The defining criterion of polars (AM Herculis stars) was their prominent softX-ray emission, which led to numerous discoveries with the EINSTEIN, EXOSAT,ROSAT and EUVE satellites. XMM-Newton observations of those X-ray selectedpolars and genuine discoveries of new polar systems reveal growing evidence thatthe prevailence or even the existence of a soft X-ray component may be ratherthe exception than the rule. In the last decade polars were discovered inoptical surveys like the SDSS and the CSS. Here we propose XMM-Newtonobservations of 5 optically selected polars to search for soft X-ray spectralcomponents, answer the question why they escaped detection in past X-ray surveysand shed new light on the intrinsic energy distribution of polars.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2012-01-26T12:37:26Z/2012-04-10T20:59:28Z
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 Axel Schwope, 2013, 'Polars - soft X-ray emittersquestionMark', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-93tcl4i
