X-ray Polarization from Black Holes: GEMS Scientific White Paper

Abstract

We present here a summary of the scientific goals behind the Gravity and Extreme Magnetism SMEX (GEMS) X-ray polarimetry mission's black hole (BH) observing program. The primary targets can be divided into two classes: stellar-mass galactic BHs in accreting binaries, and super-massive BHs in the centers of active galactic nuclei (AGN). The stellar-mass BHs can in turn be divided into various X-ray spectral states: thermal-dominant (disk), hard (radio jet), and steep power-law (hot corona). These different spectral states are thought to be generated by different accretion geometries and emission mechanisms. X-ray polarization is an ideal tool for probing the geometry around these BHs and revealing the specific properties of the accreting gas.

arXiv commentA white paper by the GEMS science working group; 21 pages, 4 figures

References in corpus (2)

• Black hole accretion disks in the canonical low-hard state
• Suzaku Observations of 4U 1957+11: Potentially the Most Rapidly Spinning Black Hole in (the Halo of) the Galaxy

Cited by in corpus (4)

• The Masses and Spins of Neutron Stars and Stellar-Mass Black Holes
• The multi-wavelength polarization of Cygnus X-1
• The Relative Importance of Faraday Rotation and QED Birefringence for the Linear Polarization of X-rays from Mass Accreting Black Holes
• Probing the gravitational Faraday rotation using quasar X-ray microlensing