Search Publications
Planck early results. IV. First assessment of the High Frequency Instrument in-flight performance
Kneissl, R.; Miville-Deschênes, M. -A.; Boulanger, F. +163 more
The Planck High Frequency Instrument (HFI) is designed to measure the temperature and polarization anisotropies of the cosmic microwave background and Galactic foregrounds in six ~30% bands centered at 100, 143, 217, 353, 545, and 857 GHz at an angular resolution of 10' (100 GHz), 7' (143 GHz), and 5' (217 GHz and higher). HFI has been operating f…
The Southern Proper Motion Program. IV. The SPM4 Catalog
Beers, Timothy C.; Lee, Young Sun; Casetti-Dinescu, Dana I. +8 more
We present the fourth installment of the Yale/San Juan Southern Proper Motion Catalog, SPM4. The SPM4 contains absolute proper motions, celestial coordinates, and B, V photometry for over 103 million stars and galaxies between the south celestial pole and -20° declination. The catalog is roughly complete to V = 17.5 and is based on photographic an…
2XMM ultraluminous X-ray source candidates in nearby galaxies
Roberts, T. P.; Mateos, S.; Walton, D. J. +1 more
Ultraluminous X-ray sources (ULXs) are some of the most enigmatic X-ray bright sources known to date. It is generally accepted that they cannot host black holes as large as those associated with active galaxies, but they appear to be significantly more luminous than their better understood Galactic X-ray binary (XRB) cousins, while displaying an i…
Galaxies in X-Ray Groups. I. Robust Membership Assignment and the Impact of Group Environments on Quenching
Koekemoer, Anton M.; Coccato, Lodovico; Leauthaud, Alexie +19 more
Understanding the mechanisms that lead dense environments to host galaxies with redder colors, more spheroidal morphologies, and lower star formation rates than field populations remains an important problem. As most candidate processes ultimately depend on host halo mass, accurate characterizations of the local environment, ideally tied to halo m…
Strong-lensing analysis of a complete sample of 12 MACS clusters at z > 0.5: mass models and Einstein radii
Broadhurst, Tom; Zitrin, Adi; Benítez, Narciso +2 more
We present the results of a strong-lensing analysis of a complete sample of 12 very luminous X-ray clusters at z > 0.5 using HST/ACS images. Our modelling technique has uncovered some of the largest known critical curves outlined by many accurately predicted sets of multiple images. The distribution of Einstein radii has a median value of ≃28 a…
Columbus crater and other possible groundwater-fed paleolakes of Terra Sirenum, Mars
Clark, R. N.; Wray, J. J.; Milliken, R. E. +11 more
Columbus crater in the Terra Sirenum region of the Martian southern highlands contains light-toned layered deposits with interbedded sulfate and phyllosilicate minerals, a rare occurrence on Mars. Here we investigate in detail the morphology, thermophysical properties, mineralogy, and stratigraphy of these deposits; explore their regional context;…
Images of Asteroid 21 Lutetia: A Remnant Planetesimal from the Early Solar System
Jorda, L.; Pätzold, M.; Bertaux, J. -L. +55 more
Images obtained by the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) cameras onboard the Rosetta spacecraft reveal that asteroid 21 Lutetia has a complex geology and one of the highest asteroid densities measured so far, 3.4 ± 0.3 grams per cubic centimeter. The north pole region is covered by a thick layer of regolith, which…
Herschel-ATLAS: counterparts from the ultraviolet-near-infrared in the science demonstration phase catalogue
Rodighiero, G.; Ivison, R. J.; Sutherland, W. +45 more
We present a technique to identify optical counterparts of 250-µm-selected sources from the Herschel-ATLAS survey. Of the 6621 250 µm > 32-mJy sources in our science demonstration catalogue we find that ∼60 per cent have counterparts brighter than r = 22.4 mag in the Sloan Digital Sky Survey. Applying a likelihood ratio technique we…
Sequence and timing of conditions on early Mars
Head, James W.; Fassett, Caleb I.
The geological record of early Mars displays a variety of features that indicate fundamental differences from more recent conditions. These include evidence for: (1) widespread aqueous alteration and phyllosilicate formation, (2) the existence of an active magnetic dynamo, (3) the erosion of extensive valley networks, some thousands of kilometers …
GOODS-Herschel: Gas-to-dust Mass Ratios and CO-to-H2 Conversion Factors in Normal and Starbursting Galaxies at High-z
Aussel, H.; Daddi, E.; Elbaz, D. +15 more
We explore the gas-to-dust mass ratio (M gas/M d) and the CO luminosity-to-M gas conversion factor (αCO) of two well-studied galaxies in the Great Observatories Origins Deep Survey North field that are expected to have different star-forming modes, the starburst GN20 at z = 4.05 and the normal star-formi…