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A SYSTEMATIC SEARCH FOR X-RAY CAVITIES IN GALAXY CLUSTERS, GROUPS, AND ELLIPTICAL GALAXIES
Shin, Jaejin,Woo, Jong-Hak,Mulchaey, John S. American Astronomical Society 2016 The Astrophysical journal Supplement series Vol.227 No.2
<P>We perform a comprehensive study of X-ray cavities using a large sample of X-ray targets selected from the Chandra archive. The sample is selected to cover a large dynamic range including galaxy clusters, groups, and individual galaxies. Using beta-modeling and unsharp masking techniques, we investigate the presence of X-ray cavities for 133 targets that have sufficient X-ray photons for analysis. We detect 148 X-ray cavities from 69 targets and measure their properties, including cavity size, angle, and distance from the center of the diffuse X-ray gas. We confirm the strong correlation between cavity size and distance from the X-ray center similar to previous studies. We find that the detection rates of X-ray cavities are similar among galaxy clusters, groups and individual galaxies, suggesting that the formation mechanism of X-ray cavities is independent of environment.</P>
A Catalog of X-Ray Point Sources in the Abell 133 Region
Shin, Jaejin,Plotkin, Richard. M.,Woo, Jong-Hak,Gallo, Elena,Mulchaey, John S. American Astronomical Society 2018 The Astrophysical journal Supplement series Vol.238 No.2
<P>As an evolutionary phase of galaxies, active galactic nuclei (AGNs) over a large range of redshifts have been utilized for understanding cosmic evolution. In particular, the population and evolution of AGNs have been investigated through the study of the cosmic X-ray background in various fields. As one of the deep fields observed by Chandra, with a total of 2.8 Ms exposures, Abell 133 is a special region for investigating AGNs, providing a testbed for probing the environmental effects on AGN triggers, since cluster environments can be different from field environments. The achieved flux limits of data at the 50%. completeness levels of 6.95 x 10(-16), 1.43 x 10(-16), and 1.57 x 10(-15) erg s(-1) cm(-2) are 0.5-8, 0.5-2, and 2-8 keV. Using the wavdetect and no-source binomial probability (i.e., p < 0.007), we analyze the combined Chandra image, detecting 1617 (in 0.5-8 keV), 1324 (in 0.5-2 keV), and 1028 (in 2-8 keV) X-ray point sources in the Abell 133 region. Here, we present the X-ray point source catalog with the source fluxes, which can be combined with multiwavelength data for future works. We find that the number count distribution of the X-ray point sources is well reproduced with a broken power-law model, while the best-fit model parameters are sensitive to the fitting range of the number count distribution. Finally, we find an excess of number density (a decrease of AGN fraction) at the central region of the cluster, which reflects the effect of dense environments on AGN triggers, a finding similar to those of other studies of galaxy clusters.</P>