Abstract
High-time-resolution X-ray observations of compact objects provide direct access to strong-field gravity, to the equation of state of ultradense matter and to black hole masses and spins. A 10 m2-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 m2 (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 <260 eV, LOFT will yield unprecedented information on strongly curved spacetimes and matter under extreme conditions of pressure and magnetic field strength.
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References
Abramowicz, M.A., Kluźniak, W.: A precise determination of black hole spin in GRO J1655-40. Astron. Astrophys. 374, L19–L20 (2001)
Bueno, J.I., García, I., Plaza, M.A.: SMOS PLM MIRAS hold-down release and deployment mechanisms. In: Warmbein, B. (ed.) 11th European Space Mechanisms and Tribology Symposium, ESMATS 2005, vol. 591, pp. 235–242. ESA Special Publication (2005)
Campana, R., Zampa, G., Feroci, M., Vacchi, A., Bonvicini, V., Del Monte, E., Evangelista, Y., Fuschino, F., Labanti, C., Marisaldi, M., Muleri, F., Pacciani, L., Rapisarda, M., Rashevsky, A., Rubini, A., Soffitta, P., Zampa, N., Baldazzi, G., Costa, E., Donnarumma, I., Grassi, M., Lazzarotto, F., Malcovati, P., Mastropietro, M., Morelli, E., Picolli, L.: Imaging performance of a large-area Silicon Drift Detector for X-ray astronomy. Nucl. Instrum. Methods A 633, 22–30 (2011)
Demorest, P.B., Pennucci, T., Ransom, S.M., Roberts, M.S.E., Hessels, J.W.T.: A two-solar-mass neutron star measured using Shapiro delay. Nature 467, 1081–1083 (2010)
Dovčiak, M., Bianchi, S., Guainazzi, M., Karas, V., Matt, G.: Relativistic spectral features from X-ray-illuminated spots and the measure of the black hole mass in active galactic nuclei. Mon. Not. R. Astron. Soc. 350, 745–755 (2004)
Ebisawa, K., Bourban, G., Bodaghee, A., Mowlavi, N., Courvoisier, T.: High-energy sources before INTEGRAL. INTEGRAL reference catalog. Astrophys. J. 411, L59–L62 (2003)
Fabian, A.C., Rees, M.J., Stella, L., White, N.E.: X-ray fluorescence from the inner disc in Cygnus X-1. Mon. Not. R. Astron. Soc. 238, 729–736 (1989)
Feroci, M., Costa, E., Soffitta, P., Del Monte, E., di Persio, G., Donnarumma, I., Evangelista, Y., Frutti, M., Lapshov, I., Lazzarotto, F., Mastropietro, M., Morelli, E., Pacciani, L., Porrovecchio, G., Rapisarda, M., Rubini, A., Tavani, M., Argan, A.: SuperAGILE: the hard X-ray imager for the AGILE space mission. Nucl. Instrum. Methods Phys. Res. A 581, 728–754 (2007)
Feroci, M., Costa, E., Del Monte, E., Donnarumma, I., Evangelista, Y., Lapshov, I., Lazzarotto, F., Pacciani, L., Rapisarda, M., Soffitta, P., di Persio, G., Frutti, M., Mastropietro, M., Morelli, E., Porrovecchio, G., Rubini, A., Antonelli, A., Argan, A., Barbiellini, G., Boffelli, F., Bulgarelli, A., Caraveo, P., Cattaneo, P.W., Chen, A.W., Cocco, V., Colafrancesco, S., Cutini, S., D’Ammando, F., de Paris, G., Di Cocco, G., Fanari, G., Ferrari, A., Fiorini, M., Fornari, F., Fuschino, F., Froysland, T., Galli, M., Gasparrini, D., Gianotti, F., Giommi, P., Giuliani, A., Labanti, C., Liello, F., Lipari, P., Longo, F., Mattaini, E., Marisaldi, M., Mauri, A., Mauri, F., Mereghetti, S., Moretti, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Pittori, C., Pontoni, C., Preger, B., Prest, M., Primavera, R., Pucella, G., Rappoldi, A., Rossi, E., Sabatini, S., Santolamazza, P., Tavani, M., Stellato, S., Tamburelli, F., Traci, A., Trifoglio, M., Trois, A., Vallazza, E., Vercellone, S., Verrecchia, F., Vittorini, V., Zambra, A., Zanello, D., Salotti, L.: Monitoring the hard X-ray sky with SuperAGILE. Astron. Astrophys. 510, A9 (2010)
Gatti, E., Rehak, P.: Semiconductor drift chamber—an application of a novel charge transport scheme. Nucl. Instrum. Methods Phys. Res. 225, 608–614 (1984)
Giacconi, R., Kellogg, E., Gorenstein, P., Gursky, H., Tananbaum, H.: An X-ray scan of the galactic plane from UHURU. Astrophys. J. 165, L27 (1971)
in’t Zand, J.J.M., Weinberg, N.N.: Evidence of heavy-element ashes in thermonuclear X-ray bursts with photospheric superexpansion. Astron. Astrophys. 520, A81 (2010)
Israel, G.L., Belloni, T., Stella, L., Rephaeli, Y., Gruber, D.E., Casella, P., Dall’Osso, S., Rea, N., Persic, M., Rothschild, R.E.: The discovery of rapid X-ray oscillations in the tail of the SGR 1806-20 hyperflare. Astrophys. J. 628, L53–L56 (2005)
Jahoda, K., Markwardt, C.B., Radeva, Y., Rots, A.H., Stark, M.J., Swank, J.H., Strohmayer, T.E., Zhang, W.: Calibration of the Rossi X-ray timing explorer proportional counter array. Astrophys. J. Suppl. 163, 401–423 (2006)
Kushpil, S., Crescio, E., Giubellino, P., Idzik, M., Kolozhvari, A., Kushpil, V., Martinez, M.I., Mazza, G., Mazzoni, A., Meddi, F., Nouais, D., Petráček, V., Piemonte, C., Rashevsky, A., Riccati, L., Rivetti, A., Tosello, F., Vacchi, A., Wheadon, R.: Beam test results of the irradiated silicon drift detector for ALICE. Nucl. Instrum. Methods Phys. Res. A 566, 94–99 (2006)
Laor, A.: Line profiles from a disk around a rotating black hole. Astrophys. J. 376, 90–94 (1991)
Lattimer, J.M., Prakash, M.: Neutron star structure and the equation of state. Astrophys. J. 550, 426–442 (2001)
Lattimer, J.M., Prakash, M.: Neutron star observations: prognosis for equation of state constraints. Phys. Rep. 442, 109–165 (2007)
Leahy, D.A., Morsink, S.M., Chung, Y., Chou, Y.: Constraints on the properties of the neutron star XTE J1814-338 from pulse-shape models. Astrophys. J. 691, 1235–1242 (2009)
Nouais, D., Beolè, S., Bondila, M., Bonvicini, V., Cerello, P., Crescio, E., Giubellino, P., Idzik, M., Kolozhvari, A., Kouchpil, S., Torres, E.L., Martinez, M.I., Mazza, G., Piano, S., Piemonte, C., Rashevsky, A., Riccati, L., Rivetti, A., Tosello, F., Trzaska, W.H., Vacchi, A., Wheadon, R., The ALICE Collaboration: The ALICE Silicon Drift Detector system. Nucl. Instrum. Methods Phys. Res. A 501, 119–125 (2003)
Peacock, A., Andresen, R.D., Manzo, G., Taylor, B.G., Villa, G., Re, S., Ives, J.C., Kellock, S.: The gas scintillation proportional counter on EXOSAT. Space Sci. Rev. 30, 525–534 (1981)
Plaza, M.A., Martinez, L., Cespedosa, F.: The development of the SMOS-MIRAS deployment system. In: Harris, R.A. (ed.) 10th European Space Mechanisms and Tribology Symposium, vol. 524, pp. 231–238. ESA Special Publication (2003)
Rashevsky, A., Bonvicini, V., Burger, P., Piano, S., Piemonte, C., Vacchi, A.: Large area silicon drift detector for the ALICE experiment. Nucl. Instrum. Methods Phys. Res. A 485, 54–60 (2002)
Shvartsman, V.F.: Neutron stars in binary systems should not be pulsars. Soviet Astron. 15, 342 (1971)
Stella, L., Vietri, M., Morsink, S.M.: Correlations in the quasi-periodic oscillation frequencies of low-mass x-ray binaries and the relativistic precession model. Astrophys. J. 524, L63–L66 (1999)
Strohmayer, T.E., Watts, A.L.: Discovery of fast X-ray oscillations during the 1998 giant flare from SGR 1900+14. Astrophys. J. 632, L111–L114 (2005)
Swank, J.H.: The Rossi X-ray timing explorer: capabilities, achievements and aims. Adv. Space Res. 38(1), 2959–2963 (2006)
Taylor, B.G., Andresen, R.D., Peacock, A., Zobl, R.: The EXOSAT mission. Space Sci. Rev. 30, 479–494 (1981). doi:10.1007/BF01246069
Turner, M.J.L., Thomas, H.D., Patchett, B.E., Reading, D.H., Makishima, K., Ohashi, T., Dotani, T., Hayashida, K., Inoue, H., Kondo, H., Koyama, K., Mitsusa, K., Ogawara, Y., Takano, S., Awaki, H., Tawara, Y., Nakamura, N.: The large area counter on GINGA. PASJ 41, 345–372 (1989)
Vacchi, A., Castoldi, A., Chinnici, S., Gatti, E., Longoni, A., Palma, F., Sampietro, M., Rehak, P., Kemmer, J.: Performance of the UA6 large-area silicon drift chamber prototype . Nucl. Instrum. Methods A 306, 187–193 (1991)
van der Klis, M.: Millisecond oscillations in X-ray binaries. ARA&A 38, 717–760 (2000)
Zampa, G., Campana, R., Feroci, M., Vacchi, A., Bonvicini, V., Del Monte, E., Evangelista, Y., Fuschino, F., Labanti, C., Marisaldi, M., Muleri, F., Pacciani, L., Rapisarda, M., Rashevsky, A., Rubini, A., Soffitta, P., Zampa, N., Baldazzi, G., Costa, E., Donnarumma, I., Grassi, M., Lazzarotto, F., Malcovati, P., Mastropietro, M., Morelli, E., Picolli, L.: Room-temperature spectroscopic performance of a very-large area silicon drift detector. Nucl. Instrum. Methods A 633, 15–21 (2011)
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Feroci, M., Stella, L., van der Klis, M. et al. The Large Observatory for X-ray Timing (LOFT). Exp Astron 34, 415–444 (2012). https://doi.org/10.1007/s10686-011-9237-2
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DOI: https://doi.org/10.1007/s10686-011-9237-2