X-ray spectroscopy of LMXB dippers offers the potential to isolate the physics of the collision of the accretion stream with the disk edge, which bears on several aspects of disk accretion. We propose to observe XB1254-69 for three binary orbits (42 ksec). Whether the absorbers are confined to the disk edge orcomprise the denser component of a two-phase medium at smaller radii, in XB1254they are most likely moderately ionized. Using the neutron star as abacklighter, we can infer the physical state of the absorber by measuring edgepositions and depths, and, if the post-impact stream is turbulent, absorptionlines. We have developed sophisticated non-LTE opacity models of 65 ions, withthe expectation that these observations will constrain rad/hydro models of the.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2001-01-22T00:27:12Z/2002-02-08T01:09:49Z
Version
PPS_NOT_AVAILABLE
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 Duane Liedahl, 2003, 'X-Raying the Stream/Disk Impact Region in XB1254-69', PPS_NOT_AVAILABLE, European Space Agency, https://doi.org/10.5270/esa-l5pru2k
