|Title||Is RX J0720.4-3125 a freely precessing neutron star?|
|Author||Dr Jacco Vink|
|Description||RX J0720.4-3125 belongs to a group of radio-quiet isolated neutron stars, whose X-ray spectra consist of broad absorption feature(s) superimposed on a blackbody continuum. It is unique in that its spectrum and flux are time variable. The cause for this is unclear, but one possibility is free precession of two different hot spots at the star surface. Free precession can reveal important information on the star.s interior structure. However, the last observation shows that the spectral evolution does not follow the prediction of a simple sinusoidal model. Continued monitoring of the spectral and timing properties is needed to reveal whether this is due to a complex and patchy surface thermal map or whether the variation is caused by effects different from precession.|
|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, 2008-12-05T00:00:00Z, 050271, 17.56_20190403_1200. https://doi.org/10.5270/esa-9inzk53|