2007/11/30 by N. J. Brassington, G. Fabbiano, D. -W. Kim +17
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Globular cluster #Luminosity #Photometry (optics) #Physics #Population #Spectral line #Stars #astro-ph
paper · pdf · doi:10.1086/591527
Accepted for publication in ApJS, 120 pages, with 14 figures. No changes from previous revision
arxiv created 2008/06/26 · openalex publication_date 2008/10/29 · arxiv updated 2009/12/01 · openalex created_date 2016/10/21 · openalex updated_date 2026/08/05
We present the properties of the discrete X-ray sources detected in our monitoring program of the 'typical' elliptical galaxy, NGC 3379, observed with Chandra ACIS-S in five separate pointings, resulting in a co-added exposure of 324 ks. From this deep observation, 132 sources have been detected within the region overlapped by all observations, 98 of which lie within the D 25 ellipse of the galaxy. These 132 sources range in L X from 6 × 10 35 erg s −1 (with 3 σ upper limit ≤4 × 10 36 erg s −1 ) to ~2 × 10 39 erg s −1 , including one source with L X > 1 × 10 39 erg s −1 , which has been classified as a ULX. From optical data, 10 X-ray sources have been determined to be coincident with a globular cluster, these sources tend to have high X-ray luminosity, with three of these sources exhibiting L X > 1 × 10 38 erg s −1 . From X-ray source photometry, it has been determined that the majority of the 132 sources that have well constrained colors, have values that are consistent with typical LMXB spectra. In addition to this, a subpopulation of 10 sources has been found to exhibit very hard spectra and it is expected that most of these sources are absorbed background AGN. There are 64 sources in this population that exhibit long-term variability, indicating that they are accreting compact objects. Five of these sources have been identified as transient candidates, with a further 3 possible transients. Spectral variations have also been identified in the majority of the source population, where a diverse range of variability has been identified, indicating that there are many different source classes located within this galaxy.