The history of Galactic star formation is coded in the ISM through elementalabundances and the ratio of the Fe-group to lighter species. This important areahas been the domain of optical and UV astronomers, whose abundances of Galacticinterstellar gas are subject to significant uncertainties due to (the unknown)depletion onto dust grains and the need to adopt a photoionization model. A newmethod, using X-ray observations can measure elemental abundances without suchbiases, and oxygen abundances are already measured with this technique. Weextend this method to measure the abundances of Fe, Ne, and Mg by the magnitudeof their absorption edges. This requires a high N(HI), so our target is a brightblazar projected close to the Galactic midplane.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2008-02-28T14:36:51Z/2008-08-19T03:53:11Z
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 Joel Bregman, 2009, 'The Galactic Abundances of Fe comma Ne comma and Mg', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-x01lzw5
