Search Publications
Two Pseudobulges in the "Boxy Bulge" Galaxy NGC 5746
Kormendy, John; Barentine, John C.
Galaxy formation and growth under the ΛCDM paradigm is expected to proceed in a hierarchical, bottom-up fashion by which small galaxies grow into large galaxies; this mechanism leaves behind large "classical bulges" kinematically distinct from "pseudobulges" grown by internal, secular processes. We use archival data (Spitzer Space Telescope 3.6 &m…
Spatially Resolved Spectroscopy of the Globular Cluster RZ 2109 and the Nature of its Black Hole
Salzer, John J.; Kundu, Arunav; Zepf, Stephen E. +7 more
We present optical Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) spectroscopy of RZ 2109, a globular cluster (GC) in the elliptical galaxy NGC 4472. This GC is notable for hosting an ultraluminous X-ray source as well as associated strong and broad [O III] λλ4959, 5007 emission. We show that the HST/STIS spectroscopy spati…
Gemini Spectroscopic Survey of Young Star Clusters in Merging/Interacting Galaxies. IV. Stephan's Quintet
Charlton, Jane C.; Konstantopoulos, Iraklis S.; Trancho, Gelys +4 more
We present a spectroscopic survey of 21 young massive clusters and complexes and one tidal dwarf galaxy (TDG) candidate in Stephan's Quintet, an interacting compact group of galaxies. All of the selected targets lie outside the main galaxies of the system and are associated with tidal debris. We find clusters with ages between a few and 125 Myr an…
The Invisible Monster Has Two Faces: Observations of epsilon Aurigae with the Herschel Space Observatory
Stencel, R. E.; Hoard, D. W.; Ladjal, D. +1 more
We present Herschel Space Observatory photometric observations of the unique, long-period eclipsing binary star epsilon Aurigae. Its extended spectral energy distribution is consistent with our previously published cool (550 K) dust disk model. We also present an archival infrared spectral energy distribution of the side of the disk facing the bri…
The Spectral and Temporal Properties of Transient Sources in Early-type Galaxies
Zezas, A.; King, A. R.; Pellegrini, S. +8 more
We report the spectral and temporal variability properties of 18 candidate transient (TC) and potential transient (PTC) sources detected in deep multi-epoch Chandra observation of the nearby elliptical galaxies, NGC 3379, NGC 4278, and NGC 4697. Only one source can be identified with a background counterpart, leaving 17 TCs + PTCs in the galaxies.…
Decorrelation Times of Photospheric Fields and Flows
Welsch, B. T.; Kusano, K.; Yamamoto, T. T. +1 more
We use autocorrelation to investigate evolution in flow fields inferred by applying Fourier local correlation tracking (FLCT) to a sequence of high-resolution (0farcs3), high-cadence (sime 2 minute) line-of-sight magnetograms of NOAA active region (AR) 10930 recorded by the narrowband filter imager of the Solar Optical Telescope aboard the Hinode …
Characterization of the X-Ray Light Curve of the γ Cas-like B1e Star HD 110432
Smith, Myron A.; Motch, Christian; Lopes de Oliveira, Raimundo
HD 110432 (BZ Cru B1Ve) is the brightest member of a small group of "γ Cas analogs" that emit copious hard X-ray flux, punctuated by ubiquitous "flares." To characterize the X-ray time history of this star, we made a series of six RXTE multi-visit observations in 2010 and an extended observation with the XMM-Newton in 2007. We analyzed these new l…
Identification of Galactic Bulge Survey X-Ray Sources with Tycho-2 Stars
Maccarone, T. J.; Torres, M. A. P.; Nelemans, G. +6 more
We identify 69 X-ray sources discovered by the Galactic Bulge Survey (GBS) that are coincident with or very close to bright stars in the Tycho-2 catalog. Additionally, two other GBS sources are resolved binary companions to Tycho-2 stars where both components are separately detected in X-rays. Most of these are likely to be real matches, but we id…
The Mass-Richness Relation of MaxBCG Clusters from Quasar Lensing Magnification Using Variability
Baltay, Charles; Rabinowitz, David; Bauer, Anne H. +3 more
Accurate measurement of galaxy cluster masses is an essential component not only in studies of cluster physics but also for probes of cosmology. However, different mass measurement techniques frequently yield discrepant results. The Sloan Digital Sky Survey MaxBCG catalog's mass-richness relation has previously been constrained using weak lensing …
RW Aur A from the X-Wind Point of View: General Features
Liu, Chun-Fan; Shang, Hsien
In this paper, the RW Aur A microjet is studied from the point of view of X-wind models. The archived Hubble Space Telescope/STIS spectra of the optical forbidden lines [O I], [S II], and [N II] from RW Aur A, taken in Cycle 8 with seven parallel slits along the jet axis, spaced at 0farcs07 apart, were analyzed. Images, position-velocity diagrams,…