The origin of the x-ray emission from the high-velocity cloud MS30.7-81.4-118
Cited 1 times inCited 0 times in
- The origin of the x-ray emission from the high-velocity cloud MS30.7-81.4-118
- Henley, David B.; Shelton, Robin L.; Kwak, Kyujin
- Issue Date
- IOP PUBLISHING LTD
- ASTROPHYSICAL JOURNAL, v.791, no.1, pp.41
- A soft X-ray enhancement has recently been reported toward the high-velocity cloud MS30.7-81.4-118 (MS30.7), a constituent of the Magellanic Stream. In order to investigate the origin of this enhancement, we have analyzed two overlapping XMM-Newton observations of this cloud. We find that the X-ray enhancement is 6′ or 100 pc across, and is concentrated to the north and west of the densest part of the cloud. We modeled the X-ray enhancement with a variety of spectral models. A single-temperature equilibrium plasma model yields a temperature of and a 0.4-2.0 keV luminosity of 7.9 × 1033 erg s-1. However, this model underpredicts the on-enhancement emission around 1 keV, which may indicate the additional presence of hotter plasma (T ≳ 107 K), or that recombination emission is important. We examined several different physical models for the origin of the X-ray enhancement. We find that turbulent mixing of cold cloud material with hot ambient material, compression or shock heating of a hot ambient medium, and charge exchange reactions between cloud atoms and ions in a hot ambient medium all lead to emission that is too faint. In addition, shock heating in a cool or warm medium leads to emission that is too soft (for reasonable cloud speeds). We find that magnetic reconnection could plausibly power the observed X-ray emission, but resistive magnetohydrodynamical simulations are needed to test this hypothesis. If magnetic reconnection is responsible for the X-ray enhancement, the observed spectral properties could potentially constrain the magnetic field in the vicinity of the Magellanic Stream.
- Appears in Collections:
- PHY_Journal Papers
- Files in This Item:
- There are no files associated with this item.
can give you direct access to the published full text of this article. (UNISTARs only)
Show full item record
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.