Among the radio-quiet pulsars discovered by Fermi, an unique source is PSRJ2021+4026 in the Gamma Cygni supernova remnant. This pulsar has shocked thehigh-energy astrophysics community by featuring a simultaneous change in fluxand frequency derivative, breaking the long-standing paradigm of pulsars asstable gamma-ray sources. Monitoring the gamma-ray mode changes at differentenergies is key to understand if such events are due to global or local changesin the magnetosphere geometry and/or configurations. We propose a ToO with XMMto study the X-ray spectral and timing behaviour of PSR J2021+4026 following amode change. This will provide the first contemporary X and gamma-ray study ofpulsar mode changes, key to decrypt this intriguing, but still obscure, aspect of pulsar physics.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2015-12-20T10:15:58Z/2015-12-22T01:24:17Z
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 Massimiliano Razzano, 2017, 'X-rays and mode changes in PSR J2021+4026 comma the first variable gamma-ray pulsar', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-dx15whq
