Search Publications
Lithium and rotation in F and G dwarfs and subgiants
Parthasarathy, M.; Mallik, Sushma V.; Pati, A. K.
Lithium abundances have been determined in 127 F and G Pop I stars based on new measurements of the equivalent width of the lambda 6707 Å Li I line from their high resolution CCD spectra. Distances and absolute magnitudes of these stars have been obtained from the Hipparcos Catalogue and their masses and ages derived, enabling us to investigate th…
An Archive of IUE Low-Dispersion Spectra of the White Dwarf Stars
Barstow, M. A.; Holberg, J. B.; Burleigh, M. R.
We have produced an archive of the ultraviolet low-dispersion spectra for the full set of white dwarf stars observed with the International Ultraviolet Explorer (IUE) satellite over the course of its 18 yr mission. This archive contains the spectra of 322 individual degenerate stars which have been processed to optimize the signal-to-noise for eac…
A statistical comparison of interplanetary shock and CME propagation models
Cho, K. -S.; Moon, Y. -J.; Dryer, M. +3 more
We have compared the prediction capability of two types of Sun-Earth connection models: (1) ensemble of physics-based shock propagation models (STOA, STOA-2, ISPM, and HAFv.2) and (2) empirical CME propagation (CME-ICME and CME-IP shock) models. For this purpose, we have selected 38 near-simultaneous pairs of coronal mass ejections (CMEs) and metr…
Physical properties of two low-luminosity mathsf {{vec z} ~ 1.9} galaxies behind the lensing cluster AC 114
Kneib, J. -P.; Pelló, R.; Lidman, C. +3 more
We present VLT/ISAAC near-infrared spectroscopy of two gravitationally-lensed z ~ 1.9 galaxies, A2 and S2, located behind the cluster AC 114. Thanks to large magnification factors, we have been successful in detecting rest-frame optical emission lines (from [O II]lambda 3727 to Hα+[N II]lambda 6584) in star-forming galaxies 1 to 2 mag fainter than…
XMM-Newton Spectroscopy of the Accretion-driven Millisecond X-Ray Pulsar XTE J1751-305 in Outburst
Tiengo, A.; Wijnands, R.; Miller, J. M. +6 more
We present an analysis of the first high-resolution spectra measured from an accretion-driven millisecond X-ray pulsar in outburst. We observed XTE J1751-305 with XMM-Newton on 2002 April 7 for approximately 35 ks. Using a simple absorbed blackbody plus power-law model, we measure an unabsorbed flux of (6.6+/-0.1)×10-10 ergs cm-2
Nonthermal Chemistry in Diffuse Clouds with Low Molecular Abundances
Federman, S. R.; Zsargó, J.
High-quality archival spectra of interstellar absorption from C I toward nine stars, taken with the Goddard High Resolution Spectrograph on the Hubble Space Telescope, were analyzed. Our sample was supplemented by two sight lines, 23 Ori and β1 Sco, for which the C I measurements of Federman, Welty, & Cardelli were used. Directions …
The photochemical formation of a titan haze analog. Structural analysis by x-ray photoelectron and infrared spectroscopy
Tran, Buu N.; Ferris, James P.; Chera, John J.
The photochemical flow reactor (D.W. Clarke et al., 2000, Icarus 147, 282-291) has been modified to minimize the incorporation of oxygen and other impurities in the photoproducts. A mixture of gases that approximate their mixing ratios on Titan (N 2, CH 4, H 2, C 2H 2, C 2H 4
Spatial Study with the Very Large Telescope of a New Resolved Edge-on Circumstellar Dust Disk Discovered at the Periphery of the ρ Ophiuchi Dark Cloud
Neuhäuser, R.; Grosso, N.; Alves, J. +3 more
We report the discovery in near-infrared (NIR) with SofI at the New Technology Telescope (NTT) of a resolved circumstellar dust disk around a 2MASS source at the periphery of the ρ Ophiuchi dark cloud. We present follow-up observations in J, H, and Ks bands, obtained with ISAAC at the Very Large Telescope (VLT) under 0.4" seeing conditi…
ISOCAM-CVF spectroscopy of the circumstellar environment of young stellar objects
Eiroa, C.; André, P.; Alexander, R. D. +2 more
We present the results of a mid-infrared (5-16.5 mu m) imaging spectroscopy survey of Young Stellar Objects (YSOs) and their surrounding environment in four low-mass star formation regions: RCrA, rho Ophiuchi, Serpens and Chamaeleon I. This survey was performed using ISOCAM and its Circular Variable Filters (CVF) and observed 42 YSO candidates: we…
The Vela pulsar in the near-infrared
Sollerman, J.; Lundqvist, P.; Shibanov, Yu. A. +1 more
We report on the first detection of the Vela pulsar in the near-infrared with the VLT/ISAAC in the Js and H bands. The pulsar magnitudes are Js=22.71+/-0.10 and H=22.04+/-0.16. We compare our results with the available multiwavelength data and show that the dereddened phase-averaged optical spectrum of the pulsar can be fitte…