Search Publications
The Low End of the Initial Mass Function in Young Large Magellanic Cloud Clusters. I. The Case of R136
Leitherer, Claus; Clampin, Mark; Nota, Antonella +2 more
We report the result of a study in which we have used very deep broadband V and I Wide Field Planetary Camera 2 images of the R136 cluster in the Large Magellanic Cloud from the Hubble Space Telescope archive to sample the luminosity function below the detection limit of 2.8 Msolar previously reached. In these new deeper images, we dete…
O VI and Multicomponent H I Absorption Associated with a Galaxy Group in the Direction of PG 0953+415: Physical Conditions and Baryonic Content
Tripp, Todd M.; Savage, Blair D.
We report the discovery of an O VI absorption system at zabs=0.14232 in a high-resolution FUV spectrum of PG 0953+415 obtained with the Space Telescope Imaging Spectrograph (STIS). Both lines of the O VI λλ1032, 1038 doublet and multicomponent H I Lyα absorption are detected, but the N V doublet and the strong lines of C II and Si III a…
A Kinematic Model for the Narrow-Line Region in NGC 4151
Gull, T. R.; Kraemer, S. B.; Crenshaw, D. M. +6 more
We present a simple kinematic model for the narrow-line region (NLR) of the Seyfert 1 galaxy NGC 4151, based on our previous observations of extended [O III] emission with the Space Telescope Imaging Spectrograph. The model is similar to a biconical radial outflow model developed for the Seyfert 2 galaxy NGC 1068, except that the bicone axis is ti…
The Star Clusters in the Starburst Irregular Galaxy NGC 1569
Gallagher, J. S.; O'Connell, Robert W.; Hunter, Deidre A. +1 more
We examine star clusters in the irregular starburst galaxy NGC 1569 from Hubble Space Telescope images taken with filters F336W, F555W, and F814W. In addition to the two super-star clusters that are well known, we identify 45 other clusters that are compact but resolved. Integrated UVI colors of the clusters span a large range, and comparison with…
Far-infrared Detection of C3 in Sagittarius B2 and IRC +10216
Cernicharo, José; Goicoechea, Javier R.; Caux, Emmanuel
We report on the detection of nine lines of the ν2 bending mode of triatomic carbon, C3, in the direction of Sagittarius B2. The R(4) and R(2) lines of C3 have been also detected in the carbon-rich star IRC +10216. The abundances of C3 in the direction of Sgr B2 and IRC +10216 are ~=3×10-8 and…
ISOCAM observations of the Chamaeleon I dark cloud
Prusti, T.; Perault, M.; Olofsson, G. +18 more
We present the results of an ISOCAM survey of the Chamaeleon I dark cloud conducted in two broad-band filters at 6.7 and 14.3 mu m. In an area of 0.59 sq.deg. we have detected a total of 282 mid-IR sources with 103 sources observed in both filters. Combining the ISOCAM observations with the I, J, and K_s data obtained with DENIS, we have found 108…
A Jet Model for the Afterglow Emission from GRB 000301C
Menten, K. M.; Galama, T. J.; Berger, E. +11 more
We present broadband radio observations of the afterglow of GRB 000301C, spanning from 1.4 to 350 GHz for the period of 3-130 days after the burst. These radio data, in addition to measurements in the optical bands, suggest that the afterglow arises from a collimated outflow, i.e., a jet. To test this hypothesis in a self-consistent manner, we emp…
Low- and High-Ionization Absorption Properties of Mg II Absorption-selected Galaxies at Intermediate Redshifts. II. Taxonomy, Kinematics, and Galaxies
Charlton, Jane C.; Schneider, Donald P.; Steidel, Charles C. +4 more
We examine a sample of 45 Mg II absorption-selected systems over the redshift range 0.4-1.4 in order to better understand the range of physical conditions present in the interstellar and halo gas associated with intermediate redshift galaxies. Mg II and Fe II absorption profiles were observed at a resolution of ~=6 km s-1 with HIRES/Kec…
Dissipation of Slow Magnetosonic Waves in Coronal Plumes
Nakariakov, V. M.; Ofman, L.; Sehgal, N.
Recently, slow magnetosonic waves were identified in polar plumes, at heights up to about 1.2 Rsolar using the Extreme Ultraviolet Imaging Telescope (EIT) observations of quasi-periodic EUV intensity fluctuations, and higher in the corona using the Ultraviolet Coronagraph Spectrometer (UVCS) white-light channel. First, we derive the lin…
Locally Optimally Emitting Clouds and the Variable Broad Emission Line Spectrum of NGC 5548
Goad, Michael R.; Korista, Kirk T.
In recent work Baldwin et al. proposed that in the geometrically extended broad-line regions (BLRs) of quasars and active galactic nuclei, a range in line-emitting gas properties (e.g., density, column density) might exist at each radius and showed that under these conditions the broad emission line spectra of these objects may be dominated by sel…