Search Publications
The Dwarf Starburst Host Galaxy of a Type Ia Supernova at z = 1.55 from CANDELS
Mobasher, Bahram; Riess, Adam G.; Hjorth, Jens +4 more
We present VLT/X-shooter observations of a high-redshift, Type Ia supernova (SN Ia) host galaxy, discovered with HST/WFC3 as part of the CANDELS Supernova project. The galaxy exhibits strong emission lines of Lyα, [O II], Hβ, [O III], and Hα at z = 1.54992+0.00008 -0.00004. From the emission-line fluxes and spectral energy di…
Planetary Nebulae Detected in the Spitzer Space Telescope GLIMPSE 3D Legacy Survey
Zhang, Yong; Kwok, Sun; Hsia, Chih-Hao
We used the data from the Spitzer Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) to investigate the mid-infrared (MIR) properties of planetary nebulae (PNs) and PN candidates. In previous studies of GLIMPSE I and II data, we have shown that these MIR data are very useful in distinguishing PNs from other emission-line objects. In the pre…
New Variable Jet Models for HH 34
Raga, A. C.; Noriega-Crespo, A.; Esquivel, A. +1 more
We consider newly derived proper motions of the HH 34 jet to reconstruct the evolution of this outflow. We first extrapolate ballistic trajectories for the knots (starting from their present-day positions and velocities) and find that at ~1000 yr in the future most of them will merge to form a larger-mass structure. This mass structure will be for…
Tidal Interactions at the Edge of the Local Group: New Evidence for Tidal Features in the Antlia Dwarf Galaxy
Conselice, Christopher J.; Penny, Samantha J.; Pimbblet, Kevin A. +3 more
Using deep B-band imaging down to ~µ B = 26 mag arcsec-2, we present evidence for tidal tails in the Antlia Dwarf galaxy, one of the most distant members of the Local Group. This elongation is in the direction of Antlia's nearest neighbor, the Magellanic-type NGC 3109. The tail is offset by <10° from a vector linkin…
Chandra and Suzaku Observations of the Be/X-Ray Star HD110432
Nowak, M. A.; Torrejón, J. M.; Schulz, N. S.
We present an analysis of a pointed 141 ks Chandra high-resolution transmission gratings observation of the Be X-ray emitting star HD110432, a prominent member of the γ Cas analogs. This observation represents the first high-resolution spectrum taken for this source as well as the longest uninterrupted observation of any γ Cas analog. The Chandra …
Discovery of Three Distant, Cold Brown Dwarfs in the WFC3 Infrared Spectroscopic Parallels Survey
Scarlata, C.; Malkan, M.; Teplitz, H. +12 more
We present the discovery of three late-type (>=T4.5) brown dwarfs, including a probable Y dwarf, in the WFC3 Infrared Spectroscopic Parallels (WISP) survey. We use the G141 grism spectra to determine the spectral types of the dwarfs and derive distance estimates based on a comparison with nearby T dwarfs with known parallaxes. These are the mos…
SN 2002bu—Another SN 2008S-like Transient
Kochanek, C. S.; Dai, X.; Szczygieł, D. M.
We observed supernova (SN) 2002bu in the near-IR with the Hubble Space Telescope (HST), the mid-IR with the Spitzer Space Telescope, and in X-rays with Swift 10 years after the explosion. If the faint L H ~ 102 L ⊙ HST near-IR source at the transient position is the near-IR counterpart of SN 2002bu, then the source…
A Period Distribution of X-Ray Binaries Observed in the Central Region of M31 with Chandra and the Hubble Space Telescope
Zezas, A.; Murray, S. S.; Garcia, M. R. +4 more
Almost all Galactic black hole (BH) binaries with low-mass donor stars are transient X-ray sources; we expect most of the X-ray transients observed in external galaxies to be BH binaries also. Obtaining period estimates for extragalactic transients is challenging, but the resulting period distribution is an important tool for modeling the evolutio…
Observational Constraints on the Molecular Gas Content in Nearby Starburst Dwarf Galaxies
McQuinn, Kristen B. W.; Cannon, John M.; Dolphin, Andrew E. +5 more
Using star formation histories derived from optically resolved stellar populations in 19 nearby starburst dwarf galaxies observed with the Hubble Space Telescope, we measure the stellar mass surface densities of stars newly formed in the bursts. By assuming a star formation efficiency (SFE), we then calculate the inferred gas surface densities pre…
Solar Energetic Particle Events and the Kiplinger Effect
Kahler, S. W.
The Kiplinger effect is an observed association of solar energetic (E > 10 MeV) particle (SEP) events with a "soft-hard-harder" (SHH) spectral evolution during the extended phases of the associated solar hard (E > 30 keV) X-ray (HXR) flares. Besides its possible use as a space weather predictor of SEP events, the Kiplinger effect has been in…