A dataset provided by the European Space Agency

Proposal ID 069305
Title Unexplained Hard X-ray Emission from Hot Single White Dwarfs
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DOI https://doi.org/10.5270/esa-fky7p29
Principal Investigator, PI Prof You-Hua Chu
Abstract The central star of the Helix Nebula, WD2226-210, is a hot white dwarf (WD). ItsX-ray emission has a soft photospheric component and a harder component peakingnear 1 keV, which cannot be explained, as it does not have a binary companion orfast stellar wind. Only one other single WD, KPD0005+5106, shows similar X-raycharacteristics unambiguously, while two PG1159-type WDs have tentativedetections of hard X-rays. We request 300 ks XMM observations of WD2226, usingRGS spectra to determine the temperature, abundances, and ionization equilibriumof the X-ray-emitting plasma, and using EPIC data to study the temporalvariations of the 1 keV emission. We also request short observations of theother three WDs to characterize their hard X-ray emission, and assess its physical implications.
Publications
Instrument EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage 2012-11-26T01:33:54Z/2013-01-01T02:39:19Z
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.
Creator Contact https://www.cosmos.esa.int/web/xmm-newton/xmm-newton-helpdesk
Date Published 2014-01-19T00:00:00Z
Keywords "hard xray", "temporal variations", "epic data", "harder component peaking", "central star", "pg1159 type wds", "soft photospheric component", "tentative detections", "xray emitting plasma", "physical implications", "hard xray emission", "XMM", "wd2226 210", "ionization equilibrium", "EPIC", "fast stellar wind", "helix nebula", "xray characteristics unambiguously", "xray emission", "single wd", "kev emission", "binary companion", "rgs spectra"
Publisher And Registrant European Space Agency
Credit Guidelines European Space Agency, Prof You-Hua Chu, 2014, 'Unexplained Hard X-ray Emission from Hot Single White Dwarfs', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-fky7p29