Search Publications
Detection of the Compressed Primary Stellar Wind in η Carinae
Gull, T. R.; Corcoran, M. F.; Madura, T. I. +2 more
A series of three Hubble Space Telescope/Space Telescope Imaging Spectrograph spectroscopic mappings, spaced approximately one year apart, reveal three partial arcs in [Fe II] and [Ni II] emissions moving outward from η Carinae. We identify these arcs with the shell-like structures, seen in the three-dimensional hydrodynamical simulations, formed …
Accurate Characterization of High-degree Modes Using MDI Observations
Larson, T. P.; Schou, J.; Korzennik, S. G. +1 more
We present the first accurate characterization of high-degree modes, derived using the best Michelson Doppler Imager (MDI) full-disk full-resolution data set available. A 90 day long time series of full-disk 2 arcsec pixel-1 resolution Dopplergrams was acquired in 2001, thanks to the high rate telemetry provided by the Deep Space Networ…
A Peculiar Faint Satellite in the Remote Outer Halo of M31
Dotter, A.; Mackey, A. D.; Martin, N. F. +9 more
We present Hubble Space Telescope imaging of a newly discovered faint stellar system, PAndAS-48, in the outskirts of the M31 halo. Our photometry reveals this object to be comprised of an ancient and very metal-poor stellar population with age >~ 10 Gyr and [Fe/H] lsim -2.3. Our inferred distance modulus (m - M)0 = 24.57 ± 0.11 confi…
The Hyades Cluster: Identification of a Planetary System and Escaping White Dwarfs
Zuckerman, B.; Xu, S.; Klein, B. +1 more
Recently, some hot DA-type white dwarfs have been proposed to plausibly be escaping members of the Hyades. We used hydrogen Balmer lines to measure the radial velocities of seven such stars and confirm that three, and perhaps two others, are/were indeed cluster members and one is not. The other candidate Hyad is strongly magnetic and its membershi…
Dust Scattering and the Radiation Pressure Force in the M82 Superwind
Thompson, Todd A.; Martini, Paul; Coker, Carl T.
Radiation pressure on dust grains may be an important physical mechanism driving galaxy-wide superwinds in rapidly star-forming galaxies. We calculate the combined dust and gas Eddington ratio (Γ) for the archetypal superwind of M82. By combining archival Galaxy Evolution Explorer data, a standard dust model, Monte Carlo dust scattering calculatio…
Source Regions of the Interplanetary Magnetic Field and Variability in Heavy-ion Elemental Composition in Gradual Solar Energetic Particle Events
Wang, Yi-Ming; Ko, Yuan-Kuen; Ng, Chee K. +2 more
Gradual solar energetic particle (SEP) events are those in which ions are accelerated to their observed energies by interactions with a shock driven by a fast coronal mass ejection (CME). Previous studies have shown that much of the observed event-to-event variability can be understood in terms of shock speed and evolution in the shock-normal angl…
Discovery of X-Ray Emission from Young Suns in the Small Magellanic Cloud
Güdel, M.; Gruendl, R. A.; Chen, Y. +11 more
We report the discovery of extended X-ray emission within the young star cluster NGC 602a in the Wing of the Small Magellanic Cloud (SMC) based on observations obtained with the Chandra X-Ray Observatory. X-ray emission is detected from the cluster core area with the highest stellar density and from a dusty ridge surrounding the H II region. We us…
HerMES: The Far-infrared Emission from Dust-obscured Galaxies
Pérez-Fournon, I.; Bock, J.; Cooray, A. +21 more
Dust-obscured galaxies (DOGs) are an ultraviolet-faint, infrared-bright galaxy population that reside at z ~ 2 and are believed to be in a phase of dusty star-forming and active galactic nucleus (AGN) activity. We present far-infrared (far-IR) observations of a complete sample of DOGs in the 2 deg2 of the Cosmic Evolution Survey. The 30…
A Deep Keck/NIRC2 Search for Thermal Emission from Planetary Companions Orbiting Fomalhaut
Currie, Thayne; Debes, John H.; Cloutier, Ryan +2 more
We present deep Keck/NIRC2 1.6 and 3.8 µm imaging of Fomalhaut to constrain the near-infrared brightness of Fomalhaut b, recently confirmed as a likely planet, and search for additional planets at r proj = 15-150 AU. Using advanced/novel point spread function subtraction techniques, we identify seven candidate substellar companion…
Galaxy and Mass Assembly (GAMA): Witnessing the Assembly of the Cluster ABELL 1882
van Kampen, E.; Edge, A. C.; Hopkins, A. M. +14 more
We present a combined optical and X-ray analysis of the rich cluster ABELL 1882 (A1882) with the aim of identifying merging substructure and understanding the recent assembly history of this system. Our optical data consist of spectra drawn from the Galaxy and Mass Assembly survey, which lends itself to this kind of detailed study thanks to its de…