Search Publications
Dynamical modeling of the stellar nucleus of M 31
Sridhar, S.; Sambhus, N.
We present stellar dynamical models of the lopsided, double-peaked nucleus of M 31, derived from Hubble Space Telescope (HST) photometry. A Schwarzschild-type method, in conjunction with Richardson-Lucy deconvolution, was employed to construct steadily rotating, hot, stellar disks. The stars orbit a massive dark object, on prograde and retrograde …
Additional TWA members?. Spectroscopic verification of kinematically selected TWA candidates
Zuckerman, B.; Bessell, M. S.; Song, I.
We present spectroscopic measurements of the 23 new candidate members of the TW Hydrae Association from \citet{MF}. Based on Hα and Li 6708 Å strengths together with location on a color-magnitude diagram for Hipparcos TWA candidates, we found only three possible new members (TYC 7760-0835-1, TYC 8238-1462-1, and TYC 8234-2856-1) in addition to the…
UBV(RI)C photometry of Hipparcos red stars
Kilkenny, D.; Marang, F.; Koen, C. +2 more
We present homogeneous and standardized UBV(RI)C photometry for nearly 550 M stars selected from the Hipparcos satellite data base using the following selection criteria: lack of obvious variability (no Hipparcos variability flag); δ<+10°(V-I)>1.7 and V magnitude fainter than about 7.6. Comparisons are made between the current pho…
Phase-resolved X-ray and optical spectroscopy of the massive binary HD 93403
Gosset, E.; Rauw, G.; Vreux, J. -M. +4 more
We report the first results of a campaign aimed at the study of early-type binaries with the XMM-Newton observatory. Phase-resolved EPIC spectroscopy of the eccentric binary HD 93403 reveals a clear orbital modulation of the X-ray luminosity as a function of the orbital phase. Below 1.0 keV, the observed X-ray flux is modulated by the opacity of t…
A New Abundance Analysis of the ONeMg Nova QU Vulpeculae
Schwarz, Greg J.
This paper presents a new determination of the ejecta elemental abundances of the moderately fast ONeMg nova QU Vul 1984 using published ultraviolet, optical, infrared, and radio observations. The technique uses an optimization code in combination with CLOUDY photoionization models to fit the emission-line spectra obtained at multiple epochs durin…
The Extended Emission-Line Region of 4C 37.43
MacKenty, John W.; Stockton, Alan; Hu, Esther M. +1 more
We have explored the nature of the extended emission-line region around the z=0.37 quasar 4C 37.43, using extensive ground-based and Hubble Space Telescope (HST) imaging and spectroscopy. The velocity field of the ionized gas shows gradual gradients within components but large jumps between components, with no obvious global organization. The HST …
Spectral Classification of the Hot Components of a Large Sample of Stars with Composite Spectra, and Implication for the Absolute Magnitudes of the Cool Supergiant Components.
Ginestet, N.; Carquillat, J. M.
A sample of 135 stars with composite spectra has been observed in the near-UV spectral region with the Aurélie spectrograph at the Observatoire de Haute-Provence. Using the spectral classifications of the cool components previously determined with near infrared spectra, we obtained reliable spectral types of the hot components of the sample system…
Mid-infrared observations of the ultraluminous galaxies IRAS 14348-1447 , IRAS 19254-7245 , and IRAS 23128-5919
Le Floc'h, E.; Madden, S. C.; Sauvage, M. +6 more
We present a study of the three ultraluminous infrared galaxies IRAS 14348-1447, IRAS 19254-7245, and IRAS 23128-5919, based on mid-infrared (MIR) spectro-imaging (5-18 mu m) observations performed with ISOCAM. We find that the MIR emission from each system, which consists of a pair of interacting late type galaxies, is principally confined to the…
Extended mid-infrared emission from VV 114: Probing the birth of a ULIRG
Le Floc'h, E.; Cesarsky, C.; Sauvage, M. +5 more
We present our 5-16 mu m spectro-imaging observations of
Location of narrowband spikes in solar flares
Benz, A. O.; Vilmer, N.; Saint-Hilaire, P.
Narrowband spikes of the decimeter type have been identified in dynamic spectrograms of Phoenix-2 of ETH Zurich and located in position with the Nançay Radioheliograph at the same frequency. The spike positions have been compared with the location of hard X-ray emission and the thermal flare plasma in soft X-rays and EUV lines. The decimetric spik…