XMM-Newton Detection of X-ray Emission from the Metal-Polluted White Dwarf G 29-38

Abstract

A recent analysis of Chandra X-ray data of the metal-polluted white dwarf (WD) G29-38 has revealed X-ray emission that can be attributed to the accretion of debris from a planetary body. In the light of this detection we revisit here archival XMM-Newton observations of G29-38 from which only an upper limit was derived in the past due to the presence of a relatively bright nearby X-ray source. An analysis of these data in multiple energy bands allows disentangling the X-ray emission at the location of G29-38 from that of the nearby source. The similar spectral properties of the source in the XMM-Newton and Chandra observations and their spatial shift, consistent with the proper motion of G29-38 between these observations, strengthen the origin of that X-ray emission from G29-38. The X-ray luminosities from both observations are consistent within 1-$\sigma$ uncertainties, so too are the best-fit plasma temperatures. Although the count number is small, there is tantalizing evidence for line emission in the 0.7-0.8 keV energy band from an optically-thin hot plasma. The most likely candidate for this line emission would be the Fe complex at 16 Å.

6 pages, 4 figures, 1 table; accepted to ApJL

References in corpus (10)

• The frequency of planetary debris around young white dwarfs
• A Catalog of Galaxy Clusters Observed by XMM-Newton
• Pollution of single white dwarfs by accretion of many small asteroids
• X-ray and Infrared Observations of Two Externally-Polluted White Dwarfs
• Numerical Simulations of Collisional Cascades at the Roche Limits of White Dwarf Stars
• A white dwarf accreting planetary material determined from X-ray observations
• Most white dwarfs with detectable dust discs show infrared variability
• Magnetism, X-rays, and Accretion Rates in WD 1145+017 and other Polluted White Dwarf Systems
• A Second Look at the Metal Line Variability of G29-38
• Hard X-ray Emission Associated with White Dwarfs. IV. Signs of Accretion from Sub-stellar Companions

Cited by in corpus (1)

• Synthetic X-ray emission from white dwarf accreting planetary material