Search Publications
Improved Photometric Redshifts with Surface Luminosity Priors
Hathi, Nimish P.; Pirzkal, Nor; Cohen, Seth +6 more
We apply Bayesian statistics with prior probabilities of galaxy surface luminosity (SL) to improve photometric redshifts. We apply the method to a sample of 1266 galaxies with spectroscopic redshifts in the GOODS North and South fields at 0.1 lsim z lsim 2.0. We start with spectrophotometric redshifts (SPZs) based on Probing Evolution and Reioniza…
Globular Cluster Populations in Four Early-Type Poststarburst Galaxies
Schweizer, François; Goudfrooij, Paul; Puzia, Thomas H. +2 more
We present a study of the globular cluster (GC) systems of four early-type poststarburst galaxies using deep g- and I-band images from the Advanced Camera for Surveys aboard the Hubble Space Telescope. All the galaxies feature shells distributed around their main bodies and are thus likely merger remnants. The color distribution of the GCs in all …
Near-Ultraviolet Sources in the Hubble Ultra Deep Field: The Catalog
Gardner, Jonathan P.; Teplitz, Harry I.; Siana, Brian +3 more
The catalog from the first high-resolution U-band image of the Hubble Ultra Deep Field, taken with Hubble's Wide-Field Planetary Camera 2 through the F300W filter, is presented. We detect 96 U-band objects and compare and combine this catalog with a Great Observatories Origins Deep Survey B-selected catalog that provides B, V, i, and z photometry,…
Intermediate-Age Clusters in a Field Containing M31 and M32 Stars
Mateo, Mario; Worthey, Guy; Rudenko, Pavlo
Hubble Space Telescope/Advanced Camera for Surveys fields toward M31 and M32 were examined for the presence of possible star clusters. On the basis of stellar photometry, two intermediate-age clusters were found in the field that contains both M31 and M32 stars. One is approximately 200 Myr of age with a mass ~400 M sun, and the other i…
Star Clusters in Pseudobulges of Spiral Galaxies
Stiavelli, Massimo; Scarlata, Claudia; Wyse, Rosemary F. G. +3 more
We present a study of the properties of the star-cluster systems around pseudobulges of late-type spiral galaxies using a sample of 11 galaxies with distances from 17 Mpc to 37 Mpc. Star clusters are identified from multiband Hubble Space Telescope ACS and WFPC2 imaging data by combining detections in three bands (F435W and F814W with ACS and F606…
XMM-Newton Observations of SDSS J143030.22 - 001115.1: An Unusually Flat-Spectrum Active Galactic Nucleus
Williams, R.; Grupe, D.; Mathur, S. +3 more
We present XMM-Newton observations of the type 1 active galactic nucleus (AGN) SDSS 1430 - 0011 (z = 0.1032). The low signal-to-noise ratio spectrum of this source obtained in a snap shot Chandra observation showed an unusually flat continuum. With the follow-up XMM-Newton observations, we find that the source spectrum is complex; it either has an…
Density Effects on Mg II Emission Lines of Mira AB
Sanad, M. R.; Bobrowsky, M.; Hamdy, M. A. +1 more
We present ultraviolet spectra of the Mira AB binary system taken by the International Ultraviolet Explorer during the period from 1979 to 1995. In this study, we concentrated on the Mg II k and h emission lines arising primarily from Mira B. The broad Mg II profiles from Mira B are enhanced on the red side of the profile and obscured on the blue …
Revealing Probable Universal Features in the Lower Red Giant Branch Luminosity Functions of Galactic Globular Clusters
Kravtsov, V. V.
This paper aims at demonstrating, for the first time, very probable universal peculiarities of the evolution of stars in the lower red giant branch (RGB) of Galactic globular clusters (GCs), reflected in two corresponding dips in the luminosity functions (LFs). By relying on the database of Hubble Space Telescope photometry of GCs, we analyze the …
The Acs Survey of Globular Clusters. V. Generating a Comprehensive Star Catalog for each Cluster
Milone, Antonino P.; Anderson, Jay; Majewski, Steven R. +10 more
The ACS Survey of Globular Clusters has used Hubble Space Telescope's Wide-Field Channel to obtain uniform imaging of 65 of the nearest globular clusters to provide an extensive homogeneous data set for a broad range of scientific investigations. The survey goals required not only a uniform observing strategy, but also a uniform reduction strategy…
The Structure of Classical Bulges and Pseudobulges: the Link Between Pseudobulges and SÉRSIC Index
Drory, Niv; Fisher, David B.
In this paper, we study the properties of pseudobulges (bulges that appear similar to disk galaxies) and classical bulges (bulges which appear similar to E-type galaxies) in bulge-disk decompositions. We show that the distribution of bulge Sérsic indices, nb , is bimodal, and this bimodality correlates with the morphology of the bulge. …