Search Publications
HST/COS Spectra of Three QSOs That Probe the Circumgalactic Medium of a Single Spiral Galaxy: Evidence for Gas Recycling and Outflow
Savage, Blair D.; Shull, J. Michael; Danforth, Charles W. +5 more
We have used the Cosmic Origins Spectrograph (COS) to obtain far-UV spectra of three closely spaced QSO sight lines that probe the circumgalactic medium (CGM) of an edge-on spiral galaxy, ESO 157-49, at impact parameters of 74 and 93 h -1 70 kpc near its major axis and 172 h -1 70 kpc along its minor axi…
Characterization of Intracluster Medium Temperature Distributions of 62 Galaxy Clusters with XMM-Newton
Fabian, A. C.; Sanders, J. S.; Peterson, J. R. +2 more
We measure the intracluster medium (ICM) temperature distributions for 62 galaxy clusters in the HIFLUGCS, an X-ray flux-limited sample, with available X-ray data from XMM-Newton. We search for correlations between the width of the temperature distributions and other cluster properties, including median cluster temperature, luminosity, size, prese…
An Archival Chandra and XMM-Newton Survey of Type 2 Quasars
Heckman, Timothy; Zakamska, Nadia L.; Ptak, Andrew +1 more
In order to investigate obscuration in high-luminosity type 2 active galactic nuclei (AGNs), we analyzed Chandra and XMM-Newton archival observations for 71 type 2 quasars detected at 0.05 < z < 0.73, which were selected based on their [O III] λ5007 emission lines. For 54 objects with good spectral fits, the observed hard X-ray luminosity ra…
The Cosmic Evolution of Faint Satellite Galaxies as a Test of Galaxy Formation and the Nature of Dark Matter
Wang, W.; Treu, T.; Lu, Y. +2 more
The standard cosmological model based on cold dark matter (CDM) predicts a large number of subhalos for each galaxy-size halo. Matching the subhalos to the observed properties of luminous satellites of galaxies in the local universe poses a significant challenge to our understanding of the astrophysics of galaxy formation. We show that the cosmic …
Rapid Gamma-Ray Flux Variability during the 2013 March Crab Nebula Flare
Cheung, C. C.; Grove, J. E.; Hays, E. +5 more
We report on a bright flare in the Crab Nebula detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. The period of significantly increased luminosity occurred in 2013 March and lasted for approximately two weeks. During this period, we observed flux variability on timescales of approximately 5 hr. The combined ph…
Timing and Spectral Properties of Be/X-Ray Pulsar EXO 2030+375 during a Type I Outburst
Maitra, Chandreyee; Paul, Biswajit; Naik, Sachindra +1 more
We present results from a study of broadband timing and spectral properties of EXO 2030+375 using a Suzaku observation. Pulsations with a period of 41.41 s and strong energy-dependent pulse profiles were clearly detected up to 100 keV. Narrow dips are seen in the profiles up to ~70 keV. The presence of prominent dips at several phases in the profi…
Multi-wavelength Hubble Space Telescope Photometry of Stellar Populations in NGC 288
Anderson, J.; Milone, A. P.; Marino, A. F. +5 more
We present new UV observations for NGC 288, taken with the WFC3 detector on board the Hubble Space Telescope, and combine them with existing optical data from the archive to explore the multiple-population phenomenon in this globular cluster (GC). The WFC3's UV filters have demonstrated an uncanny ability to distinguish multiple populations along …
The Abundance, Ortho/Para Ratio, and Deuteration of Water in the High-mass Star-forming Region NGC 6334 I
Ceccarelli, C.; Comito, C.; Schilke, P. +6 more
We present Herschel/HIFI observations of 30 transitions of water isotopologues toward the high-mass star-forming region NGC 6334 I. The line profiles of H16 2O, H17 2O, H18 2O, and HDO show a complex pattern of emission and absorption components associated with the embedded hot core…
Stellar Populations of Lyman Break Galaxies at z ~= 1-3 in the HST/WFC3 Early Release Science Observations
Holtzman, J. A.; O'Connell, R. W.; Finkelstein, S. L. +24 more
We analyze the spectral energy distributions (SEDs) of Lyman break galaxies (LBGs) at z ~= 1-3 selected using the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) UVIS channel filters. These HST/WFC3 observations cover about 50 arcmin2 in the GOODS-South field as a part of the WFC3 Early Release Science program. These LBGs at z ~…
Solar Magnetic Tracking. IV. The Death of Magnetic Features
Lamb, D. A.; DeForest, C. E.; Parnell, C. E. +2 more
The removal of magnetic flux from the quiet-Sun photosphere is important for maintaining the statistical steady state of the magnetic field there, for determining the magnetic flux budget of the Sun, and for estimating the rate of energy injected into the upper solar atmosphere. Magnetic feature death is a measurable proxy for the removal of detec…