We propose a 50-ks XMM-Newton observation of the unusual neutron star X-raybinary SAX J2224.9+5421. Our target was discovered by BeppoSAX/WFC when itexhibited a thermonuclear X-ray burst. Follow-up observations aiming toconstrain the persistent emission were performed virgul8 h later and detected thesource at a 0.5-10 keV luminosity of L_Xvirgul1E33 erg/s. This is very peculiar sinceneutron star X-ray binaries are generally considered to be in quiescence atluminosities of L_Xvirgul1E31-1E33 erg/s, while they display accretion outbursts withluminosities of L_Xvirgul1E34-1E38 erg/s. We propose for a detailed investigation ofthe X-ray spectrum of SAX J2224.9+5421 to gain insight into its nature andextraordinary behavior.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2013-05-29T06:03:43Z/2013-05-30T00:05:37Z
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 Nathalie Degenaar, 2014, 'The X-ray spectrum of the unusual neutron star X-ray binary SAX J2224.9+5421', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-0wkos1u
