Search Publications
Star Formation in the Cluster Merger DLSCL J0916.2+2953
Dawson, W. A.; Lemaux, B. C.; Wittman, D. +3 more
We investigate star formation in DLSCL J0916.2+2953, a dissociative merger of two clusters at z = 0.53 that has progressed {1.1}-0.4+1.3 Gyr since the first pass-through. We attempt to reveal the effects a collision may have had on the evolution of the cluster galaxies by tracing their star formation history. We probe current…
Stagnant Shells in the Vicinity of the Dusty Wolf-Rayet-OB Binary WR 112
Moffat, A. F. J.; Schödel, R.; Ressler, M. E. +3 more
We present high spatial resolution mid-infrared images of the nebula around the late-type carbon-rich Wolf-Rayet (WC)-OB binary system WR 112 taken by the recently upgraded VLT spectrometer and imager for the mid-infrared (VISIR) with the PAH1, Ne ii_2, and Q3 filters. The observations reveal a morphology resembling a series of arc-like filaments …
Gas Sloshing in Abell 2204: Constraining the Properties of the Magnetized Intracluster Medium
Andrade-Santos, Felipe; Jones, Christine; Li, Zhiyuan +2 more
The rich galaxy cluster Abell 2204 exhibits edges in its X-ray surface brightness at ∼65 and 35 {kpc} west and east of its center, respectively. The presence of these edges, which were interpreted as sloshing cold fronts, implies that the intracluster medium (ICM) was recently disturbed. We analyze the properties of the ICM using multiple Chandra …
Isophote Shapes of Early-type Galaxies in Massive Clusters at z ∼ 1 and 0
Perlmutter, Saul; Morokuma, Tomoki; Doi, Mamoru +5 more
We compare the isophote shape parameter a4 of early-type galaxies (ETGs) between z ∼ 1 and 0 as a proxy for dynamics to investigate the epoch at which the dynamical properties of ETGs are established, using cluster ETG samples with stellar masses of {log}({M}* /{M}⊙ )≥slant 10.5 which have spectroscopic redshifts. …
Insights from Synthetic Star-forming Regions. II. Verifying Dust Surface Density, Dust Temperature, and Gas Mass Measurements with Modified Blackbody Fitting
Dale, James E.; Robitaille, Thomas P.; Koepferl, Christine M.
We use a large data set of realistic synthetic observations (produced in Paper I of this series) to assess how observational techniques affect the measurement physical properties of star-forming regions. In this part of the series (Paper II), we explore the reliability of the measured total gas mass, dust surface density and dust temperature maps …
A Radio Emission Analysis of Classical Nova V351 Pup (1991)
Strader, Jay; Chomiuk, Laura; Finzell, Thomas +2 more
Previously, Nova Puppis 1991 (V351 Pup) was measured to host one of the most massive ejections claimed in the literature. Multi-frequency radio detections from one epoch were published for this nova in the 1990's; and yet, the remaining data collected by the Karl G. Jansky Very Large Array (VLA) have remained unpublished. In this paper, we analyze…
Identification of the Hard X-Ray Source Dominating the E > 25 keV Emission of the Nearby Galaxy M31
Lien, A.; Lehmer, B. D.; Hornschemeier, A. E. +15 more
We report the identification of a bright hard X-ray source dominating the M31 bulge above 25 keV from a simultaneous NuSTAR-Swift observation. We find that this source is the counterpart to Swift J0042.6+4112, which was previously detected in the Swift BAT All-sky Hard X-ray Survey. This Swift BAT source had been suggested to be the combined emiss…
Investigating the Evolution of the Dual AGN System ESO 509-IG066
Harrison, F. A.; Stern, D.; Treister, E. +13 more
We analyze the evolution of the dual active galactic nucleus (AGN) in ESO 509-IG066, a galaxy pair located at z = 0.034 whose nuclei are separated by 11 kpc. Previous observations with XMM-Newton on this dual AGN found evidence for two moderately obscured ({N}{{H}} ∼ 1022 cm-2) X-ray luminous ({L}{{X}} ∼…
Exploring the Helium Core of the δ Scuti Star CoRoT 102749568 with Asteroseismology
Li, Yan; Chen, Xinghao; Chen, Yanhui +2 more
Based on regularities in rotational splitting, we seek possible multiplets for the observed frequencies of CoRoT 102749568. There are 21 sets of multiplets identified, including four sets of multiplets with l = 1, nine sets of multiplets with l = 2, and eight sets of multiplets with l = 3. In particular, there are three complete triplets (f10…
A Systematic Study of the Thermal and Nonthermal Emission in the Supernova Remnant RCW 86 with Suzaku
Katsuda, Satoru; Vink, Jacco; Bamba, Aya +2 more
Diffusive shock acceleration by the shockwaves in supernova remnants (SNRs) is widely accepted as the dominant source for Galactic cosmic rays. However, it is unknown what determines the maximum energy of accelerated particles. The surrounding environment could be one of the key parameters. The SNR RCW 86 shows both thermal and nonthermal X-ray em…