|
|||||
|
|
GRAVITAS: general relativistic astrophysics via timing and spectroscopy |
|
| Authors: | Kirpal Nandra Didier Barret Andy Fabian Lothar Strueder Richard Willingale Mike Watson Peter Jonker Hideyo Kunieda Giovanni Miniutti Christian Motch Peter Predehl |
| Institution: | 1. Max Planck Institute for Extraterrestrial Physics, 85741, Garching, Germany 2. Institut de Recherche en Astrophysique et Plan??tologie, 9, Avenue du Colonel Roche, BP 44346, 31028, Toulouse Cedex 4, France 3. Institute of Astronomy, Madingley Road, Cambridge, CB3 0HA, UK 4. Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH, UK 5. SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA, Utrecht, The Netherlands 6. Division of Particle and Astrophysical Science,Graduate School of Science, Nagoya University, Furo-cho, Nagoya, 464-8602, Japan 7. Centro de Astrobiologia (CSIC-INTA), Centro de Astrobiologia (CAB), ESA - European Space Astronomy Center (ESAC), P.O. Box 78, 28691, Villanueva de la Ca?ada, Madrid, Spain 8. Observatoire Astronomique de Strasbourg, 11 Rue de l??Universit??, 67000, Strasbourg, France |
| Abstract: | GRAVITAS is an X-ray observatory, designed and optimised to address the ESA Cosmic Vision theme of ??Matter under extreme conditions??. It was submitted as a response to the call for M3 mission proposals. The concept centres around an X-ray telescope of unprecedented effective area, which will focus radiation emitted from close to the event horizon of black holes or the surface of neutron stars. To reveal the nature and behaviour of matter in the most extreme astrophysical environments, GRAVITAS targets a key feature in the X-ray spectra of compact objects: the iron K?? line at ~6.5?keV. The energy, profile, and variability of this emission line, and the properties of the surrounding continuum emission, shaped by General Relativity (GR) effects, provide a unique probe of gravity in its strong field limit. Among its prime targets are hundreds of supermassive black holes in bright Active Galactic Nuclei (AGN), which form the perfect laboratory to help understand the physical processes behind black hole growth. Accretion plays a fundamental role in the shaping of galaxies throughout cosmic time, via the process of feedback. Modest (~sub-arcmin) spatial resolution would deliver the necessary sensitivity to extend high quality X-ray spectroscopy of AGN to cosmologically-relevant distances. Closer to home, ultra-high count rate capabilities and sub-millisecond time resolution enable the study of GR effects and the equation of state of dense matter in the brightest X-ray binaries in our own Galaxy, using multiple probes, such as the broad iron line, the shape of the disk continuum emission, quasi-periodic oscillations, reverberation mapping, and X-ray burst oscillations. The enormous advance in spectral and timing capability compared to current or planned X-ray observatories would enable a vast array of additional scientific investigations, spanning the entire range of contemporary astrophysics from stars to distant galaxy clusters. Despite its breakthrough capabilities, all enabling technologies for GRAVITAS are already in a high state of readiness. It is based on ultra light-weight X-ray optics and a focal plane detector using silicon technology. The baseline launcher would be a Soyuz?CFregat to place GRAVITAS into a zero inclination, low-earth orbit, providing low and relatively stable background. |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ | |