Search Publications
Energy partition in two solar flare/CME events
Kucharek, H.; Mewaldt, R. A.; Mason, G. M. +12 more
Using coordinated observations from instruments on the Advanced Composition Explorer (ACE), the Solar and Heliospheric Observatory (SOHO), and the Ramaty High Energy Solar Spectroscopic Imager (RHESSI), we have evaluated the energetics of two well-observed flare/CME events on 21 April 2002 and 23 July 2002. For each event, we have estimated the en…
2MASS NIR photometry for 693 candidate globular clusters in M 31 and the Revised Bologna Catalogue
Bellazzini, M.; Galleti, S.; Federici, L. +2 more
We have identified in the 2MASS database 693 known and candidate globular clusters in M 31. The 2MASS J, H, K magnitudes of these objects have been transformed to the same homogeneous photometric system of existing near infrared photometry of M 31 globulars, finally yielding J, H, K integrated photometry for 279 confirmed M 31 clusters, 406 unconf…
The binary progenitor of Tycho Brahe's 1572 supernova
Filippenko, Alexei V.; Foley, Ryan J.; Ibata, Rodrigo +8 more
The brightness of type Ia supernovae, and their homogeneity as a class, makes them powerful tools in cosmology, yet little is known about the progenitor systems of these explosions. They are thought to arise when a white dwarf accretes matter from a companion star, is compressed and undergoes a thermonuclear explosion. Unless the companion star is…
Automated recognition of coronal mass ejections (CMEs) in near-real-time data
Berghmans, D.; Robbrecht, E.
This paper presents a new method and first applications of software that we have developed to autonomously detect CMEs in image sequences from LASCO (Large Angle Spectrometric Coronagraph). The crux of the software is the detection of CMEs as bright ridges in (time, height) maps using the Hough transform. The next step employs clustering and morph…
Bar Evolution over the Last 8 Billion Years: A Constant Fraction of Strong Bars in the GEMS Survey
Bell, Eric F.; Ravindranath, Swara; Somerville, Rachel S. +25 more
One-third of present-day spirals host optically visible strong bars that drive their dynamical evolution. However, the fundamental question of how bars evolve over cosmological times has yet to be resolved, and even the frequency of bars at intermediate redshifts remains controversial. We investigate the frequency of bars out to z ~ 1 drawing on a…
The host of GRB 030323 at z=3.372: A very high column density DLA system with a low metallicity
Pian, E.; Palazzi, E.; Kouveliotou, C. +29 more
We present photometry and spectroscopy of the afterglow of GRB 030323. VLT spectra of the afterglow show damped Lyα (DLA) absorption and low- and high-ionization lines at a redshift z=3.3718±0.0005. The inferred neutral hydrogen column density, log N(H I)=21.90±0.07, is larger than any (GRB- or QSO-) DLA H I column density inferred directly from L…
The Cassini Cosmic Dust Analyzer
Grande, M.; Krivov, A. V.; Kempf, S. +41 more
The Cassini-Huygens Cosmic Dust Analyzer (CDA) is intended to provide direct observations of dust grains with masses between 10-19 and 10-9 kg in interplanetary space and in the jovian and saturnian systems, to investigate their physical, chemical and dynamical properties as functions of the distances to the Sun, to Jupiter a…
A Galactic O Star Catalog
Walborn, Nolan R.; Maíz-Apellániz, Jesús; Galué, Héctor Á. +1 more
We have produced a catalog of 378 Galactic O stars with accurate spectral classifications that is complete for V<8 but includes many fainter stars. The catalog provides cross-identifications with other sources; coordinates (obtained in most cases from Tycho-2 data); astrometric distances for 24 of the nearest stars; optical (Tycho-2, Johnson, a…
Faint Galaxies in Deep Advanced Camera for Surveys Observations
Infante, L.; Zheng, W.; Feldman, P. D. +33 more
We present the analysis of the faint galaxy population in the Advanced Camera for Surveys (ACS) Early Release Observation fields VV 29 (UGC 10214) and NGC 4676. These observations cover a total area of 26.3 arcmin2 and have depths close to that of the Hubble Deep Fields in the deepest part of the VV 29 image, with 10 σ detection limits …
The Cassini Ultraviolet Imaging Spectrograph Investigation
West, Robert A.; Lane, Arthur L.; Colwell, Joshua E. +16 more
The Cassini Ultraviolet Imaging Spectrograph (UVIS) is part of the remote sensing payload of the Cassini orbiter spacecraft. UVIS has two spectrographic channels that provide images and spectra covering the ranges from 56 to 118 nm and 110 to 190 nm. A third optical path with a solar blind CsI photocathode is used for high signal-to-noise-ratio st…