Search Publications
Shock Heating of the Merging Galaxy Cluster A521
Brunetti, G.; Giacintucci, S.; Bourdin, H. +2 more
A521 is an interacting galaxy cluster located at z = 0.247, hosting a low-frequency radio halo connected to an eastern radio relic. Previous Chandra observations hinted at the presence of an X-ray brightness edge at the position of the relic, which may be a shock front. We analyze a deep observation of A521 recently performed with XMM-Newton in or…
Lyα Escape from z ~ 0.03 Star-forming Galaxies: The Dominant Role of Outflows
Leitherer, Claus; Wofford, Aida; Salzer, John
The usefulness of H I Lyα photons for characterizing star formation in the distant universe is limited by our understanding of the astrophysical processes that regulate their escape from galaxies. These processes can only be observed in detail out to a few × 100 Mpc. Past nearby (z < 0.3) spectroscopic studies are based on small samples and/or …
Red Giant Branch Bump Brightness and Number Counts in 72 Galactic Globular Clusters Observed with the Hubble Space Telescope
Udalski, Andrzej; Pinsonneault, Marc H.; Nataf, David M. +1 more
We present the broadest and most precise empirical investigation of red giant branch bump (RGBB) brightness and number counts ever conducted. We implement a new method and use data from two Hubble Space Telescope globular cluster (GC) surveys to measure the brightness and star counts of the RGBB in 72 GCs. The median measurement precision is 0.018…
An X-Ray View of the Jet Cycle in the Radio-loud AGN 3C120
Miller, Eric D.; Fabian, Andrew C.; Brenneman, Laura W. +10 more
We present a study of the central engine in the broad-line radio galaxy 3C120 using a multi-epoch analysis of a deep XMM-Newton observation and two deep Suzaku pointings (in 2012). In order to place our spectral data into the context of the disk-disruption/jet-ejection cycles displayed by this object, we monitor the source in the UV/X-ray bands, a…
The Impact of Starbursts on the Circumgalactic Medium
Heckman, Timothy; Wild, Vivienne; Borthakur, Sanchayeeta +2 more
We present a study exploring the impact of a starburst on the properties of the surrounding circumgalactic medium (CGM): gas located beyond the galaxy's stellar body and extending out to the virial radius (~200 kpc). We obtained ultraviolet spectroscopic data from the Cosmic Origins Spectrograph (COS) probing the CGM of 20 low-redshift foreground …
A Cosmic Microwave Background Lensing Mass Map and Its Correlation with the Cosmic Infrared Background
Bock, J.; Conley, A.; Bleem, L. E. +54 more
We use a temperature map of the cosmic microwave background (CMB) obtained using the South Pole Telescope at 150 GHz to construct a map of the gravitational convergence to z ~ 1100, revealing the fluctuations in the projected mass density. This map shows individual features that are significant at the ~4σ level, providing the first image of CMB le…
Measuring the Rotational Periods of Isolated Magnetic White Dwarfs
Burleigh, Matthew R.; Marsh, Thomas R.; Knigge, Christian +2 more
We present time-series photometry of 30 isolated magnetic white dwarfs, surveyed with the Jacobus Kapteyn Telescope between 2002 August and 2003 May. We find that 9 were untestable due to varying comparison stars, but of the remaining 21, 5 (24%) are variable with reliably derived periods, while a further 9 (43%) are seen to vary during our study,…
The Ultra-long GRB 111209A. II. Prompt to Afterglow and Afterglow Properties
Piro, L.; De Pasquale, M.; Klotz, A. +7 more
The "ultra-long" gamma-ray burst GRB 111209A at redshift z = 0.677 is the longest GRB ever observed thus far, with a rest frame prompt emission duration of ~4 hr. In order to explain the burst exceptional longevity, a low-metallicity blue supergiant progenitor was invoked. In this article we further constrain the phenomenology and progenitor prope…
The COS/UVES Absorption Survey of the Magellanic Stream. I. One-tenth Solar Abundances along the Body of the Stream
Richter, Philipp; Bland-Hawthorn, Joss; Fox, Andrew J. +5 more
The Magellanic Stream (MS) is a massive and extended tail of multi-phase gas stripped out of the Magellanic Clouds and interacting with the Galactic halo. In this first paper of an ongoing program to study the Stream in absorption, we present a chemical abundance analysis based on HST/COS and VLT/UVES spectra of four active galactic nuclei (RBS 14…
An Extremely Luminous and Variable Ultraluminous X-Ray Source in the Outskirts of Circinus Observed with NuSTAR
Ptak, A.; Harrison, F.; Stern, D. +16 more
Following a serendipitous detection with the Nuclear Spectroscopic Telescope Array (NuSTAR), we present a multi-epoch spectral and temporal analysis of an extreme ultraluminous X-ray source (ULX) located in the outskirts of the Circinus galaxy, hereafter Circinus ULX5, including coordinated XMM-Newton+NuSTAR follow-up observations. The NuSTAR data…