Search Publications
Iron Line and Diffuse Hard X-Ray Emission from the Starburst Galaxy M82
Heckman, Timothy M.; Strickland, David K.
We examine the properties of the diffuse hard X-ray emission in the classic starburst galaxy M82. We use new Chandra ACIS-S observations in combination with reprocessed archival Chandra ACIS-I and XMM-Newton observations. We find that E~6.7 keV Fe Heα emission is present in the central |r|<200 pc, |z|<100 pc of M82 in all data sets, in addit…
X-Ray Thermal Coronae of Galaxies in Hot Clusters: Ubiquity of Embedded Mini-Cooling Cores
Vikhlinin, A.; Forman, W.; Sun, M. +3 more
We present a systematic investigation of X-ray thermal coronae in 157 early-type and 22 late-type galaxies from a survey of 25 hot (kT>3 keV), nearby (z<0.05) clusters, based on Chandra archival data. Cool galactic coronae (kT=0.5-1.1 keV generally) have been found to be common, >60% in LKs>2L* galaxies…
Molecular Hydrogen Emission from Protoplanetary Disks. II. Effects of X-Ray Irradiation and Dust Evolution
Tsujimoto, M.; Nomura, H.; Aikawa, Y. +2 more
Detailed models for the density and temperature profiles of gas and dust in protoplanetary disks are constructed by taking into account X-ray and UV irradiation from a central T Tauri star, as well as dust size growth and settling toward the disk midplane. The spatial and size distributions of dust grains are numerically computed by solving the co…
Cosmic Evolution of Black Holes and Spheroids. II. Scaling Relations at z=0.36
Treu, Tommaso; Malkan, Matthew A.; Blandford, Roger D. +1 more
We use high-resolution images obtained with the Advanced Camera for Surveys on board the Hubble Space Telescope to determine morphology, nuclear luminosity, and structural parameters of the spheroidal component for a sample of 20 Seyfert galaxies at z=0.36. We combine these measurements with spectroscopic information from the Keck Telescope to det…
Quantitative Forecasting of Major Solar Flares
Rust, David M.; Georgoulis, Manolis K.
We define the effective connected magnetic field, Beff, a single metric of the flaring potential in solar active regions. We calculated Beff for 298 active regions (93 X- and M-flaring, 205 nonflaring) as recorded by SOHO/MDI during a 10 yr period covering much of solar cycle 23. We find that Beff is a robust crite…
Optical-to-Mid-Infrared Observations of Lyα Galaxies at z~5 in the Hubble Ultra Deep Field: A Young and Low-Mass Population
Malhotra, S.; Rhoads, J. E.; Xu, C. +1 more
High-redshift galaxies selected on the basis of strong Lyα emission tend to be young and have small physical sizes. We show this by analyzing the spectral energy distribution of nine Lyα-emitting galaxies (LAEs) at 4.0<z<5.7 in the Hubble Ultra Deep Field. Rest-frame UV-to-optical (700 Å < λ < 7500 Å) luminosities, or upper limits, are…
The X-Ray Concentration-Virial Mass Relation
Humphrey, Philip J.; Buote, David A.; Brighenti, Fabrizio +4 more
We present the concentration (c)-virial mass (M) relation of 39 galaxy systems ranging in mass from individual early-type galaxies up to the most massive galaxy clusters, (0.06-20)×1014 Msolar. We selected for analysis the most relaxed systems possessing the highest quality data currently available in the Chandra and XMM-Newt…
Beaming Binaries: A New Observational Category of Photometric Binary Stars
Mazeh, Tsevi; Zucker, Shay; Alexander, Tal
The new photometric spaceborne survey missions COROT and Kepler will be able to detect minute flux variations in binary stars due to relativistic beaming caused by the line-of-sight motion of their components. In all but very short period binaries (P>10 days), these variations will dominate over the ellipsoidal and reflection periodic variabili…
The Physical Nature of Rest-UV Galaxy Morphology during the Peak Epoch of Galaxy Formation
Pettini, Max; Erb, Dawn K.; Shapley, Alice E. +5 more
Motivated by the irregular and little-understood morphologies of z~2-3 galaxies, we use nonparametric coefficients to quantify the morphologies of 216 galaxies that have been spectroscopically confirmed to lie at redshifts z=1.8-3.4 in the GOODS-N field. Using measurements of UV and optical spectral lines, multiband photometric data, and stellar p…
The Morphological Content of 10 EDisCS Clusters at 0.5 < z < 0.8
Pelló, R.; Poggianti, B.; Milvang-Jensen, B. +12 more
We describe Hubble Space Telescope (HST) imaging of 10 of the 20 ESO Distant Cluster Survey (EDisCS) fields. Each ~40 arcmin2 field was imaged in the F814W filter with the Advanced Camera for Surveys Wide Field Camera. Based on these data, we present visual morphological classifications for the ~920 sources per field that are brighter t…