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233 results on '"In T Zand, J. J. M."'

1. Radiation Tolerance of Low-Noise Photoreceivers for the LISA Space Mission

Author

Colcombet, P., Dinu-Jaeger, N., Inguimbert, C., Nuns, T., Bruhier, S., Christensen, N., Hofverberg, P., van Bakel, N., van Beuzekom, M., Mistry, T., Visser, G., Pascucci, D., Izumi, K., Komori, K., Heinzel, G., Fernandez Barranco, G., in t Zand, J. J. M., Laubert, P., and Frericks, M.

Abstract

This study investigates the effects of space environmental radiation on the performance of In0.53Ga0.47As quadrant photodiodes (QPDs) and assesses their suitability for the laser interferometer space antenna (LISA) mission. QPDs of 1.0-, 1.5-, and 2.0-mm diameter were irradiated with 20- and 60-MeV protons, 0.5- and 1-MeV electrons, and Co60 gamma rays. An exposure corresponding to a displacement damage equivalent fluence (DDEF) of $1.0\times 10+ 12 $ p/cm2 for 20- and 60-MeV protons and a total ionizing dose (TID) of 237 krad were applied, exceeding the radiation requirements for the LISA mission by a factor of approximately 5. Experiments were conducted to measure changes in QPD dark current, capacitance, and responsivity. The QPDs were integrated with a low-noise dc-coupled transimpedance amplifier (TIA) to form the quadrant photoreceiver (QPR). QPR noise and performance in an interferometric system like LISA were also performed. Although radiation impacted their dark current and responsivity, almost all QPDs met LISA’s validation criteria and did not demonstrate any critical failure. These findings suggest that the tested QPDs are promising candidates for LISA and other space-based missions.

Published
2024
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2. A catalogue of unusually long thermonuclear bursts on neutron stars.

Author

Alizai, K, Chenevez, J, Cumming, A, Degenaar, N, Falanga, M, Galloway, D K, in 't Zand, J J M, Jaisawal, G K, Keek, L, Kuulkers, E, Lampe, N, Schatz, H, and Serino, M

Subjects
NEUTRON stars, X-ray bursts, X-ray binaries, GAMMA ray bursts, CATALOGS, STELLAR photospheres, CATALOGING
Abstract

Rare, energetic (long) thermonuclear (Type I) X-ray bursts are classified either as intermediate-duration or 'supern' bursts, based on their duration. Intermediate-duration bursts lasting a few to tens of minutes are thought to arise from the thermonuclear runaway of a relatively thick (≈1010 g cm−2) helium layer, while superbursts lasting hours are attributed to the detonation of an underlying carbon layer. We present a catalogue of 84 long thermonuclear bursts from 40 low-mass X-ray binaries, and defined from a new set of criteria distinguishing them from the more frequent short bursts. The three criteria are: (1) a total energy release longer than 1040 erg, (2) a photospheric radius expansion phase longer than 10 s, and (3) a burst time-scale longer than 70 s. This work is based on a comprehensive systematic analysis of 70 bursts found with INTEGRAL, RXTE, Swift, BeppoSAX, MAXI , and NICER , as well as 14 long bursts from the literature that were detected with earlier generations of X-ray instruments. For each burst, we measure its peak flux and fluence, which eventually allows us to confirm the distinction between intermediate-duration bursts and superbursts. Additionally, we list 18 bursts that only partially meet the above inclusion criteria, possibly bridging the gap between normal and intermediate-duration bursts. With this catalogue, we significantly increase the number of long-duration bursts included in the MINBAR and thereby provide a substantial sample of these rare X-ray bursts for further study. [ABSTRACT FROM AUTHOR]

Published
2023
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4. eXTP: Enhanced X-Ray Timing and Polarimetry Mission

Author

Zhang, S. N, Feroci, M, Santangelo, A, Dong, Y. W, Feng, H, Lu, F. J, Nandra, K, Wang, Z. S, Zhang, S, Bozzo, E, Brandt, S, De Rosa, A, Gou, L. J, Hernanz, M, Van der Klis, M, LI, X. D, Liu, Y, Orleanski, P, Pareschi, G, Pohl, M, Poutanen, J, Qu, J. L, Schanne, S, Stella, L, Uttley, P, Watts, A, Xu, R. X, Yu, W. F, In 't Zand, J. J. M, Zane, S, Alvarez, L, Amati, L, Baldini, L, Bambi, C, Basso, S, Bhattacharyya, S, Bellazzini, R, Belloni, T, Bellutti, P, Bianchi, S, Brez, A, Bursa, M, Burwitz, V, Tagliaferri, G, Budtz-Jorgensen, C, Caiazzo, I, Campana, R, Cao, X. L, Casella, P, Chen, C. Y, Chen, L, Chen, T. X, Chen, Y, Chen, Y. P, Civitani, M, Coti Zelati, F, Cui, W, Cui, W. W, Dai, Z. G, Del Monte, E, De Martino, D, Di Cosimo, S, Diebold, S, Dovciak, M, Donnarumma, I, Doroshenko, V, Esposito, P, Evangelista, Y, Favre, Y, Friedrich, P, Fuschino, F, Galvez, J. L, Gao, Z. L, Ge, M. Y, Gevin, O, Goetz, D, Han, D. W, Heyl, J, Horak, J, Hu, W, Huang, F, Huang, Q. S, Hudec, R, Huppenkothen. D, Israel, G. L, Ingram, A, Karas, V, Karelin, D, Jenke, P. A, Ji, L, Kennedy, T, Korpela, S, Kunneriath, D, Labanti, C, Li, G, Li, X, Li, Z. S, Liang, E. W, Limousin, O, Lin, L, Ling, Z. X, Liu, H. B, Liu, H. W, Liu, Z, Lu, B, Lund, N, Lai, D, Luo, B, Luo, T, Ma, B, Mahmoodifar, S, Marisaldi, M, Martindale, A, Meidinger, N, Men, Y. P, Michalska, M, Mignani, R, Minuti, M, Motta, S, Muleri, F, Neilsen, J, Orlandini, M, Pan, A. T, Patruno, A, Perinati, E, Picciotto, A, Piemonte, C, Pinchera, M, Rachevski, A, Rapisarda, M, Rea, N, Rossi, E. M. R, Rubini, A, Sala, G, Shu, X. W, Sgro, C, Shen, Z. X, Soffitta, P, Song, L. M, Spandre, G, Stratta, G, Strohmayer, T. E, Sun, L, Svoboda, J, Tenzer, C, Tong, H, Taverna, R, Torok, G, Turolla, R, Vacchi, A, Wang, J, Wang, J. X, Walton, D, Wang, K, Wang, J. F, Wang, R. J, Wang, Y. F, Weng, S. S, Wilms, J, Winter, B, Wu, X, Wu, X. F, Xiong, S. L, Xu, Y. P, Xue, Y. Q, Yan, Z, Yang, S, Yang, X, Yang, Y. J, Yuan, F, Yuan, W. M, Yuan, Y. F, Zampa, G, Zampa, N, Zdziarski, A, Zhang, C, Zhang, C. L, Zhang, L, Zhang, X, Zhang, Z, Zhang, W. D, Zheng, S. J, Zhou, P, and Zhou, X. L

Subjects
Astrophysics
Abstract

eXTP is a science mission designed to study the state of matter under extreme conditions of density, gravity and magnetism. Primary goals are the determination of the equation of state of matter at supra-nuclear density, the measurement of QED effects in highly magnetized star, and the study of accretion in the strong-field regime of gravity. Primary targets include isolated and binary neutron stars, strong magnetic field systems like magnetars, and stellar-mass and supermassive black holes. The mission carries a unique and unprecedented suite of state-of-the-art scientific instruments enabling for the first time ever the simultaneous spectral-timing-polarimetry studies of cosmic sources in the energy range from 0.5-30 keV (and beyond). Key elements of the payload are: the Spectroscopic Focusing Array (SFA) - a set of 11 X-ray optics for a total effective area of approx. 0.9 m(exp. 2) and 0.6 m(exp. 2) at 2 keV and 6 keV respectively, equipped with Silicon Drift Detectors offering less than 180 eV spectral resolution; the Large Area Detector (LAD) - a deployable set of 640 Silicon Drift Detectors, for a total effective area of approx. 3.4 m(exp. 2), between 6 and 10 keV, and spectral resolution better than 250 eV; the Polarimetry Focusing Array (PFA) - a set of 2 X-ray telescope, for a total effective area of 250 cm(exp. 2) at 2 keV, equipped with imaging gas pixel photoelectric polarimeters; the Wide Field Monitor (WFM) - a set of 3 coded mask wide field units, equipped with position-sensitive Silicon Drift Detectors, each covering a 90 degrees x 90 degrees field of view. The eXTP international consortium includes major institutions of the Chinese Academy of Sciences and Universities in China, as well as major institutions in several European countries and the United States. The predecessor of eXTP, the XTP mission concept, has been selected and funded as one of the so-called background missions in the Strategic Priority Space Science Program of the Chinese Academy of Sciences since 2011. The strong European participation has significantly enhanced the scientific capabilities of eXTP. The planned launch date of the mission is earlier than 2025.

Published
2016
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6. NICER detection of strong photospheric expansion during a thermonuclear x-ray burst from 4U 1820-30

Author

Massachusetts Institute of Technology. Department of Physics, MIT Kavli Institute for Astrophysics and Space Research, Keek, L., Arzoumanian, Z., Chakrabarty, Deepto, Chenevez, J., Gendreau, K. C., Guillot, S., Güver, T., Homan, J., Jaisawal, G. K., LaMarr, Beverly J., Lamb, F. K., Mahmoodifar, S., Markwardt, C. B., Okajima, T., Strohmayer, T. E., in ’t Zand, J. J. M., Massachusetts Institute of Technology. Department of Physics, MIT Kavli Institute for Astrophysics and Space Research, Keek, L., Arzoumanian, Z., Chakrabarty, Deepto, Chenevez, J., Gendreau, K. C., Guillot, S., Güver, T., Homan, J., Jaisawal, G. K., LaMarr, Beverly J., Lamb, F. K., Mahmoodifar, S., Markwardt, C. B., Okajima, T., Strohmayer, T. E., and in ’t Zand, J. J. M.

Abstract

The Neutron Star Interior Composition Explorer (NICER) on the International Space Station (ISS) observed strong photospheric expansion of the neutron star in 4U 1820-30 during a Type I X-ray burst. A thermonuclear helium flash in the star's envelope powered a burst that reached the Eddington limit. Radiation pressure pushed the photosphere out to ∼200 km, while the blackbody temperature dropped to 0.45 keV. Previous observations of similar bursts were performed with instruments that are sensitive only above 3 keV, and the burst signal was weak at low temperatures. NICER's 0.2-12 keV passband enables the first complete detailed observation of strong expansion bursts. The strong expansion lasted only 0.6 s, and was followed by moderate expansion with a 20 km apparent radius, before the photosphere finally settled back down at 3 s after the burst onset. In addition to thermal emission from the neutron star, the NICER spectra reveal a second component that is well fit by optically thick Comptonization. During the strong expansion, this component is six times brighter than prior to the burst, and it accounts for 71% of the flux. In the moderate expansion phase, the Comptonization flux drops, while the thermal component brightens, and the total flux remains constant at the Eddington limit. We speculate that the thermal emission is reprocessed in the accretion environment to form the Comptonization component, and that changes in the covering fraction of the star explain the evolution of the relative contributions to the total flux. ©2018

Published
2020

7. Erratum: The Swift Bulge Survey: optical and near-IR follow-up featuring a likely symbiotic X-ray binary & a focused wind CV

Author

Shaw, A W, primary, Heinke, C O, primary, Maccarone, T J, primary, Sivakoff, G R, primary, Strader, J, primary, Bahramian, A, primary, Degenaar, N, primary, Kennea, J A, primary, Kuulkers, E, primary, Rau, A, primary, Rivera Sandoval, L E, primary, Shishkovsky, L, primary, Swihart, S J, primary, Tetarenko, A J, primary, Wijnands, R, primary, and in ’t Zand, J J M, primary

Published
2020
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8. The Swift Bulge Survey: optical and near-IR follow-up featuring a likely symbiotic X-ray binary and a focused wind CV

Author

Shaw, A W, primary, Heinke, C O, additional, Maccarone, T J, additional, Sivakoff, G R, additional, Strader, J, additional, Bahramian, A, additional, Degenaar, N, additional, Kennea, J A, additional, Kuulkers, E, additional, Rau, A, additional, Rivera Sandoval, L E, additional, Shishkovsky, L, additional, Swihart, S J, additional, Tetarenko, A J, additional, Wijnands, R, additional, and in ’t Zand, J J M, additional

Published
2020
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10. Observatory science with eXTP

Author

Royal Society (UK), European Research Council, European Commission, National Natural Science Foundation of China, National Basic Research Program (China), National Science Foundation (US), Ministerio de Economía y Competitividad (España), Polish Academy of Sciences, in´t Zand, J. J. M., Bozz, Enrico, Qu, J. L., Li, X. D., Amati, L., Chen, Yang, Donnarumma, I., Doroshenko, V., Drake, S. A., Hernanz, Margarita, Jenke, P. A., Maccarone, T. J., Mahmoodifar, S., De Martino, D., De Rosa, Alessandra, Rossi, E. M., Rowlinson, A., Sala, Gloria, Stratta, G., Tauris, T. M., Wilms, Jörn, Wu, X. F., Zhou, P., Agudo, Iván, Atteia, J. L., Andersson, N., Baglio, Maria Cristina, Ballantyne, D. R., Baykal, A., Behar, E., Belloni, T., Bhattacharyya, S., Bianchi, Stefano, Bilous, A., Blay, Pere, Braga, J., Brandt, S., Brown, E. F., Bucciantini, N., Burderi, L., Cackett, E.M., Campana, R., Campana, Sergio, Casella, P., Cavecchi, Y., Chambers, F., Chen, L., Chen, Y. P., Iwasawa, Kazushi, Izzo, L., José, Jordi, Linares, Manuel, Miniutti, Giovanni, Pérez-Torres, Miguel A., Rodríguez-Gil, Pablo, Torres, Diego F., Altamirano, Diego, Royal Society (UK), European Research Council, European Commission, National Natural Science Foundation of China, National Basic Research Program (China), National Science Foundation (US), Ministerio de Economía y Competitividad (España), Polish Academy of Sciences, in´t Zand, J. J. M., Bozz, Enrico, Qu, J. L., Li, X. D., Amati, L., Chen, Yang, Donnarumma, I., Doroshenko, V., Drake, S. A., Hernanz, Margarita, Jenke, P. A., Maccarone, T. J., Mahmoodifar, S., De Martino, D., De Rosa, Alessandra, Rossi, E. M., Rowlinson, A., Sala, Gloria, Stratta, G., Tauris, T. M., Wilms, Jörn, Wu, X. F., Zhou, P., Agudo, Iván, Atteia, J. L., Andersson, N., Baglio, Maria Cristina, Ballantyne, D. R., Baykal, A., Behar, E., Belloni, T., Bhattacharyya, S., Bianchi, Stefano, Bilous, A., Blay, Pere, Braga, J., Brandt, S., Brown, E. F., Bucciantini, N., Burderi, L., Cackett, E.M., Campana, R., Campana, Sergio, Casella, P., Cavecchi, Y., Chambers, F., Chen, L., Chen, Y. P., Iwasawa, Kazushi, Izzo, L., José, Jordi, Linares, Manuel, Miniutti, Giovanni, Pérez-Torres, Miguel A., Rodríguez-Gil, Pablo, Torres, Diego F., and Altamirano, Diego

Abstract

In this White Paper we present the potential of the enhanced X-ray Timing and Polarimetry (eXTP) mission for studies related to Observatory Science targets. These include flaring stars, supernova remnants, accreting white dwarfs, low and high mass X-ray binaries, radio quiet and radio loud active galactic nuclei, tidal disruption events, and gamma-ray bursts. eXTP will be excellently suited to study one common aspect of these objects: their often transient nature. Developed by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Science, the eXTP mission is expected to be launched in the mid 2020s.© 2018, Science China Press and Springer-Verlag GmbH Germany, part of Springer Nature.

Published
2019

11. NICER Discovers Spectral Lines during Photospheric Radius Expansion Bursts from 4U 1820−30: Evidence for Burst-driven Winds

Author

Strohmayer, T. E., Altamirano, D., Arzoumanian, Z., Bult, P. M., Chakrabarty, D., Chenevez, J., Fabian, A. C., Gendreau, K. C., Guillot, S., In 't Zand, J. J. M., Jaisawal, G. K., Keek, L., Kosec, P., Ludlam, R. M., Mahmoodifar, S., Malacaria, Christian, Miller, J. M., Strohmayer, T. E., Altamirano, D., Arzoumanian, Z., Bult, P. M., Chakrabarty, D., Chenevez, J., Fabian, A. C., Gendreau, K. C., Guillot, S., In 't Zand, J. J. M., Jaisawal, G. K., Keek, L., Kosec, P., Ludlam, R. M., Mahmoodifar, S., Malacaria, Christian, and Miller, J. M.

Abstract

We report the discovery with the Neutron Star Interior Composition Explorer (NICER) of narrow emission and absorption lines during photospheric radius expansion (PRE) X-ray bursts from the ultracompact binary 4U 1820−30. NICER observed 4U 1820−30 in 2017 August during a low-flux, hard spectral state, accumulating about 60 ks of exposure. Five thermonuclear X-ray bursts were detected, of which four showed clear signs of PRE. We extracted spectra during the PRE phases and fit each to a model that includes a Comptonized component to describe the accretion-driven emission, and a blackbody for the burst thermal radiation. The temperature and spherical emitting radius of the fitted blackbody are used to assess the strength of PRE in each burst. The two strongest PRE bursts (burst pair 1) had blackbody temperatures of ≈0.6 keV and emitting radii of ≈100 km (at a distance of 8.4 kpc). The other two bursts (burst pair 2) had higher temperatures (≈0.67 keV) and smaller radii (≈75 km). All of the PRE bursts show evidence of narrow line emission near 1 keV. By coadding the PRE phase spectra of burst pairs 1 and, separately, 2, we find, in both coadded spectra, significant, narrow, spectral features near 1.0 (emission), 1.7, and 3.0 keV (both in absorption). Remarkably, all the fitted line centroids in the coadded spectrum of burst pair 1 appear systematically blueshifted by a factor of 1.046 ± 0.006 compared to the centroids of pair 2, strongly indicative of a gravitational shift, a wind-induced blueshift, or more likely some combination of both effects. The observed shifts are consistent with this scenario in that the stronger PRE bursts in pair 1 reach larger photospheric radii, and thus have weaker gravitational redshifts, and they generate faster outflows, yielding higher blueshifts. We discuss possible elemental identifications for the observed features in the context of recent burst-driven wind models.

Published
2019

12. NICER Discovers Spectral Lines during Photospheric Radius Expansion Bursts from 4U 1820−30: Evidence for Burst-driven Winds

Author

Strohmayer, T. E., primary, Altamirano, D., additional, Arzoumanian, Z., additional, Bult, P. M., additional, Chakrabarty, D., additional, Chenevez, J., additional, Fabian, A. C., additional, Gendreau, K. C., additional, Guillot, S., additional, in ’t Zand, J. J. M., additional, Jaisawal, G. K., additional, Keek, L., additional, Kosec, P., additional, Ludlam, R. M., additional, Mahmoodifar, S., additional, Malacaria, Christian, additional, and Miller, J. M., additional

Published
2019
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15. NICER Detection of Strong Photospheric Expansion during a Thermonuclear X-Ray Burst from 4U 1820–30

Author

Keek, L., Arzoumanian, Z., Chakrabarty, D., Chenevez, J., Gendreau, K. C., Guillot, S., Güver, T., Homan, J., Jaisawal, G. K., LaMarr, B., Lamb, F. K., Mahmoodifar, S., Markwardt, C. B., Okajima, T., Strohmayer, T. E., in ’t Zand, J. J. M., Keek, L., Arzoumanian, Z., Chakrabarty, D., Chenevez, J., Gendreau, K. C., Guillot, S., Güver, T., Homan, J., Jaisawal, G. K., LaMarr, B., Lamb, F. K., Mahmoodifar, S., Markwardt, C. B., Okajima, T., Strohmayer, T. E., and in ’t Zand, J. J. M.

Abstract

The Neutron Star Interior Composition Explorer (NICER) on the International Space Station (ISS) observed strong photospheric expansion of the neutron star in 4U 1820–30 during a Type I X-ray burst. A thermonuclear helium flash in the star’s envelope powered a burst that reached the Eddington limit. Radiation pressure pushed the photosphere out to ∼200 km, while the blackbody temperature dropped to 0.45 keV. Previous observations of similar bursts were performed with instruments that are sensitive only above 3 keV, and the burst signal was weak at low temperatures. NICER's 0.2–12 keV passband enables the first complete detailed observation of strong expansion bursts. The strong expansion lasted only 0.6 s, and was followed by moderate expansion with a 20 km apparent radius, before the photosphere finally settled back down at 3 s after the burst onset. In addition to thermal emission from the neutron star, the NICER spectra reveal a second component that is well fit by optically thick Comptonization. During the strong expansion, this component is six times brighter than prior to the burst, and it accounts for 71% of the flux. In the moderate expansion phase, the Comptonization flux drops, while the thermal component brightens, and the total flux remains constant at the Eddington limit. We speculate that the thermal emission is reprocessed in the accretion environment to form the Comptonization component, and that changes in the covering fraction of the star explain the evolution of the relative contributions to the total flux.

Published
2018

17. NICER Detection of Strong Photospheric Expansion during a Thermonuclear X-Ray Burst from 4U 1820–30

Author

Keek, L., primary, Arzoumanian, Z., additional, Chakrabarty, D., additional, Chenevez, J., additional, Gendreau, K. C., additional, Guillot, S., additional, Güver, T., additional, Homan, J., additional, Jaisawal, G. K., additional, LaMarr, B., additional, Lamb, F. K., additional, Mahmoodifar, S., additional, Markwardt, C. B., additional, Okajima, T., additional, Strohmayer, T. E., additional, and in ’t Zand, J. J. M., additional

Published
2018
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20. Probing the emission physics and weak/soft population of Gamma-Ray Bursts with LOFT

Author

Amati, L., Stratta, G., Atteia, J. -L, Pasquale, M., Del Monte, E., Gendre, B., Götz, D., Guidorzi, C., Izzo, L., Kouveliotou, C., Osborne, J., Penacchioni, A. V., Romano, P., Sakamoto, T., Salvaterra, R., Schanne, S., In T Zand, J. J. M., Lucio Angelo Antonelli, Braga, J., Brandt, S., Bucciantini, N., Castro-Tirado, A., D Elia, V., Feroci, M., Fuschino, F., Guetta, D., Longo, F., Lyutikov, M., Maccarone, T., Mangano, V., Marisaldi, M., Mereghetti, S., O Brien, P., Rossi, E. M., Ryde, F., Soffitta, P., Troja, E., Wijers, R. A. M. J., and Zhang, B.

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

This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT for the study of gamma-ray bursts. For a summary, we refer to the paper., White Paper in Support of the Mission Concept of the Large Observatory for X-ray Timing

Published
2015

21. A SOFT X-RAY SPECTRAL EPISODE FOR THE CLOCKED BURSTER, GS 1826–24 AS MEASURED BYSWIFTANDNuSTAR

Author

Chenevez, J., primary, Galloway, D. K., additional, in ’t Zand, J. J. M., additional, Tomsick, J. A., additional, Barret, D., additional, Chakrabarty, D., additional, Fürst, F., additional, Boggs, S. E., additional, Christensen, F. E., additional, Craig, W. W., additional, Hailey, C. J., additional, Harrison, F. A., additional, Romano, P., additional, Stern, D., additional, and Zhang, W. W., additional

Published
2016
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22. The rapid decay of the optical emission from GRB 980326 and its possible implications

Author

Groot, P. J., Galama, T. J., Vreeswijk, P. M., Wijers, R. A. M. J., Pian, E., Palazzi, E., Paradijs, J., Kouveliotou, C., In T Zand, J. J. M., Heise, J., Robinson, C., Tanvir, N., Lidman, C., C.G. Tinney, Keane, M., Briggs, M., Hurley, K., Gonzalez, J. -F, Hall, P., Smith, M. G., Covarrubias, R., Jonker, P. G., Casares, J., Masetti, N., Frontera, F., Feroci, M., Piro, L., Costa, E., Smith, R., Jones, B., Windridge, D., Bland-Hawthorn, J., Veilleux, S., Garcia, M., Brown, W. R., Stanek, K. Z., Castro-Tirado, A. J., Gorosabel, J., Greiner, J., Jäger, K., Böhm, A., Fricke, K. J., Artificial intelligence, Economics, Tinbergen Institute, (Astro)-Particles Physics, and High Energy Astrophys. & Astropart. Phys (API, FNWI)

Subjects
Physics, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Optical decay, Power law, Space and Planetary Science, Spectral slope, Exponent, Optical emission spectroscopy, Gamma-ray burst, Constant (mathematics)
Abstract

We report the discovery of the optical counterpart to GRB 980326. Its rapid optical decay can be characterized by a power law with exponent -2.10 +/- 0.13 and a constant underlying source at R_c=25.5 +/- 0.5. Its optical colours 2.1 days after the burst imply a spectral slope of -0.66 +/- 0.70. The gamma-ray spectrum as observed with BATSE shows that it is among the 4% softest bursts ever recorded. We argue that the rapid optical decay may be a reason for the non-detection of some low-energy afterglows of GRBs., 13 pages, 3 Postscipt figures, Astrophysical Journal Letters, accepted May 29, 1998

Published
1998

23. The Large Observatory for X-ray Timing (LOFT)

Author

Feroci, M., Stella, L., Klis, M., Courvoisier, T. J. -L, Hernanz, M., Hudec, R., Santangelo, A., Walton, D., Zdziarski, A., Barret, D., Belloni, T., Braga, José, Brandt, S., Budtz-Jørgensen, C., Campana, S., Den Herder, J. -W, Huovelin, J., Israel, G. L., Pohl, M., Ray, P., Vacchi, A., Zane, S., Argan, A., Primo Attinà, Bertuccio, G., Bozzo, E., Campana, R., Chakrabarty, D., Costa, E., Rosa, A., Del Monte, E., Di Cosimo, S., Donnarumma, I., Evangelista, Y., Haas, D., Jonker, P., Korpela, S., Labanti, C., Malcovati, P., Mignani, R., Muleri, F., Rapisarda, M., Rashevsky, A., Rea, N., Rubini, A., Tenzer, C., Wilson-Hodge, C., Winter, B., Wood, K., Zampa, G., Zampa, N., Abramowicz, M. A., Alpar, M. A., Altamirano, D., Alvarez, J. M., Amati, L., Amoros, C., Antonelli, L. A., Artigue, R., Azzarello, P., Bachetti, M., Baldazzi, G., Barbera, M., Barbieri, C., Basa, S., Baykal, A., Belmont, R., Boirin, L., Bonvicini, V., Burderi, L., Bursa, M., Cabanac, C., Cackett, E., Caliandro, G. A., Casella, P., Chaty, S., Chenevez, J., Coe, M. J., Collura, A., Corongiu, A., Covino, S., Cusumano, G., D Amico, Frank, Dall Osso, S., Martino, D., Paris, G., Di Persio, G., Di Salvo, T., Done, C., Dovčiak, M., Drago, A., Ertan, U., Fabiani, S., Falanga, M., Fender, R., Ferrando, P., Della Monica Ferreira, D., Fraser, G., Frontera, F., Fuschino, F., Galvez, J. L., Gandhi, P., Giommi, P., Godet, O., Göǧüş, E., Goldwurm, A., Götz, D., Grassi, M., Guttridge, P., Hakala, P., Henri, G., Hermsen, W., Horak, J., Hornstrup, A., In T Zand, J. J. M., Isern, J., Kalemci, E., Kanbach, G., Karas, V., Kataria, D., Kennedy, T., Klochkov, D., Kluźniak, W., Kokkotas, K., Kreykenbohm, I., Krolik, J., Kuiper, L., Kuvvetli, I., Kylafis, N., Lattimer, J. M., Lazzarotto, F., Leahy, D., Lebrun, F., Lin, D., Lund, N., Maccarone, T., Malzac, J., Marisaldi, M., Martindale, A., Mastropietro, M., Mcclintock, J., Mchardy, I., Mendez, M., Mereghetti, S., Miller, M. C., Mineo, T., Morelli, E., Morsink, S., Motch, C., Motta, S., Muñoz-Darias, T., Naletto, G., Neustroev, V., Nevalainen, J., Olive, J. F., Orio, M., Orlandini, M., Orleanski, P., Ozel, F., Pacciani, L., Paltani, S., Papadakis, I., Papitto, A., Patruno, A., Pellizzoni, A., Petráček, V., Petri, J., Petrucci, P. O., Phlips, B., Picolli, L., Possenti, A., Psaltis, D., Rambaud, D., Reig, P., Remillard, R., Rodriguez, J., Romano, P., Romanova, M., Schanz, T., Schmid, C., Segreto, A., Shearer, A., Smith, A., Smith, P. J., Soffitta, P., Stergioulas, N., Stolarski, M., Stuchlik, Z., Tiengo, A., Torres, D., Török, G., Turolla, R., Uttley, P., Vaughan, S., Vercellone, S., Waters, R., Watts, A., Wawrzaszek, R., Webb, N., Wilms, J., Zampieri, L., Zezas, A., Ziolkowski, J., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, AstroParticule et Cosmologie (APC (UMR_7164)), 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), APC - Astrophysique des Hautes Energies (APC - AHE), 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), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Astronomy, 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), 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), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), 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), M. Feroci, L. Stella, M. v. der, T. Courvoisier, M. Hernanz, R. Hudec, A. Santangelo, D. Walton, A. Zdziarski, D. Barret, T. Belloni, J. Braga, S. Brandt, C. Budtz-Jorgensen, S. Campana, J. d. Herder, J. Huovelin, G. Israel, M. Pohl, P. Ray, A. Vacchi, S. Zane, A. Argan, P. Attina, G. Bertuccio, E. Bozzo, R. Campana, D. Chakrabarty, E. Costa, A. D. Rosa, E. D. Monte, S. D. Cosimo, I. Donnarumma, Y. Evangelista, D. Haa, P. Jonker, S. Korpela, C. Labanti, P. Malcovati, R. Mignani, F. Muleri, M. Rapisarda, A. Rashevsky, N. Rea, A. Rubini, C. Tenzer, C. Wilson-Hodge, B. Winter, K. Wood, G. Zampa, N. Zampa, M. Abramowicz, M. Alpar, D. Altamirano, J. Alvarez, L. Amati, C. Amoro, L. Antonelli, R. Artigue, P. Azzarello, M. Bachetti, G. Baldazzi, M. Barbera, C. Barbieri, S. Basa, A. Baykal, R. Belmont, L. Boirin, V. Bonvicini, L. Burderi, M. Bursa, C. Cabanac, E. Cackett, G. Caliandro, P. Casella, S. Chaty, J. Chenevez, M. Coe, A. Collura, A. Corongiu, S. Covino, G. Cusumano, F. D'Amico, S. Dall'Osso, D. D. Martino, G. D. Pari, G. D. Persio, T. D. Salvo, C. Done, M. Dovciak, A. Drago, U. Ertan, S. Fabiani, M. Falanga, R. Fender, P. Ferrando, D. Ferreira, G. Fraser, F. Frontera, F. Fuschino, J. Galvez, P. Gandhi, P. Giommi, O. Godet, E. Gogu, A. Goldwurm, D. Gotz, M. Grassi, P. Guttridge, P. Hakala, G. Henri, W. Hermsen, J. Horak, A. Hornstrup, J. i. Zand, J. Isern, E. Kalemci, G. Kanbach, V. Kara, D. Kataria, T. Kennedy, D. Klochkov, W. Kluzniak, K. Kokkota, I. Kreykenbohm, J. Krolik, L. Kuiper, I. Kuvvetli, N. Kylafi, J. Lattimer, F. Lazzarotto, D. Leahy, F. Lebrun, D. Lin, N. Lund, T. Maccarone, J. Malzac, M. Marisaldi, A. Martindale, M. Mastropietro, J. McClintock, I. McHardy, M. Mendez, S. Mereghetti, M. Miller, T. Mineo, E. Morelli, S. Morsink, C. Motch, S. Motta, T. Munoz-Daria, G. Naletto, V. Neustroev, J. Nevalainen, J. Olive, M. Orio, M. Orlandini, P. Orleanski, F. Ozel, L. Pacciani, S. Paltani, I. Papadaki, A. Papitto, A. Patruno, A. Pellizzoni, V. Petracek, J. Petri, P. Petrucci, B. Phlip, L. Picolli, A. Possenti, D. Psalti, D. Rambaud, P. Reig, R. Remillard, J. Rodriguez, P. Romano, M. Romanova, T. Schanz, C. Schmid, A. Segreto, A. Shearer, A. Smith, P. Smith, P. Soffitta, N. Stergioula, M. Stolarski, Z. Stuchlik, A. Tiengo, D. Torre, G. Torok, R. Turolla, P. Uttley, S. Vaughan, S. Vercellone, R. Water, A. Watt, R. Wawrzaszek, N. Webb, J. Wilm, L. Zampieri, A. Zeza, J. Ziolkowski, High Energy Astrophys. & Astropart. Phys (API, FNWI), Feroci, M., Stella, L., van der Klis, M., Courvoisier, T. J.-L., Hernanz, M., Hudec, R., Santangelo, A., Walton, D., Zdziarski, A., Barret, D., Belloni, T., Braga, J., Brandt, S., Budtz-Jørgensen, C., Campana, S., den Herder, J.-W., Huovelin, J., Israel, G. L., Pohl, M., Ray, P., Vacchi, A., Zane, S., Argan, A., Attinà, P., Bertuccio, G., Bozzo, E., Campana, R., Chakrabarty, D., Costa, E., De Rosa, A., Del Monte, E., Di Cosimo, S., Donnarumma, I., Evangelista, Y., Haas, D., Jonker, P., Korpela, S., Labanti, C., Malcovati, P., Mignani, R., Muleri, F., Rapisarda, M., Rashevsky, A., Rea, N., Rubini, A., Tenzer, C., Wilson-Hodge, C., Winter, B., Wood, K., Zampa, G., Zampa, N., Abramowicz, M. A., Alpar, M. A., Altamirano, D., Alvarez, J. M., Amati, L., Amoros, C., Antonelli, L. A., Artigue, R., Azzarello, P., Bachetti, M., Baldazzi, G., Barbera, M., Barbieri, C., Basa, S., Baykal, A., Belmont, R., Boirin, L., Bonvicini, V., Burderi, L., Bursa, M., Cabanac, C., Cackett, E., Caliandro, G. A., Casella, P., Chaty, S., Chenevez, J., Coe, M. J., Collura, A., Corongiu, A., Covino, S., Cusumano, G., D'Amico, F., Dall'Osso, S., De Martino, D., De Paris, G., Di Persio, G., Di Salvo, T., Done, C., Dovčiak, M., Drago, A., Ertan, U., Fabiani, S., Falanga, M., Fender, R., Ferrando, P., Della Monica Ferreira, D., Fraser, G., Frontera, F., Fuschino, F., Galvez, J. L., Gandhi, P., Giommi, P., Godet, O., Göǧüş, E., Goldwurm, A., Götz, D., Grassi, M., Guttridge, P., Hakala, P., Henri, G., Hermsen, W., Horak, J., Hornstrup, A., in't Zand, J. J. M., Isern, J., Kalemci, E., Kanbach, G., Karas, V., Kataria, D., Kennedy, T., Klochkov, D., Kluźniak, W., Kokkotas, K., Kreykenbohm, I., Krolik, J., Kuiper, L., Kuvvetli, I., Kylafis, N., Lattimer, J. M., Lazzarotto, F., Leahy, D., Lebrun, F., Lin, D., Lund, N., Maccarone, T., Malzac, J., Marisaldi, M., Martindale, A., Mastropietro, M., McClintock, J., McHardy, I., Mendez, M., Mereghetti, S., Miller, M. C., Mineo, T., Morelli, E., Morsink, S., Motch, C., Motta, S., Muñoz-Darias, T., Naletto, G., Neustroev, V., Nevalainen, J., Olive, J. F., Orio, M., Orlandini, M., Orleanski, P., Ozel, F., Pacciani, L., Paltani, S., Papadakis, I., Papitto, A., Patruno, A., Pellizzoni, A., Petráček, V., Petri, J., Petrucci, P. O., Phlips, B., Picolli, L., Possenti, A., Psaltis, D., Rambaud, D., Reig, P., Remillard, R., Rodriguez, J., Romano, P., Romanova, M., Schanz, T., Schmid, C., Segreto, A., Shearer, A., Smith, A., Smith, P. J., Soffitta, P., Stergioulas, N., Stolarski, M., Stuchlik, Z., Tiengo, A., Torres, D., Török, G., Turolla, R., Uttley, P., Vaughan, S., Vercellone, S., Waters, R., Watts, A., Wawrzaszek, R., Webb, N., Wilms, J., Zampieri, L., Zezas, A., Ziolkowski, J., 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), 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, and Università di Bologna [Bologna] (UNIBO)-Università di Bologna [Bologna] (UNIBO)

Subjects
Event horizon, X-ray timing, Mission, 7. Clean energy, 01 natural sciences, neutron stars, T175 Industrial research. Research and development, BINARIES, Settore FIS/05 - Astronomia E Astrofisica, ALICE, SILICON DRIFT DETECTOR, Observatory, EQUATION, neutron star, 010303 astronomy & astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Astrophysics::Instrumentation and Methods for Astrophysics, Missions, X-ray timing, compact objects, black holes, neutron stars, compact objects, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, PROPORTIONAL COUNTER, [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Active galactic nucleus, Cosmic Vision, X-ray astronomy, high time variability, Astrophysics::High Energy Astrophysical Phenomena, black holes, Missions, FOS: Physical sciences, 0103 physical sciences, OSCILLATIONS, Instrumentation and Methods for Astrophysics (astro-ph.IM), Supermassive black hole, 010308 nuclear & particles physics, Astronomy, CONSTRAINTS, Astronomy and Astrophysics, Galaxy, Black hole, Neutron star, Space and Planetary Science, QB460-466 Astrophysics, DISCOVERY, BLACK-HOLE, SUPERAGILE
Abstract

High-time-resolution X-ray observations of compact objects provide direct access to strong-field gravity, to the equation of state of ultra-dense matter and to black hole masses and spins. A 10 m^2-class instrument in combination with good spectral resolution is required to exploit the relevant diagnostics and answer two of the fundamental questions of the European Space Agency (ESA) Cosmic Vision Theme "Matter under extreme conditions", namely: does matter orbiting close to the event horizon follow the predictions of general relativity? What is the equation of state of matter in neutron stars? The Large Observatory For X-ray Timing (LOFT), selected by ESA as one of the four Cosmic Vision M3 candidate missions to undergo an assessment phase, will revolutionise the study of collapsed objects in our galaxy and of the brightest supermassive black holes in active galactic nuclei. Thanks to an innovative design and the development of large-area monolithic Silicon Drift Detectors, the Large Area Detector (LAD) on board LOFT will achieve an effective area of ~12 m^2 (more than an order of magnitude larger than any spaceborne predecessor) in the 2-30 keV range (up to 50 keV in expanded mode), yet still fits a conventional platform and small/medium-class launcher. With this large area and a spectral resolution of, 29 pages, 10 figures. Accepted for publication in Experimental Astronomy

Published
2012

26. GRB990123: multiwavelength afterglow study

Author

Maiorano, E., Masetti, N., Palazzi, E., Frontera, F., Grandi, P., Pian, E., Amati, L., Nicastro, L., Paolo Soffitta, Corsi, A., Piro, L., Antonelli, L. A., Costa, E., Feroci, M., Heise, J., and In T Zand, J. J. M.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics
Abstract

We report on the BeppoSAX and multiwavelength data analysis of the afterglow of Gamma-Ray Burst (GRB) 990123. Mainly due to its exceptional brightness, this is the only source for which the Wide Field Cameras have allowed an early detection of the X-ray afterglow between about 20 and 60 min after the GRB trigger. Besides, again for the first time, high-energy emission from the afterglow was detected up to 60 keV. The backwards extrapolation of the afterglow decay smoothly reconnects with the late GRB emission, thus indicating that both are consistent with being produced by the same phenomenon. For the X-ray afterglow we found a power-law decay with index alpha_X = 1.46 +/- 0.04; the spectrum has a power-law shape with photon index Gamma about 2. An extensive set of multiwavelength observations on the afterglow, collected from the literature and made during the BeppoSAX pointing, allowed constructing a Spectral Flux Distribution. We performed an analysis of the GRB afterglow emission in the context of the "fireball" model., 4 pages, 2 figures, 1 table. Poster presented at the 4th Workshop Gamma-Ray Bursts in the Afterglow Era, Rome,18-22 October 2004. Editors: L. Piro, L. Amati, S. Covino, and B. Gendre. Il Nuovo Cimento, in press

Published
2005

33. Discovery of type-I X-ray bursts from GRS 1741.9-2853

Author

Cocchi, M., Angela Bazzano, Natalucci, L., Ubertini, P., Heise, J., Muller, J. M., and In T Zand, J. J. M.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

For the first time X-ray bursts have been detected from a sky position consistent with the one of GRS 1741.9-2853, a GRANAT transient source located only ~10' from the Galactic Centre. A total of 3 bursts have been observed by the Wide Field Cameras telescopes on board BeppoSAX during a monitoring observation of the Sgr A region in August-September 1996. The characteristics of the events are consistent with type-I bursts, thus identifying the source as a likely low-mass X-ray binary containing a neutron star. Evidence of photospheric radius expansion due to super-Eddington luminosity is present in one of the observed bursts, thus leading to an estimate og the source distance (~8 kpc)., 4 pages, 3 figures. Accepted for publication in A&A Letters

Published
1999

34. Long term BeppoSAX-WFC monitoring of GRS 1758-258

Author

Cocchi, M., Smith, J. M. S., Muller, J. M., Angela Bazzano, Natalucci, L., Ubertini, P., Heise, J., and In T Zand, J. J. M.

Subjects
Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics
Abstract

Following a series of deep observations of the Galactic Bulge region performed with the Wide Field Cameras on board BeppoSAX, it has been possible to study throughout a long time period a number of persistent X-ray sources. We report on the behaviour of GRS 1758-258, an X-ray binary suggested as a black hole candidate on the basis of its timing and spectral characteristics. The source has been monitored for almost 2 years since August 1996; preliminary results of the data analysis are shown hereafter., 4 pages, 3 figures, proc. 3rd INTEGRAL Workshop - Taormina 1998

Published
1999

35. A new X-ray outburst in the globular cluster NGC 6440: SAX J1748.9-2021

Author

In T Zand, J. J. M., Verbunt, F., Strohmayer, T. E., Angela Bazzano, Cocchi, M., Heise, J., Kerkwijk, M. H., Muller, J. M., Natalucci, L., Smith, M. J. S., and Ubertini, P.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

For the second time in 27 years a bright transient X-ray source has been detected coincident with the globular cluster NGC 6440. It was found to be active in August, 1998, with the Wide Field Camera and the narrow field instruments on the BeppoSAX spacecraft, and with the All-Sky Monitor and the Proportional Counter Array on the RossiXTE spacecraft. Four X-ray bursts were detected, at least one of which shows the characteristics of a thermonuclear flash on a neutron star, in analogy with some ~20 optically identified low-mass X-ray binaries. The broad-band spectrum is hard as is common among low-mass X-ray binaries of lower luminosity (>~10^37 erg/s) and can be explained by a Comptonized model. During the burst the >30 keV emission brightened, consistent with part of the burst emission being Compton up scattered within ~10^11 cm., 10 pages, accepted for publication in A&A

Published
1999
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36. Broad-band X-ray measurements of GS 1826-238

Author

In T Zand, J. J. M., Heise, J., Kuulkers, E., Angela Bazzano, Cocchi, M., and Ubertini, P.

Subjects
Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics
Abstract

The broad band X-ray spectrum of the low-mass X-ray binary (LMXB) GS1826-238 was measured with the narrow-field instruments on BeppoSAX on April 6 and 7, 1997. The spectrum is consistent with the Comptonization of a 0.6 keV thermal spectrum by a hot cloud of temperature equivalent kT=20 keV. During the observation two type I X-ray bursts were detected. From the bursts an upper limit to the distance could be derived of 8 kpc. Combined with an elsewhere determined lower limit of 4 kpc this implies a persistent X-ray luminosity between 3.5 X 10^36 and 1.4 X 10^37 erg/s which is fairly typical for a LMXB X-ray burster. The accurate determination of the energetics of the two bursts and the persistent emission confirm results with the Wide Field Cameras on BeppoSAX in a narrower bandpass (Ubertini et al. 1999). Comparison with independent X-ray measurements taken at other times indicates that GS 1826-238 since its turn-on in 1988 is a rather stable accretor, which is in line with the strong regularity of type I X-ray bursts.

Published
1999
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37. BeppoSAX follow-up search for the X-ray afterglow of GRB970111

Author

Feroci, M., Antonelli, L. A., Guainazzi, M., Muller, J. M., Enrico Costa, Piro, L., Heise, J., In T Zand, J. J. M., Frontera, F., Dal Flume, D., Nicastro, L., Orlandini, M., Palazzi, E., Zavattini, G., Giommi, P., Parmar, A. N., Owens, A., Castro-Tirado, A. J., Maccarone, M. C., and Butler, R. C.

Subjects
Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics
Abstract

The BeppoSAX satellite has recently opened a new way towards the solution of the long standing gamma-ray bursts' (GRBs) enigma, providing accurate coordinates few hours after the event thus allowing for multiwavelength follow-up observational campaigns. The BeppoSAX Narrow Field Instruments observed the region of sky containing GRB970111 16 hours after the burst. In contrast to other GRBs observed by BeppoSAX no bright afterglow was unambiguously observed. A faint source (1SAXJ1528.1+1937) is detected in a position consistent with the BeppoSAX Wide Field Camera position, but unconsistent with the IPN annulus. Whether 1SAXJ1528.1+1937 is associated with GRB970111 or not, the X-ray intensity of the afterglow is significantly lower than expected, based on the properties of the other BeppoSAX GRB afterglows. Given that GRB970111 is one of the brightest GRBs observed, this implies that there is no obvious relation between the GRB gamma-ray peak flux and the intensity of the X-ray afterglow., Comment: 5 pages, LaTeX A&A style, 3 postscript figures; A&A Letters accepted

Published
1998
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40. Detection of X-ray bursts in the globular cluster NGC 6652

Author

In T Zand, J. J. M., Verbunt, F., Heise, J., Muller, J. M., Angela Bazzano, Cocchi, M., Natalucci, L., and Ubertini, P.

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

Two type I X-ray bursts were detected from a position consistent with the transient X-ray source in NGC 6652 with the Wide Field Camera of the BeppoSAX satellite, strongly suggesting that this transient is a neutron star. Our detection brings to ten the number of X-ray sources in globular clusters in which a type I X-ray burst has been seen, out of twelve known bright sources. The statistical evidence that the fraction of low-mass X-ray binaries which contain a black hole accretor is smaller in globular clusters than in the galactic disk is suggestive, but as yet not compelling., Comment: Published in A&A, 1998, vol. 329, L37; 5 pages, 3 figures

Published
1997
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47. What ignites on the neutron star of 4U 0614+091?

Author

Kuulkers, E., primary, in 't Zand, J. J. M., additional, Atteia, J.-L., additional, Levine, A. M., additional, Brandt, S., additional, Smith, D. A., additional, Linares, M., additional, Falanga, M., additional, Sánchez-Fernández, C., additional, Markwardt, C. B., additional, Strohmayer, T. E., additional, Cumming, A., additional, and Suzuki, M., additional

Published
2010
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