SIMBAD references

2014ApJ...794...61Z - Astrophys. J., 794, 61 (2014/October-2)

Spectral modeling of the charge-exchange X-ray emission from M82.


Abstract (from CDS):

It has been proposed that the charge-exchange (CX) process at the interface between hot and cool interstellar gases could contribute significantly to the observed soft X-ray emission in star-forming galaxies. We analyze the XMM-Newton/reflection grating spectrometer (RGS) spectrum of M82 using a newly developed CX model combined with a single-temperature thermal plasma to characterize the volume-filling hot gas. The CX process is largely responsible for not only the strongly enhanced forbidden lines of the Kα triplets of various He-like ions but also good fractions of the Lyα transitions of C VI (∼87%), O VIII, and N VII ( ≳ 50%) as well. In total about a quarter of the X-ray flux in the RGS 6-30 Å band originates in the CX. We infer an ion incident rate of 3x1051/s undergoing CX at the hot and cool gas interface and an effective area of the interface of ∼2x1045 cm2 that is one order of magnitude larger than the cross section of the global biconic outflow. With the CX contribution accounted for, the best-fit temperature of the hot gas is 0.6 keV, and the metal abundances are approximately solar. We further show that the same CX/thermal plasma model also gives an excellent description of the EPIC-pn spectrum of the outflow Cap, projected at 11.6 kpc away from the galactic disk of M82. This analysis demonstrates that the CX is potentially an important contributor to the X-ray emission from starburst galaxies and also an invaluable tool to probe the interface astrophysics.

Abstract Copyright:

Journal keyword(s): galaxies: individual: M82 - galaxies: starburst - X-rays: galaxies

Simbad objects: 3

goto Full paper

goto View the reference in ADS

To bookmark this query, right click on this link: simbad:2014ApJ...794...61Z and select 'bookmark this link' or equivalent in the popup menu


© Université de Strasbourg/CNRS

    • Contact