arXiv subjects

C. Hailey

Publications and source records attributed to C. Hailey.

21 records · Page 2Linked to original sources

arXiv2011

The COSPIX mission: focusing on the energetic and obscured Universe

Tracing the formation and evolution of all supermassive black holes, including the obscured ones, understanding how black holes influence their surroundings and how matter behaves under extreme conditions, are recognized as key science objectives to be addressed by the next generation of instruments. These are the main goals of the COSPIX proposal, made to ESA in December 2010 in the context of its call for selection of the M3 mission. In addition, COSPIX, will also provide key measurements on the non thermal Universe, particularly in relation to the question of the acceleration of particles, as well as on many other fundamental questions as for example the energetic particle content of clusters of galaxies. COSPIX is proposed as an observatory operating from 0.3 to more than 100 keV. The payload features a single long focal length focusing telescope offering an effective area close to ten times larger than any scheduled focusing mission at 30 keV, an angular resolution better than 20 arcseconds in hard X-rays, and polarimetric capabilities within the same focal plane instrumentation. In this paper, we describe the science objectives of the mission, its baseline design, and its performances, as proposed to ESA.

astro-ph.IM↗

arXiv2002

XMM-Newton EPIC observations of Her X-1

We present spin-resolved X-ray data of the neutron star binary Her X-1 taken using the EPIC detectors on XMM-Newton. The data were taken at three distinct epochs through the 35 day precession period. The energy dependent light curves of this source vary significantly from epoch to epoch. It is known that the relative phasing of the soft (<1 keV) and hard (>2 keV) X-rays varies. Here, we find that the phase shift between the soft and hard bands during the main-on state is considerably different from that observed in the past. Further, it continues to change significantly during the other two observations. This suggests that we are observing, for the first time, a it substantial and continuous variation in the tilt of the disk, as it is expected if the accretion disk is precessing in the system. Analysis of the spin resolved data confirms that the equivalent width variation of the fluorescence Fe K line at \~6.4 keV follows that of the soft X-ray emission in the main-on state, thus suggesting a common origin for Fe K line and thermal component. The Fe K line is considerably broader when the source is brightest.

astro-ph↗

arXiv1999

EXIST: A High Sensitivity Hard X-ray Imaging Sky Survey Mission for ISS

A deep all-sky imaging hard x-ray survey and wide-field monitor is needed to extend soft (ROSAT) and medium (ABRIXAS2) x-ray surveys into the 10-100 keV band (and beyond) at comparable sensitivity (~0.05 mCrab). This would enable discovery and study of >3000 obscured AGN, which probably dominate the hard x-ray background; detailed study of spectra and variability of accreting black holes and a census of BHs in the Galaxy; Gamma-ray bursts and associated massive star formation (PopIII) at very high redshift and Soft Gamma-ray Repeaters throughout the Local Group; and a full galactic survey for obscured supernova remnants. The Energetic X-ray Imaging Survey Telescope (EXIST) is a proposed array of 8 x 1m^2 coded aperture telescopes fixed on the International Space Station (ISS) with 160deg x 40deg field of view which images the full sky each 90 min orbit. EXIST has been included in the most recent NASA Strategic Plan as a candidate mission for the next decade. An overview of the science goals and mission concept is presented.

astro-ph↗