RX J0720 belongs to a group of seven radio-quiet isolated neutron stars withsimilar properties. It is unique in that it shows long term variations in itsspectral parameters, like black body temperature, size of the emitting area andthe depth of the absorption feature. Furthermore, a phase coherent pulse timinganalysis assuming a constant spin period derivative shows large timingresiduals. The cause of this enigmatic behaviour is still a matter of debate:cyclic variations are expected if the neutron star precesses while a suddenevent like a glitch may cause a gradual evolution after a relatively fastchange. The recent results from our XMM-Newton observations indicate that thetiming residuals follow an abs(sine) behaviour with the minimum expected around next year.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2009-09-22T04:27:35Z/2009-09-22T13:01:38Z
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, Mr Markus Hohle, 2010, 'RX J0720 evolution: precession comma glitching comma or the last flutterings of a magnetar', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-cvbv9x3
