We propose XMM-Newton observations of 4 carefully selected ultracool dwarfs(UCDs), supported by EVLA monitoring, to systematically investigate magneticactivity near the spectral type M/L transition. Our targets are nearby (< 20pc),known to maintain magnetic fields (direct field detections), they yield evidencefor chromospheres (Halpha emission) and have known rotation rate (v sini). Thisallows us to study the connection between chromospheric and coronal activity,their relation with rotation, and possibly study flares at the bottom of themain-sequence. In AO11 only two objects, both slowly rotating, were observed.For AO13 we focus on fast rotators. A statistical and unbiased sample is neededto test our hypothesis of two populations of UCDs with distinct radio/X-ray/rotation properties.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2014-09-01T19:26:54Z/2015-03-17T15:14:09Z
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 Beate Stelzer, 2016, 'The nature of magnetic activity at the low-mass end of the main-sequence', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-1iq6ir0
