Long RGS observations toward the low redshift, high galactic latitude ActiveGalactic Nuclei (AGNs: Mrk 421, PKS 2155 and 3C273) have shown clear evidencefor what appears to be a local (zvirgul0), highly ionized absorbing medium betrayedby the O VII 1s-2p resonance transition feature seen at 21.6A. While thedetection of such a gas is indeed enticing, we currently cannot entirely ruleout the possibility that the spectral feature is partially of interstellarorigin, due to the lack of an appropriate control sample dataset of comparablestatistics. We propose that XMM/Newton perform a short pointing toward the lowmass X-Ray binary (LMXB) Sco X-1, in which the RGS detectors are read outfrequently enough to avoid event pileup.
Instrument
RGS1, RGS2
Temporal Coverage
2003-03-03T16:13:50Z/2003-03-04T02:03:51Z
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 Andrew Rasmussen, 2004, 'Measurement of the Interstellar Absorption Spectrum toward Sco X-1', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-rzo8il9
