Search Publications
The Star Formation History of the Large Magellanic Cloud
Zaritsky, Dennis; Harris, Jason
We present the first ever global, spatially resolved reconstruction of the star formation history (SFH) of the Large Magellanic Cloud (LMC), based on the application of our StarFISH analysis software to the multiband photometry of 20 million of its stars from the Magellanic Clouds Photometric Survey. The general outlines of our results are consist…
The Spitzer Local Volume Legacy: Survey Description and Infrared Photometry
Dalcanton, J. J.; Walter, F.; Dale, D. A. +21 more
The survey description and the near-, mid-, and far-infrared flux properties are presented for the 258 galaxies in the Local Volume Legacy (LVL). LVL is a Spitzer Space Telescope legacy program that surveys the local universe out to 11 Mpc, built upon a foundation of ultraviolet, Hα, and Hubble Space Telescope imaging from 11HUGS (11 Mpc Hα and Ul…
Spitzer Quasar and Ulirg Evolution Study (QUEST). IV. Comparison of 1 Jy Ultraluminous Infrared Galaxies with Palomar-Green Quasars
Lutz, D.; Genzel, R.; Sturm, E. +16 more
We report the results from a comprehensive study of 74 ultraluminous infrared galaxies (ULIRGs) and 34 Palomar-Green (PG) quasars within z ~ 0.3 observed with the Spitzer Infrared Spectrograph (IRS). The contribution of nuclear activity to the bolometric luminosity in these systems is quantified using six independent methods that span a range in w…
Identification of hydrated silicate minerals on Mars using MRO-CRISM: Geologic context near Nili Fossae and implications for aqueous alteration
Murchie, Scott L.; Ehlmann, Bethany L.; Mustard, John F. +9 more
The Noachian terrain west of the Isidis basin hosts a diverse collection of alteration minerals in rocks comprising varied geomorphic units within a 100,000 km2 region in and near the Nili Fossae. Prior investigations in this region by the Observatoire pour l'Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) instrument on Mars Expre…
The ultraluminous state
Done, Chris; Roberts, Timothy P.; Gladstone, Jeanette C.
We revisit the question of the nature of ultraluminous X-ray sources (ULXs) through a detailed investigation of their spectral shape, using the highest quality X-ray data available in the XMM-Newton public archives (>~10000 counts in their EPIC spectrum). We confirm that simple spectral models commonly used for the analysis and interpretation o…
Liquid water on Enceladus from observations of ammonia and 40Ar in the plume
Young, D. T.; Ip, W. -H.; Lunine, J. I. +13 more
Jets of water ice from surface fractures near the south pole of Saturn's icy moon Enceladus produce a plume of gas and particles. The source of the jets may be a liquid water region under the ice shell-as suggested most recently by the discovery of salts in E-ring particles derived from the plume-or warm ice that is heated, causing dissociation of…
Sodium salts in E-ring ice grains from an ocean below the surface of Enceladus
Kempf, S.; Postberg, F.; Srama, R. +5 more
Saturn's moon Enceladus emits plumes of water vapour and ice particles from fractures near its south pole, suggesting the possibility of a subsurface ocean. These plume particles are the dominant source of Saturn's E ring. A previous in situ analysis of these particles concluded that the minor organic or siliceous components, identified in many ic…
UV Continuum Slope and Dust Obscuration from z ~ 6 to z ~ 2: The Star Formation Rate Density at High Redshift
Chary, R. -R.; Giavalisco, M.; van Dokkum, P. +6 more
We provide a systematic measurement of the rest-frame UV continuum slope β over a wide range in redshift (z ~ 2-6) and rest-frame UV luminosity (0.1 L* z = 3 to 2 L* z = 3) to improve estimates of the star formation rate (SFR) density at high redshift. We utilize the deep optical and infrared data (Advanced Camera for Surveys…
Universality of Solar-Wind Turbulent Spectrum from MHD to Electron Scales
Saur, J.; Alexandrova, O.; Schwartz, S. J. +4 more
To investigate the universality of magnetic turbulence in space plasmas, we analyze seven time periods in the free solar wind under different plasma conditions. Three instruments on Cluster spacecraft operating in different frequency ranges give us the possibility to resolve spectra up to 300 Hz. We show that the spectra form a quasiuniversal spec…
The Kiloparsec-scale Kinematics of High-redshift Star-forming Galaxies
Pettini, Max; Erb, Dawn K.; Shapley, Alice E. +4 more
We present the results of a spectroscopic survey of the kinematic structure of star-forming galaxies at redshift z ~ 2-3 using Keck/OSIRIS integral field spectroscopy. Our sample is comprised of 12 galaxies between redshifts z ~ 2.0 and 2.5 and one galaxy at z ~ 3.3 which are well detected in either Hα or [O III] emission. These galaxies are gener…