SIMBAD references

2007A&A...473..783R - Astronomy and Astrophysics, volume 473, 783-789 (2007/10-3)

X-ray emission from the stellar population in M32.


Abstract (from CDS):

Using Chandra observations, we study the X-ray emission of the stellar population in the compact dwarf elliptical galaxy M32. The proximity of M32 allows one to resolve all bright point sources with luminosities higher than 8x1033erg/s in the 0.5-7keV band. The remaining (unresolved) emission closely follows the galaxy's optical light and is characterized by an emissivity per unit stellar mass of ∼4.3x1027erg/s/M in the 2-10keV energy band. The spectrum of the unresolved emission above a few keV smoothly joins the X-ray spectrum of the Milky Way's ridge measured with RXTE and INTEGRAL. These results strongly suggest that weak discrete X-ray sources (accreting white dwarfs and active binary stars) provide the bulk of the ``diffuse'' emission of this gas-poor galaxy. Within the uncertainties, the average X-ray properties of the M32 stars are consistent with those of the old stellar population in the Milky Way. The inferred cumulative soft X-ray (0.5-2keV) emissivity is however smaller than is measured in the immediate Solar vicinity in our Galaxy. This difference is probably linked to the contribution of young (age ≪1Gyr) stars, which are abundant in the Solar neighborhood but practically absent in M32. Combining Chandra, RXTE and INTEGRAL data, we obtain a broad-band (0.5-60keV) X-ray spectrum of the old stellar population in galaxies.

Abstract Copyright:

Journal keyword(s): ISM: general - galaxies: dwarf - galaxies: individual: M32 - galaxies: general - galaxies: stellar content - X-rays: diffuse background

Status at CDS:  

Simbad objects: 7

goto Full paper

goto View the reference in ADS

To bookmark this query, right click on this link: simbad:2007A&A...473..783R and select 'bookmark this link' or equivalent in the popup menu


© Université de Strasbourg/CNRS

    • Contact