The X-ray source associated with the M31 globular cluster Bovirgul135 (hereafter XBo135) may contain the largest stellar mass black hole (BH) to date. It has beenobserved several times with Chandra and XMM-Newton, and has always exhibitedemission spectra characteristic of the BH low state. XBo 135 exhibited thisbehaviour at virgul4-6E+38 erg/s, suggesting a primary mass >50 Solar masses.Possible formation scenarios include stellar mergers in the cluster center, orthe direct collapse of a metal poor high mass star. We request 120 ks ofXMM-Newton time to investigate the metalicity, and a 5 ks Chandra pointing toaccurately locate the source. These observations will test the feasibility ofthese scenarios; in particular, a high metalicity will rule out direct collapse.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2012-06-26T05:23:25Z/2012-06-27T15:22:40Z
Version
17.56_20190403_1200
Mission Description
The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earths atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis.
European Space Agency, Dr Robin Barnard, 2013, 'A new heavyweight champion for stellar mass BHsquestionMark XMM and Chandra investigate', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-4dmhau2
