A. Zezas

Compact Object Modeling with the StarTrack Population Synthesis Code

We present a comprehensive description of the population synthesis code StarTrack. The original code has been significantly modified and updated. Special emphasis is placed here on processes leading to the formation and further evolution of compact objects (white dwarfs, neutron stars, and black holes). Both single and binary star populations are considered. The code now incorporates detailed calculations of all mass transfer phases, a full implementation of orbital evolution due to tides, as well as the most recent estimates of magnetic braking. This updated version of StarTrack can be used for a wide variety of problems, with relevance to observations with many current and planned observatories, e.g., studies of X-ray binaries (Chandra, XMM-Newton), gravitational radiation sources (LIGO, LISA), and gamma-ray burst progenitors (HETE-II, Swift). The code has already been used in studies of Galactic and extragalactic X-ray binary populations, black holes in young star clusters, Type Ia supernova progenitors, and double compact object populations. Here we describe in detail the input physics, we present the code calibration and tests, and we outline our current studies in the context of X-ray binary populations.

Chandra Observations of “The Antennae” Galaxies (NGC 4038/9)

We report the results of a deep Chandra ACIS pointing at the merging system NGC 4038/9. We detect an extraordinarily luminous population of X-ray sources, with luminosity well above that of XRBs in M31 and the Milky Way. If these sources are unbeamed XRBs, our observations may point to them being 10-(a few)100 M☉ black hole counterparts. We detect an X-ray bright hot ISM, with features including bright superbubbles associated with the actively star-forming knots, regions where hot and warm (Hα) ISM intermingle, and a large-scale outflow.

Chandra High-Resolution Camera observations of the luminous X-ray source in the starburst galaxy M82

We have analyzed Chandra High Resolution Camera observations of the starburst galaxy M82, concentrating on the most luminous x-ray source. We find a position for the source of

Chandra Discovery of a Tree in the X-Ray Forest toward PKS 2155–304: The Local Filament?

\rm R.A. = 09^h 55^m 50^s.2, decl. = +69^{\circ} 40\arcmin 46\arcsec.7

Rapid Compton-thick/Compton-thin Transitions in the Seyfert 2 Galaxy NGC 1365

(J2000) with a

Chandra Observations of “The Antennae” Galaxies (NGC 4038/4039). III. X-Ray Properties and Multiwavelength Associations of the X-Ray Source Population

1\sigma

Occultation Measurement of the Size of the X-Ray-emitting Region in the Active Galactic Nucleus of NGC 1365

radial error of

The mass of the missing baryons in the X-ray forest of the warm–hot intergalactic medium

0.7\arcsec

Radio Emission from an Ultraluminous X-ray Source

. The accurate x-ray position shows that the luminous source is not at the dynamical centre of M82 nor coincident with any suggested radio AGN candidate. The source is highly variable between observations, which suggests that the source is a compact object and not a supernova or remnant. There is no significant short term variability within the observations. Dynamical friction and the off-center position place an upper bound of

Chandra Observations of “The Antennae” Galaxies (NGC 4038/4039). IV. The X-Ray Source Luminosity Function and the Nature of Ultraluminous X-Ray Sources

10^{5} - 10^{6} M_{\odot}