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1. Long-term Study of the 2020 Magnetar-like Outburst of the Young Pulsar PSR J1846-0258 in Kes 75

Author

R. Sathyaprakash, N. Rea, F. Coti Zelati, A. Borghese, M. Pilia, M. Trudu, M. Burgay, R. Turolla, S. Zane, P. Esposito, S. Mereghetti, S. Campana, D. Götz, A. Y. Ibrahim, G. L. Israel, A. Possenti, and A. Tiengo

Subjects
Magnetars, X-ray transient sources, Rotation powered pulsars, Neutron stars, Astrophysics, QB460-466
Abstract

Magnetar-like activity has been observed in a large variety of neutron stars. PSR J1846−0258 is a young 327 ms radio-quiet pulsar with a large rotational power (∼8 × 10 ^36 erg s ^−1 ), and resides at the center of the supernova remnant Kes 75. It is one of the rare examples of a high-magnetic-field pulsar showing characteristics both of magnetars and radio pulsars, and can thus provide important clues on the differences in the emission mechanisms between these two classes. In 2006, PSR J1846−0258 was detected to undergo an outburst for the first time, accompanied by a large flux increase, millisecond X-ray bursts, significant spectral changes, and a large timing glitch. In the period between 2020 May and June, after 14 yr of quiescent stable emission, the source underwent a second magnetar-like outburst, which was followed up with several observations by Neutron Star Interior Composition Explorer, XMM-Newton, NuSTAR, and Swift. In this work, we report on the long-term timing and X-ray spectral properties of the source following the 2020 outburst, and place upper limits on any source activity at radio wavelengths. We demonstrate that the pulsed flux increased by a factor >6 during the outburst, followed by nontrivial variability in the spin-down rate. Our timing analysis shows that the spin frequency and its derivative are clearly affected by magnetospheric activity due to the outburst. We find hints for an oscillation in the frequency derivative with a timescale of 50–60 days, recovering later on to stable quiescence.

Published
2024
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2. An X-Ray and Radio View of the 2022 Reactivation of the Magnetar SGR J1935+2154

Author

A. Y. Ibrahim, A. Borghese, F. Coti Zelati, E. Parent, A. Marino, O. S. Ould-Boukattine, N. Rea, S. Ascenzi, D. P. Pacholski, S. Mereghetti, G. L. Israel, A. Tiengo, A. Possenti, M. Burgay, R. Turolla, S. Zane, P. Esposito, D. Götz, S. Campana, F. Kirsten, M. P. Gawroński, and J. W. T. Hessels

Subjects
Neutron stars, Magnetars, Astrophysics, QB460-466
Abstract

Recently, the Galactic magnetar SGR J1935+2154 has garnered attention due to its emission of an extremely luminous radio burst, reminiscent of fast radio bursts (FRBs). SGR J1935+2154 is one of the most active magnetars, displaying flaring events nearly every year, including outbursts as well as short and intermediate bursts. Here, we present our results on the properties of the persistent and bursting X-ray emission from SGR J1935+2154 during the initial weeks following its outburst on 2022 October 10. The source was observed with XMM-Newton and NuSTAR (quasi-)simultaneously during two epochs, separated by ∼5 days. The persistent emission spectrum is well described by an absorbed blackbody plus power-law model up to an energy of ∼25 keV. No significant changes were observed in the blackbody temperature ( kT _BB ∼ 0.4 keV) and emitting radius ( R _BB ∼ 1.9 km) between the two epochs. However, we observed a slight variation in the power-law parameters. Moreover, we detected X-ray pulsations in all the data sets and derived a spin-period derivative of $\dot{P}=5.52(5)\times {10}^{-11}$ s s ^−1 . This is 3.8 times larger than the value measured after the first recorded outburst in 2014. Additionally, we performed quasi-simultaneous radio observations using three 25–32 m class radio telescopes for a total of 92.5 hr to search for FRB-like radio bursts and pulsed emission. However, our analysis did not reveal any radio bursts or periodic emission.

Published
2024
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3. Deep X-Ray and Radio Observations of the First Outburst of the Young Magnetar Swift J1818.0−1607

Author

A. Y. Ibrahim, A. Borghese, N. Rea, F. Coti Zelati, E. Parent, T. D. Russell, S. Ascenzi, R. Sathyaprakash, D. Götz, S. Mereghetti, M. Topinka, M. Rigoselli, V. Savchenko, S. Campana, G. L. Israel, A. Tiengo, R. Perna, R. Turolla, S. Zane, P. Esposito, G. A. Rodríguez Castillo, V. Graber, A. Possenti, C. Dehman, M. Ronchi, and S. Loru

Subjects
Neutron stars, Magnetars, Astrophysics, QB460-466
Abstract

Swift J1818.0−1607 is a radio-loud magnetar with a spin period of 1.36 s and a dipolar magnetic field strength of B ∼ 3 × 10 ^14 G, which is very young compared to the Galactic pulsar population. We report here on the long-term X-ray monitoring campaign of this young magnetar using XMM-Newton, NuSTAR, and Swift from the activation of its first outburst in 2020 March until 2021 October, as well as INTEGRAL upper limits on its hard X-ray emission. The 1–10 keV magnetar spectrum is well modeled by an absorbed blackbody with a temperature of kT _BB ∼ 1.1 keV and apparent reduction in the radius of the emitting region from ∼0.6 to ∼0.2 km. We also confirm the bright diffuse X-ray emission around the source extending between ∼50″ and ∼110″. A timing analysis revealed large torque variability, with an average spin-down rate $\dot{\nu }\,\sim $ −2.3 × 10 ^−11 Hz ^2 that appears to decrease in magnitude over time. We also observed Swift J1818.0−1607 with the Karl G. Jansky Very Large Array on 2021 March 22. We detected the radio counterpart to Swift J1818 measuring a flux density of S _v = 4.38 ± 0.05 mJy at 3 GHz and a half-ringlike structure of bright diffuse radio emission located at ∼90″ to the west of the magnetar. We tentatively suggest that the diffuse X-ray emission is due to a dust-scattering halo and that the radio structure may be associated with the supernova remnant of this young pulsar, based on its morphology.

Published
2023
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4. Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A

Author

B. P. Abbott, R. Abbott, T. D. Abbott, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. B. Adya, C. Affeldt, M. Afrough, B. Agarwal, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, L. Aiello, A. Ain, P. Ajith, B. Allen, G. Allen, A. Allocca, M. A. Aloy, P. A. Altin, A. Amato, A. Ananyeva, S. B. Anderson, W. G. Anderson, S. V. Angelova, S. Antier, S. Appert, K. Arai, M. C. Araya, J. S. Areeda, N. Arnaud, K. G. Arun, S. Ascenzi, G. Ashton, M. Ast, S. M. Aston, P. Astone, D. V. Atallah, P. Aufmuth, C. Aulbert, K. AultONeal, C. Austin, A. Avila-Alvarez, S. Babak, P. Bacon, M. K. M. Bader, S. Bae, P. T. Baker, F. Baldaccini, G. Ballardin, S. W. Ballmer, S. Banagiri, J. C. Barayoga, S. E. Barclay, B. C. Barish, D. Barker, K. Barkett, F. Barone, B. Barr, L. Barsotti, M. Barsuglia, D. Barta, J. Bartlett, I. Bartos, R. Bassiri, A. Basti, J. C. Batch, M. Bawaj, J. C. Bayley, M. Bazzan, B. Bécsy, C. Beer, M. Bejger, I. Belahcene, A. S. Bell, B. K. Berger, G. Bergmann, J. J. Bero, C. P. L. Berry, D. Bersanetti, A. Bertolini, J. Betzwieser, S. Bhagwat, R. Bhandare, I. A. Bilenko, G. Billingsley, C. R. Billman, J. Birch, I. A. Birney, O. Birnholtz, S. Biscans, S. Biscoveanu, A. Bisht, M. Bitossi, C. Biwer, M. A. Bizouard, J. K. Blackburn, J. Blackman, C. D. Blair, D. G. Blair, R. M. Blair, S. Bloemen, O. Bock, N. Bode, M. Boer, G. Bogaert, A. Bohe, F. Bondu, E. Bonilla, R. Bonnand, B. A. Boom, R. Bork, V. Boschi, S. Bose, K. Bossie, Y. Bouffanais, A. Bozzi, C. Bradaschia, P. R. Brady, M. Branchesi, J. E. Brau, T. Briant, A. Brillet, M. Brinkmann, V. Brisson, P. Brockill, J. E. Broida, A. F. Brooks, D. A. Brown, D. D. Brown, S. Brunett, C. C. Buchanan, A. Buikema, T. Bulik, H. J. Bulten, A. Buonanno, D. Buskulic, C. Buy, R. L. Byer, M. Cabero, L. Cadonati, G. Cagnoli, C. Cahillane, J. Calderón Bustillo, T. A. Callister, E. Calloni, J. B. Camp, M. Canepa, P. Canizares, K. C. Cannon, H. Cao, J. Cao, C. D. Capano, E. Capocasa, F. Carbognani, S. Caride, M. F. Carney, J. Casanueva Diaz, C. Casentini, S. Caudill, M. Cavaglià, F. Cavalier, R. Cavalieri, G. Cella, C. B. Cepeda, P. Cerdá-Durán, G. Cerretani, E. Cesarini, S. J. Chamberlin, M. Chan, S. Chao, P. Charlton, E. Chase, E. Chassande-Mottin, D. Chatterjee, K. Chatziioannou, B. D. Cheeseboro, H. Y. Chen, X. Chen, Y. Chen, H.-P. Cheng, H. Chia, A. Chincarini, A. Chiummo, T. Chmiel, H. S. Cho, M. Cho, J. H. Chow, N. Christensen, Q. Chu, A. J. K. Chua, S. Chua, A. K. W. Chung, S. Chung, G. Ciani, R. Ciolfi, C. E. Cirelli, A. Cirone, F. Clara, J. A. Clark, P. Clearwater, F. Cleva, C. Cocchieri, E. Coccia, P.-F. Cohadon, D. Cohen, A. Colla, C. G. Collette, L. R. Cominsky, M. Constancio Jr., L. Conti, S. J. Cooper, P. Corban, T. R. Corbitt, I. Cordero-Carrión, K. R. Corley, N. Cornish, A. Corsi, S. Cortese, C. A. Costa, M. W. Coughlin, S. B. Coughlin, J.-P. Coulon, S. T. Countryman, P. Couvares, P. B. Covas, E. E. Cowan, D. M. Coward, M. J. Cowart, D. C. Coyne, R. Coyne, J. D. E. Creighton, T. D. Creighton, J. Cripe, S. G. Crowder, T. J. Cullen, A. Cumming, L. Cunningham, E. Cuoco, T. Dal Canton, G. Dálya, S. L. Danilishin, S. D’Antonio, K. Danzmann, A. Dasgupta, C. F. Da Silva Costa, V. Dattilo, I. Dave, M. Davier, D. Davis, E. J. Daw, B. Day, S. De, D. DeBra, J. Degallaix, M. De Laurentis, S. Deléglise, W. Del Pozzo, N. Demos, T. Denker, T. Dent, R. De Pietri, V. Dergachev, R. De Rosa, R. T. DeRosa, C. De Rossi, R. DeSalvo, O. de Varona, J. Devenson, S. Dhurandhar, M. C. Díaz, L. Di Fiore, M. Di Giovanni, T. Di Girolamo, A. Di Lieto, S. Di Pace, I. Di Palma, F. Di Renzo, Z. Doctor, V. Dolique, F. Donovan, K. L. Dooley, S. Doravari, I. Dorrington, R. Douglas, M. Dovale Álvarez, T. P. Downes, M. Drago, C. Dreissigacker, J. C. Driggers, Z. Du, M. Ducrot, P. Dupej, S. E. Dwyer, T. B. Edo, M. C. Edwards, A. Effler, H.-B. Eggenstein, P. Ehrens, J. Eichholz, S. S. Eikenberry, R. A. Eisenstein, R. C. Essick, D. Estevez, Z. B. Etienne, T. Etzel, M. Evans, T. M. Evans, M. Factourovich, V. Fafone, H. Fair, S. Fairhurst, X. Fan, S. Farinon, B. Farr, W. M. Farr, E. J. Fauchon-Jones, M. Favata, M. Fays, C. Fee, H. Fehrmann, J. Feicht, M. M. Fejer, A. Fernandez-Galiana, I. Ferrante, E. C. Ferreira, F. Ferrini, F. Fidecaro, D. Finstad, I. Fiori, D. Fiorucci, M. Fishbach, R. P. Fisher, M. Fitz-Axen, R. Flaminio, M. Fletcher, H. Fong, J. A. Font, P. W. F. Forsyth, S. S. Forsyth, J.-D. Fournier, S. Frasca, F. Frasconi, Z. Frei, A. Freise, R. Frey, V. Frey, E. M. Fries, P. Fritschel, V. V. Frolov, P. Fulda, M. Fyffe, H. Gabbard, B. U. Gadre, S. M. Gaebel, J. R. Gair, L. Gammaitoni, M. R. Ganija, S. G. Gaonkar, C. Garcia-Quiros, F. Garufi, B. Gateley, S. Gaudio, G. Gaur, V. Gayathri, N. Gehrels, G. Gemme, E. Genin, A. Gennai, D. George, J. George, L. Gergely, V. Germain, S. Ghonge, Abhirup Ghosh, Archisman Ghosh, S. Ghosh, J. A. Giaime, K. D. Giardina, A. Giazotto, K. Gill, L. Glover, E. Goetz, R. Goetz, S. Gomes, B. Goncharov, G. González, J. M. Gonzalez Castro, A. Gopakumar, M. L. Gorodetsky, S. E. Gossan, M. Gosselin, R. Gouaty, A. Grado, C. Graef, M. Granata, A. Grant, S. Gras, C. Gray, G. Greco, A. C. Green, E. M. Gretarsson, P. Groot, H. Grote, S. Grunewald, P. Gruning, G. M. Guidi, X. Guo, A. Gupta, M. K. Gupta, K. E. Gushwa, E. K. Gustafson, R. Gustafson, O. Halim, B. R. Hall, E. D. Hall, E. Z. Hamilton, G. Hammond, M. Haney, M. M. Hanke, J. Hanks, C. Hanna, M. D. Hannam, O. A. Hannuksela, J. Hanson, T. Hardwick, J. Harms, G. M. Harry, I. W. Harry, M. J. Hart, C.-J. Haster, K. Haughian, J. Healy, A. Heidmann, M. C. Heintze, H. Heitmann, P. Hello, G. Hemming, M. Hendry, I. S. Heng, J. Hennig, A. W. Heptonstall, M. Heurs, S. Hild, T. Hinderer, D. Hoak, D. Hofman, K. Holt, D. E. Holz, P. Hopkins, C. Horst, J. Hough, E. A. Houston, E. J. Howell, A. Hreibi, Y. M. Hu, E. A. Huerta, D. Huet, B. Hughey, S. Husa, S. H. Huttner, T. Huynh-Dinh, N. Indik, R. Inta, G. Intini, H. N. Isa, J.-M. Isac, M. Isi, B. R. Iyer, K. Izumi, T. Jacqmin, K. Jani, P. Jaranowski, S. Jawahar, F. Jiménez-Forteza, W. W. Johnson, N. K. Johnson-McDaniel, D. I. Jones, R. Jones, R. J. G. Jonker, L. Ju, J. Junker, C. V. Kalaghatgi, V. Kalogera, B. Kamai, S. Kandhasamy, G. Kang, J. B. Kanner, S. J. Kapadia, S. Karki, K. S. Karvinen, M. Kasprzack, W. Kastaun, M. Katolik, E. Katsavounidis, W. Katzman, S. Kaufer, K. Kawabe, F. Kéfélian, D. Keitel, A. J. Kemball, R. Kennedy, C. Kent, J. S. Key, F. Y. Khalili, I. Khan, S. Khan, Z. Khan, E. A. Khazanov, N. Kijbunchoo, Chunglee Kim, J. C. Kim, K. Kim, W. Kim, W. S. Kim, Y.-M. Kim, S. J. Kimbrell, E. J. King, P. J. King, M. Kinley-Hanlon, R. Kirchhoff, J. S. Kissel, L. Kleybolte, S. Klimenko, T. D. Knowles, P. Koch, S. M. Koehlenbeck, S. Koley, V. Kondrashov, A. Kontos, M. Korobko, W. Z. Korth, I. Kowalska, D. B. Kozak, C. Krämer, V. Kringel, B. Krishnan, A. Królak, G. Kuehn, P. Kumar, R. Kumar, S. Kumar, L. Kuo, A. Kutynia, S. Kwang, B. D. Lackey, K. H. Lai, M. Landry, R. N. Lang, J. Lange, B. Lantz, R. K. Lanza, A. Lartaux-Vollard, P. D. Lasky, M. Laxen, A. Lazzarini, C. Lazzaro, P. Leaci, S. Leavey, C. H. Lee, H. K. Lee, H. M. Lee, H. W. Lee, K. Lee, J. Lehmann, A. Lenon, M. Leonardi, N. Leroy, N. Letendre, Y. Levin, T. G. F. Li, S. D. Linker, T. B. Littenberg, J. Liu, R. K. L. Lo, N. A. Lockerbie, L. T. London, J. E. Lord, M. Lorenzini, V. Loriette, M. Lormand, G. Losurdo, J. D. Lough, C. O. Lousto, G. Lovelace, H. Lück, D. Lumaca, A. P. Lundgren, R. Lynch, Y. Ma, R. Macas, S. Macfoy, B. Machenschalk, M. MacInnis, D. M. Macleod, I. Magaña Hernandez, F. Magaña-Sandoval, L. Magaña Zertuche, R. M. Magee, E. Majorana, I. Maksimovic, N. Man, V. Mandic, V. Mangano, G. L. Mansell, M. Manske, M. Mantovani, F. Marchesoni, F. Marion, S. Márka, Z. Márka, C. Markakis, A. S. Markosyan, A. Markowitz, E. Maros, A. Marquina, F. Martelli, L. Martellini, I. W. Martin, R. M. Martin, D. V. Martynov, K. Mason, E. Massera, A. Masserot, T. J. Massinger, M. Masso-Reid, S. Mastrogiovanni, A. Matas, F. Matichard, L. Matone, N. Mavalvala, N. Mazumder, R. McCarthy, D. E. McClelland, S. McCormick, L. McCuller, S. C. McGuire, G. McIntyre, J. McIver, D. J. McManus, L. McNeill, T. McRae, S. T. McWilliams, D. Meacher, G. D. Meadors, M. Mehmet, J. Meidam, E. Mejuto-Villa, A. Melatos, G. Mendell, R. A. Mercer, E. L. Merilh, M. Merzougui, S. Meshkov, C. Messenger, C. Messick, R. Metzdorff, P. M. Meyers, H. Miao, C. Michel, H. Middleton, E. E. Mikhailov, L. Milano, A. L. Miller, B. B. Miller, J. Miller, M. Millhouse, M. C. Milovich-Goff, O. Minazzoli, Y. Minenkov, J. Ming, C. Mishra, S. Mitra, V. P. Mitrofanov, G. Mitselmakher, R. Mittleman, D. Moffa, A. Moggi, K. Mogushi, M. Mohan, S. R. P. Mohapatra, M. Montani, C. J. Moore, D. Moraru, G. Moreno, S. R. Morriss, B. Mours, C. M. Mow-Lowry, G. Mueller, A. W. Muir, Arunava Mukherjee, D. Mukherjee, S. Mukherjee, N. Mukund, A. Mullavey, J. Munch, E. A. Muñiz, M. Muratore, P. G. Murray, K. Napier, I. Nardecchia, L. Naticchioni, R. K. Nayak, J. Neilson, G. Nelemans, T. J. N. Nelson, M. Nery, A. Neunzert, L. Nevin, J. M. Newport, G. Newton, K. K. Y. Ng, T. T. Nguyen, D. Nichols, A. B. Nielsen, S. Nissanke, A. Nitz, A. Noack, F. Nocera, D. Nolting, C. North, L. K. Nuttall, J. Oberling, G. D. O’Dea, G. H. Ogin, J. J. Oh, S. H. Oh, F. Ohme, M. A. Okada, M. Oliver, P. Oppermann, Richard J. Oram, B. O’Reilly, R. Ormiston, L. F. Ortega, R. O’Shaughnessy, S. Ossokine, D. J. Ottaway, H. Overmier, B. J. Owen, A. E. Pace, J. Page, M. A. Page, A. Pai, S. A. Pai, J. R. Palamos, O. Palashov, C. Palomba, A. Pal-Singh, Howard Pan, Huang-Wei Pan, B. Pang, P. T. H. Pang, C. Pankow, F. Pannarale, B. C. Pant, F. Paoletti, A. Paoli, M. A. Papa, A. Parida, W. Parker, D. Pascucci, A. Pasqualetti, R. Passaquieti, D. Passuello, M. Patil, B. Patricelli, B. L. Pearlstone, M. Pedraza, R. Pedurand, L. Pekowsky, A. Pele, S. Penn, C. J. Perez, A. Perreca, L. M. Perri, H. P. Pfeiffer, M. Phelps, O. J. Piccinni, M. Pichot, F. Piergiovanni, V. Pierro, G. Pillant, L. Pinard, I. M. Pinto, M. Pirello, M. Pitkin, M. Poe, R. Poggiani, P. Popolizio, E. K. Porter, A. Post, J. Powell, J. Prasad, J. W. W. Pratt, G. Pratten, V. Predoi, T. Prestegard, M. Prijatelj, M. Principe, S. Privitera, G. A. Prodi, L. G. Prokhorov, O. Puncken, M. Punturo, P. Puppo, M. Pürrer, H. Qi, V. Quetschke, E. A. Quintero, R. Quitzow-James, F. J. Raab, D. S. Rabeling, H. Radkins, P. Raffai, S. Raja, C. Rajan, B. Rajbhandari, M. Rakhmanov, K. E. Ramirez, A. Ramos-Buades, P. Rapagnani, V. Raymond, M. Razzano, J. Read, T. Regimbau, L. Rei, S. Reid, D. H. Reitze, W. Ren, S. D. Reyes, F. Ricci, P. M. Ricker, S. Rieger, K. Riles, M. Rizzo, N. A. Robertson, R. Robie, F. Robinet, A. Rocchi, L. Rolland, J. G. Rollins, V. J. Roma, R. Romano, C. L. Romel, J. H. Romie, D. Rosińska, M. P. Ross, S. Rowan, A. Rüdiger, P. Ruggi, G. Rutins, K. Ryan, S. Sachdev, T. Sadecki, L. Sadeghian, M. Sakellariadou, L. Salconi, M. Saleem, F. Salemi, A. Samajdar, L. Sammut, L. M. Sampson, E. J. Sanchez, L. E. Sanchez, N. Sanchis-Gual, V. Sandberg, J. R. Sanders, B. Sassolas, B. S. Sathyaprakash, P. R. Saulson, O. Sauter, R. L. Savage, A. Sawadsky, P. Schale, M. Scheel, J. Scheuer, J. Schmidt, P. Schmidt, R. Schnabel, R. M. S. Schofield, A. Schönbeck, E. Schreiber, D. Schuette, B. W. Schulte, B. F. Schutz, S. G. Schwalbe, J. Scott, S. M. Scott, E. Seidel, D. Sellers, A. S. Sengupta, D. Sentenac, V. Sequino, A. Sergeev, D. A. Shaddock, T. J. Shaffer, A. A. Shah, M. S. Shahriar, M. B. Shaner, L. Shao, B. Shapiro, P. Shawhan, A. Sheperd, D. H. Shoemaker, D. M. Shoemaker, K. Siellez, X. Siemens, M. Sieniawska, D. Sigg, A. D. Silva, L. P. Singer, A. Singh, A. Singhal, A. M. Sintes, B. J. J. Slagmolen, B. Smith, J. R. Smith, R. J. E. Smith, S. Somala, E. J. Son, J. A. Sonnenberg, B. Sorazu, F. Sorrentino, T. Souradeep, A. P. Spencer, A. K. Srivastava, K. Staats, A. Staley, M. Steinke, J. Steinlechner, S. Steinlechner, D. Steinmeyer, S. P. Stevenson, R. Stone, D. J. Stops, K. A. Strain, G. Stratta, S. E. Strigin, A. Strunk, R. Sturani, A. L. Stuver, T. Z. Summerscales, L. Sun, S. Sunil, J. Suresh, P. J. Sutton, B. L. Swinkels, M. J. Szczepańczyk, M. Tacca, S. C. Tait, C. Talbot, D. Talukder, D. B. Tanner, M. Tápai, A. Taracchini, J. D. Tasson, J. A. Taylor, R. Taylor, S. V. Tewari, T. Theeg, F. Thies, E. G. Thomas, M. Thomas, P. Thomas, K. A. Thorne, K. S. Thorne, E. Thrane, S. Tiwari, V. Tiwari, K. V. Tokmakov, K. Toland, M. Tonelli, Z. Tornasi, A. Torres-Forné, C. I. Torrie, D. Töyrä, F. Travasso, G. Traylor, J. Trinastic, M. C. Tringali, L. Trozzo, K. W. Tsang, M. Tse, R. Tso, L. Tsukada, D. Tsuna, D. Tuyenbayev, K. Ueno, D. Ugolini, C. S. Unnikrishnan, A. L. Urban, S. A. Usman, H. Vahlbruch, G. Vajente, G. Valdes, N. van Bakel, M. van Beuzekom, J. F. J. van den Brand, C. Van Den Broeck, D. C. Vander-Hyde, L. van der Schaaf, J. V. van Heijningen, A. A. van Veggel, M. Vardaro, V. Varma, S. Vass, M. Vasúth, A. Vecchio, G. Vedovato, J. Veitch, P. J. Veitch, K. Venkateswara, G. Venugopalan, D. Verkindt, F. Vetrano, A. Viceré, A. D. Viets, S. Vinciguerra, D. J. Vine, J.-Y. Vinet, S. Vitale, T. Vo, H. Vocca, C. Vorvick, S. P. Vyatchanin, A. R. Wade, L. E. Wade, M. Wade, R. Walet, M. Walker, L. Wallace, S. Walsh, G. Wang, H. Wang, J. Z. Wang, W. H. Wang, Y. F. Wang, R. L. Ward, J. Warner, M. Was, J. Watchi, B. Weaver, L.-W. Wei, M. Weinert, A. J. Weinstein, R. Weiss, L. Wen, E. K. Wessel, P. Weßels, J. Westerweck, T. Westphal, K. Wette, J. T. Whelan, S. E. Whitcomb, B. F. Whiting, C. Whittle, D. Wilken, D. Williams, R. D. Williams, A. R. Williamson, J. L. Willis, B. Willke, M. H. Wimmer, W. Winkler, C. C. Wipf, H. Wittel, G. Woan, J. Woehler, J. Wofford, K. W. K. Wong, J. Worden, J. L. Wright, D. S. Wu, D. M. Wysocki, S. Xiao, H. Yamamoto, C. C. Yancey, L. Yang, M. J. Yap, M. Yazback, Hang Yu, Haocun Yu, M. Yvert, A. Zadrożny, M. Zanolin, T. Zelenova, J.-P. Zendri, M. Zevin, L. Zhang, M. Zhang, T. Zhang, Y.-H. Zhang, C. Zhao, M. Zhou, Z. Zhou, S. J. Zhu, X. J. Zhu, A. B. Zimmerman, M. E. Zucker, J. Zweizig, (LIGO Scientific Collaboration and Virgo Collaboration), E. Burns, P. Veres, D. Kocevski, J. Racusin, A. Goldstein, V. Connaughton, M. S. Briggs, L. Blackburn, R. Hamburg, C. M. Hui, A. von Kienlin, J. McEnery, R. D. Preece, C. A. Wilson-Hodge, E. Bissaldi, W. H. Cleveland, M. H. Gibby, M. M. Giles, R. M. Kippen, S. McBreen, C. A. Meegan, W. S. Paciesas, S. Poolakkil, O. J. Roberts, M. Stanbro, (Fermi Gamma-ray Burst Monitor), V. Savchenko, C. Ferrigno, E. Kuulkers, A. Bazzano, E. Bozzo, S. Brandt, J. Chenevez, T. J.-L. Courvoisier, R. Diehl, A. Domingo, L. Hanlon, E. Jourdain, P. Laurent, F. Lebrun, A. Lutovinov, S. Mereghetti, L. Natalucci, J. Rodi, J.-P. Roques, R. Sunyaev, P. Ubertini, and (INTEGRAL)

Subjects
binaries: close, gamma-ray burst: general, gravitational waves, Astrophysics, QB460-466
Abstract

On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anti-Coincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory . The probability of the near-simultaneous temporal and spatial observation of GRB 170817A and GW170817 occurring by chance is $5.0\times {10}^{-8}$ . We therefore confirm binary neutron star mergers as a progenitor of short GRBs. The association of GW170817 and GRB 170817A provides new insight into fundamental physics and the origin of short GRBs. We use the observed time delay of $(+1.74\pm 0.05)\,{\rm{s}}$ between GRB 170817A and GW170817 to: (i) constrain the difference between the speed of gravity and the speed of light to be between $-3\times {10}^{-15}$ and $+7\times {10}^{-16}$ times the speed of light, (ii) place new bounds on the violation of Lorentz invariance, (iii) present a new test of the equivalence principle by constraining the Shapiro delay between gravitational and electromagnetic radiation. We also use the time delay to constrain the size and bulk Lorentz factor of the region emitting the gamma-rays. GRB 170817A is the closest short GRB with a known distance, but is between 2 and 6 orders of magnitude less energetic than other bursts with measured redshift. A new generation of gamma-ray detectors, and subthreshold searches in existing detectors, will be essential to detect similar short bursts at greater distances. Finally, we predict a joint detection rate for the Fermi Gamma-ray Burst Monitor and the Advanced LIGO and Virgo detectors of 0.1–1.4 per year during the 2018–2019 observing run and 0.3–1.7 per year at design sensitivity.

Published
2017
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5. The ASTRI Mini-Array of Cherenkov Telescopes at the Observatorio del Teide

Author

S., Scuderi, A., Giuliani, G., Pareschi, G., Tosti, O., Catalano, E., Amato, A., Antonelli L., J., Becerra Gonzáles, G., Bellassai, Bigongiari, B., Biondo, M., Böttcher, G., Bonanno, G., Bonnoli, P., Bruno, A., Bulgarelli, R., Canestrari, M., Capalbi, P., Caraveo, M., Cardillo, V., Conforti, G., Contino, M., Corpora, A., Costa, G., Cusumano, A., D'Aí, E., de Gouveia Dal Pino, R., Della Ceca, D., Escribano Rodriguez E. Falceta Gonçalves, C., Fermino, M., Fiori, V., Fioretti, M., Fiorini, S., Gallozzi, C., Gargano, S., Garozzo, S., Germani, A., Ghedina, F., Gianotti, S., Giarrusso, R., Gimenes, V., Giordano, A., Grillo, C., Grivel Gelly, D., Impiombato, F., Incardona, S., Incorvaia, S., Iovenitti, A., La Barbera, N., La Palombara, V., La Parola, A., Lamastra, L., Lessio, G., Leto, F., Lo Gerfo, M., Lodi, S., Lombardi, F., Longo, F., Lucarelli, C., Maccarone M., D., Marano, E., Martinetti, S., Mereghetti, A., Micciché, R., Millul, T., Mineo, D., Mollica, G., Morlino, A., Morselli, G., Naletto, G., Nicotra, A., Pagliaro, N., Parmiggiani, G., Piano, F., Pintore, E., Poretti, B., Olmi, G., Rodeghiero, G., Rodriguez Fernandez, P., Romano, G., Romeo, F., Russo, P., Sangiorgi, G., Saturni F., H., Schwarz J., Sciacca, G., Sironi, G., Sottile, A., Stamerra, G., Tagliaferri, V., Testa, G., Umana, M., Uslenghi, S., Vercellone, L., Zampieri, and R, Zanmar Sanchez

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The ASTRI Mini-Array (MA) is an INAF project to build and operate a facility to study astronomical sources emitting at very high-energy in the TeV spectral band. The ASTRI MA consists of a group of nine innovative Imaging Atmospheric Cherenkov telescopes. The telescopes will be installed at the Teide Astronomical Observatory of the Instituto de Astrofisica de Canarias (IAC) in Tenerife (Canary Islands, Spain) on the basis of a host agreement with INAF. Thanks to its expected overall performance, better than those of current Cherenkov telescopes' arrays for energies above \sim 5 TeV and up to 100 TeV and beyond, the ASTRI MA will represent an important instrument to perform deep observations of the Galactic and extra-Galactic sky at these energies., Comment: 19 pages, 22 figures

Published
2022
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6. The discovery, monitoring and environment of SGR J1935+2154

Author

Israel, G. L., Esposito, P., Rea, N., Zelati, F. Coti, Tiengo, A., Campana, S., Castillo, S. Mereghetti G. A. Rodriguez, Gotz, D., Burgay, M., Possenti, A., Zane, S., and Turolla, R.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We report on the discovery of a new member of the magnetar class, SGR J1935+2154, and on its timing and spectral properties measured by an extensive observational campaign carried out between July 2014 and March 2015 with Chandra and XMM-Newton (11 pointings). We discovered the spin period of SGR J1935+2154 through the detection of coherent pulsations at a period of about 3.24s. The magnetar is slowing-down at a rate of 1.43(1)x10^{-11} s/s and with a decreasing trend due to a negative second period derivative of -3.5(7)x10^{-19} s/s^2. This implies a surface dipolar magnetic field strength of about 2.2x10^{14} G, a characteristic age of about 3.6kyr and, a spin-down luminosity L_{sd} of about 1.7x10^{34} erg/s. The source spectrum is well modelled by a blackbody with temperature of about 500eV plus a power-law component with photon index of about 2. The source showed a moderate long-term variability, with a flux decay of about 25\% during the first four months since its discovery, and a re-brightening of the same amount during the second four months. The X-ray data were also used to study the source environment. In particular, we discovered a diffuse emission extending on spatial scales from about 1" up to at least 1' around SGR J1935+2154 both in Chandra and XMM-Newton data. This component is constant in flux (at least within uncertainties) and its spectrum is well modelled by a power-law spectrum steeper than that of the pulsar. Though a scattering halo origin seems to be more probable we cannot exclude that part, or all, of the diffuse emission is due to a pulsar wind nebula., Comment: To appear in MNRAS; 10 pages, 3 color figures, 4 tables

Published
2016
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9. The first seven months of the 2020 X-ray outburst of the magnetar SGR J1935+2154

Author

A Borghese, F Coti Zelati, G L Israel, M Pilia, M Burgay, M Trudu, S Zane, R Turolla, N Rea, P Esposito, S Mereghetti, A Tiengo, and A Possenti

Subjects
Space and Planetary Science, Astronomy and Astrophysics
Abstract

The magnetar SGR J1935+2154 underwent a new active episode on 2020 April 27–28, when a forest of hundreds of X-ray bursts and a large enhancement of the persistent flux were detected. For the first time, a radio burst with properties similar to those of fast radio bursts and with a X-ray counterpart was observed from this source, showing that magnetars can power at least a group of fast radio bursts. In this paper, we report on the X-ray spectral and timing properties of SGR J1935+2154 based on a long-term monitoring campaign with Chandra, XMM–Newton, NuSTAR, Swift, and NICER covering a time-span of ∼7 months since the outburst onset. The broad-band spectrum exhibited a non-thermal power-law component (Γ ∼ 1.2) extending up to ∼20–25 keV throughout the campaign and a blackbody component with temperature decreasing from ∼1.5 keV at the outburst peak to ∼0.45 keV in the following months. We found that the luminosity decay is well described by the sum of two exponential functions, reflecting the fast decay (∼1 d) at the early stage of the outburst followed by a slower decrease (∼30 d). The source reached quiescence about ∼80 d after the outburst onset, releasing an energy of ∼6 × 1040 erg during the outburst. We detected X-ray pulsations in the XMM–Newton data sets and derived an average spin-down rate of ∼3.5 × 10−11 s s−1 using the spin period measurements derived in this work and three values reported previously during the same active period. Moreover, we report on simultaneous radio observations performed with the Sardinia Radio Telescope. No evidence for periodic or single-pulse radio emission was found.

Published
2022

10. Deep X-ray and radio observations of the first outburst of the young magnetar Swift J1818.0-1607

Author

A. Y. Ibrahim, A. Borghese, N. Rea, F. Coti Zelati, E. Parent, T. D. Russell, S. Ascenzi, R. Sathyaprakash, D. Götz, S. Mereghetti, M. Topinka, M. Rigoselli, V. Savchenko, S. Campana, G. L. Israel, A. Tiengo, R. Perna, R. Turolla, S. Zane, P. Esposito, G. A. Rodríguez Castillo, V. Graber, A. Possenti, C. Dehman, M. Ronchi, S. Loru, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - High Energy Astrophysical Phenomena
Abstract

Swift J1818.0-1607 is a radio-loud magnetar with a spin period of 1.36 s and a dipolar magnetic field strength of B~3E14 G, which is very young compared to the Galactic pulsar population. We report here on the long-term X-ray monitoring campaign of this young magnetar using XMM-Newton, NuSTAR, and Swift from the activation of its first outburst in March 2020 until October 2021, as well as INTEGRAL upper limits on its hard X-ray emission. The 1-10 keV magnetar spectrum is well modeled by an absorbed blackbody with a temperature of kT_BB~1.1 keV, and apparent reduction in the radius of the emitting region from ~0.6 to ~0.2 km. We also confirm the bright diffuse X-ray emission around the source extending between ~50'' and ~110''. A timing analysis revealed large torque variability, with an average spin-down rate nudot~-2.3E-11 Hz^2 that appears to decrease in magnitude over time. We also observed Swift J1818.0-1607 with the Karl G. Jansky Very Large Array (VLA) on 2021 March 22. We detected the radio counterpart to Swift J1818.0-1607 measuring a flux density of S_v = 4.38+/-0.05 mJy at 3 GHz, and a half ring-like structure of bright diffuse radio emission located at ~90'' to the west of the magnetar. We tentatively suggest that the diffuse X-ray emission is due to a dust scattering halo and that the radio structure may be associated with the supernova remnant of this young pulsar, based on its morphology., 19 pages, 8 figures, accepted for publication on ApJ

Published
2022

11. X-ray observation of the Roche-lobe-filling white dwarf plus hot subdwarf system ZTF J213056.71+442046.5

Author

S. Mereghetti, N. La Palombara, T. Kupfer, T. R. Marsh, C. M. Copperwheat, K. Deshmukh, P. Esposito, T. Maccarone, F. Pintore, M. Rigoselli, L. Rivera Sandoval, and A. Tiengo

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Space and Planetary Science, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics, QB
Abstract

ZTF J213056.71+442046.5 is the prototype of a small class of recently discovered compact binaries composed of a white dwarf and a hot subdwarf that fills its Roche-lobe. Its orbital period of only 39 min is the shortest known for the objects in this class. Evidence for a high orbital inclination (i=86 deg) and for the presence of an accretion disk has been inferred from a detailed modeling of its optical photometric and spectroscopic data. We report the results of an XMM-Newton observation carried out on 2021 January 7. ZTF J213056.71+442046.5 was clearly detected by the Optical Monitor, which showed a periodic variability in the UV band (200-400 nm), with a light curve similar to that seen at longer wavelengths. Despite accretion on the white dwarf at an estimated rate of the order of 10^{-9} M_sun/yr, no X-rays were detected with the EPIC instrument, with a limit of ~10^{30} erg/s on the 0.2-12 keV luminosity. We discuss possible explanations for the lack of a strong X-ray emission from this system., Comment: Accepted for publication on The Astrophysical Journal

Published
2022

12. Cherenkov Telescope Array : the World’s largest VHE gamma-ray observatory

Author

Roberta Zanin, H. Abdalla, H. Abe, S. Abe, A. Abusleme, F. Acero, A. Acharyya, V. Acin Portella, K. Ackley, R. Adam, C. Adams, S.S. Adhikari, I. Aguado Ruesga, I. Agudo, R. Aguilera, A. Aguirre Santaella, F. Aharonian, A. Alberdi, R. Alfaro, J. Alfaro, C. Alispach, R. Aloisio, R. Alves Batista, J.P. Amans, L. Amati, E. Amato, L. Ambrogi, G. Ambrosi, M. Ambrosio, R. Ammendola, J. Anderson, M. Anduze, E.O. Anguner, L.A. Antonelli, V. Antonuccio, P. Antoranz, R. Anutarawiramkul, J. Aragunde Gutierrez, C. Aramo, A. Araudo, M. Araya, A. Arbet Engels, C. Arcaro, V. Arendt, C. Armand, T. Armstrong, F. Arqueros, L. Arrabito, B. Arsioli, M. Artero, K. Asano, Y. Ascasibar, J. Aschersleben, M. Ashley, P. Attina, P. Aubert, C. B. Singh, D. Baack, A. Babic, M. Backes, V. Baena, S. Bajtlik, A. Baktash, C. Balazs, M. Balbo, O. Ballester, J. Ballet, B. Balmaverde, A. Bamba, R. Bandiera, A. Baquero Larriva, P. Barai, C. Barbier, V. Barbosa Martins, M. Barcelo, M. Barkov, M. Barnard, L. Baroncelli, U. Barres de Almeida, J.A. Barrio, D. Bastieri, P.I. Batista, I. Batkovic, C. Bauer, R. Bautista González, J. Baxter, U. Becciani, J. Becerra González, Y. Becherini, G. Beck, J. Becker Tjus, W. Bednarek, A. Belfiore, L. Bellizzi, R. Belmont, W. Benbow, D. Berge, E. Bernardini, M.I. Bernardos, K. Bernlöhr, A. Berti, M. Berton, B. Bertucci, V. Beshley, N. Bhatt, S. Bhattacharyya, W. Bhattacharyya, B. Y. Bi, G. Bicknell, N. Biederbeck, C. Bigongiari, A. Biland, R. Bird, E. Bissaldi, J. Biteau, M. Bitossi, O. Blanch, M. Blank, J. Blazek, J. Bobin, C. Boccato, F. Bocchino, C. Boehm, M. Bohacova, C. Boisson, J. Boix, J.P. Bolle, J. Bolmont, G. Bonanno, C. Bonavolontà, L. Bonneau Arbeletche, G. Bonnoli, P. Bordas, J. Borkowski, R. Bose, D. Bose, Z. Bosnjak, E. Bottacini, Markus Böttcher, M.T. Botticella, C. Boutonnet, F. Bouyjou, V. Bozhilov, E. Bozzo, L. Brahimi, C. Braiding, S. Brau Nogue, S. Breen, J. Bregeon, M. Breuhaus, A. Brill, W. Brisken, E. Brocato, A.M. Brown, K. Brügge, P. Brun, F. Brun, L. Brunetti, G. Brunetti, P. Bruno, A. Bruno, A. Bruzzese, N. Bucciantini, J. H. Buckley, R. Bühler, A. Bulgarelli, T. Bulik, M. Bünning, M. Bunse, M. Burton, A. Burtovoi, M. Buscemi, S. Buschjager, G. Busetto, J. Buss, K. Byrum, A. Caccianiga, F. Cadoux, A. Calanducci, C. Calderon, J. Calvo Tovar, R. A. Cameron, P. Campana, R. Canestrari, F. Cangemi, B. Cantlay, M. Capalbi, M. Capasso, M. Cappi, A. Caproni, R. Capuzzo Dolcetta, P. Caraveo, V. Cárdenas, L. Cardiel, M. Cardillo, C. Carlile, S. Caroff, R. Carosi, A. Carosi, E. Carquin, M. Carrere, J.M. Casandjian, S. Casanova, F. Cassol, F. Catalani, O. Catalano, D. Cauz, A. Ceccanti, C. Celestino Silva, K. Cerny, M. Cerruti, E. Chabanne, P. Chadwick, Y. Chai, P. Chambery, C. Champion, S. Chaty, A. Chen, K. Cheng, M. Chernyakova, G. Chiaro, A. Chiavassa, M. Chikawa, V.R. Chitnis, J. Chudoba, L. Chytka, S. Cikota, A. Circiello, P. Clark, M. Colak, E. Colombo, S. Colonges, A. Comastri, A. Compagnino, V. Conforti, E. Congiu, R. Coniglione, J. Conrad, F. Conte, J.L. Contreras, P. Coppi, R. Cornat, J. Coronado Blazquez, J. Cortina, A. Costa, H. Costantini, G. Cotter, B. Courty, S. Covino, S. Crestan, P. Cristofari, R. Crocker, J. Croston, K. Cubuk, O. Cuevas, X. Cui, G. Cusumano, S. Cutini, G. D'Amico, F. D'Ammando, P. D'Avanzo, P. Da Vela, M. Dadina, S. Dai, M. Dalchenko, M. Dall'Ora, M.K. Daniel, J. Dauguet, I. Davids, J. Davies, B. Dawson, A. De Angelis, A.E. de Araujo Carvalho, M. de Bony de Lavergne, G. De Cesare, F. de Frondat, I. de la Calle, E. de Gouveia Dal Pino, B. De Lotto, A. De Luca, D. De Martino, M. de Naurois, E. de Ona Wilhelmi, F. De Palma Persio, N. De Simone, V. de Souza Valle, E. Delagnes, G. Deleglise Reznicek, C. Delgado, A.G. Delgado Giler, J. Delgado Mengual Valle, Domenico Della Volpe, D. Depaoli, J. Devin, T. Di Girolamo, C. Di Giulio Pierro, L. Di Venere, C. Díaz, C. Dib, S. Diebold, S. Digel, A. Djannati Atai, J. Djuvsland, A. Dmytriiev, K. Docher, A. Domínguez, D. Dominis Prester, A. Donini, D. Dorner, M. Doro, Rita Cassia dos Anjos, J.L. Dournaux, T. Downes, G. Drake, H. Drass, D. Dravins, C. Duangchan, A. Duara, G. Dubus, L. Ducci, C. Duffy, D. Dumora, K. Dundas Mora, A. Durkalec, V.V. Dwarkadas, J. Ebr, C. Eckner, J. Eder, E. Edy, K. Egberts, S. Einecke, C. Eleftheriadis, D. Elsässer, G. Emery, D. Emmanoulopoulos, J.P. Ernenwein, M. Errando, P. Escarate, J. Escudero, C. Espinoza, S. Ettori, A. Eungwanichayapant, P. Evans, C. Evoli, M. Fairbairn, D. Falceta Goncalves, A. Falcone, V. Fallah Ramazanı, R. Falomo, K. Farakos, G. Fasola, A. Fattorini, Y. Favre, R. Fedora, E. Fedorova, K. Feijen, Q. Feng, G. Ferrand, G. Ferrara, O. Ferreira, M. Fesquet, E. Fiandrini, A. Fiasson, M. Filipovic, D. Fink, J.P. Finley, V. Fioretti, D.F.G. Fiorillo, M. Fiorini, S. Flis, H. Flores, L. Foffano, C. Fohr, M.V. Fonseca, L. Font, G. Fontaine, O. Fornieri, P. Fortin, L. Fortson, N. Fouque, B. Fraga, A. Franceschini, F.J. Franco, L. Freixas Coromina, L. Fresnillo, D. Fugazza, Y. Fujita, S. Fukami, Y. Fukazawa, D. Fulla, S. Funk, A. Furniss, S. Gabici, D. Gaggero, G. Galanti, P. Galdemard, Y. A. Gallant, D. Galloway, S. Gallozzi, V. Gammaldi, R. Garcia, L. E. García-Muñoz, E. Garcia Lopez, F. Gargano, C. Gargano, S. Garozzo, D. Gascon, T. Gasparetto, D. Gasparrini, H. Gasparyan, M. Gaug, N. Geffroy, A. Gent, S. Germani, A. Ghalumyan, A. Ghedina, G. Ghirlanda, F. Gianotti, S. Giarrusso, M. Giarrusso, G. Giavitto, B. Giebels, N. Giglietto, V. Gika, F. Gillardo, R. Gimenes, F. Giordano, E. Giro, M. Giroletti, Andrea Giuliani, M. Gjaja, J.F. Glicenstein, P. Gliwny, H. Goksu, P. Goldoni, J.L. Gomez, M.M. Gonzalez, Juan Manuel Gonzalez, K.S. Gothe, D. Gotz Coelho, T. Grabarczyk, R. Graciani, P. Grandi, G. Grasseau, D. Grasso, D. Green, J. Green, T. Greenshaw, P. Grespan, A. Grillo, M.H. Grondin, J. Grube, V. Guarino, B. Guest, O. Gueta, M. Günduz, S. Gunji, G. Gyuk, J. Hackfeld, D. Hadasch, L. Hagge, A. Hahn, J.E. Hajlaoui, A. Halim, P. Hamal, W. Hanlon, Y. Harada, M.J. Hardcastle, M. Harvey Collado, T. Haubold, A. Haupt, M. Havelka, K. Hayashi, M. Hayashida, H. He, L. Heckmann, M. Heller, F. Henault, Gilles Henri, G. Hermann, S. Hernández Cadena, J. Herrera Llorente, O. Hervet, J. Hinton, A. Hiramatsu, K. Hirotani, B. Hnatyk, R. Hnatyk, J.K. Hoang, D. H.H. Hoffmann, C. Hoischen, J. Holder, M. Holler, B. Hona, D. Horan, Dieter Horns, P. Horvath, J. Houles, M. Hrabovsky, D. Hrupec, Y. Huang, J.‑M. Huet, G. Hughes, G. Hull, T.B. Humensky, M. Hütten, M. Iarlori, J.M. Illa, R. Imazawa, T. Inada, F. Incardona, A. Ingallinera, S. Inoue, T. Inoue, Y. Inoue, F. Iocco, K. Ioka, M. Ionica, S. Iovenitti, A. Iriarte, K. Ishio, W. Ishizaki, Y. Iwamura, J. Jacquemier, M. Jacquemont, M. Jamrozy, P. Janecek, F. Jankowsky, A. JardinBlicq, C. Jarnot, P. Jean Martínez, L. Jocou, N. Jordana, M. Josselin, I. JungRichardt, F.J.P.A. Junqueira, C. Juramy Gilles, P. Kaaret, L.H.S. Kadowaki, M. Kagaya, R. Kankanyan, D. Kantzas, V. Karas, A. Karastergiou, S. Karkar, J. Kasperek, H. Katagiri, J. Kataoka, K. Katarzynski, S. Katsuda, N. Kawanaka, D. Kazanas, D. Kerszberg, B. Khélifi, M.C. Kherlakian, T.P. Kian, D.B. Kieda, T. Kihm, S. Kim, S. Kisaka, R. Kissmann, R. Kleijwegt, G. Kluge, W. Kluźniak, J. Knapp, A. Kobakhidze, Y. Kobayashi, B. Koch, J. Kocot, K. Kohri, N. Komin, A. Kong, K. Kosack, F. Krack, M. Krause, F. Krennrich, H. Kubo, V. N. Kudryavtsev, S. Kunwar, J. Kushida, P. Kushwaha, Barbera Parola, G. La Rosa, R. Lahmann, A. Lamastra, M. Landoni, D. Landriu, R.G. Lang, J. Lapington, P. Laporte, P. Lason, J. Lasuik, J. Lazendic Galloway, T. Le Flour, P. Le Sidaner, S. Leach, S.H. Lee, W.H. Lee, S. Lee Oliveira, A. Lemiere, M. Lemoine Goumard, J.P. Lenain, F. Leone, V. Leray, G. Leto, F. Leuschner, R. Lindemann, E. Lindfors, L. Linhoff, I. Liodakis, A. Lipniacka, M. Lobo, Thomas Lohse, S. Lombardi, A. Lopez, M. Lopez, R. Lopez Coto, F. Louis, M. Louys, F. Lucarelli, H. Ludwig Boudi, P.L. Luque Escamilla, M.C. Maccarone, E. Mach, A.J. Maciejewski, J. Mackey, P. Maeght, C. Maggio, G. Maier, P. Majumdar, M. Makariev, M. Mallamaci, R. Malta Nunes de Almeida, D. Malyshev, D. Mandat, G. Maneva, M. Manganaro, P. Manigot, K. Mannheim, N. Maragos, D. Marano, M. Marconi, A. Marcowith, M. Marculewicz, B. Marcun, J. Marin, N. Marinello, P. Marinos, S. Markoff, P. Marquez, G. Marsella, J. M. Martin, P. G. Martin, M. Martinez, G. Martinez, O. Martinez, H. Martinez Huerta, C. Marty, R. Marx, N. Masetti, P. Massimino, H. Matsumoto, N. Matthews, G. Maurin, W. Max Moerbeck, N. Maxted, M.N. Mazziotta, S.M. Mazzola, J.D. Mbarubucyeye, L. Mc Comb, I. McHardy, S. McKeague, S. McMuldroch, E. Medina, D. Medina Miranda, A. Melandri, C. Melioli, D. Melkumyan, S. Menchiari, S. Mereghetti, G. Merino Arevalo, E. Mestre, J.L. Meunier, T. Meures, S. Micanovic, M. Miceli, M. Michailidis, J. Michalowski, T. Miener, I. Mievre, J. D. Miller, T. Mineo, M. Minev, J.M. Miranda, A. Mitchell, T. Mizuno, B. A. Mode, R. Moderski, L. Mohrmann, E. Molinari, T. Montaruli, I. Monteiro, C. Moore, A. Moralejo, D. Morcuende Parrilla, E. Moretti, K. Mori, P. Moriarty, K. Morik, P. Morris, A. Morselli, K. Mosshammer, R. Mukherjee, J. Muller, C. Mundell, J. Mundet, T. Murach, A. Muraczewski, H. Muraishi, I. Musella, A. Musumarra, A. Nagai, S. Nagataki, T. Naito, T. Nakamori, K. Nakashima, K. Nakayama, N. Nakhjiri, G. Naletto, D. Naumann, L. Nava, M.A. Nawaz, H. Ndiyavala, D. Neise, L. Nellen, R. Nemmen, N. Neyroud, K. Ngernphat, T. Nguyen Trung, L. Nicastro, L. Nickel, J. Niemiec, D. Nieto, C. Nigro, M. Nikołajuk, D. Ninci, K. Noda, Y. Nogami, S. Nolan, R. P. Norris, D. Nosek, M. Nöthe, V. Novotny, S. Nozaki, F. Nunio, P. O'Brien, K. Obara, Y. Ohira, M. Ohishi, S. Ohm, T. Oka, N. Okazaki, A. Okumura, C. Oliver, G. Olivera, B. Olmi, M. Orienti, R. Orito, M. Orlandini, E. Orlando, J.P. Osborne, M. Ostrowski, N. Otte, E. Ovcharov, E. Owen, I. Oya, A. Ozieblo, M. Padovani, A. Pagliaro, A. Paizis, M. Palatiello, M. Palatka, E. Palazzi, J.‑L. Panazol, D. Paneque, S. Panny, Francesca Romana Pantaleo, M. Panter, M. Paolillo, A. Papitto, A. Paravac, J.M. Paredes, G. Pareschi, N. Parmiggiani, R.D. Parsons, P. Paśko, S. R. Patel, B. Patricelli, L. Pavletic, S. Pavy, A. Peer, M. Pecimotika, M.G. Pellegriti, P. Peñil Del Campo, A. Pepato, S. Perard, C. Perennes, M. Peresano, A. Perez Aguilera, J. Perez Romero, M.A. Perez Torres, M. Persic, P. O. Petrucci, O. Petruk, B. Peyaud, K. Pfrang, E. Pian, P. Piatteli, E. Pietropaolo, R. Pillera, D. Pimentel, F. Pintore, C. Pio Garcia, G. Pirola, F. Piron, S. Pita, M. Pohl, V. Poireau, A. Pollo, M. Polo, C. Pongkitivanichkul, J. Porthault, J. Powell, D. Pozo, R.R. Prado, E. Prandini, J. Prast, K. Pressard, G. Principe, N. Produit, D. Prokhorov, H. Prokoph, H. Przybilski, E. Pueschel, G. Pühlhofer, I. Puljak, M.L. Pumo, M. Punch, F. Queiroz, J. Quinn, A. Quirrenbach, P.J. Rajda, R. Rando, S. Razzaque, S. Recchia, P. Reichherzer, O. Reimer, A. Reisenegger, Q. Remy, M. Renaud, T. Reposeur, B. Reville, J.M. Reymond, J. Reynolds, D. Ribeiro, M. Ribo, G. Richards, J. Rico, F. Rieger, L. Riitano, M. Riquelme, D. Riquelme, S. Rivoire, V. Rizi, E. Roache, M. Roche, J. Rodriguez, G. Rodriguez Fernandez, J.C. Rodriguez Ramirez, J.J. Rodriguez Vazquez, G. Rojas, P. Romano, G. Romeo Lobato, C. Romoli, M. Roncadelli, J. Rosado, A. Rosales de Leon, G. Rowell, A. Rugliancich, J.E. Ruiz del Mazo, C. Rulten, C. Russell, F. Russo Hatlen, S. Safi Harb, L. Saha, V. Sahakian, S. Sailer, T. Saito, N. Sakaki, S. Sakurai, G. Salina, H. Salzmann, D. Sanchez, H. Sandaker, A. Sandoval, P. Sangiorgi, M. Sanguillon, H. Sano, M. Santander, A. Santangelo, R. Santos Lima, A. Sanuy, L. Sapozhnikov, T. Saric, S. Sarkar, H. Sasaki, N. Sasaki, Y. Sato, F.G. Saturni, M. Sawada, J. Schaefer, A. Scherer, J. Scherpenberg, P. Schipani, B. Schleicher, J. Schmoll, M. Schneider, H. Schoorlemmer, P. Schovanek, F. Schussler, B. Schwab, U. Schwanke, J. Schwarz, E. Sciacca, S. Scuderi, M. Seglar Arroyo, I. Seitenzahl, D. Semikoz, O. Sergijenko, J.E. Serna Franco, Karol Seweryn, V. Sguera, A. Shalchi, R.Y. Shang, P. Sharma, L. Sidoli, J. Sieiro, H. Siejkowski, A. Sillanpaa, B.B. Singh, K.K. Singh, A. Sinha, C. Siqueira, J. Sitarek, P. Sizun, V. Sliusar, D. Sobczynska, R.W. Sobrinho, H. Sol, G. Sottile, H. Spackman, S. Spencer, G. Spengler, D. Spiga, W. Springer, A. Stamerra, S. Stanic, R. Starling, Ł. Stawarz, Stanislav Stefanik, C. Stegmann, A. Steiner, S. Steinmassl, C. Stella, R. Sternberger, M. Sterzel, C. Stevens, B. Stevenson, T. Stolarczyk, G. Stratta, U. Straumann, J. Striskovic, M. Strzys, R. Stuik, M. Suchenek, Y. Sunada, Tiina Suomijarvi, T. Suric, H. Suzuki, P. Swierk, T. Szepieniec, K. Tachihara, G. Tagliaferri, H. Tajima, N. Tajima, D. Tak, H. Takahashi, M. Takahashi, J. Takata, R. Takeishi, T. Tam, M. Tanaka, T. Tanaka, S. Tanaka, M. Tavani, F. Tavecchio, T. Tavernier, A. Russ Taylor, L.A. Tejedor, P. Temnikov, K. Terauchi, J.C. Terrazas, R. Terrier, T. Terzic, M. Teshima, D. Thibaut, F. Thocquenne, W. Tian, L. Tibaldo, A. Tiengo, M. Tluczykont, C.J. Todero Peixoto, K. Toma, L. Tomankova, J. Tomastik, M. Tornikoski, D.F. Torres, E. Torresi, G. Tosti, L. Tosti, N. Tothill, F. Toussenel, G. Tovmassian, C. Trichard, M. Trifoglio, A. Trois, S. Truzzi, A. Tsiahina, B. Turk, A. Tutone, Y. Uchiyama, P. Utayarat, L. Vaclavek, M. Vacula, V. Vagelli, F. Vagnetti, J.A. Valdivia, M. Valentino, A. Valio, B. Vallage, P. Vallania Quispe, A.M. van den Berg, W. van Driel, C. van Eldik, C. van Rensburg, Brian van Soelen, J. Vandenbroucke, G. Vasileiadis, V. Vassiliev, M. Vazquez Acosta, M. Vecchi, A. Vega, J. Veh, P. Veitch, C. Venter, S. Ventura, S. Vercellone, V. Verguilov, G. Verna, S. Vernetto, V. Verzi, G.P. Vettolani, C. Veyssiere, I. Viale, A. Viana, N. Viaux, J. Vignatti, C.F. Vigorito, J. Villanueva, V. Vitale, V. Vittorini, V. Vodeb, N. Vogel, V. Voisin, S. Vorobiov, M. Vrastil, T. Vuillaume, S.J. Wagner, P. Wagner, K. Wakazono, S.P. Wakely, M. Ward, D. Warren, J. Watson, M. Wechakama, P. Wegner, A. Weinstein, C. Weniger, F. Werner, H. Wetteskind, M. L. White, A. Wierzcholska, S. Wiesand, R. Wijers, M. Wilkinson, M. Will, J. Williams, T. J. Williamson, A. Wolter, Y.W. Wong, M. Wood, T. Yamamoto, H. Yamamoto, Y. Yamane, R. Yamazaki, S. Yanagita, L. Yang, S. Yoo, T. Yoshida, T. Yoshikoshi, P. Yu, A. Yusafzai, Michael Zacharias, B. Zaldivar, L. Zampieri, R. Zanin, R. Zanmar Sanchez, D. Zaric, M. Zavrtanik, D. Zavrtanik, Andrzej Zdziarski, A. Zech, H. Zechlin, A. Zenin, A. Zerwekh, K. Ziętara, A. Zink, J. Ziolkowski, M. Zivec, A. Zmija, Współautorami artykułu są członkowie CTA Observatory, CTA Consortium i LST Collaboration w liczbie 1139, Astronomy, Research unit Nuclear & Hadron Physics, and Research unit Astroparticle Physics

Subjects
Physics, Observatory, Gamma ray, Astronomy
Abstract

Very-high Energy (VHE) gamma-ray astroparticle physics is a relatively young field, and observations over the past decade have surprisingly revealed almost two hundred VHE emitters which appear to act as cosmic particle accelerators. These sources are an important component of the Universe, influencing the evolution of stars and galaxies. At the same time, they also act as a probe of physics in the most extreme environments known - such as in supernova explosions, and around or after the merging of black holes and neutron stars. However, the existing experiments have provided exciting glimpses, but often falling short of supplying the full answer. A deeper understanding of the TeV sky requires a significant improvement in sensitivity at TeV energies, a wider energy coverage from tens of GeV to hundreds of TeV and a much better angular and energy resolution with respect to the currently running facilities. The next generation gamma-ray observatory, the Cherenkov Telescope Array Observatory (CTAO), is the answer to this need. In this talk I will present this upcoming observatory from its design to the construction, and its potential science exploitation. CTAO will allow the entire astronomical community to explore a new discovery space that will likely lead to paradigm-changing breakthroughs. In particular, CTA has an unprecedented sensitivity to short (sub-minute) timescale phenomena, placing it as a key instrument in the future of multi-messenger and multi-wavelength time domain astronomy. I will conclude the talk presenting the first scientific results obtained by the LST-1, the prototype of one CTAO telescope type - the Large-Sized Telescope, that is currently under commission., PoS: Proceedings of Science, 395, ISSN:1824-8039, Proceedings of 37th International Cosmic Ray Conference (ICRC2021)

Published
2022

13. Galactic Observatory Science with the ASTRI Mini-Array at the Observatorio del Teide

Author

A. D'Aì, E. Amato, A. Burtovoi, A.A. Compagnino, M. Fiori, A. Giuliani, N. La Palombara, A. Paizis, G. Piano, F.G. Saturni, A. Tutone, A. Belfiore, M. Cardillo, S. Crestan, G. Cusumano, M. Della Valle, M. Del Santo, A. La Barbera, V. La Parola, S. Lombardi, S. Mereghetti, G. Morlino, F. Pintore, P. Romano, S. Vercellone, A. Antonelli, C. Arcaro, C. Bigongiari, M. Böettcher, P. Bruno, A. Bulgarelli, V. Conforti, A. Costa, E. de Gouveia Dal Pino, V. Fioretti, S. Germani, A. Ghedina, F. Gianotti, V. Giordano, F. Incardona, G. Leto, F. Longo, A. López Oramas, F. Lucarelli, B. Olmi, A. Pagliaro, N. Parmiggiani, G. Romeo, A. Stamerra, V. Testa, G. Tosti, G. Umana, L. Zampieri, P. Caraveo, and G. Pareschi

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract

The ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Mini-Array will be composed of nine imaging atmospheric Cherenkov telescopes at the Observatorio del Teide site. The array will be best suited for astrophysical observations in the 0.3-200 TeV range with an angular resolution of few arc-minutes and an energy resolution of 10-15\%. A core-science programme in the first four years will be devoted to a limited number of key targets, addressing the most important open scientific questions in the very-high energy domain. At the same time, thanks to a wide field of view of about 10 degrees, ASTRI Mini-Array will observe many additional field sources, which will constitute the basis for the long-term observatory programme that will eventually cover all the accessible sky. In this paper, we review different astrophysical Galactic environments, e.g. pulsar wind nebulae, supernova remnants, and gamma-ray binaries, and show the results from a set of ASTRI Mini-Array simulations of some of these field sources made to highlight the expected performance of the array (even at large offset angles) and the important additional observatory science that will complement the core-science program., Comment: Accepted for publication in Journal of High-Energy Astrophysics

Published
2022
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14. ASTRI Mini-Array Core Science at the Observatorio del Teide

Author

S. Vercellone, C. Bigongiari, A. Burtovoi, M. Cardillo, O. Catalano, A. Franceschini, S. Lombardi, L. Nava, F. Pintore, A. Stamerra, F. Tavecchio, L. Zampieri, R. Alves Batista, E. Amato, L.A. Antonelli, C. Arcaro, J. Becerra González, G. Bonnoli, M. Böttcher, G. Brunetti, A.A. Compagnino, S. Crestan, A. D'Aì, M. Fiori, G. Galanti, A. Giuliani, E.M. de Gouveia Dal Pino, J.G. Green, A. Lamastra, M. Landoni, F. Lucarelli, G. Morlino, B. Olmi, E. Peretti, G. Piano, G. Ponti, E. Poretti, P. Romano, F.G. Saturni, S. Scuderi, A. Tutone, G. Umana, J.A. Acosta-Pulido, P. Barai, A. Bonanno, G. Bonanno, P. Bruno, A. Bulgarelli, V. Conforti, A. Costa, G. Cusumano, M. Del Santo, M.V. del Valle, R. Della Ceca, D.A. Falceta-Gonçalves, V. Fioretti, S. Germani, R.J. García-López, A. Ghedina, F. Gianotti, V. Giordano, M. Kreter, F. Incardona, S. Iovenitti, A. La Barbera, N. La Palombara, V. La Parola, G. Leto, F. Longo, A. López-Oramas, M.C. Maccarone, S. Mereghetti, R. Millul, G. Naletto, A. Pagliaro, N. Parmiggiani, C. Righi, J.C. Rodríguez-Ramírez, G. Romeo, P. Sangiorgi, R. Santos de Lima, G. Tagliaferri, V. Testa, G. Tosti, M. Vázquez Acosta, N. Żywucka, P.A. Caraveo, and G. Pareschi

Subjects
ASTRI, Imaging atmospheric Cherenkov arrays, Very high-energy gamma ray astrophysics, Astroparticle, High Energy Astrophysical Phenomena (astro-ph.HE), Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract

The ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) Project led by the Italian National Institute for Astrophysics (INAF) is developing and will deploy at the Observatorio del Teide a mini-array (ASTRI Mini-Array) composed of nine telescopes similar to the small-size dual-mirror Schwarzschild-Couder telescope (ASTRI-Horn) currently operating on the slopes of Mt. Etna in Sicily. The ASTRI Mini-Array will surpass the current Cherenkov telescope array differential sensitivity above a few tera-electronvolt (TeV), extending the energy band well above hundreds of TeV. This will allow us to explore a new window of the electromagnetic spectrum, by convolving the sensitivity performance with excellent angular and energy resolution figures. In this paper we describe the Core Science that we will address during the first four years of operation, providing examples of the breakthrough results that we will obtain when dealing with current open questions, such as the acceleration of cosmic rays, cosmology and fundamental physics and the new window, for the TeV energy band, of the time-domain astrophysics., Comment: Published in Journal of High Energy Astrophysics. 46 Figures, 7 Tables

Published
2022
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15. X-ray observations of the isolated black hole candidate OGLE-2011-BLG-0462 , and other collapsed objects discovered through gravitational microlensing

Author

S. Mereghetti, L. Sidoli, G. Ponti, and A. Treves

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Space and Planetary Science, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics
Abstract

Isolated black holes and neutron stars can be revealed through the observation of long duration gravitational microlensing events. A few candidates have been found in surveys of stars in the direction of the Galactic bulge. Recently, thanks to the addition of astrometric information at milliarcsecond level, it has been possible to reduce the uncertainties in the masses and distances for some of these "dark" gravitational lenses and select the most promising candidates. These isolated compact objects might emit X-rays powered by accretion from the interstellar medium. Using data of the Chandra, XMM-Newton, and INTEGRAL satellites, we searched for X-ray emission in the isolated black hole candidate OGLE-2011-BLG-0462, and in several other putative collapsed objects found with gravitational microlensing. OGLE-2011-BLG-0462 has been recently interpreted as a 7.1 M_sun black hole at a distance of 1.6 kpc, although a different group obtained a mass range (1.6-4.4 M_sun) that cannot exclude a massive neutron star. We have derived upper limits on the flux from OGLE-2011-BLG-0462 of 9$\times10^{-15}$ erg cm$^{-2}$ s$^{-1}$ in the 0.5-7 keV range and $\sim2\times10^{-12}$ erg cm$^{-2}$ s$^{-1}$ in the 17-60 keV range. The implied X-ray luminosity is consistent with the small radiative efficiency expected for a black hole and disfavours a neutron star interpretation. Limits down to a factor about five lower are obtained for the soft X-ray flux of other candidates, but their interpretation is affected by larger uncertainties in the masses, distances and spatial velocities., Comment: Accepted for publication on The Astrophysical Journal, 3 figures, 3 tables

Published
2022
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17. First detection of the Crab Nebula at TeV energies with a Cherenkov telescope in dual-mirror Schwarzschild-Couder configuration: the ASTRI-Horn telescope

Author

S. Lombardi, O. Catalano, S. Scuderi, L. A. Antonelli, G. Pareschi, E. Antolini, L. Arrabito, G. Bellassai, K. Bernlöhr, C. Bigongiari, B. Biondo, G. Bonanno, G. Bonnoli, G. M. Böttcher, J. Bregeon, P. Bruno, R. Canestrari, M. Capalbi, P. Caraveo, P. Conconi, V. Conforti, G. Contino, G. Cusumano, E. M. de Gouveia Dal Pino, A. Distefano, G. Farisato, C. Fermino, M. Fiorini, A. Frigo, S. Gallozzi, C. Gargano, S. Garozzo, F. Gianotti, S. Giarrusso, R. Gimenes, E. Giro, A. Grillo, D. Impiombato, S. Incorvaia, N. La Palombara, V. La Parola, G. La Rosa, G. Leto, F. Lucarelli, M. C. Maccarone, D. Marano, E. Martinetti, A. Miccichè, R. Millul, T. Mineo, G. Nicotra, G. Occhipinti, I. Pagano, M. Perri, G. Romeo, F. Russo, B. Sacco, P. Sangiorgi, F. G. Saturni, A. Segreto, G. Sironi, G. Sottile, A. Stamerra, L. Stringhetti, G. Tagliaferri, M. Tavani, V. Testa, M. C. Timpanaro, G. Toso, G. Tosti, M. Trifoglio, G. Umana, S. Vercellone, R. Zanmar Sanchez, C. Arcaro, A. Bulgarelli, M. Cardillo, E. Cascone, A. Costa, A. D’Aì, F. D’Ammando, M. Del Santo, V. Fioretti, A. Lamastra, S. Mereghetti, F. Pintore, G. Rodeghiero, P. Romano, J. Schwarz, E. Sciacca, F. R. Vitello, A. Wolter, Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), 24420530 - Böttcher, Markus, ITA, USA, FRA, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)

Subjects
Cherenkov Telescope Array, reflection: efficiency, Astrophysics, 7. Clean energy, 01 natural sciences, law.invention, energy: threshold, Observatory, law, hardware, Cherenkov, data analysis [Methods], mirror, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, electronics, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Schwarzschild, observatory, Cardinal point, supernovae: individual: Crab Nebula, gamma ray: emission, techniques: miscellaneous, individual: Crab Nebula [Supernovae], Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, technique: miscellaneous, Astrophysics and Astronomy, gamma rays: general, telescopes, methods: data analysis, Astrophysics::High Energy Astrophysical Phenomena, general [Gamma rays], miscellaneous [Techniques], FOS: Physical sciences, Context (language use), programming, VHE, Telescope, 0103 physical sciences, detector: pixel, photomultiplier: silicon, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Instrumentation and Methods for Astrophysics (astro-ph.IM), Cherenkov radiation, 010308 nuclear & particles physics, Astronomy, Astronomy and Astrophysics, calibration, supernovae: individual (Crab Nebula), Crab Nebula, Cherenkov counter, Space and Planetary Science, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], statistical, Telescopes, astro-ph.IM
Abstract

We report on the first detection of very high-energy (VHE) gamma-ray emission from the Crab Nebula by a Cherenkov telescope in dual-mirror Schwarzschild-Couder (SC) configuration. The result has been achieved by means of the 4 m size ASTRI-Horn telescope, operated on Mt. Etna (Italy) and developed in the context of the Cherenkov Telescope Array Observatory preparatory phase. The dual-mirror SC design is aplanatic and characterized by a small plate scale, allowing us to implement large field of view cameras with small-size pixel sensors and a high compactness. The curved focal plane of the ASTRI camera is covered by silicon photo-multipliers (SiPMs), managed by an unconventional front-end electronics based on a customized peak-sensing detector mode. The system includes internal and external calibration systems, hardware and software for control and acquisition, and the complete data archiving and processing chain. The observations of the Crab Nebula were carried out in December 2018, during the telescope verification phase, for a total observation time (after data selection) of 24.4 h, equally divided into on- and off-axis source exposure. The camera system was still under commissioning and its functionality was not yet completely exploited. Furthermore, due to recent eruptions of the Etna Volcano, the mirror reflection efficiency was reduced. Nevertheless, the observations led to the detection of the source with a statistical significance of 5.4 sigma above an energy threshold of ~3 TeV. This result provides an important step towards the use of dual-mirror systems in Cherenkov gamma-ray astronomy. A pathfinder mini-array based on nine large field-of-view ASTRI-like telescopes is under implementation., 6 pages, 2 figures

Published
2020

18. NICER Study of Pulsed Thermal X-Rays from Calvera: A Neutron Star Born in the Galactic Halo?

Author

S. Mereghetti, M. Rigoselli, R. Taverna, L. Baldeschi, S. Crestan, R. Turolla, and S. Zane

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Space and Planetary Science, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics
Abstract

Calvera (1RXS J141256.0+792204) is an isolated neutron star detected only through its thermal X-ray emission. Its location at high Galactic latitude ($b=+37^\circ$) is unusual if Calvera is a relatively young pulsar, as suggested by its spin period (59 ms) and period derivative ($3.2 \times 10^{-15}$ Hz s$^{-1}$). Using the Neutron Star Interior Composition Explorer (NICER), we obtained a phase-connected timing solution spanning four years which allowed us to measure the second derivative of the frequency $\ddot\nu = -2.5 \times 10^{-23}$ Hz s$^{-2}$ and to reveal timing noise consistent with that of normal radio pulsars. A magnetized hydrogen atmosphere model, covering the entire star surface, provides a good description of the phase-resolved spectra and energy-dependent pulsed fraction. However, we find that a temperature map more anisotropic than that produced by a dipole field is required, with a hotter zone concentrated towards the poles. By adding two small polar caps, we find that the surface effective temperature and that of the caps are ~0.1 and ~0.36 keV, respectively. The inferred distance is ~3.3 kpc. We confirm the presence of an absorption line at 0.7 keV associated to the emission from the whole star surface, difficult to interpret as a cyclotron feature and more likely originating from atomic transitions. We searched for pulsed $\gamma$-ray emission by folding seven years of Fermi-LAT data using the X-ray ephemeris, but no evidence for pulsations was found. Our results favour the hypothesis that Calvera is a normal rotation-powered pulsar, with the only peculiarity of being born at a large height above the Galactic disk., Comment: Accepted for publication in ApJ, 12 pages, 6 figures, 4 tables

Published
2021

19. Hot subdwarf wind models with accurate abundances I. Hydrogen dominated stars HD 49798 and BD+18$^\circ\,$2647

Author

Maja Vučković, Jiri Krticka, S. Mereghetti, F. Pintore, Jan Janík, Péter Németh, Iva Krtičková, J. Kubat, ITA, GBR, and CS

Subjects
Physics, 010308 nuclear & particles physics, Metallicity, FOS: Physical sciences, chemistry.chemical_element, Astronomy and Astrophysics, Astrophysics, Effective temperature, Light curve, 01 natural sciences, Subdwarf, Stars, chemistry, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Radiative transfer, 010303 astronomy & astrophysics, Stellar evolution, Solar and Stellar Astrophysics (astro-ph.SR), Helium
Abstract

Hot subdwarfs are helium burning objects in late stages of their evolution. These stars can develop winds driven by light absorption in the lines of heavier elements. The wind strength depends on chemical composition which can significantly vary from star to star. We aim to understand the influence of metallicity on the strength of the winds of the hot hydrogen-rich subdwarfs HD 49798 and BD+18$^\circ\,$2647. We used UV and optical spectra to derive stellar parameters and abundances. For derived stellar parameters, we predicted wind structure (including mass-loss rates and terminal velocities) with our METUJE code. We derived effective temperature $T_\text{eff}=45\,900\,$K and mass $M=1.46\,M_\odot$ for HD 49798 and $T_\text{eff}=73\,000\,$K and $M=0.38\,M_\odot$ for BD+18$^\circ\,$2647. The abundances can be interpreted as a result of interplay between stellar evolution and diffusion. HD 49798 has a strong wind that does not allow for chemical separation and consequently it shows solar chemical composition modified by hydrogen burning. On the other hand, we did not find any wind in BD+18$^\circ\,$2647 and its abundances are therefore most likely affected by radiative diffusion. Accurate abundances do not lead to a significant modification of wind mass-loss rate for HD 49798, because the increase of the contribution of Fe and Ni to the radiative force is compensated by the decrease of the force due to other elements. The resulting wind mass-loss rate $\dot M=2.1\times10^{-9}\,M_\odot\,\text{yr}^{-1}$ predicts an X-ray light curve during the eclipse which closely agrees with observations. On the other hand, the absence of the wind in BD+18$^\circ\,$2647 for accurate abundances is a result of its peculiar chemical composition. Wind models with accurate abundances provide more reliable wind parameters, but the influence of abundances on the wind parameters is limited in many cases., 11 pages, accepted for publication in Astronomy & Astrophysics

Published
2019

21. The Strongest Magnetic Fields in the Universe

Author

T. Piran, Rudolf A. Treumann, S. Mereghetti, Maurizio Falanga, V. S. Beskin, M. Lyutikov, and André Balogh

Subjects
Physics, Astrophysics, Magnetic field
Published
2016

22. Enhanced detection of terrestrial gamma-ray flashes by AGILE

Author

M. Marisaldi, A. Argan, A. Ursi, T. Gjesteland, F. Fuschino, C. Labanti, M. Galli, M. Tavani, C. Pittori, F. Verrecchia, F. D'Amico, N. Østgaard, S. Mereghetti, R. Campana, P. W. Cattaneo, A. Bulgarelli, S. Colafrancesco, S. Dietrich, F. Longo, F. Gianotti, P. Giommi, A. Rappoldi, M. Trifoglio, A. Trois, Marisaldi, M., Argan, A., Ursi, A., Gjesteland, T., Fuschino, F., Labanti, C., Galli, M., Tavani, M., Pittori, C., Verrecchia, F., D'Amico, F., Ostgaard, N., Mereghetti, S., Campana, R., Cattaneo, P. W., Bulgarelli, A., Colafrancesco, S., Dietrich, S., Longo, F., Gianotti, F., Giommi, P., Rappoldi, A., Trifoglio, M., and Trois, A.

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Solar Physics, Astrophysics, and Astronomy, Atmospheric Science, FOS: Physical sciences, terrestrial gamma-ray flashes, terrestrial gamma‐ray flashes, atmospheric electricity, TGF, Space Physics (physics.space-ph), Lightning, Research Letters, Physics - Space Physics, Atmospheric Processes, Research Letter, Matematikk og Naturvitenskap: 400 [VDP], Instruments and Techniques, AGILE TGF, Astrophysics - High Energy Astrophysical Phenomena
Abstract

At the end of March 2015 the onboard software configuration of the Astrorivelatore Gamma a Immagini Leggero (AGILE) satellite was modified in order to disable the veto signal of the anticoincidence shield for the minicalorimeter instrument. The motivation for such a change was the understanding that the dead time induced by the anticoincidence prevented the detection of a large fraction of Terrestrial Gamma‐Ray Flashes (TGFs). The configuration change was highly successful resulting in an increase of one order of magnitude in TGF detection rate. As expected, the largest fraction of the new events has short duration (, Key Points Tenfold improvement in TGF detection rate by AGILE is obtained after a major configuration changeThe sample is dead time‐free, with TGF durations as short as 20 μsThe relationship between TGF duration and likelihood of association with lightning is confirmed

Published
2015

23. Characterization of a tagged gamma-ray beam line at the DAPhNE Beam Test Facility

Author

P. W. Cattaneo, A. Argan, F. Boffelli, A. Bulgarelli, B. Buonomo, A. W. Chen, F. D'Ammando, L. Foggetta, T. Froysland, F. Fuschino, M. Galli, F. Gianotti, A. Giuliani, M. Marisaldi, G. Mazzitelli, A. Pellizzoni, M. Prest, G. Pucella, L. Quintieri, A. Rappoldi, M. Tavani, M. Trifoglio, A. Trois, P. Valente, E. Vallazza, S. Vercellone, A. Zambra, G. Barbiellini, P. Caraveo, V. Cocco, E. Costa, G. . Paris, E. . Monte, G. . Cocco, I. Donnarumma, Y. Evangelista, M. Feroci, A. Ferrari, M. Fiorini, C. Labanti, I. Lapshov, F. Lazzarotto, P. Lipari, M. Mastropietro, S. Mereghetti, E. Morelli, E. Moretti, A. Morselli, L. Pacciani, F. Perotti, G. Piano, P. Picozza, M. Pilia, G. Porrovecchio, M. Rapisarda, A. Rubini, S. Sabatini, P. Soffitta, E. Striani, V. Vittorini, D. Zanello, S. Colafrancesco, P. Giommi, C. Pittori, P. Santolamazza, F. Verrecchia, L. Salotti, LONGO, FRANCESCO, P. W., Cattaneo, A., Argan, F., Boffelli, A., Bulgarelli, B., Buonomo, A. W., Chen, F., D'Ammando, L., Foggetta, T., Froysland, F., Fuschino, M., Galli, F., Gianotti, A., Giuliani, Longo, Francesco, M., Marisaldi, G., Mazzitelli, A., Pellizzoni, M., Prest, G., Pucella, L., Quintieri, A., Rappoldi, M., Tavani, M., Trifoglio, A., Troi, P., Valente, E., Vallazza, S., Vercellone, A., Zambra, G., Barbiellini, P., Caraveo, V., Cocco, E., Costa, Paris, G., Monte, E., Cocco, G., I., Donnarumma, Y., Evangelista, M., Feroci, A., Ferrari, M., Fiorini, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, M., Mastropietro, S., Mereghetti, E., Morelli, E., Moretti, A., Morselli, L., Pacciani, F., Perotti, G., Piano, P., Picozza, M., Pilia, G., Porrovecchio, M., Rapisarda, A., Rubini, S., Sabatini, P., Soffitta, E., Striani, V., Vittorini, D., Zanello, S., Colafrancesco, P., Giommi, C., Pittori, P., Santolamazza, F., Verrecchia, and L., Salotti

Subjects
MonteCarlo Simulations, Gamma-ray Satellites, Calibrations, Gamma-ray Satellites, Calibrations, MonteCarlo Simulations
Published
2012

24. First results on Gamma-ray Bursts localized with the INTEGRAL Burst Alert System

Author

S. Mereghetti

Subjects
Physics, Nuclear and High Energy Physics, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Cosmic ray, Field of view, Astrophysics, Gamma detection, Gamma-ray burst, Alert system, Atomic and Molecular Physics, and Optics
Abstract

The INTEGRAL Burst Alert System (IBAS) is continuously running software for the real time detection of Gamma Ray Bursts (GRBs) and the rapid distribution of their coordinates. During the first six months of operations, six GRBs have been detected in the field of view of the INTEGRAL instruments and localized by IBAS. Positions with an accuracy of a few arc minutes are currently distributed by IBAS to the community for follow-up observations within a few tens of seconds of the event.

Published
2004

25. The Extraordinary Gamma-Ray Flare Of The Blazar 3c 454.3

Author

E. Striani, S. Vercellone, M. Tavani, V. Vittorini, F. D’Ammando, I. Donnarumma, L. Pacciani, G. Pucella, A. Bulgarelli, M. Trifoglio, F. Gianotti, P. Giommi, A. Argan, G. Barbiellini, P. Caraveo, P. W. Cattaneo, A. W. Chen, E. Costa, G. De Paris, E. Del Monte, G. Di Cocco, Y. Evangelista, M. Feroci, A. Ferrari, M. Fiorini, F. Fuschino, M. Galli, A. Giuliani, M. Giusti, C. Labanti, F. Lazzarotto, P. Lipari, F. Longo, M. Marisaldi, S. Mereghetti, E. Morelli, E. Moretti, A. Morselli, A. Pellizzoni, F. Perotti, G. Piano, P. Picozza, M. Pilia, M. Prest, M. Rapisarda, A. Rappoldi, S. Sabatini, E. Scalise, P. Soffitta, A. Trois, E. Vallazza, A. Zambra, D. Zanello, C. Pittori, F. Verrecchia, P. Santolamazza, F. Lucarelli, S. Colafrancesco, L. A. Antonelli, L. Salotti, E., Striani, S., Vercellone, M., Tavani, V., Vittorini, F., D'Ammando, I., Donnarumma, L., Pacciani, G., Pucella, A., Bulgarelli, M., Trifoglio, F., Gianotti, P., Giommi, A., Argan, G., Barbiellini, P., Caraveo, P. W., Cattaneo, A. W., Chen, E., Costa, G. D., Pari, E. D., Monte, G. D., Cocco, Y., Evangelista, M., Feroci, A., Ferrari, M., Fiorini, F., Fuschino, M., Galli, A., Giuliani, M., Giusti, C., Labanti, F., Lazzarotto, P., Lipari, Longo, Francesco, M., Marisaldi, S., Mereghetti, E., Morelli, E., Moretti, A., Morselli, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, M., Prest, M., Rapisarda, A., Rappoldi, S., Sabatini, E., Scalise, P., Soffitta, A., Troi, E., Vallazza, A., Zambra, D., Zanello, C., Pittori, F., Verrecchia, P., Santolamazza, F., Lucarelli, S., Colafrancesco, L. A., Antonelli, L., Salotti, Striani E, Vercellone S, Tavani M, Vittorini V, DAmmando F, Donnarumma I, Pacciani L, Pucella G, Bulgarelli A, Trifoglio M, Gianotti F, Giommi P, Argan A, Barbiellini G, Caraveo P, Cattaneo PW, Chen AW, 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, Morelli E, 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 LA, and Salotti L

Subjects
Agile, Cosmology and Nongalactic Astrophysics (astro-ph.CO), blazar, gamma detection, Astrophysics::High Energy Astrophysical Phenomena, Flux, FOS: Physical sciences, Astrophysics, Type (model theory), Vela, High Energy Gamma-ray Astronomy, AGILE satellite, Active Galactic Nuclei, law.invention, Pulsar, law, Blazar, Physics, gamma rays: galaxies – quasars: individual (3C 454.3), Gamma ray, Astronomy and Astrophysics, Quasar, Space and Planetary Science, Astrophysics - Cosmology and Nongalactic Astrophysics, Flare
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

26. Multiwavelength Observations Of 3c 454.3. Ii. The Agile 2007 December Campaign

Author

I. Donnarumma, G. Pucella, V. Vittorini, F. D'Ammando, S. Vercellone, C. M. Raiteri, M. Villata, M. Perri, W. P. Chen, R. L. Smart, J. Kataoka, N. Kawai, Y. Mori, G. Tosti, D. Impiombato, T. Takahashi, R. Sato, M. Tavani, A. Bulgarelli, A. W. Chen, A. Giuliani, F. Longo, L. Pacciani, A. Argan, G. Barbiellini, F. Boffelli, P. Caraveo, P. W. Cattaneo, V. Cocco, T. Contessi, E. Costa, E. Del Monte, G. De Paris, G. Di Cocco, Y. Evangelista, M. Feroci, A. Ferrari, M. Fiorini, T. Froysland, M. Frutti, F. Fuschino, M. Galli, F. Gianotti, C. Labanti, I. Lapshov, F. Lazzarotto, P. Lipari, M. Marisaldi, M. Mastropietro, S. Mereghetti, E. Morelli, E. Moretti, A. Morselli, A. Pellizzoni, F. Perotti, G. Piano, P. Picozza, M. Pilia, G. Porrovecchio, M. Prest, M. Rapisarda, A. Rappoldi, A. Rubini, S. Sabatini, E. Scalise, P. Soffitta, E. Striani, M. Trifoglio, A. Trois, E. Vallazza, A. Zambra, D. Zanello, C. Pittori, P. Santolamazza, F. Verrecchia, P. Giommi, L. A. Antonelli, S. Colafrancesco, L. Salotti, Donnarumma I, Pucella G, Vittorini V, DAmmando F, Vercellone S, Raiteri CM, Villata M, Perri M, Chen WP, Smart RL, Kataoka J, Kawai N, Mori Y, Tosti G, Impiombato D, Takahashi T, Sato R, Tavani M, Bulgarelli A, Chen AW, Giuliani A, Longo F, Pacciani L, Argan A, Barbiellini G, Boffelli F, Caraveo P, Cattaneo PW, 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, Piano G, 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 A, Colafrancesco S, Salotti L, I., Donnarumma, G., Pucella, V., Vittorini, F., D'Ammando, S., Vercellone, C. M., Raiteri, M., Villata, M., Perri, W. P., Chen, R. L., Smart, J., Kataoka, N., Kawai, Y., Mori, G., Tosti, D., Impiombato, T., Takahashi, R., Sato, M., Tavani, A., Bulgarelli, A. W., Chen, A., Giuliani, Longo, Francesco, L., Pacciani, A., Argan, G., Barbiellini, F., Boffelli, P., Caraveo, P. W., Cattaneo, V., Cocco, T., Contessi, E., Costa, E. D., Monte, G. D., Pari, G. D., Cocco, Y., Evangelista, M., Feroci, A., Ferrari, M., Fiorini, T., Froysland, M., Frutti, F., Fuschino, M., Galli, F., Gianotti, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, M., Marisaldi, M., Mastropietro, S., Mereghetti, E., Morelli, E., Moretti, A., Morselli, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, G., Porrovecchio, M., Prest, M., Rapisarda, A., Rappoldi, A., Rubini, S., Sabatini, E., Scalise, P., Soffitta, E., Striani, M., Trifoglio, A., Troi, E., Vallazza, A., Zambra, D., Zanello, C., Pittori, P., Santolamazza, F., Verrecchia, P., Giommi, A., Antonelli, S., Colafrancesco, and L., Salotti

Subjects
Agile, Photon, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, Flux, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, High Energy Gamma-ray Astronomy, AGILE satellite, Active Galactic Nuclei, blazar, law.invention, law, Target of opportunity, quasars: general, multiwavelength campaign, Blazar, Astrophysics::Galaxy Astrophysics, Line (formation), Physics, High Energy Astrophysical Phenomena (astro-ph.HE), We report on the second Astrorivelatore Gamma a Immagini Leggero (AGILE) multiwavelength campaign of the blazar 3C 454.3 during the first half of 2007 December. This campaign involved AGILE, Spitzer, Swift, Suzaku, the Whole Earth Blazar Telescope (WEBT) consortium, the Rapid Eye Mount (REM), and the Multicolor Imaging Telescopes for Survey and Monstrous Explosions (MITSuME) telescopes, offering a broadband coverage that allowed for a simultaneous sampling of the synchrotron and inverse Compton (IC) emissions. The two-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 ~250 × 10^-8 photons cm^-2 s^-1 above 100 MeV, typical of its flaring states. The simultaneous optical and γ-ray monitoring allowed us to study the time lag associated with the variability in the two energy bands, resulting in a possible lsimone-day delay of the γ-ray emission with respect to the optical one. From the simultaneous optical and γ-ray fast flare detected on December 12, we can constrain the delay between the γ-ray and optical emissions within 12 hr. Moreover, we obtain three spectral energy distributions (SEDs) with simultaneous data for 2007 December 5, 13, and 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 = 106 K surrounding the jet, is required to account simultaneously for the softness of the synchrotron and the hardness of the IC emissions during those epochs, Astronomy and Astrophysics, galaxies: jets, radiation mechanisms: non-thermal, Corona, Synchrotron, Space and Planetary Science, galaxies: individual: 3C 454.3, Astrophysics - High Energy Astrophysical Phenomena, gamma rays: observations, Astrophysics - Cosmology and Nongalactic Astrophysics, Flare
Abstract

著者人数：79名, Accepted: 2009-10-29, 資料番号: SA1000754000

Published
2009

27. THE JUNE 2008 FLARE OF MARKARIAN 421 FROM OPTICAL TO TeV ENERGIES

Author

I. Donnarumma, V. Vittorini, S. Vercellone, E. Del Monte, M. Feroci, F. D'Ammando, L. Pacciani, A. W. Chen, M. Tavani, A. Bulgarelli, A. Giuliani, F. Longo, G. Pucella, A. Argan, G. Barbiellini, F. Boffelli, P. Caraveo, P. W. Cattaneo, V. Cocco, E. Costa, G. De Paris, G. Di Cocco, Y. Evangelista, M. Fiorini, T. Froysland, M. Frutti, F. Fuschino, M. Galli, F. Gianotti, C. Labanti, I. Lapshov, F. Lazzarotto, P. Lipari, M. Marisaldi, M. Mastropietro, S. Mereghetti, E. Morelli, A. Morselli, A. Pellizzoni, F. Perotti, P. Picozza, G. Porrovecchio, M. Prest, M. Rapisarda, A. Rappoldi, A. Rubini, P. Soffitta, M. Trifoglio, A. Trois, E. Vallazza, A. Zambra, D. Zanello, C. Pittori, P. Santolamazza, F. Verrecchia, P. Giommi, S. Colafrancesco, L. Salotti, M. Villata, C. M. Raiteri, W. P. Chen, N. V. Efimova, B. Jordan, T. S. Konstantinova, E. Koptelova, O. M. Kurtanidze, V. M. Larionov, J. A. Ros, A. C. Sadun, H. Anderhub, L. A. Antonelli, P. Antoranz, M. Backes, C. Baixeras, S. Balestra, J. A. Barrio, H. Bartko, D. Bastieri, J. Becerra González, J. K. Becker, W. Bednarek, K. Berger, E. Bernardini, A. Biland, R. K. Bock, G. Bonnoli, P. Bordas, D. Borla Tridon, V. Bosch-Ramon, T. Bretz, I. Britvitch, M. Camara, E. Carmona, A. Chilingarian, S. Commichau, J. L. Contreras, J. Cortina, M. T. Costado, S. Covino, V. Curtef, F. Dazzi, A. De Angelis, E. De Cea del Pozo, R. de los Reyes, B. De Lotto, M. De Maria, F. De Sabata, C. Delgado Mendez, A. Dominguez, D. Dorner, M. Doro, D. Elsaesser, M. Errando, D. Ferenc, E. Fernández, R. Firpo, M. V. Fonseca, L. Font, N. Galante, R. J. García López, M. Garczarczyk, M. Gaug, F. Goebel, D. Hadasch, M. Hayashida, A. Herrero, D. Höhne-Mönch, J. Hose, C. C. Hsu, S. Huber, T. Jogler, D. Kranich, A. La Barbera, A. Laille, E. Leonardo, E. Lindfors, S. Lombardi, M. López, E. Lorenz, P. Majumdar, G. Maneva, N. Mankuzhiyil, K. Mannheim, L. Maraschi, M. Mariotti, M. Martínez, D. Mazin, M. Meucci, M. Meyer, J. M. Miranda, R. Mirzoyan, J. Moldón, M. Moles, A. Moralejo, D. Nieto, K. Nilsson, J. Ninkovic, I. Oya, R. Paoletti, J. M. Paredes, M. Pasanen, D. Pascoli, F. Pauss, R. G. Pegna, M. A. Perez-Torres, M. Persic, L. Peruzzo, F. Prada, E. Prandini, N. Puchades, A. Raymers, W. Rhode, M. Ribó, J. Rico, M. Rissi, A. Robert, S. Rügamer, A. Saggion, T. Y. Saito, M. Salvati, M. Sanchez-Conde, P. Sartori, K. Satalecka, V. Scalzotto, V. Scapin, T. Schweizer, M. Shayduk, K. Shinozaki, S. N. Shore, N. Sidro, A. Sierpowska-Bartosik, A. Sillanpää, J. Sitarek, D. Sobczynska, F. Spanier, A. Stamerra, L. S. Stark, L. Takalo, F. Tavecchio, P. Temnikov, D. Tescaro, M. Teshima, M. Tluczykont, D. F. Torres, N. Turini, H. Vankov, A. Venturini, V. Vitale, R. M. Wagner, W. Wittek, V. Zabalza, F. Zandanel, R. Zanin, J. Zapatero, V. Acciari, E. Aliu, T. Arlen, M. Beilicke, W. Benbow, S. M. Bradbury, J. H. Buckley, V. Bugaev, Y. Butt, K. Byrum, A. Cannon, A. Cesarini, Y. C. Chow, L. Ciupik, P. Cogan, P. Colin, W. Cui, M. K. Daniel, R. Dickherber, C. Duke, T. Ergin, S. J. Fegan, J. P. Finley, G. Finnegan, P. Fortin, A. Furniss, D. Gall, G. H. Gillanders, R. Guenette, G. Gyuk, J. Grube, D. Hanna, J. Holder, D. Horan, C. M. Hui, T. Brian Humensky, A. Imran, P. Kaaret, N. Karlsson, M. Kertzman, D. Kieda, J. Kildea, A. Konopelko, H. Krawczynski, F. Krennrich, M. J. Lang, S. LeBohec, G. Maier, A. McCann, M. McCutcheon, A. Milovanovic, P. Moriarty, T. Nagai, R. A. Ong, A. N. Otte, D. Pandel, J. S. Perkins, A. Pichel, M. Pohl, K. Ragan, L. C. Reyes, P. T. Reynolds, E. Roache, H. J. Rose, M. Schroedter, G. H. Sembroski, A. W. Smith, D. Steele, S. P. Swordy, M. Theiling, J. A. Toner, L. Valcarcel, A. Varlotta, S. P. Wakely, J. E. Ward, T. C. Weekes, A. Weinstein, D. A. Williams, S. Wissel, M. Wood, B. Zitzer, I., Donnarumma, V., Vittorini, S., Vercellone, E. D., Monte, M., Feroci, F., D'Ammando, L., Pacciani, A. W., Chen, M., Tavani, A., Bulgarelli, A., Giuliani, Longo, Francesco, G., Pucella, A., Argan, G., Barbiellini, F., Boffelli, P., Caraveo, P. W., Cattaneo, V., Cocco, E., Costa, G. D., Pari, G. D., Cocco, Y., Evangelista, M., Fiorini, T., Froysland, M., Frutti, F., Fuschino, M., Galli, F., Gianotti, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, M., Marisaldi, M., Mastropietro, S., Mereghetti, E., Morelli, A., Morselli, A., Pellizzoni, F., Perotti, P., Picozza, G., Porrovecchio, M., Prest, M., Rapisarda, A., Rappoldi, A., Rubini, P., Soffitta, M., Trifoglio, A., Troi, E., Vallazza, A., Zambra, D., Zanello, C., Pittori, P., Santolamazza, F., Verrecchia, P., Giommi, S., Colafrancesco, L., Salotti, M., Villata, C. M., Raiteri, W. P., Chen, N. V., Efimova, B., Jordan, T. S., Konstantinova, E., Koptelova, O. M., Kurtanidze, V. M., Larionov, J. A., Ro, A. C., Sadun, H., Anderhub, L. A., Antonelli, P., Antoranz, M., Backe, C., Baixera, S., Balestra, J. A., Barrio, H., Bartko, D., Bastieri, J. B., Gonzalez, J. K., Becker, W., Bednarek, K., Berger, E., Bernardini, A., Biland, R. K., Bock, G., Bonnoli, P., Borda, D. B., Tridon, V., Bosch Ramon, T., Bretz, I., Britvitch, M., Camara, E., Carmona, A., Chilingarian, S., Commichau, J. L., Contrera, J., Cortina, M. T., Costado, S., Covino, V., Curtef, F., Dazzi, A. D., Angeli, E. D., Del Pozo, R. D., Reye, B. D., Lotto, M. D., Maria, F. D., Sabata, C. D., Mendez, A., Dominguez, D., Dorner, M., Doro, D., Elsaesser, M., Errando, D., Ferenc, E., Fernandez, R., Firpo, M. V., Fonseca, L., Font, N., Galante, R. J. G., Lopez, M., Garczarczyk, M., Gaug, F., Goebel, D., Hadasch, M., Hayashida, A., Herrero, D., Hohne Monch, J., Hose, C. C., Hsu, S., Huber, T., Jogler, D., Kranich, A. L., Barbera, A., Laille, E., Leonardo, E., Lindfor, S., Lombardi, M., Lopez, E., Lorenz, P., Majumdar, G., Maneva, N., Mankuzhiyil, K., Mannheim, L., Maraschi, M., Mariotti, M., Martinez, D., Mazin, M., Meucci, M., Meyer, J. M., Miranda, R., Mirzoyan, J., Moldon, M., Mole, A., Moralejo, D., Nieto, K., Nilsson, J., Ninkovic, I., Oya, R., Paoletti, J. M., Parede, M., Pasanen, D., Pascoli, F., Pau, R. G., Pegna, M. A., Perez Torre, M., Persic, L., Peruzzo, F., Prada, E., Prandini, N., Puchade, A., Raymer, W., Rhode, M., Ribo, J., Rico, M., Rissi, A., Robert, S., Rugamer, A., Saggion, T. Y., Saito, M., Salvati, M., Sanchez Conde, P., Sartori, K., Satalecka, V., Scalzotto, V., Scapin, T., Schweizer, M., Shayduk, K., Shinozaki, S. N., Shore, N., Sidro, A., Sierpowska Bartosik, A., Sillanpaa, J., Sitarek, D., Sobczynska, F., Spanier, A., Stamerra, L. S., Stark, L., Takalo, F., Tavecchio, P., Temnikov, D., Tescaro, M., Teshima, M., Tluczykont, D. F., Torre, N., Turini, H., Vankov, A., Venturini, V., Vitale, R. M., Wagner, W., Wittek, V., Zabalza, F., Zandanel, R., Zanin, J., Zapatero, V., Acciari, E., Aliu, T., Arlen, M., Beilicke, W., Benbow, S. M., Bradbury, J. H., Buckley, V., Bugaev, Y., Butt, K., Byrum, A., Cannon, A., Cesarini, Y. C., Chow, L., Ciupik, P., Cogan, P., Colin, W., Cui, M. K., Daniel, R., Dickherber, C., Duke, T., Ergin, S. J., Fegan, J. P., Finley, G., Finnegan, P., Fortin, A., Furni, D., Gall, G. H., Gillander, R., Guenette, G., Gyuk, J., Grube, D., Hanna, J., Holder, D., Horan, C. M., Hui, T. B., Humensky, A., Imran, P., Kaaret, N., Karlsson, M., Kertzman, D., Kieda, J., Kildea, A., Konopelko, H., Krawczynski, F., Krennrich, M. J., Lang, S., Lebohec, G., Maier, A., Mccann, M., Mccutcheon, A., Milovanovic, P., Moriarty, T., Nagai, R. A., Ong, A. N., Otte, D., Pandel, J. S., Perkin, A., Pichel, M., Pohl, K., Ragan, L. C., Reye, P. T., Reynold, E., Roache, H. J., Rose, M., Schroedter, G. H., Sembroski, A. W., Smith, D., Steele, S. P., Swordy, M., Theiling, J. A., Toner, L., Valcarcel, A., Varlotta, S. P., Wakely, J. E., Ward, T. C., Weeke, A., Weinstein, D. A., William, S., Wissel, M., Wood, B., Zitzer, Donnarumma I, Vittorini V, Vercellone S, del Monte E, Feroci M, DAmmando F, Pacciani L, Chen A W, Tavani M, Bulgarelli A, Giuliani A, Longo F, Pucella G, Argan A, Barbiellini G, Boffelli F, Caraveo P, Cattaneo P W, Cocco V, Costa E, DeParis G, Di Cocco G, Evangelista Y, 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, Picozza P, Porrovecchio G, Prest M, Rapisarda M, Rappoldi A, Rubini A, Soffitta 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, Chen W P, Efimova N V, Jordan B, Konstantinova T S, Koptelova E, Kurtanidze O M, Larionov V M, Ros J A, Sadun A C, Anderhub H, Antonelli L A, Antoranz P, Backes M, Baixeras C, Balestra S, Barrio J A, Bartko H, Bastieri D, González J Becerra, Becker J K, Bednarek W, Berger K, Bernardini E, Biland A, Bock R K, Bonnoli G, Bordas P, Tridon D Borla, Bosch-Ramon V, Bretz T, Britvitch I, Camara M, Carmona E, Chilingarian A, Commichau S, Contreras J L, Cortina J, Costado M T, Covino S, Curtef V, Dazzi F, DeAngelis A, DeCea del Pozo E, de los Reyes R, DeLotto B, DeMaria M, DeSabata F, Mendez C Delgado, Dominguez A, Dorner D, Doro M, Elsaesser D, Errando M, Ferenc D, Fernández E, Firpo R, Fonseca M V, Font L, Galante N, García López R J, Garczarczyk M, Gaug M, Goebel F, Hadasch D, Hayashida M, Herrero A, Höhne-Mönch D, Hose J, Hsu C C, Huber S, Jogler T, Kranich D, La Barbera A, Laille A, Leonardo E, Lindfors E, Lombardi S, López M, Lorenz E, Majumdar P, Maneva G, Mankuzhiyil N, Mannheim K, Maraschi L, Mariotti M, Martínez M, Mazin D, Meucci M, Meyer M, Miranda J M, Mirzoyan R, Moldón J, Moles M, Moralejo A, Nieto D, Nilsson K, Ninkovic J, Oya I, Paoletti R, Paredes J M, Pasanen M, Pascoli D, Pauss F, Pegna R G, Perez-Torres M A, Persic M, Peruzzo L, Prada F, Prandini E, Puchades N, Raymers A, Rhode W, Ribó M, Rico J, Rissi M, Robert A, Rügamer S, Saggion A, Saito T Y, Salvati M, Sanchez-Conde M, Sartori P, Satalecka K, Scalzotto V, Scapin V, Schweizer T, Shayduk M, Shinozaki K, Shore S N, Sidro N, Sierpowska-Bartosik A, Sillanpää A, Sitarek J, Sobczynska D, Spanier F, Stamerra A, Stark L S, Takalo L, Tavecchio F, Temnikov P, Tescaro D, Teshima M, Tluczykont M, Torres D F, Turini N, Vankov H, Venturini A, Vitale V, Wagner R M, Wittek W, Zabalza V, Zandanel F, Zanin R, Zapatero J, Acciari V, Aliu E, Arlen T, Beilicke M, Benbow W, Bradbury S M, Buckley J H, Bugaev V, Butt Y, Byrum K, Cannon A, Cesarini A, Chow Y C, Ciupik L, Cogan P, Colin P, Cui W, Daniel M K, Dickherber R, Duke C, Ergin T, Fegan S J, Finley J P, Finnegan G, Fortin P, Furniss A, Gall D, Gillanders G H, Guenette R, Gyuk G, Grube J, Hanna D, Holder J, Horan D, Hui C M, Humensky T Brian, Imran A, Kaaret P, Karlsson N, Kertzman M, Kieda D, Kildea J, Konopelko A, Krawczynski H, Krennrich F, Lang M J, LeBohec S, Maier G, McCann A, McCutcheon M, Milovanovic A, Moriarty P, Nagai T, Ong R A, Otte A N, Pandel D, Perkins J S, Pichel A, Pohl M, Ragan K, Reyes L C, Reynolds P T, Roache E, Rose H J, Schroedter M, Sembroski G H, Smith A W, Steele D, Swordy S P, Theiling M, Toner J A, Valcarcel L, Varlotta A, Wakely S P, Ward J E, Weekes T C, Weinstein A, Williams D A, Wissel S, Wood M, and Zitzer B

Subjects
campaign, Raigs còsmics, BL Lacertae: individual: Mrk421, galaxies: jets, X-Rays: Galaxies, gamma rays: observations, radiation mechanisms: nonthermal, bl-lacertae objects, blazars, Flux, Astrophysics, 01 natural sciences, 7. Clean energy, High Energy Gamma-ray Astronomy, law.invention, Raigs gamma, law, optical, MAGIC (telescope), Agile, blazr, X-ray, gamma, high energy observation, 010303 astronomy & astrophysics, webt, Physics, x-ray-spectra, Astrophysics (astro-ph), gamma-rays, lac objects, xmm-newton, Spectral energy distribution, Electrónica, Física nuclear, Raigs X, Electricidad, Flare, outburst, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, 0103 physical sciences, X-rays, BL Lacertae objects: individual (Mrk 421) – gamma rays: observations – galaxies: jets – radiation mechanisms: non-thermal – X-rays: galaxies, Blazar, Cosmic rays, 010308 nuclear & particles physics, Gamma rays, Astronomy and Astrophysics, Active Galactic Nuclei, radiation mechanisms: non-thermal, Light curve, Galaxies, Galàxies, MAGIC telescope, Space and Planetary Science, Very High Energy Gamma-ray Astronomy, ddc:520, AGILE satellite, bl lacertae objects: individual (mrk 421), Energy (signal processing), Lepton
Abstract

We present optical, X-ray, high energy ($\lessapprox 30$ GeV) and very high energy ($\gtrapprox 100$ GeV; VHE) observations of the high-frequency peaked blazar Mrk 421 taken between 2008 May 24 and June 23. A high energy $\gamma$-ray signal was detected by AGILE with \sqrt{TS}=4.5 on June 9--15, with $F(E>100 \mathrm{MeV})= 42^{+14}_{-12}\times 10^{-8}$ photons cm$^{-2}$ s$^{-1}$. This flaring state is brighter than the average flux observed by EGRET by a factor of $\sim$3, but still consistent with the highest EGRET flux. In hard X-rays (20-60 keV) SuperAGILE resolved a 5-day flare (June 9-15) peaking at $\sim$ 55 mCrab. SuperAGILE, RXTE/ASM and Swift/BAT data show a correlated flaring structure between soft and hard X-rays. Hints of the same flaring behavior are also detected in the simultaneous optical data provided by the GASP-WEBT. A Swift/XRT observation near the flaring maximum revealed the highest 2-10 keV flux ever observed from this source, of 2.6 $\times 10^{-9}$ erg cm$^{-2}$ s$^{-1}$ (i.e. > 100 mCrab). A peak synchrotron energy of $\sim$3 keV was derived, higher than typical values of $\sim$0.5-1 keV. VHE observations with MAGIC and VERITAS on June 6-8 show the flux peaking in a bright state, well correlated with the X-rays. This extraordinary set of simultaneous data, covering a twelve-decade spectral range, allowed for a deep analysis of the spectral energy distribution as well as of correlated light curves. The $\gamma$-ray flare can be interpreted within the framework of the synchrotron self-Compton model in terms of a rapid acceleration of leptons in the jet., Comment: accepted for publication in ApJL, 7 pages, 2 figures, 1 table

Published
2009

28. Three new X-ray emitting sdO stars discovered with Chandra

Author

N. La Palombara, P. Esposito(), S. Mereghetti(), and A. Tiengo()

Subjects
astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.SR, Astrophysics - Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics - High Energy Astrophysical Phenomena, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

X-ray observations of sdO stars are a useful tool to investigate their properties, but so far only two sdO stars were detected at X-rays. We observed a complete flux-limited sample of 19 sdO stars with the Chandra HRC-I camera to measure the count rate of the detected sources or to set a tight upper limit on it for the undetected sources. We obtained a robust detection of BD+37 1977 and Feige 34 and a marginal detection of BD+28 4211. The estimated luminosity of BD+37 1977 is above 10^31 erg/s, which is high enough to suggest the possible presence of an accreting compact companion. This possibility is unlikely for all the other targets (both detected and undetected), since in their case L_X < 10^30 erg/s. On the other hand, for all 19 targets the estimated value of L_X (or its upper limit) implies an X-ray/bolometric flux ratio that agrees with log(L_X/L_bol) = -6.7 +/- 0.5, which is the range of values typical of main-sequence and giant O stars. Therefore, for Feige 34 and BD+28 4211 the observed X-ray flux is most probably due to intrinsic emission. The same is possibile for the 16 undetected stars., 6 pages. Accepted for publication by Astronomy and Astrophysics

Published
2014

29. Properties of terrestrial gamma ray flashes detected by AGILE MCAL below 30\u2009MeV

Author

M. Marisaldi, F. Fuschino, M. Tavani, S. Dietrich, C. Price, M. Galli, C. Pittori, F. Verrecchia, S. Mereghetti, P. W. Cattaneo, S. Colafrancesco, A. Argan, C. Labanti, F. Longo, E. Del Monte, G. Barbiellini, A. Giuliani, A. Bulgarelli, R. Campana, A. Chen, F. Gianotti, P. Giommi, F. Lazzarotto, A. Morselli, M. Rapisarda, A. Rappoldi, M. Trifoglio, A. Trois, and S. Vercellone

Published
2014

30. Searching for New Be/X-ray Binaries in the Galactic Plane: the Case of GS 0834 – 43, 1WGA J1958.2+3232 and AXJ1820.5–1434

Author

A. Pizzella, V. F. Polcaro, Stefano Covino, Sergio Campana, Paul Roche, S. Mereghetti, Luigi Stella, G. L. Israel, and F. Verrecchia

Subjects
Physics, Pulsar, Observatory, ROSAT, X-ray, Astronomy, Astrophysics, Galactic plane, Sample (graphics)
Abstract

Over the last year we obtained X-ray (ROSAT, BeppoSAX and ASCA) and optical (at ESO and at the Astronomical Observatory of Loiano) to infra-red (AAO) observations of a sample of newly discovered X-ray pulsars. Among this sample we discovered the likely optical counterpart of three of them located in the Galactic plane: GS 0834–43, 1WGA J1958.2+3232 and AX J1820.5–1434.

Published
2000

31. The science of AGILE: part II

Author

C. Pittori, M. Tavani, G. Barbiellini, A. Argan, N. Auricchio, A. Bulgarelli, P. Caraveo, E. Celesti, A. Chen, V. Cocco, E. Costa, E. Del Monte, G. Di Cocco, G. Fedel, M. Feroci, M. Fiorini, T. Froysland, M. Galli, F. Gianotti, A. Giuliani, C. Labanti, I. Lapshov, F. Lazzarotto, P. Lipari, F. Longo, E. Mattaini, S. Mereghetti, E. Morelli, A. Morselli, L. Pacciani, A. Pellizzoni, F. Perotti, P. Picozza, C. Pontoni, G. Porrovecchio, B. Preger, M. Prest, M. Rapisarda, E. Rossi, A. Rubini, P. Soffitta, M. Trifoglio, E. Vallazza, S. Vercellone, D. Zanello, C., Pittori, M., Tavani, G., Barbiellini, A., Argan, N., Auricchio, A., Bulgarelli, P., Caraveo, E., Celesti, A., Chen, V., Cocco, E., Costa, Monte, E., Cocco, G., G., Fedel, M., Feroci, M., Fiorini, T., Froysland, M., Galli, F., Gianotti, A., Giuliani, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, Longo, Francesco, E., Mattaini, S., Mereghetti, E., Morelli, A., Morselli, L., Pacciani, A., Pellizzoni, F., Perotti, P., Picozza, C., Pontoni, G., Porrovecchio, B., Preger, M., Prest, M., Rapisarda, E., Rossi, A., Rubini, P., Soffitta, M., Trifoglio, E., Vallazza, S., Vercellone, and D., Zanello

Subjects
AGILE, Nuclear and High Energy Physics, gamma-ray astrophysics, satellite, track reconstruction, X and gamma imaging, point spread function, Atomic and Molecular Physics, and Optics
Published
2002

32. X-ray selected Wolf-Rayet stars: The discovery of Th35-42 and prospects for future X-ray surveys

Author

S. Mereghetti, T. Belloni, F. Haberl, and W. Voges

Abstract

The X-ray source 1E 1024.0-5732, serendipitously discovered with the Einstein Observatory, was previously interpreted as a rapidly spinning neutron star, accreting matter from its massive early-type companion, the emission-line star Th35-42. However, new ROSAT data do not support the presence of a neutron star in this source. A more likely scenario, also indicated by recent optical spectroscopy, involves X-ray emission from the colliding winds of a WR+O binary. Surprisingly, this star remained unnoticed during an extensive optical search for new Wolf-Rayet stars, carried out in this region of sky. Stimulated by the discovery of this first X-ray selected WR star, we have undertaken a search for similar objects in the data from the ROSAT All Sky Survey.

Published
1995

33. The first deep X-ray and optical observations of the closest isolated radio pulsar

Author

A. Tiengo, R. Mignani, A. De Luca, P. Esposito, S. Mereghetti, A. Pellizzoni, Marta Burgay, Nicolò D’Amico, Paolo Esposito, Alberto Pellizzoni, and Andrea Possenti

Subjects
Surface (mathematics), Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Astrophysics::High Energy Astrophysical Phenomena, Diagram, X-ray, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Neutron star, Gravitational lens, Pulsar, Position (vector), Astrophysics - High Energy Astrophysical Phenomena
Abstract

With a distance of 170 pc, PSR J2144-3933 is the closest isolated radio pulsar currently known. It is also the slowest and least energetic radio pulsar; indeed, its radio emission is difficult to account for with standard pulsar models, since its position in the P-Pdot diagram is far beyond typical "death lines". Here we present the first deep X-ray and optical observations of PSR J2144-3933, performed in 2009 with XMM-Newton and the VLT, from which we can set one of the most robust upper limits on the surface temperature of a neutron star. We have also explored the possibility of measuring the neutron star mass from the gravitational lensing effect on a background optical source., 4 pages, 3 figures; to appear in the Proceedings of the Pulsar Conference 2010, Chia, Sardinia (Italy), 10-15 October 2010

Published
2011

34. SGR 0418+5729: a low-magnetic-field magnetar

Author

P. Esposito, N. Rea, R. Turolla, G. L. Israel, S. Zane, L. Stella, C. Kouveliotou, S. Mereghetti, A. Tiengo, D. Götz, E. Göğüş, Marta Burgay, Nicolò D’Amico, Paolo Esposito, Alberto Pellizzoni, and Andrea Possenti

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), education.field_of_study, Astrophysics::High Energy Astrophysical Phenomena, Population, Flux, FOS: Physical sciences, Astrophysics, Magnetar, Magnetic field, Dipole, Neutron star, Pulsar, Astrophysics - High Energy Astrophysical Phenomena, Gamma-ray burst, education
Abstract

Soft gamma-ray repeaters and anomalous X-ray pulsars are a small (but growing) group of X-ray sources characterized by the emission of short bursts and by a large variability in their persistent flux. They are believed to be magnetars, i.e. neutron stars powered by extreme magnetic fields 1E14-1E15 G). We found evidence for a magnetar with a low magnetic field, SGR 0418+5729, recently detected after it emitted bursts similar to those of soft gamma-ray repeaters. New X-ray observations show that its dipolar magnetic field cannot be greater than 8E12 G, well in the range of ordinary radio pulsars, implying that a high surface dipolar magnetic field is not necessarily required for magnetar-like activity. The magnetar population may thus include objects with a wider range of magnetic-field strengths, ages and evolutionary stages than observed so far., Comment: 4 pages, 2 figures; to appear in the Proceedings of the Pulsar Conference 2010, Chia, Sardinia (Italy), 10-15 October 2010

Published
2011
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35. The observation of GRBs with AGILE and the interesting cases of GRB 090618 and GRB 100724B

Author

E. Del Monte, G. Barbiellini, F. Fuschino, A. Giuliani, F. Longo, M. Marisaldi, E. Moretti, M. Trifoglio, A. Argan, A. Bulgarelli, P. Caraveo, P. W. Cattaneo, A. Chen, E. Costa, G. Di Cocco, I. Donnarumma, Y. Evangelista, M. Feroci, M. Galli, F. Gianotti, C. Labanti, I. Lapshov, F. Lazzarotto, P. Lipari, S. Mereghetti, A. Morselli, L. Pacciani, A. Pellizzoni, F. Perotti, P. Picozza, M. Pilia, M. Prest, G. Pucella, M. Rapisarda, A. Rappoldi, P. Soffitta, M. Tavani, A. Trois, E. Vallazza, S. Vercellone, V. Vittorini, C. Pittori, L. Salotti, J. E. McEnery, J. L. Racusin, and N. Gehrels

Subjects
Physics, Astrophysics::High Energy Astrophysical Phenomena, Delayed onset, Gamma ray, Astronomy, Spectral analysis, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Gamma-ray burst, Redshift
Abstract

The AGILE satellite, in orbit since 2007, is localizing about 0.5 GRBs per month with the hard X‐ray imager SuperAGILE (18–60 keV) and is detecting around 1 GRB per week with the non‐imaging Minicalorimeter (0.35–100 MeV). Up to now the AGILE Gamma Ray Imaging Detector firmly detected four GRBs in the energy band between 20 MeV and few GeV. In this presentation we review the status of the GRBs observation with AGILE, we discuss the upper limits in the gamma‐ray band of the non‐detected events and we show some interesting bursts, especially GRB 090618 (bright in soft and hard‐X rays, optical and radio but lacking GeV emission) and GRB 100724B (with a bright GeV emission simultaneous to hard‐X rays without delayed onset).

Published
2011

36. Accretion of clumpy wind in supergiant HMXBs

Author

L. Ducci, L. Sidoli, S. Mereghetti, P. Romano, A. Paizis, A. Comastri, L. Angelini, and M. Cappi

Subjects
Stellar wind, Physics, Neutron star, Wind model, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Solar and Stellar Astrophysics, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Circular symmetry, Supergiant, Astrophysics::Galaxy Astrophysics, Accretion (astrophysics)
Abstract

We have developed a clumpy wind model for OB supergiants with both a spherical and a non spherical symmetry. We have explored the resulting effects of the accretion of such a wind onto a neutron star. We have applied this model to explain the observed X‐ray faring activity in both persistent and transient sources (Supergiant Fast X‐ray Transients).

Published
2010

37. The discovery of a massive white dwarf in the peculiar binary system HD 49798∕RX J0648.0–4418

Author

S. Mereghetti, A. Tiengo, P. Esposito, N. La Palombara, G. L. Israel, L. Stella, A. Comastri, L. Angelini, and M. Cappi

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, White dwarf, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Accretion (astrophysics), Common envelope, Supernova, Astrophysics - Solar and Stellar Astrophysics, Orbital motion, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Binary system, Astrophysics - High Energy Astrophysical Phenomena, Chandrasekhar limit, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Eclipse
Abstract

An XMM-Mewton observation performed in May 2008 has confirmed that the 13 seconds pulsations in the X-ray binary HD 49798/RX J0648.0-4418 are due to a rapidly rotating white dwarf. From the pulse time delays induced by the 1.55 days orbital motion, and the system's inclination, constrained by the duration of the X-ray eclipse discovered in this observation, we could derive a mass of 1.28+/-0.05 M_sun for the white dwarf. The future evolution of this post common envelope binary system will likely involve a new phase of mass accretion through Roche-lobe overflow that could drive the already massive white dwarf above the Chandrasekhar limit and produce a Type Ia supernova., Comment: Proceedings of the conference X-Ray Astronomy 2009, Present Status, multiwavelength approach and future perspectives, September 7 - 11, 2009, Bologna, Italy

Published
2010

38. Discovery of 2.6 s pulsations in SGR1627–41

Author

P. Esposito, A. Tiengo, A. De Luca, G. Israel, S. Mereghetti, N. Rea, R. Turolla, S. Zane, M. Burgay, A. Possenti, P. Romano, D. Götz, A. Comastri, L. Angelini, and M. Cappi

Subjects
Physics, Neutron star, Pulsar, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Solar and Stellar Astrophysics, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Magnetar
Abstract

Here we report on XMM‐Newton and Chandra observations that allowed us to measure the pulsation period and spin‐down rate of SGR 1627–41, the only known magnetar for which these key pieces of information were still missing.

Published
2010

39. The ‘soft’ excess in low-luminosity X-ray pulsars

Author

N. La Palombara, S. Mereghetti, L. Sidoli, P. Esposito, A. Tiengo, A. Comastri, L. Angelini, and M. Cappi

Subjects
Physics, Brightness, Neutron star, Pulsar, Astrophysics::High Energy Astrophysical Phenomena, X-ray binary, X-ray, Astronomy, Black-body radiation, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Radius, Luminosity
Abstract

We report on the XMM‐Newton observations of three persistent, long‐period and low‐luminosity Be/NS binary pulsars. In all of them the spectral analysis show a clear blackbody excess over the main power‐law component, which, unlike the other more luminous pulsars, is characterized by a high temperature (kTBB>1 keV) and a small radius (RBB

Published
2010

40. A low luminosity state in the massive X-ray binary SAX J0635+0533

Author

N. La Palombara, S. Mereghetti, A. Comastri, L. Angelini, and M. Cappi

Subjects
Physics, Brightness, Accretion (meteorology), Pulsar, Be star, Astrophysics::High Energy Astrophysical Phenomena, X-ray binary, Astronomy, Astrophysics, Binary system, Rotation, Luminosity
Abstract

We report on the XMM‐Newton observations of SAX J0635+0533, the fastest pulsar in a Be/NS binary system (Pspin = 33.8 ms). The precise localization provided by these observations confirms the association of SAX J0635+0533 with a Be star. The source was found, for the first time, in a low intensity state, a factor ∼30 lower than that seen in all previous observations. In view of this small luminosity, we reconsider the peculiarities of this source in both the accretion and rotation powered scenarios.

Published
2010

41. The spectacular X-ray echo of a magnetar burst

Author

A. Tiengo, G. Vianello, P. Esposito, S. Mereghetti, A. Comastri, L. Angelini, and M. Cappi

Subjects
Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Brightness, Scattering, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, Astrophysics, Magnetar, Astrophysics - Astrophysics of Galaxies, Radio telescope, Interstellar medium, Pulsar, Astrophysics of Galaxies (astro-ph.GA), Astrophysics - High Energy Astrophysical Phenomena, Cosmic dust
Abstract

The Anomalous X-ray Pulsar (AXP) 1E 1547.0-5408 reactivated in 2009 January with the emission of dozens of short bursts. Follow-up observations with Swift/XRT and XMM-Newton showed the presence of multiple expanding rings around the position of the AXP. These rings are due to scattering, by different layers of interstellar dust, of a very high fluence burst emitted by 1E 1547.0-5408 on 2009 January 22. Thanks to the exceptional brightness of the X-ray rings, we could carry out a detailed study of their spatial and spectral time evolution until 2009 February 4. This analysis gives the possibility to estimate the distance of 1E 1547.0-5408. We also derived constraints on the properties of the dust and of the burst responsible for this rare phenomenon., Comment: Proceedings of the conference X-Ray Astronomy 2009, Present Status, multiwavelength approach and future perspectives, September 7 - 11, 2009, Bologna, Italy

Published
2010
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42. An Ultra-Massive Fast-Spinning White Dwarf in a Peculiar Post Common Envelope Binary System

Author

S. Mereghetti, A. Tiengo, P. Esposito, N. La Palombara, G. L. Israel, L. Stella, Vicky Kologera, and Marc van der Sluys

Subjects
Physics, Astrophysics::High Energy Astrophysical Phenomena, Carbon detonation, Astronomy, White dwarf, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Binary pulsar, Black dwarf, Common envelope, Millisecond pulsar, Binary star, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Circumbinary planet, Astrophysics::Galaxy Astrophysics
Abstract

HD49798/RX J0648.0‐4418 is the only known X‐ray binary composed by a hot sub‐dwarf and an X‐ray pulsar. An XMM‐Newton observation performed in May 2008 has shown that the 13 seconds pulsations are due to a rapidly rotating white dwarf. From the pulse time delays induced by the 1.55 days orbital motion, and the system’s inclination, constrained by the duration of the X‐ray eclipse discovered in this observation, it has been possible to accurately measure the masses of the two stars of this post common envelope binary. With a mass of 1.28±0.05M⊙, RX J0648.0‐4418 is one of the most massive white dwarf and the one with the shortest spin period. The future evolution of this binary system will involve a new phase of mass accretion through Roche‐lobe overflow that could drive the already massive white dwarf above the Chandrasekhar limit and produce a Type Ia supernova or a millisecond pulsar.

Published
2010

43. The massive and fast-spinning white dwarf companion of HD 49798

Author

S. Mereghetti, A. Tiengo, P. Esposito, N. La Palombara, G. L. Israel, L. Stella, Klaus Werner, and T. Rauch

Subjects
Physics, Astrophysics::High Energy Astrophysical Phenomena, Carbon detonation, White dwarf, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Binary pulsar, Black dwarf, Pulsar, Millisecond pulsar, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Circumbinary planet, Blue dwarf, Astrophysics::Galaxy Astrophysics
Abstract

We discuss the properties of HD49798/RXJ0648.0–4418 the only known X‐ray binary composed by a hot sub‐dwarf and an X‐ray pulsar. We recently found evidence that the pulsations are due to a very massive (1.28 M⊙), fast rotating (13 s) white dwarf. The future evolution of this post common envelope binary will involve a new phase of mass accretion through Roche‐lobe overflow that could drive the white dwarf above the Chandrasekhar limit and produce a Type Ia supernova explosion or a millisecond pulsar.

Published
2010

44. SVOM: a new mission for Gamma-Ray Burst Studies

Author

D. Götz, J. Paul, S. Basa, J. Wei, S. N. Zhang, J.-L. Atteia, D. Barret, B. Cordier, A. Claret, J. Deng, X. Fan, J. Y. Hu, M. Huang, P. Mandrou, S. Mereghetti, Y. Qiu, B. Wu, Charles Meegan, Chryssa Kouveliotou, and Neil Gehrels

Subjects
Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Spectrometer, Gravitational wave, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy, Field of view, Quasar, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Cosmology, law.invention, Telescope, law, Astrophysics - Instrumentation and Methods for Astrophysics, Gamma-ray burst, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the SVOM (Space-based multi-band astronomical Variable Object Monitor) mission, that is being developed in cooperation between the Chinese National Space Agency (CNSA), the Chinese Academy of Science (CAS) and the French Space Agency (CNES). Its scientific objectives include the study of the GRB phenomenon, GRB physics and progenitors, cosmology, and fundamental physics. SVOM is designed to detect all known types of Gamma-Ray Bursts (GRBs), to provide fast and reliable GRB positions, to measure the broadband spectral characteristics and temporal properties of the GRB prompt emission. This will be obtained in first place thanks to a set of four space flown instruments. A wide field (~2 sr) coded mask telescope (ECLAIRs), operating in the 4-250 keV energy range, will provide the triggers and localizations, while a gamma-ray non-imaging spectrometer (GRM), sensitive in the 50 keV-5 MeV domain, will extend the prompt emission energy coverage. After a satellite slew, in order to place the GRB direction within field of view of the two narrow field instruments - a soft X-ray (XIAO), and a visible telescope (VT) - the GRB position will be refined and the study of the early phases of the GRB afterglow will be possible. A set of three ground based dedicated instruments, two robotic telescopes (GFTs) and a wide angle optical monitor (GWAC), will complement the space borne instruments. Thanks to the low energy trigger threshold (~4 keV) of the ECLAIRs, SVOM is ideally suited for the detection of soft, hence potentially most distant, GRBs. Its observing strategy is optimized to facilitate follow-up observations from the largest ground based facilities., Comment: Proceedings of the 6th Huntsville Symposium on Gamma-Ray Bursts (October 20-23 2008). Figures in colour with respect to the published version

Published
2009

45. AGILE View of TGFs

Author

F. Fuschino, F. Longo, M. Marisaldi, C. Labanti, M. Galli, A. Bulgarelli, F. Gianotti, M. Trifoglio, G. Di Cocco, A. Argan, G. Barbiellini, M. Basset, F. Boffelli, P. Caraveo, P. W. Cattaneo, A. W. Chen, V. Cocco, E. Costa, F. D’Ammando, E. Del Monte, G. De Paris, G. Di Persio, I. Donnarumma, Y. Evangelista, M. Feroci, A. Ferrari, M. Fiorini, L. Foggetta, T. Froysland, M. Frutti, A. Giuliani, I. Lapshov, F. Lazzarotto, F. Liello, P. Lipari, M. Mastropietro, E. Mattaini, F. Mauri, S. Mereghetti, A. Morselli, E. Moretti, L. Pacciani, A. Pellizzoni, F. Perotti, P. Picozza, C. Pontoni, G. Porrovecchio, M. Prest, G. Pucella, M. Rapisarda, A. Rappoldi, A. Rubini, P. Soffitta, M. Tavani, A. Trois, E. Vallazza, S. Vercellone, V. Vittorini, A. Zambra, D. Zanello, C. Pittori, F. Verrecchia, S. Cutini, D. Gasparrini, G. Fanari, B. Preger, P. Santolamazza, P. Giommi, L. A. Antonelli, S. Colafrancesco, L. Salotti, Norma B. Crosby, Tai-Yin Huang, and Michael J. Rycroft

Subjects
Physics, COSMIC cancer database, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Astrophysics::Instrumentation and Methods for Astrophysics, Gamma ray, Astronomy, Astrophysics, Lightning, Sky, Observatory, Thunderstorm, Satellite, Gamma-ray burst, media_common
Abstract

The AGILE Satellite [8] [9], launched the 23rd April 2007, is an italian mission devoted to high energy gamma‐ray astrophysics in the 30 MeV–50 GeV range, with a window in the hard‐X domain 18–60 keV. One of the on‐board detectors, the Mini‐Calorimeter (MCAL), was also designed to work as all sky transient monitor in the energy range 0.33–100 MeV. Though the main purpose of MCAL is the detection of cosmological Gamma‐Ray‐Bursts (GRB), MCAL detected transient events with a very brief duration, few msec, that does not match timing and spectral features of known cosmic GRB. These events more likely agree with the features of typical Terrestrial Gamma‐Ray Flashes as described in the literature and previously detected by the BATSE instrument onboard the Compton Gamma Ray Observatory and the RHESSI satellite. The characteristics of the detected TGF candidate events, as well as their geographical distribution will be presented and discussed.

Published
2009

46. Quiet but still bright: XMM-Newton observations of the soft gamma-ray repeater SGR0526-66

Author

A. Tiengo, P. Esposito, S. Mereghetti, G. L. Israel, L. Stella, R. Turolla, S. Zane, N. Rea, D. Götz, M. Feroci, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Photon, Gamma ray, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Magnetar, law.invention, Luminosity, Neutron star, Space and Planetary Science, law, Astrophysics - High Energy Astrophysical Phenomena, Large Magellanic Cloud, Supernova remnant, Flare
Abstract

SGR 0526-66 was the first soft gamma-ray repeater (SGR) from which a giant flare was detected in March 1979, suggesting the existence of magnetars, i.e. neutron stars powered by the decay of their extremely strong magnetic field. Since then, very little information has been obtained on this object, mainly because it has been burst-inactive since 1983 and the study of its persistent X-ray emission has been hampered by its large distance and its location in a X-ray bright supernova remnant in the Large Magellanic Cloud. Here we report on a comprehensive analysis of all the available XMM-Newton observations of SGR 0526-66. In particular, thanks to a deep observation taken in 2007, we measured its pulsation period (P = 8.0544 +/- 0.0002 s) 6 years after its latest detection by Chandra. This allowed us to detect for the first time a significant reduction of its spin-down rate. From a comparison with two shorter XMM-Newton observations performed in 2000 and 2001, we found no significant changes in the spectrum, which is well modelled by an absorbed power-law with nH = 4.6E+21 cm^-2 and photon index = 3.27. The high luminosity (about 4E+35 erg/s, in the 1-10 keV energy band) still observed about 25 years after the latest detection of bursting activity places SGR 0526-66 in the group of bright and persistent magnetar candidates., 5 pages, 3 figures (1 color) and 2 tables; Accepted for publication in MNRAS Letters

Published
2009

47. The Simbol-X Mission

Author

P. Ferrando, M. Arnaud, U. Briel, E. Cavazzuti, R. Clédassou, J. L. Counil, F. Fiore, P. Giommi, A. Goldwurm, O. Lamarle, P. Laurent, F. Lebrun, G. Malaguti, S. Mereghetti, G. Micela, G. Pareschi, M. Piermaria, J. P. Roques, A. Santangelo, G. Tagliaferri, Jéro^me Rodriguez, Phillippe Ferrando, APC - Astrophysique des Hautes Energies (APC - AHE), AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Dipartimento di Astronomia, Universita degli Studi di Bologna, Università di Bologna [Bologna] (UNIBO)-Università di Bologna [Bologna] (UNIBO), Centre National d'Études Spatiales [Toulouse] (CNES), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), INAF - Osservatorio Astronomico di Palermo (OAPa), Istituto Nazionale di Astrofisica (INAF), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Brera (OAB), Philippe Ferrando & Jerôme Rodriguez, SIMBOL-X, Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Dipartimento di Astronomia, Universita degli Studi di Bologna, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Astrophysics::High Energy Astrophysical Phenomena, Cosmic ray, 010502 geochemistry & geophysics, 7. Clean energy, 01 natural sciences, Particle detector, Domain (software engineering), law.invention, 010309 optics, Telescope, Acceleration, accretion, law, Observatory, 0103 physical sciences, clusters, Aerospace engineering, Cosmic rays, 0105 earth and related environmental sciences, and superclusters, Physics, Galaxy groups, large scale structure of the Universe, Spacecraft, business.industry, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Infall, Particle acceleration, X- and gamma-ray telescopes and instrumentation, and accretion disks, business, Astronomical and space-research instrumentation
Abstract

International audience; The elucidation of key questions in astrophysics, in particular those related to black hole physics and census, and to particle acceleration mechanisms, necessitates to develop new observational capabilities in the hard X-ray domain with performances several orders of magnitude better than presently available. Relying on two spacecrafts in a formation flying configuration, Simbol-X will provide the world-wide astrophysics community with a single optics long focal length telescope. This observatory will have unrivaled performances in the hard X-ray domain, up to ~80 keV, as well as very good characteristics in the soft X-ray domain, down to ~0.5 keV. The Simbol-X mission has successfully passed a phase A study, jointly conducted by CNES and ASI, with the participation of German laboratories. It is now entering phase B studies with the participation of new international partners, for a launch in 2015. We give in this paper a general overview of the mission, as consolidated at the start of phase B.

Published
2008

48. The X-ray pulsations of the isolated neutron star RX J1856.5–3754

Author

S. Mereghetti, A. Tiengo, C. Bassa, Z. Wang, A. Cumming, and V. M. Kaspi

Subjects
Physics, Neutron star, Pulsar, Astrophysics::High Energy Astrophysical Phenomena, ROSAT, X-ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics
Abstract

Using public data from the XMM‐Newton archive we have discovered pulsations at 7 s in the isolated neutron star RX J1856.5–3754, thus confirming that this source is similar to the other six thermally emitting, nearby neutron stars discovered in soft X‐rays with ROSAT. The pulsations are detected in eight XMM‐Newton observations spanning from April 2002 to March 2007. Using the two latest observations, reported here for the first time, we derive a new upper limit of Ṗ

Published
2008

49. AGILE and the Gamma-Ray Bursts

Author

M. Tavani, A. Argan, G. Barbiellini, A. Bulgarelli, P. Cattaneo, P. Caraveo, A. Chen, E. Costa, G. De Paris, E. Del Monte, G. Di Cocco, I. Donnarumma, Y. Evangelista, M. Feroci, F. Fuschino, M. Galli, F. Gianotti, A. Giuliani, C. Labanti, I. Lapshov, F. Lazzarotto, P. Lipari, F. Longo, M. Marisaldi, S. Mereghetti, A. Morselli, A. Pellizzoni, F. Perotti, P. Picozza, M. Prest, G. Pucella, M. Rapisarda, P. Soffitta, M. Trifoglio, A. Trois, E. Vallazza, S. Vercellone, V. Vittorini, A. Zambra, P. Giommi, C. Pittori, B. Preger, F. Verrecchia, L. A. Antonelli, L. Salotti, M. Galassi, David Palmer, and Ed Fenimore

Subjects
Physics, Calorimeter (particle physics), Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Astronomy, Field of view, Gamma-ray astronomy, Astrophysics, Universe, Orbit (dynamics), Angular resolution, Satellite, Gamma-ray burst, media_common
Abstract

AGILE is an ASI high‐energy astrophysics mission dedicated to the observation of the Universe. The satellite was successfully launched on April 23, 2007 to a quasi equatorial low‐background orbit. The AGILE instrument is very compact and light (∼100 kg): a gamma‐ray imager (sensitive in the energy band 30 MeV–50 GeV) is the central part of the instrument that includes also a light hard X‐ray imager (18–60 keV) positioned on top of the instrument, and an omnidirectional Calorimeter (350 keV–100 MeV). AGILE is aimed at the study of the most energetic phenomena of our Universe including AGNs, GRBs, Galactic sources and transients. For the first time in gamma‐ray astrophysics, AGILE reaches a field of view of about 3 sr with excellent angular resolution and good sensitivity. The unique combination of a hard X‐ray imager and a gamma‐ray imager is ideal for GRB and transient studies that constitute a crucial part of the AGILE scientific program. We summarize here the main characteristics of the GRB broad‐band d...

Published
2008

50. The first Suzaku observation of SGR 1806-20

Author

P. Esposito, A. Tiengo, S. Zane, R. Turolla, S. Mereghetti, D. Götz, G. L. Israel, N. Rea, C. Bassa, Z. Wang, A. Cumming, and V. M. Kaspi

Subjects
Physics, Spectral properties, Astrophysics (astro-ph), Flux, FOS: Physical sciences, Context (language use), Astrophysics, Magnetar, law.invention, Neutron star, Pulsar, law, Flare
Abstract

The soft gamma-ray repeater SGR 1806-20 has been attracting a lot of attention owing to the fact that in December 2004 it emitted the most powerful giant flare ever observed. Here we present the results of the first Suzaku observation of SGR 1806-20, that seems to have reached a state characterized by a flux close to the pre-flare level and by a relatively soft spectrum. Despite this, the source remained quite active, as testified by several short bursts observed by Suzaku. We discuss the broadband spectral properties of SGR 1806-20 in the context of the magnetar model, considering its recent theoretical developments., 3 pages, 1 figure. Proceedings of the conference "40 Years of Pulsars, Millisecond Pulsars, Magnetars and More", Montreal, August 12-17 2007. AIP, in press

Published
2007

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