Search Publications
Compact E+A Galaxies as a Progenitor of Massive Compact Quiescent Galaxies at 0.2 < z < 0.8
Hwang, Ho Seong; Geller, Margaret J.; Damjanov, Ivana +5 more
We search the Sloan Digital Sky Survey and the Baryon Oscillation Sky Survey to identify ∼5500 massive compact quiescent galaxy candidates at 0.2 < z < 0.8. We robustly classify a subsample of 438 E+A galaxies based on their spectral properties and make this catalog publicly available. We examine sizes, stellar population ages, and kinematic…
Symbiotic Stars in X-Rays. III. Suzaku Observations
Nuñez, N. E.; Nelson, T.; Mukai, K. +2 more
We describe the X-ray emission as observed by Suzaku from five symbiotic stars that we selected for deep Suzaku observations after their initial detection with ROSAT, ASCA, and Swift. We find that the X-ray spectra of all five sources can be adequately fit with absorbed optically thin thermal plasma models, with either single- or multi-temperature…
UV Spectroscopy of Star-grazing Comets Within the 49 Ceti Debris Disk
Roberge, Aki; Miles, Brittany E.; Welsh, Barry
We present the analysis of time-variable Doppler-shifted absorption features in far-UV spectra of the unusual 49 Ceti debris disk. This nearly edge-on disk is one of the brightest known and is one of the very few containing detectable amounts of circumstellar (CS) gas as well as dust. In our two visits of Hubble Space Telescope STIS spectra, varia…
The Prevalence and Impact of Wolf-Rayet Stars in Emerging Massive Star Clusters
Massey, Philip; Johnson, Kelsey E.; Indebetouw, Rémy +1 more
We investigate Wolf-Rayet (WR) stars as a source of feedback contributing to the removal of natal material in the early evolution of massive star clusters. Despite previous work suggesting that massive star clusters clear out their natal material before the massive stars evolve into the WR phase, WR stars have been detected in several emerging mas…
Soft X-Ray Excess from Shocked Accreting Plasma in Active Galactic Nuclei
Tombesi, Francesco; Takahashi, Masaaki; Clark, Peter +2 more
We propose a novel theoretical model to describe the physical identity of the soft X-ray excess that is ubiquitously detected in many Seyfert galaxies, by considering a steady-state, axisymmetric plasma accretion within the innermost stable circular orbit around a black hole (BH) accretion disk. We extend our earlier theoretical investigations on …
A Hot Gaseous Galaxy Halo Candidate with Mg X Absorption
Bregman, Joel N.; Qu, Zhijie
The hot gas in galaxy halos may account for a significant fraction of missing baryons in galaxies, and some of these gases can be traced by high ionization absorption systems in QSO UV spectra. Using high S/N Hubble Space Telescope/Cosmic Origins Spectrograph spectra, we discovered a high ionization state system at z = 1.1912 in the sightline towa…
Discovery of X-Ray Emission from the Galactic Supernova Remnant G32.8-0.1 with Suzaku
Safi-Harb, Samar; Petre, Robert; Terada, Yukikatsu +6 more
We present the first dedicated X-ray study of the supernova remnant (SNR) G32.8-0.1 (Kes 78) with Suzaku. X-ray emission from the whole SNR shell has been detected for the first time. The X-ray morphology is well correlated with the emission from the radio shell, while anti-correlated with the molecular cloud found in the SNR field. The X-ray spec…
Source Regions of the Type II Radio Burst Observed During a CME-CME Interaction on 2013 May 22
Krupar, V.; Gopalswamy, N.; Mäkelä, P. +2 more
We report on our study of radio source regions during the type II radio burst on 2013 May 22 based on direction-finding analysis of the Wind/WAVES and STEREO/WAVES (SWAVES) radio observations at decameter-hectometric wavelengths. The type II emission showed an enhancement that coincided with the interaction of two coronal mass ejections (CMEs) lau…
Stellar Boron Abundances near the Main-sequence Turnoff of the Open Cluster NGC 3293 and Implications for the Efficiency of Rotationally Driven Mixing in Stellar Envelopes
Langer, Norbert; Proffitt, Charles R.; Lennon, Daniel J. +1 more
Spectra from the Hubble Space Telescope Cosmic Origins Spectrograph and the Space Telescope Imaging Spectrograph covering the B III resonance line have been obtained for 10 early-B stars near the turnoff of the young Galactic open cluster NGC 3293. This is the first sample of boron abundance determinations in a single, clearly defined population o…
Observation and Analysis of Ballistic Downflows in an M-class Flare with the Interface Region Imaging Spectrograph
Brannon, Sean R.
Despite significant advances in instrumentation, there remain no studies that analyze observations of on-disk flare loop plasma flows covering the entire evolution from chromospheric evaporation, through plasma cooling, to draining downflows. We present results from an imaging and spectroscopic observation from the Interface Region Imaging Spectro…