Search Publications
High-Redshift Quasars in the COSMOS Survey: The Space Density of z > 3 X-Ray Selected QSOs
Ilbert, O.; Salvato, M.; Merloni, A. +19 more
We present a new measurement of the space density of high-redshift (zsime 3.0-4.5), X-ray-selected quasi-stellar objects (QSOs) obtained by exploiting the deep and uniform multiwavelength coverage of the COSMOS survey. We have assembled a large (40 objects), homogeneous sample of z > 3 QSOs with X-ray flux F 0.5-2 keV > 10-15…
Isotropic Luminosity Indicators in a Complete AGN Sample
Rieke, George H.; Rigby, Jane R.; Diamond-Stanic, Aleksandar M.
The [O IV] λ25.89 µm line has been shown to be an accurate indicator of active galactic nucleus (AGN) intrinsic luminosity in that it correlates well with hard (10-200 keV) X-ray emission. We present measurements of [O IV] for 89 Seyfert galaxies from the unbiased revised Shapley-Ames (RSA) sample. The [O IV] luminosity distributions of obsc…
Dynamical Evolution of AGN Host Galaxies—Gas In/Out-Flow Rates in Seven NUGA Galaxies
Schinnerer, Eva; Emsellem, Eric; Rix, Hans-Walter +4 more
To examine the role of the host galaxy structure in fueling nuclear activity, we estimated gas flow rates from several kpc down to the inner few 10 pc for seven nearby spiral galaxies, selected from the NUclei of GAlaxies sample. We calculated gravitational torques from near-infrared images and determined gas in/out-flow rates as a function of rad…
Numerical Experiments of Wave-like Phenomena Caused by the Disruption of an Unstable Magnetic Configuration
Lin, Jun; Shen, Chengcai; Wang, Hongjuan
The origin of the Moreton wave observed in the chromosphere and the EIT wave observed in the corona during the eruption remains an active research subject. We investigate numerically in this work the evolutionary features of the magnetic configuration that includes a current-carrying flux rope, which is used to model the filament, after the loss o…
Dissecting the Gravitational Lens B1608+656. I. Lens Potential Reconstruction
McKean, J. P.; Treu, T.; Blandford, R. D. +4 more
Strong gravitational lensing is a powerful technique for probing galaxy mass distributions and for measuring cosmological parameters. Lens systems with extended source-intensity distributions are particularly useful for this purpose since they provide additional constraints on the lens potential (mass distribution). We present a pixelated approach…
New Tests for Disruption Mechanisms of Star Clusters: Methods and Application to the Antennae Galaxies
Whitmore, Bradley C.; Fall, S. Michael; Chandar, Rupali
We present new tests for disruption mechanisms of star clusters based on the bivariate mass-age distribution g(M, τ). In particular, we derive formulae for g(M, τ) for two idealized models in which the rate of disruption depends on the masses of the clusters and one in which it does not. We then compare these models with our Hubble Space Telescope…
New Limits on Sterile Neutrinos from Suzaku Observations of the Ursa Minor Dwarf Spheroidal Galaxy
Loewenstein, Michael; Biermann, Peter L.; Kusenko, Alexander
We present results of our search for X-ray line emission associated with the radiative decay of the sterile neutrino, a well motivated dark matter candidate, in Suzaku Observatory spectra of the Ursa Minor dwarf spheroidal galaxy. These data represent the first deep observation of one of these extreme mass-to-light systems and the first dedicated …
Discovery of Gamma-Ray Emission From the Shell-Type Supernova Remnant RCW 86 With Hess
Santangelo, A.; Quirrenbach, A.; Ripken, J. +151 more
The shell-type supernova remnant (SNR) RCW 86, possibly associated with the historical supernova SN 185, with its relatively large size (about 40' in diameter) and the presence of nonthermal X-rays is a promising target for γ-ray observations. The high sensitivity, good angular resolution of a few arcminutes and the large field of view of the High…
Obscured Star Formation in Intermediate-Density Environments: A Spitzer Study of the Abell 901/902 Supercluster
Papovich, Casey; Bell, Eric F.; Gallazzi, Anna +23 more
We explore the amount of obscured star formation as a function of environment in the Abell 901/902 (A901/902) supercluster at z = 0.165 in conjunction with a field sample drawn from the A901 and CDFS fields, imaged with the Hubble Space Telescope as part of the Space Telescope A901/902 Galaxy Evolution Survey and Galaxy Evolution from Morphology a…
Dust-Bounded Ultraluminous Infrared Galaxies: Model Predictions for Infrared Spectroscopic Surveys
Abel, N. P.; van Hoof, P. A. M.; Satyapal, S. +2 more
The observed faintness of infrared fine-structure line emission along with the warm far-infrared (FIR) colors of ultraluminous infrared galaxies (ULIRGs) is a long-standing problem. In this work, we calculate the line and continuum properties of a cloud exposed to an active galactic nucleus (AGN) and starburst spectral energy distribution. We use …