Search Publications
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 …
An Energetic AGN Outburst Powered by a Rapidly Spinning Supermassive Black Hole or an Accreting Ultramassive Black Hole
Kirkpatrick, C. C.; McNamara, B. R.; Nulsen, P. E. J. +4 more
Powering the 1062 erg nuclear outburst in the MS0735.6+7421 cluster central galaxy by accretion with a 10% mass-to-energy conversion efficiency implies that its putative supermassive black hole (SMBH) grew by ~6 × 108 M sun over the past 100 Myr. Guided by data at several wavelengths, we place upper limits on the a…
The Implications of a High Cosmic-Ray Ionization Rate in Diffuse Interstellar Clouds
Indriolo, Nick; Fields, Brian D.; McCall, Benjamin J.
Diffuse interstellar clouds show large abundances of H+ 3 which can only be maintained by a high ionization rate of H2. Cosmic rays are the dominant ionization mechanism in this environment, so the large ionization rate implies a high cosmic-ray flux, and a large amount of energy residing in cosmic rays. In this pa…