GT- While the majority of X-ray sources from serendipitous surveys have beenidentified, a significant fraction (10-20%) have no optical counterpart down tomagnitudes, Rvirgul20. These objects have eluded identification to date; possiblecandidates are diskless quasars, isolated neutron stars, optically-poorclusters, or even a new category of high Lx/Lopt sources not yet discovered. Wepropose observations of two bright X-ray sources from WGACAT with high opticalto X-ray flux ratios (>80, this limit is higher than that for any known classof object). The XMM images will give accurate X-ray positions for these sourceswhich, together with the OM data, provide firm evidence for theiridentification or for follow-up work, if necessary.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2002-07-02T18:38:15Z/2002-07-05T11:21:11Z
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, Prof Keith Mason, 2003, 'The nature of high Lx/Lopt sources', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-01narjg
