The 2013 outburst of a transient very faint X-ray binary, 23 arcsec from Sgr A*
Abstract
We report observations using the Swift/XRT, NuSTAR, and Chandra X-ray telescopes of the transient X-ray source CXOGC J174540.0-290005 during its 2013 outburst. Due to its location in the field of multiple observing campaigns targeting Sgr A*, this is one of the best-studied outbursts of a very faint X-ray binary (VFXB; peak LX < 1036 erg s-1) yet recorded, with detections in 173 ks of X-ray observations over 50 d. VFXBs are of particular interest, due to their unusually low outburst luminosities and time-averaged mass transfer rates, which are hard to explain within standard accretion physics and binary evolution. The 2013 outburst of CXOGC J174540.0-290005 peaked at LX(2-10 keV) = 5.0 × 1035 erg s-1, and all data above 1034 erg s-1 were well fitted by an absorbed power law of photon index ∼1.7, extending from 2 keV out to ≳70 keV. We discuss the implications of these observations for the accretion state of CXOGC J174540.0-290005.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- July 2014
- DOI:
- 10.1093/mnras/stu887
- arXiv:
- arXiv:1405.0267
- Bibcode:
- 2014MNRAS.442..372K
- Keywords:
-
- accretion;
- accretion discs;
- X-rays: binaries;
- X-rays: individual: CXOGC J174540.0-290005;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 12 pages, 4 figures, MNRAS in press