|Title||The nature of quiescent emission in the neutron star Cen X-4|
|Author||Dr Edward Cackett|
|Description||The neutron star LMXB, Cen X-4, has been in quiescence since 1979. Its quiescent X-ray emission consists of both a thermal and power-law component, with variability observed on timescales as short as hundreds of seconds and as long as years. Yet, this variability is not understood. We recently found Cen X- 4 in a historically low-state, over 5 times fainter than before. Such a difference requires the thermal component to vary. This poses a big problem for using thermal emission to measure neutron star radii and constrain the dense matter equation of state. To investigate the nature of this variability and the emission mechanisms from X-rays through to the optical, we propose four, 12 ks observations of Cen X-4 to obtain good X-ray spectra and accurate photometry in 5 optical-UV filters.|
|Publication||No observations found associated with the current proposal|
|Instrument||EMOS1, EMOS2, EPN, OM, RGS1, RGS2|
|Mission Description||The European Space Agency's (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESA's 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 Earth's 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.
|Publisher And Registrant||European Space Agency|
|Credit Guidelines||European Space Agency, 2012-02-18T00:00:00Z, 065447, 17.56_20190403_1200. https://doi.org/10.5270/esa-2m8a4xo|