Search Publications
Surface photometry and structure of high redshift disk galaxies in the HDF-S NICMOS field
Tamm, A.; Tenjes, P.
Aims.We report on a photometric study of a sample of 22 disk galaxies in the Hubble Deep Field South NICMOS parallel field. The redshift range of the galaxies is z=0.5{-}2.6.Methods.We use deep NICMOS J and H band and STIS open mode images, taken as part of the HDF-S project, to construct rest-frame B-profiles and (U-V) color profiles of the galax…
The First Direct Spectroscopic Detection of a White Dwarf Primary in an AM CVn System
Szkody, Paula; Howell, Steve B.; Sion, Edward M. +2 more
We report the results of a synthetic spectral analysis of HST STIS spectra of the AM CVn-type cataclysmic variable CP Eri obtained when the system was in quiescence. The FUV spectrum is best fitted by a helium-dominated, hybrid composition (DBAZ) white dwarf with Teff~17,000+/-1000 K, logg~8, He/H abundance ratio by number ~1000, metall…
High redshift Lyα halos
De Breuck, C.; van Breugel, W.; Croft, S. +5 more
We review current evidence for the existence of large emission-line halos around high redshift radio galaxies. Detailed narrow-band imaging and spectroscopic studies of these systems may help us understand the early stages of massive forming galaxies and AGN feedback.
Delayed Photoionization Feedback in a Super Star Cluster in SBS 0335-052E
Vanzi, Leonardo; Sauvage, Marc; Thompson, Rodger I. +2 more
SBS 0335-052 is a well-studied blue compact dwarf galaxy with one of the lowest metallicities of any known galaxy. It also contains six previously identified super star clusters. We combine archival HST NICMOS images in the Paα line and the 1.6 µm continuum of the eastern component, SBS 0335-052E, with other space- and ground-based data to p…
First Doppler images of the very young K2-dwarf PW Andromedae = HD 1405
Strassmeier, K. G.; Rice, J. B.
Aims.We present the first Doppler images of the single pre-main-sequence star PW And. Its position in the HR-diagram suggests it to be in the rapid-braking phase just prior to arrival on the ZAMS.
Methods: .Images are obtained from seven individual spectral lines as well as from 5-nm wide chunks of spectrum that invert a total of 58 line profi…
Cool Customers in the Stellar Graveyard. III. Limits to Substellar Objects around nearby White Dwarfs using the Canada-France-Hawaii Telescope
Ge, Jian; Debes, John H.; Ftaclas, Christ
Results from a ground-based high-contrast imaging survey of 13 nearby white dwarfs for substellar objects are presented. We place strict upper limits on the type of substellar objects present, ruling out the presence of anything larger than ~14MJ for eight of the white dwarfs at separations >19 AU and corresponding to primordial sepa…
Shocks: Commonalities in Solar-Terrestrial Chains
Schwartz, Steven J.
Shocks are found throughout the heliosphere, wherever supersonic (or super-magnetosonic) flows encounter obstacles or other, slowly moving, media. Although some of the physical parameters are in different regimes, all shocks heat and decelerate the media incident upon them. Most shocks must propagate in a collisionless plasma, thereby adding impor…
IR band intensities of DC 3N and HC 315N: Implication for observations of Titan's atmosphere
Jolly, Antoine; Bénilan, Yves; Raulin, Francois +1 more
We have obtained the infrared spectra and the corresponding absolute band intensities for two HC 3N isotopomers: DC 3N and HC 315N. Our results for DC 3N are in good agreement with previous measurements except for the ν2 and ν3 stretching modes. For HC 315…
The WFPC2 Archival Pure Parallels Project
Casertano, Stefano; Ferguson, Henry; Koekemoer, Anton +4 more
We introduce the WFPC2 Archival Pure Parallels Project, in which the methods and procedures described here are used to obtain a near-automatic combination of WFPC2 images obtained as part of the WFPC2 Archival Parallels Program. Several techniques have been developed or refined to ensure proper alignment, registration, and combination of overlappi…
Solar energetic particle flux enhancement as an indicator of halo coronal mass ejection geoeffectiveness
Watermann, J.; Gleisner, H.
Nearly all strong magnetic storms are generated by halo coronal mass ejections (CMEs), but most frontside halo CMEs are not followed by strong storms. Hence additional information is required to discriminate highly geoeffective CMEs from those less geoeffective. There is a tendency for the strongest magnetic storms to be generated by the fastest C…