At orbital phase zero (i.e., the O star secondary intervening our line of sightto the black hole primary), Cyg X-1 shows X-ray dips due to highly variableabsorption in matter in the accretion stream. Studying the physics of these dipsrequires joint XMM/Chandra-HETGS/RXTE observations: XMM-Newton provides thecrucially important spectral continuum through the broad Fe line region at CCDresolution and it achieves high signal-to-noise in the <2keV band, allowing thedipping events to be temporally resolved and spectrally modeled on short timescales. The simultaneous Chandra data provide high resolution spectroscopy ofthe dipping events (albeit at a lower time resolution compared to XMM-Newton),while RXTE provides the hard X-ray continuum out to >150keV.
Instrument
EPN, RGS1, RGS2
Temporal Coverage
2008-04-18T11:54:38Z/2008-04-19T04:25:16Z
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 Joern Wilms, 2009, 'Joint XMM-Newton comma Chandra comma and RXTE Observations of Dips in Cyg X-1', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-8xury3o
