Search Publications
Observations of Mass Loss from the Transiting Exoplanet HD 209458b
France, Kevin; Stocke, John T.; Yang, Hao +4 more
Using the new Cosmic Origins Spectrograph on the Hubble Space Telescope, we obtained moderate-resolution, high signal/noise ultraviolet spectra of HD 209458 and its exoplanet HD 209458b during transit, both orbital quadratures, and secondary eclipse. We compare transit spectra with spectra obtained at non-transit phases to identify spectral featur…
Physical Conditions in a Young, Unreddened, Low-metallicity Galaxy at High Redshift
Pettini, Max; Erb, Dawn K.; Shapley, Alice E. +3 more
Increasingly large samples of galaxies are now being discovered at redshifts z ~ 5-6 and higher. Many of these objects are inferred to be young, low in mass, and relatively unreddened, but detailed analysis of their high quality spectra will not be possible until the advent of future facilities. In this paper, we shed light on the physical conditi…
Dichotomy of Solar Coronal Jets: Standard Jets and Blowout Jets
Cirtain, Jonathan W.; Moore, Ronald L.; Sterling, Alphonse C. +1 more
By examining many X-ray jets in Hinode/X-Ray Telescope coronal X-ray movies of the polar coronal holes, we found that there is a dichotomy of polar X-ray jets. About two thirds fit the standard reconnection picture for coronal jets, and about one third are another type. We present observations indicating that the non-standard jets are counterparts…
z ~ 7 Galaxies in the HUDF: First Epoch WFC3/IR Results
Trenti, M.; Oesch, P. A.; Carollo, C. M. +7 more
We present a sample of 16 robust z ~ 7 z 850-drop galaxies detected by the newly installed Wide Field Camera 3 (WFC3)/IR on the Hubble Space Telescope. Our analysis is based on the first epoch data of the HUDF09 program covering the Hubble Ultra Deep Field with 60 orbits of Y 105, J 125, and H 160 observ…
The Distance, Mass, and Radius of the Neutron Star in 4U 1608-52
Güver, Tolga; Özel, Feryal; Cabrera-Lavers, Antonio +1 more
Low-mass X-ray binaries (LMXBs) that show thermonuclear bursts are ideal sources for constraining the equation of state of neutron star matter. The lack of independent distance measurements for most of these sources, however, prevent a systematic exploration of the masses and radii of the neutron stars, hence limiting the equation-of-state studies…
Bulgeless Giant Galaxies Challenge Our Picture of Galaxy Formation by Hierarchical Clustering
Kormendy, John; Bender, Ralf; Drory, Niv +1 more
To better understand the prevalence of bulgeless galaxies in the nearby field, we dissect giant Sc-Scd galaxies with Hubble Space Telescope (HST) photometry and Hobby-Eberly Telescope (HET) spectroscopy. We use the HET High Resolution Spectrograph (resolution R ≡ λ/FWHM ~= 15, 000) to measure stellar velocity dispersions in the nuclear star cluste…
A Weak Lensing Study of X-ray Groups in the Cosmos Survey: Form and Evolution of the Mass-Luminosity Relation
Koekemoer, Anton M.; Elvis, Martin; Ellis, Richard S. +27 more
Measurements of X-ray scaling laws are critical for improving cosmological constraints derived with the halo mass function and for understanding the physical processes that govern the heating and cooling of the intracluster medium. In this paper, we use a sample of 206 X-ray-selected galaxy groups to investigate the scaling relation between X-ray …
Comprehensive Analysis of Coronal Mass Ejection Mass and Energy Properties Over a Full Solar Cycle
Howard, R. A.; Patsourakos, S.; Michalek, G. +3 more
The LASCO coronagraphs, in continuous operation since 1995, have observed the evolution of the solar corona and coronal mass ejections (CMEs) over a full solar cycle with high-quality images and regular cadence. This is the first time that such a data set becomes available and constitutes a unique resource for the study of CMEs. In this paper, we …
The Stellar Mass Density and Specific Star Formation Rate of the Universe at z ~ 7
Franx, Marijn; Labbé, Ivo; Kriek, Mariska +4 more
We use a robust sample of 11 z ~ 7 galaxies (z 850 dropouts) to estimate the stellar mass density (SMD) of the universe when it was only ~750 Myr old. We combine the very deep optical to near-infrared photometry from the Hubble Space Telescope Advanced Camera for Surveys and NICMOS cameras with mid-infrared Spitzer Infrared Array Camera…
A Correlation Between Stellar Activity and Hot Jupiter Emission Spectra
Knutson, Heather A.; Howard, Andrew W.; Isaacson, Howard
We present evidence for a correlation between the observed properties of hot Jupiter emission spectra and the activity levels of the host stars measured using Ca II H & K emission lines. We find that planets with dayside emission spectra that are well-described by standard one-dimensional atmosphere models with water in absorption (HD 189733, …