Search Publications
Using Hα Morphology and Surface Brightness Fluctuations to Age-date Star Clusters in M83
Mutchler, Max; McCarthy, Patrick J.; Calzetti, Daniela +22 more
We use new WFC3 observations of the nearby grand-design spiral galaxy M83 to develop two independent methods for estimating the ages of young star clusters. The first method uses the physical extent and morphology of Hα emission to estimate the ages of clusters younger than τ ≈ 10 Myr. It is based on the simple premise that the gas in very young (…
MUSTANG High Angular Resolution Sunyaev-Zel'dovich Effect Imaging of Substructure in Four Galaxy Clusters
Sun, M.; Sarazin, C. L.; Devlin, M. J. +6 more
We present resolved images of four massive clusters of galaxies through the Sunyaev-Zel'dovich effect (SZE). These measurements, made at 90 GHz with the MUSTANG receiver on the Green Bank Telescope (GBT), reveal pressure substructure to the intracluster medium (ICM) in three of the four systems. The SZE and X-ray morphology of MACS0744.8+3927 are …
The Spectroscopic Signature of Quasi-periodic Upflows in Active Region Timeseries
De Pontieu, Bart; McIntosh, Scott W.; Tian, Hui
Quasi-periodic propagating disturbances are frequently observed in coronal intensity image sequences. These disturbances have historically been interpreted as being the signature of slow-mode magnetoacoustic waves propagating into the corona. The detailed analysis of Hinode EUV Imaging Spectrometer (EIS) timeseries observations of an active region…
Studying Extreme Ultraviolet Wave Transients with a Digital Laboratory: Direct Comparison of Extreme Ultraviolet Wave Observations to Global Magnetohydrodynamic Simulations
Lugaz, Noé; Downs, Cooper; Roussev, Ilia I. +3 more
In this work, we describe our effort to explore the signatures of large-scale extreme ultraviolet (EUV) transients in the solar corona (EUV waves) using a three-dimensional thermodynamic magnetohydrodynamic model. We conduct multiple simulations of the 2008 March 25 EUV wave (~18:40 UT), observed both on and off of the solar disk by the STEREO-A a…
Off-limb Solar Coronal Wavefronts from SDO/AIA Extreme-ultraviolet Observations—Implications for Particle Production
Schwadron, N. A.; Korreck, K. E.; Lobzin, V. V. +2 more
We derive kinematic properties for two recent solar coronal transient waves observed off the western solar limb with the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) mission. The two waves occurred over ~10 minute intervals on consecutive days—2010 June 12 and 13. For the first time, off-limb waves are imaged wi…
The zCOSMOS-SINFONI Project. I. Sample Selection and Natural-seeing Observations
Lutz, D.; Daddi, E.; Förster Schreiber, N. M. +21 more
The zCOSMOS-SINFONI project is aimed at studying the physical and kinematical properties of a sample of massive z ~ 1.4-2.5 star-forming galaxies, through SINFONI near-infrared integral field spectroscopy (IFS), combined with the multiwavelength information from the zCOSMOS (COSMOS) survey. The project is based on one hour of natural-seeing observ…
Fluid Dynamics of Stellar Jets in Real Time: Third Epoch Hubble Space Telescope Images of HH 1, HH 34, and HH 47
Hartigan, P.; Frank, A.; Foster, J. M. +6 more
We present new, third-epoch Hubble Space Telescope Hα and [S II] images of three Herbig-Haro (HH) jets (HH 1&2, HH 34, and HH 47) and compare the new images with those from previous epochs. The high spatial resolution, coupled with a time series whose cadence is of order both the hydrodynamic and radiative cooling timescales of the flow, allow…
RCW 86: A Type Ia Supernova in a Wind-blown Bubble
Blair, William P.; Reynolds, Stephen P.; Raymond, John C. +7 more
We report results from a multi-wavelength analysis of the Galactic supernova remnant RCW 86, the proposed remnant of the supernova of 185 A.D. We show new infrared observations from the Spitzer Space Telescope and the Wide-Field Infrared Survey Explorer, where the entire shell is detected at 24 and 22 µm. We fit the infrared flux ratios with…
Discovery of a Multiply Lensed Submillimeter Galaxy in Early HerMES Herschel/SPIRE Data
Pérez-Fournon, I.; Rodighiero, G.; Valtchanov, I. +88 more
We report the discovery of a bright (f(250 µm)>400 mJy), multiply lensed submillimeter galaxy HERMES J105751.1+573027 in Herschel/SPIRE Science Demonstration Phase data from the HerMES project. Interferometric 880 µm Submillimeter Array observations resolve at least four images with a large separation of ~9''. A high-resolution adap…
A Population of X-Ray Weak Quasars: PHL 1811 Analogs at High Redshift
Brandt, W. N.; Hall, Patrick B.; Schneider, Donald P. +6 more
We report the results from Chandra and XMM-Newton observations of a sample of 10 type 1 quasars selected to have unusual UV emission-line properties (weak and blueshifted high-ionization lines; strong UV Fe emission) similar to those of PHL 1811, a confirmed intrinsically X-ray weak quasar. These quasars were identified by the Sloan Digital Sky Su…