In our systematic search for serendipitous sources (serendips) in the NuSTARdata, we have found a very bright (7.5 mCrab in the 2-10 keV band) serendip(J0923 s1) near the edge of one of the NuSTAR fields of view. The source hasbeen previously detected in the soft X-ray band, but its nature is unknown.Based on its X-ray spectrum, its optical counterpart, and its long-termvariability (as seen by MAXI), it must be Galactic, and, while some of itsproperties are suggestive of a magnetic Cataclysmic Variable, other propertiescause problems with this interpretation. One interesting possibility is that itmay be an accreting black hole with a high temperature disk. We propose NuSTARand XMM-Newton observations to determine the nature of J0923 s1.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2016-11-24T13:00:00Z/2016-11-24T19:23:20Z
Version
19.17_20220121_1250
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 John Tomsick, 2017, 'DETERMINING THE NATURE OF THE BRIGHTEST SERENDIPITOUS NUSTAR SOURCE', 19.17_20220121_1250, European Space Agency, https://doi.org/10.5270/esa-ze042ws
