancesco, S., Santolamazza, P., Antonelli, A., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The study of relativistic particle acceleration is a major topic of high-energy astrophysics. It is well known that massive black holes in active galaxies can release a substantial fraction of their accretion power into energetic particles, producing gamma-rays and relativistic jets. Galactic microquasars (hosting a compact star of 1-10 solar masses which accretes matter from a binary companion) also produce relativistic jets. However, no direct evidence of particle acceleration above GeV energies has ever been obtained in microquasar ejections, leaving open the issue of the occurrence and timing of extreme matter energization during jet formation. Here we report the detection of transient gamma-ray emission above 100 MeV from the microquasar Cygnus X-3, an exceptional X-ray binary which sporadically produces powerful radio jets. Four gamma-ray flares (each lasting 1-2 days) were detected by the AGILE satellite simultaneously with special spectral states of Cygnus X-3 during the period mid-2007/mid-2009. Our observations show that very efficient particle acceleration and gamma-ray propagation out of the inner disk of a microquasar usually occur a few days before major relativistic jet ejections. Flaring particle energies can be thousands of times larger than previously detected maximum values (with Lorentz factors of 105 and 102 for electrons and protons, respectively). We show that the transitional nature of gamma-ray flares and particle acceleration above GeV energies in Cygnus X-3 is clearly linked to special radio/X-ray states preceding strong radio flares. Thus gamma-rays provide unique insight into the nature of physical processes in microquasars., Comment: 29 pages (including Supplementary Information), 8 figures, 2 tables version submitted to Nature on August 7, 2009 (accepted version available at http://www.nature.com/nature/journal/vaop/ncurrent/pdf/nature08578.pdf)
Published: 2009
Full Text: View/download PDF

47. Multiwavelength observations of 3C 454.3 II. The AGILE 2007 December campaign

Author: Donnarumma, I., Pucella, G., Vittorini, V., D'Ammando, F., Vercellone, S., Raiteri, C. M., Villata, M., Perri, M., Chen, W. P., Smart, R. L., Kataoka, J., Kawai, N., Mori, Y., Tosti, G., Impiombato, D., Takahashi, T., Sato, R., Tavani, M., Bulgarelli, A., Chen, A. W., Giuliani, A., Longo, F., Pacciani, L., Argan, A., Barbiellini, G., Boffelli, F., Caraveo, P., Cattaneo, P. W., Cocco, V., Contessi, T., Costa, E., Del Monte, E., De Paris, G., Di Cocco, G., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Froysland, T., Frutti, M., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Marisaldi, M., Mastropietro, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pellizzoni, A., Perotti, F., Picozza, P., Pilia, M., Porrovecchio, G., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Sabatini, S., Scalise, E., Soffitta, P., Striani, E., Trifoglio, M., Trois, A., Vallazza, E., Zambra, A., Zanello, D., Pittori, C., Santolamazza, P., Verrecchia, F., Giommi, P., Antonelli, L. A., Colafrancesco, S., and Salotti, L.
Subjects: Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report on the second AGILE multiwavelength campaign of the blazar 3C 454.3 during the first half of December 2007. This campaign involved AGILE, Spitzer, Swift,Suzaku,the WEBT consortium,the REM and MITSuME telescopes,offering a broad band coverage that allowed for a simultaneous sampling of the synchrotron and inverse Compton (IC) emissions.The 2-week AGILE monitoring was accompanied by radio to optical monitoring by WEBT and REM and by sparse observations in mid-Infrared and soft/hard X-ray energy bands performed by means of Target of Opportunity observations by Spitzer, Swift and Suzaku, respectively.The source was detected with an average flux of~250x10^{-8}ph cm^-2s^-1 above 100 MeV,typical of its flaring states.The simultaneous optical and gamma-ray monitoring allowed us to study the time-lag associated with the variability in the two energy bands, resulting in a possible ~1-day delay of the gamma-ray emission with respect to the optical one. From the simultaneous optical and gamma-ray fast flare detected on December 12, we can constrain the delay between the gamma-ray and optical emissions within 12 hours. Moreover, we obtain three Spectral Energy Distributions (SEDs) with simultaneous data for 2007 December 5, 13, 15, characterized by the widest multifrequency coverage. We found that a model with an external Compton on seed photons by a standard disk and reprocessed by the Broad Line Regions does not describe in a satisfactory way the SEDs of 2007 December 5, 13 and 15. An additional contribution, possibly from the hot corona with T=10^6 K surrounding the jet, is required to account simultaneously for the softness of the synchrotron and the hardness of the inverse Compton emissions during those epochs., Comment: 13 pages, 8 figures, 2 tables, Accepted for publication in ApJ
Published: 2009
Full Text: View/download PDF

48. Monitoring the hard X-ray sky with SuperAGILE

Author: Feroci, M., Costa, E., Del Monte, E., Donnarumma, I., Evangelista, Y., Lapshov, I., Lazzarotto, F., Pacciani, L., Rapisarda, M., Soffitta, P., Di Persio, G., Frutti, M., Mastropietro, M., Morelli, E., Porrovecchio, G., Rubini, A., Antonelli, A., Argan, A., Barbiellini, G., Boffelli, F., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Chen, A. W., Cocco, V., Colafrancesco, S., Cutini, S., D'Ammando, F., De Paris, G., Di Cocco, G., Fanari, G., Ferrari, A., Fiorini, M., Fornari, F., Fuschino, F., Froysland, T., Galli, M., Gasparrini, D., Gianotti, F., Giommi, P., Giuliani, A., Labanti, C., Liello, F., Lipari, P., Longo, F., Mattaini, E., Marisaldi, M., Mauri, A., Mauri, F., Mereghetti, S., Moretti, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Pittori, C., Pontoni, C., Preger, B., Prest, M., Primavera, R., Pucella, G., Rappoldi, A., Rossi, E., Sabatini, S., Santolamazza, P., Tavani, M., Stellato, S., Tamburelli, F., Traci, A., Trifoglio, M., Trois, A., Vallazza, E., Vercellone, S., Verrecchia, F., Vittorini, V., Zambra, A., Zanello, D., and Salotti, L.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: SuperAGILE is the hard X-ray monitor of the AGILE gamma ray mission, in orbit since 23$^{rd}$ April 2007. It is an imaging experiment based on a set of four independent silicon strip detectors, equipped with one-dimensional coded masks, operating in the nominal energy range 18-60 keV. The main goal of SuperAGILE is the observation of cosmic sources simultaneously with the main gamma-ray AGILE experiment, the Gamma Ray Imaging Detector (GRID). Given its $\sim$steradian-wide field of view and its $\sim$15 mCrab day-sensitivity, SuperAGILE is also well suited for the long-term monitoring of Galactic compact objects and the detection of bright transients. The SuperAGILE detector properties and design allow for a 6 arcmin angular resolution in each of the two independent orthogonal projections of the celestial coordinates. Photon by photon data are continuously available by the experiment telemetry, and are used to derive images and fluxes of individual sources, with integration times depending on the source intensity and position in the field of view. In this paper we report on the main scientific results achieved by SuperAGILE over its first two years in orbit, until April 2009., Comment: Accepted for publication on Astronomy & Astrophysics
Published: 2009
Full Text: View/download PDF

49. Multiwavelength observations of a TeV-Flare from W Comae

Author: VERITAS collaboration, Acciari, V. A., Aliu, E., Aune, T., Beilicke, M., Benbow, W., Bottcher, M., Boltuch, D., Buckley, J. H., Bradbury, S. M., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Ciupik, L., Cogan, P., Cui, W., Dickherber, R., Duke, C., Falcone, A., Finley, J. P., Fortin, P., Fortson, L., Furniss, A., Galante, N., Gall, D., Gibbs, K., Gillanders, G. H., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McArthur, S., McCann, A., McCutcheon, M., Millis, J., Moriarty, P., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reyes, L. C., Reynolds, P. T., Roache, E., Rose, H. J., Sembroski, G. H., Smith, A. W., Steele, D., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Team, The AGILE, Pian, E., Vercellone, S., Donnarumma, I., D'Ammando, F., Bulgarelli, A., Chen, A. W., Giuliani, A., Longo, F., Pacciani, L., Pucella, G., Vittorini, V., Tavani, M., Argan, A., Barbiellini, G., Caraveo, P., Cattaneo, P. W., Cocco, V., Costa, E., Del Monte, E., De Paris, G., Di Cocco, G., Evangelista, Y., Feroci, M., Fiorini, M., Froysland, T., Frutti, M., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Marisaldi, M., Mastropietro, M., Mereghetti, S., Morelli, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Soffitta, S. Sabatini P., Trifoglio, M., Trois, A., Vallazza, E., Zambra, A., Zanello, D., Pittori, C., Santolamazza, P., Verrecchia, F., Giommi, P., Colafrancesco, S., Salotti, L., Villata, M., Raiteri, C. M., Aller, H. D., Aller, M. F., Arkharov, A. A., Efimova, N. V., Larionov, V. M., Leto, P., Ligustri, R., Lindfors, E., Pasanen, M., Kurtanidze, O. M., Tetradze, S. D., Lahteenmaki, A., Kotiranta, M., Cucchiara, A., Romano, P., Nesci, R., Pursimo, T., Heidt, J., Benitez, E., Hiriart, D., Nilsson, K., Berdyugin, A., Mujica, R., Dultzin, D., Lopez, J. M., Mommert, M., Sorcia, M., and Perez, I. de la Calle
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report results from an intensive multiwavelength campaign on the intermediate-frequency-peaked BL Lacertae object W Com (z=0.102) during a strong outburst of very high energy gamma-ray emission in June 2008. The very high energy gamma-ray signal was detected by VERITAS on 2008 June 7-8 with a flux F(>200 GeV) = (5.7+-0.6)x10^-11 cm-2s-1, about three times brighter than during the discovery of gamma-ray emission from W Com by VERITAS in 2008 March. The initial detection of this flare by VERITAS at energies above 200 GeV was followed by observations in high energy gamma-rays (AGILE, E>100 MeV), and X-rays (Swift and XMM-Newton), and at UV, and ground-based optical and radio monitoring through the GASP-WEBT consortium and other observatories. Here we describe the multiwavelength data and derive the spectral energy distribution (SED) of the source from contemporaneous data taken throughout the flare., Comment: 26 pages, 5 figures; Accepted for publication by The Astrophysical Journal
Published: 2009
Full Text: View/download PDF

50. AGILE detection of a rapid gamma-ray flare from the blazar PKS 1510-089 during the GASP-WEBT monitoring

Author: D'Ammando, F., Pucella, G., Raiteri, C. M., Villata, M., Vittorini, V., Vercellone, S., Donnarumma, I., Longo, F., Tavani, M., Argan, A., Barbiellini, G., Boffelli, F., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Chen, A. W., Cocco, V., Costa, E., Del Monte, E., De Paris, G., Di Cocco, G., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Marisaldi, M., Mereghetti, S., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Prest, M., Rapisarda, M., Rappoldi, A., Sabatini, S., Soffitta, P., Trifoglio, M., Trois, A., Vallazza, E., Zambra, A., Zanello, D., Agudo, I., Aller, M. F., Aller, H. D., Arkharov, A. A., Bach, U., Benitez, E., Berdyugin, A., Blinov, D. A., Buemi, C. S., Chen, W. P., Di Paola, A., Di Rico, G., Dultzin, D., Fuhrmann, L., Gomez, J. L., Gurwell, M. A., Jorstad, S. G., Heidt, J., Hiriart, D., Hsiao, H. Y., Kimeridze, G., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Kurtanidze, O., Larionov, V. M., Leto, P., Lindfors, E., Lopez, J. M., Marscher, A. P., McHardy, I. M., Melnichuk, D. A., Mommert, M., Mujica, R., Nilsson, K., Pasanen, M., Roca-Sogorb, M., Sorcia, M., Takalo, L. O., Taylor, B., Trigilio, C., Troitsky, I. S., Umana, G., Antonelli, L. A., Colafrancesco, S., Cutini, S., Gasparrini, D., Pittori, C., Preger, B., Santolamazza, P., Verrecchia, F., Giommi, P., and Salotti, L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We report the detection by the AGILE satellite of a rapid gamma-ray flare from the powerful gamma-ray quasar PKS 1510-089, during a pointing centered on the Galactic Center region from 1 March to 30 March 2008. This source has been continuosly monitored in the radio-to-optical bands by the GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT). Moreover, the gamma-ray flaring episode triggered three ToO observations by the Swift satellite in three consecutive days, starting from 20 March 2008. In the period 1-16 March 2008, AGILE detected gamma-ray emission from PKS 1510-089 at a significance level of 6.2-sigma with an average flux over the entire period of (84 +/- 17) x 10^{-8} photons cm^{-2} s^{-1} for photon energies above 100 MeV. After a predefined satellite re-pointing, between 17 and 21 March 2008, AGILE detected the source at a significance level of 7.3-sigma, with an average flux (E > 100 MeV) of (134 +/- 29) x 10^{-8} photons cm^{-2} s^{-1} and a peak level of (281 +/- 68) x 10^{-8} photons cm^{-2} s^{-1} with daily integration. During the observing period January-April 2008, the source also showed an intense and variable optical activity, with several flaring episodes and a significant increase of the flux was observed at millimetric frequencies. Moreover, in the X-ray band the Swift/XRT observations seem to show an harder-when-brighter behaviour of the source spectrum. The spectral energy distribution of mid-March 2008 is modelled with a homogeneous one-zone synchrotron self Compton emission plus contributions from inverse Compton scattering of external photons from both the accretion disc and the broad line region. Indeed, some features in the optical-UV spectrum seem to indicate the presence of Seyfert-like components, such as the little blue bump and the big blue bump., Comment: 10 pages, 4 figures and 2 tables, accepted for publication in A&A
Published: 2009
Full Text: View/download PDF

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Publication Type

Journal

Region

Database

Publisher

1,014 results on '"Perotti F"'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources