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Infrared Spectral Energy Distributions of Nearby Galaxies
Helou, G.; Roussel, H.; Leitherer, C. +25 more
The Spitzer Infrared Nearby Galaxies Survey (SINGS) is carrying out a comprehensive multiwavelength survey on a sample of 75 nearby galaxies. The 1-850 µm spectral energy distributions (SEDs) are presented using broadband imaging data from Spitzer, 2MASS, ISO, IRAS, and SCUBA. The infrared colors derived from the globally integrated Spitzer …
An Intermediate-Mass Black Hole in the Globular Cluster G1: Improved Significance from New Keck and Hubble Space Telescope Observations
Ho, Luis C.; Gebhardt, Karl; Rich, R. M.
We present dynamical models for the massive globular cluster G1. The goal is to measure or place a significant upper limit on the mass of any central black hole. Whether or not globular clusters contain central massive black holes has important consequences for a variety of studies. We use new kinematic data obtained with Keck and new photometry f…
The Assembly History of Field Spheroidals: Evolution of Mass-to-Light Ratios and Signatures of Recent Star Formation
Treu, Tommaso; van Dokkum, Pieter G.; Coil, Alison +6 more
We present a comprehensive catalog of high signal-to-noise ratio spectra obtained with DEIMOS on the Keck II telescope for a sample of F850LP<22.43 (AB) field spheroidal (E+S0 galaxies; 165) and bulge-dominated disk (61) galaxies in the redshift range 0.2<z<1.2, selected on the basis of visual morphology from the northern field of the Gre…
Relativistic Accretion Disk Models of High-State Black Hole X-Ray Binary Spectra
Hubeny, Ivan; Davis, Shane W.; Turner, Neal J. +1 more
We present calculations of non-LTE, relativistic accretion disk models applicable to the high/soft state of black hole X-ray binaries. We include the effects of thermal Comptonization and bound-free and free-free opacities of all abundant ion species. Taking into account the relativistic propagation of photons from the local disk surface to an obs…
HST STIS Spectroscopy of the Triple Nucleus of M31: Two Nested Disks in Keplerian Rotation around a Supermassive Black Hole
Richstone, Douglas; Kormendy, John; Lauer, Tod R. +12 more
We present Hubble Space Telescope (HST) spectroscopy of the nucleus of M31 obtained with the Space Telescope Imaging Spectrograph (STIS). Spectra that include the Ca II infrared triplet (λ~=8500 Å) see only the red giant stars in the double brightness peaks P1 and P2. In contrast, spectra taken at λ~=3600-5100 Å are sensitive to the tiny blue nucl…
Stellar Populations in 10 Clump-Cluster Galaxies of the Hubble Ultra Deep Field
Elmegreen, Bruce G.; Elmegreen, Debra Meloy
Color-color diagrams for the clump and interclump emission in 10 clump-cluster galaxies of the Hubble Ultra Deep Field (UDF) are made from B,V, i, and z images and compared with models to determine redshifts, star formation histories, and galaxy masses. These galaxies are members of a class dominated by 5-10 giant clumps, with no exponential disk …
The Age Distribution of Massive Star Clusters in the Antennae Galaxies
Whitmore, Bradley C.; Fall, S. Michael; Chandar, Rupali
We determine the age distribution of star clusters in the Antennae galaxies (NGC 4038/9) for two mass-limited samples (M>3×104 Msolar and M>2×105 Msolar). This is based on integrated broadband UBVI and narrowband Hα photometry from deep images taken with the Hubble Space Telescope. We find that the…
Masses of Star Clusters in the Nuclei of Bulgeless Spiral Galaxies
Ho, L. C.; Rix, H. -W.; Shields, J. C. +6 more
In the last decade star clusters have been found in the centers of spiral galaxies across all Hubble types. We here present a spectroscopic study of the exceptionally bright (106-108 Lsolar) but compact (re~5 pc) nuclear star clusters in very late type spirals with the Ultraviolet and Visual Echelle Spec…
GEMS: The Surface Brightness and Surface Mass Density Evolution of Disk Galaxies
Bell, Eric F.; Somerville, Rachel S.; Wisotzki, Lutz +14 more
We combine HST imaging from the GEMS (Galaxy Evolution from Morphologies and SEDs) survey with photometric redshifts from COMBO-17 to explore the evolution of disk-dominated galaxies since z<~1.1. The sample is composed of all GEMS galaxies with Sérsic indices n<2.5, derived from fits to the galaxy images. We account fully for selection effe…
The Surprisingly Steep Mass Profile of A1689, from a Lensing Analysis of Subaru Images
Kong, X.; Broadhurst, T.; Umetsu, K. +4 more
Subaru observations of A1689 (z=0.183) are used to derive an accurate, model-independent mass profile for the entire cluster, r<~2 Mpc h-1, by combining magnification bias and distortion measurements. The projected mass profile steepens quickly with increasing radius, falling away to zero at r~1.0 Mpc h-1, well short of th…