Search Publications
The Stellar Population of the Chamaeleon I Star-forming Region
Luhman, K. L.
I present a new census of the stellar population in the Chamaeleon I star-forming region. Using optical and near-IR photometry and follow-up spectroscopy, I have discovered 50 new members of Chamaeleon I, expanding the census of known members to 226 objects. Fourteen of these new members have spectral types later than M6, which doubles the number …
COSMOS: Three-dimensional Weak Lensing and the Growth of Structure
Ellis, Richard; Mobasher, Bahram; Leauthaud, Alexie +17 more
We present a three-dimensional cosmic shear analysis of the Hubble Space Telescope COSMOS survey, the largest ever optical imaging program performed in space. We have measured the shapes of galaxies for the telltale distortions caused by weak gravitational lensing and traced the growth of that signal as a function of redshift. Using both 2D and 3D…
COSMOS Morphological Classification with the Zurich Estimator of Structural Types (ZEST) and the Evolution Since z = 1 of the Luminosity Function of Early, Disk, and Irregular Galaxies
Kneib, J. -P.; Aussel, H.; Sanders, D. B. +26 more
Motivated by the desire to reliably and automatically classify structure of thousands of COSMOS galaxies, we present ZEST, the Zurich Estimator of Structural Types. To classify galaxy structure, ZEST uses (1) five nonparametric diagnostics: asymmetry, concentration, Gini coefficient, second-order moment of the brightest 20% of galaxy pixels, and e…
Deep GALEX Imaging of the COSMOS HST Field: A First Look at the Morphology of z ~ 0.7 Star-forming Galaxies
Aussel, H.; Sanders, D. B.; Ilbert, O. +34 more
We present a study of the morphological nature of redshift z~0.7 star-forming galaxies using a combination of HST ACS, GALEX, and ground-based images of the COSMOS field. Our sample consists of 8146 galaxies, 5777 of which are detected in the GALEX near-ultraviolet band (2310 Å or ~1360 Å rest frame) down to a limiting magnitude of 25.5 (AB), and …
Evolution of the Frequency of Luminous (>=L*V) Close Galaxy Pairs at z < 1.2 in the COSMOS Field
Sanders, D. B.; Kartaltepe, J. S.; Murayama, T. +8 more
We measure the fraction of luminous galaxies in pairs at projected separations of 5-20 kpc out to z=1.2 in the Cosmic Evolution Survey (COSMOS) field using ACS images and photometric redshifts derived from an extensive multiwavelength data set. Analysis of a complete sample of 106,188 galaxies more luminous than MV=-19.8 (~L*…
The XMM-Newton Wide-Field Survey in the COSMOS Field. III. Optical Identification and Multiwavelength Properties of a Large Sample of X-Ray-Selected Sources
Finoguenov, A.; Taniguchi, Y.; Salvato, M. +31 more
We present the optical identification of a sample of 695 X-ray sources detected in the first 1.3 deg2 of the COSMOS XMM-Newton survey, down to a 0.5-2 keV (2-10 keV) limiting flux of ~10-15 erg cm-2 s-1 (~5×10-15 erg cm-2 s-1). In order to identify the correct optical cou…
COSBO: The MAMBO 1.2 Millimeter Imaging Survey of the COSMOS Field
Lutz, D.; Aussel, H.; Menten, K. M. +20 more
The inner 20×20 arcmin2 of the COSMOS field was imaged at 250 GHz (1.2 mm) to an rms noise level of ~1 mJy per 11" beam using the Max-Planck Millimeter Bolometer Array (MAMBO-2) at the IRAM 30 m telescope. We detect 15 sources at significance between 4 and 7 σ, 11 of which are also detected at 1.4 GHz with the VLA with a flux density &g…
The Redshift Evolution of Early-Type Galaxies in COSMOS: Do Massive Early-Type Galaxies Form by Dry Mergers?
Kneib, J. -P.; Aussel, H.; Cimatti, A. +26 more
We study the evolution since z~1 of the rest-frame B luminosity function of ETGs in ~0.7 deg2 in the COSMOS field. In order to identify all progenitors of local ETGs we construct the sample of high-z galaxies using two complementary criteria: (1) a morphological selection based on the Zurich Estimator of Structural Types and (2) a photo…
The ACS Fornax Cluster Survey. I. Introduction to the Survey and Data Reduction Procedures
Jordán, Andrés; Infante, Leopoldo; Tonry, John L. +7 more
The Fornax Cluster is a conspicuous cluster of galaxies in the southern hemisphere and the second largest collection of early-type galaxies within <~20 Mpc after the Virgo Cluster. In this paper, we present a brief introduction to the ACS Fornax Cluster Survey-a program to image, in the F475W (g475) and F850LP (z850) bandp…
Abundances and Behavior of 12CO, 13CO, and C2 in Translucent Sight Lines
York, D. G.; Sonnentrucker, P.; Welty, D. E. +1 more
Using UV spectra obtained with FUSE, HST, and/or IUE together with higher resolution optical spectra, we determine interstellar column densities of 12CO, 13CO, and/or C2 for 10 Galactic sight lines with E(B-V) ranging from 0.37 to 0.72. The N(CO)/N(H2) ratio varies over a factor of 100 in this sample, d…