Related papers: Enhanced X-ray emission from candidate Lyman conti…
Ring galaxies are fascinating laboratories: a catastrophic impact between two galaxies (one not much smaller than the other) has produced fireworks especially in the larger one, when hit roughly perpendicularly to the plane. We analyze the…
The [CII]$_{158\mu m}$ line has long been proposed as a promising line to spectroscopically confirm galaxies in the epoch of reionization. In this paper we present the results of new ALMA observations spectral scanning for [CII] in six…
We present the star formation histories, luminosities, colors, mass to light ratios, and halo masses of "galaxies" formed in a simulation of cosmological reionization. We compare these galaxies with Lyman Break Galaxies observed at high…
Before the end of the epoch of reionization, the Hydrogen in the Universe was predominantly neutral. This leads to a strong attenuation of Ly$\alpha$ lines of $z\gtrsim6$ galaxies in the intergalactic medium. Nevertheless, Ly$\alpha$ has…
To reionize the early universe, high-energy photons must escape the galaxies that produce them. It has been suggested that stellar feedback drives galactic outflows out of star-forming regions, creating low density channels through which…
We have derived the X-ray luminosities of a sample of galaxies in groups, making careful allowance for contaminating intragroup emission. The L_X:L_B and L_X:L_{FIR} relations of spiral galaxies in groups appear to be indistinguishable from…
It is currently unknown whether the Universe was reionized by quasars or stars at z>5. We point out that quasars can be best distinguished from stellar systems by their X-ray emission. Based on a simple hierarchical CDM model, we predict…
The possibility that star-forming galaxies may leak ionizing photons is at the heart of many present-day studies that investigate the reionization of the Universe. We test this hypothesis on local blue compact dwarf galaxies of very high…
X-ray observations of the Galactic X-ray binaries (XRB) revealed numerous highly ionized metal absorption lines. However, it is unclear whether such lines are produced by the hot interstellar medium (ISM) or the circumstellar medium (CSM)…
We present an X-ray analysis of fourteen nearby (z < 0.044) AGN in low mass galaxies (M_* <= 5*10^9 Msun) selected based on their optical variability (Baldassare et al. 2020). Comparing and contrasting different AGN selection techniques in…
Ultraluminous X-ray sources are non-nuclear point sources exceeding the Eddington luminosity of a 10 Solar mass black hole. Modern consensus for a majority of the ULX population is that they are powered by stellar-mass black holes or…
Statistical properties of X-ray luminosity and temperature are studied for 52 early-type galaxies based on the ROSAT PSPC data. All of the X-ray luminous galaxies show largely extended emission with a radius of a few times of 10$r_e$, while…
X-ray luminosity function derived from observations of X-ray sources in galactic bulges can be explained by prinicipal evolutionary relations for mass accretion rate onto the compact object. The observed mean distribution of individual…
Inspired by the discovery of the Phoenix cluster by the South Pole Telescope team, we initiated a search for other massive clusters of galaxies missing from the standard X-ray catalogs. We began by identifying 25 cluster candidates not…
We study the visibility of the Lyman Alpha (Lya) emission line during the Epoch of Reionization (EoR). Combining galactic outflow models with large-scale semi-numeric simulations of reionization, we quantify the probability distribution…
GALEX has identified large numbers of extra galactic objects that are too faint to be observed by FUSE. These star forming systems are potential sources of Lyman continuum (Lyc) radiation and may contribute to the metagalactic background…
Ultraluminous X-ray sources are extragalactic, off-nucleus, point sources in galaxies with an X-ray luminosity above 3x10^39 erg/s, thought to be powered by accretion onto a compact object. Possible explanations include accretion onto…
The Chandra component of the Great Observatories All-Sky LIRG Survey (GOALS) presently contains 44 luminous and ultraluminous infrared galaxies with log (Lir/Lsun) = 11.73-12.57. Omitting 15 obvious AGNs, the other galaxies are, on average,…
The distribution and properties of the first galaxies and quasars are critical pieces of the puzzle in understanding galaxy evolution and cosmic reionization. Previous studies have often excluded unresolved sources as potential low redshift…
The goal of searching back in cosmic time to find star formation during the epoch of reionization will soon be within reach. We assess the detectability of high-redshift galaxies by combining cosmological hydrodynamic simulations of galaxy…