We propose deep XMM-Newton observations of two bright ultraluminous X-raysources, NGC 4559 X7 and NGC 5204 X-1. Short observations of these ULXs haverevealed spectral soft excesses, consistent with an accretion disc around anintermediate-mass black hole. We will use two diagnostic tests, only accessiblethrough high signal-to-noise data, to test whether the accreting IMBH hypothesisremains viable after rigorous examination. Specifically, we will look forcurvature in the 2 - 10 keV X-ray spectrum, which is not expected if IMBHsoperate in accretion states similar to Galactic black hole binaries, and we willplace limits on the underlying black hole masses by deriving the form of thepower spectral density for each source.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2006-11-15T20:21:34Z/2006-11-26T07:44:53Z
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 Timothy Roberts, 2007, 'Testing the accreting intermediate-mass black hole hypothesis in two ULXs', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-9mhrney
