Search Publications
Cosmic Evolution of Stellar Disk Truncations: From z ~ 1 to the Local Universe
Beckman, J. E.; Trujillo, I.; Azzollini, R.
We have conducted the largest systematic search so far for stellar disk truncations in disklike galaxies at intermediate redshift (z < 1.1), using the Great Observatories Origins Deep Survey-South (GOODS-S) data from the Hubble Space Telescope ACS. Focusing on type II galaxies (i.e., downbending profiles), we explore whether the position of the…
A Spectroscopic Orbit for Regulus
Rivinius, Th.; Štefl, S.; Baade, D. +8 more
We present a radial velocity study of the rapidly rotating B star Regulus that indicates the star is a single-lined spectroscopic binary. The orbital period (40.11 days) and probable semimajor axis (0.35 AU) are large enough that the system is not interacting at present. However, the mass function suggests that the secondary has a low mass (M…
Cassini UVIS observations of the Io plasma torus. IV. Modeling temporal and azimuthal variability
Delamere, P. A.; Bagenal, F.; Steffl, A. J.
In this fourth paper in a series, we present a model of the remarkable temporal and azimuthal variability of the Io plasma torus observed during the Cassini encounter with Jupiter. Over a period of three months, the Cassini Ultraviolet Imaging Spectrograph (UVIS) observed a dramatic variation in the average torus composition. Superimposed on this …
Stratigraphy and structure of interior layered deposits in west Candor Chasma, Mars, from High Resolution Stereo Camera (HRSC) stereo imagery and derived elevations
Scholten, F.; Neukum, G.; Hauber, E. +5 more
Interior layered deposits (ILDs) within western Candor Chasma were studied by mapping lithologies, measuring layer attitudes and comparing the stratigraphy of two adjacent mounds. Layering tends to dip in the same direction as the local topographic slope, although at different angles. Regionally consistent attitudes do exist, suggesting postdeposi…
AKARI Near-Infrared Spectroscopy: Detection of H2O and CO2 Ices toward Young Stellar Objects in the Large Magellanic Cloud
Onaka, Takashi; Ita, Yoshifusa; Sakon, Itsuki +4 more
We present the first results of AKARI Infrared Camera near-infrared spectroscopic survey of the Large Magellanic Cloud (LMC). We detected absorption features of the H2O ice 3.05 µm and the CO2 ice 4.27 µm stretching mode toward seven massive young stellar objects (YSOs). These samples are for the first time spectr…
Spitzer Observations of Star Formation in the Extreme Outer Disk of M83 (NGC5236)
Meurer, Gerhardt R.; Calzetti, Daniela; Walter, Fabian +4 more
Spitzer Infrared Array Camera (IRAC) observations of two fields in the extended UV disk (XUV-disk) of M83 have been recently obtained, ~3 R HII away from the center of the galaxy (R HII = 6.6 kpc). Galaxy Evolution Explorer (GALEX) UV images have shown the two fields to host in situ recent star formation. The IRAC images are …
Influence of Low-Degree High-Order p-Mode Splittings on the Solar Rotation Profile
Eff-Darwich, A.; Korzennik, S. G.; Jiménez-Reyes, S. J. +3 more
The solar rotation profile is well constrained down to about 0.25R⊙ thanks to the study of acoustic modes. Since the radius of the inner turning point of a resonant acoustic mode is inversely proportional to the ratio of its frequency to its degree, only the low-degree p modes reach the core. The higher the order of these modes, the dee…
Field Line Shrinkage in Flares Observed by the X-Ray Telescope on Hinode
Reeves, Katharine K.; Forbes, Terry G.; Seaton, Daniel B.
The X-Ray Telescope on Hinode has observed individual loops of plasma moving downward in a manner that is consistent with field line shrinkage in the aftermath of reconnection at higher altitudes. An on-disk B3.8 flare observed on 2007 May 2 has loops that clearly change in shape from cusp-shaped to more rounded. In addition, bright loops are obse…
Furthering our understanding of electrostatic solitary waves through Cluster multispacecraft observations and theory
Gurnett, D. A.; Lakhina, G. S.; Tsurutani, B. T. +9 more
Nonlinear isolated electrostatic solitary waves (ESWs) are observed routinely at many of Earth’s major boundaries by the Wideband Data (WBD) plasma wave receivers that are mounted on the four Cluster satellites. The current study discusses two aspects of ESWs: their characteristics in the magnetosheath, and their propagation in the magnetosheath a…
Chandra Observations of the Pulsar B1929+10 and Its Environment
Garmire, G. P.; Pavlov, G. G.; Misanovic, Z.
We report on two Chandra observations of the 3 Myr old pulsar B1929+10, which reveal a faint compact (~9'' × 5'') nebula elongated in the direction perpendicular to the pulsar's proper motion, two patchy wings, and a possible short (~3'') jet emerging from the pulsar. In addition, we detect a tail extending up to a…