Search Publications

Spectral Behavior of the Symbiotic Nova HM Sge in the Ultraviolet

Sanad, M. R.; Abdel-Sabour, M. A.

Ultraviolet observations of the symbiotic nova HM Sge were obtained from the International Ultraviolet Explorer (IUE) through the interval from 1980 - 1992. Three line profiles demonstrating the variations of some emission lines at different dates are presented. We determined the reddening of HM Sge from the 2200 Å absorption feature; the estimate…

Chemical Abundances and Physical Parameters of HII Regions in the Magellanic Clouds

Meléndez, J.; Steiner, J.; Carlos Reyes, R. E. +2 more

We used ultraviolet, optical and infrared data of eleven HII regions in the Magellanic Clouds in order to determine their physical parameters and chemical abundances. The photoionization modeling of six HII regions in the LMC and five HII regions in the SMC, allowed us to derive the abundances of He, C, N, O, Ne, S and Ar, which were compared with…

Low Redshift BAL QSOs in the Eigenvector 1 Context

Marziani, P.; Zamanov, R.; Braito, V. +4 more

We attempt to characterize the geometry of Broad Absorption Line (BAL) QSOs by studying a low redshift sample of 12 sources. We find that the majority of these sources are Population A quasars as defined in Sulentic et al. (2000a, broad HbetaFWHM ≤ 4000 km s(-1) ). A possible correlation between terminal velocity and absolute V magnitude suggests …

Determination of the Mass Loss Rate and the Terminal Velocity of Stellar Winds. I. Genetic Algorithm for Automatic Line Profile Fitting

Georgiev, L.; Hernández, X.

A new method for automatic fitting of Pline profiles in UV spectra of stellar winds is presented. The line source function is calculated using Sobolev's approximation and the emergent flux is obtained by exact integration of the equation of the radiation transport (similar to the SEI method described by Lamers et al. (1987)). The quality of the fi…

Ultraviolet Spectroscopy of the Massive LMC Multiple Systems Sk-67^0m#circ;18 (Br 5) and HD 36402 (Br 31)

Koenigsberger, G.; Auer, L. H.; Moffat, A. F. J.

Following previous IUE-based spectroscopic studies of WR+O binaries in the Galaxy and in the SMC, we present a similar study of the two systems, Br 5 [O3 If^*(+O) + O8-B0 I(+OB?)] and Br 31 [WC4(+O?) + O8 I:] in the Large Magellanic Cloud. We detect wind eclipse effects in the WC4+O (P = 3.033 d) pair in Br 31 similar to, but weaker than those obs…

A Spectrographic Study of the Interacting Eclipsing Binary RY Scuti: An Episode in the Rapid Mass Loss Stage or a Protoplanetary Nebula?

Sahade, J.; West, R. M.; Skul'Sky, M. Yu.

RY Scuti, the 11-day [Fe III] eclipsing binary, has been reinvestigated on the basis of spectrographic material obtained in Chile at the European Southern Observatory, La Silla, and at the Cerro Tololo Interamerican Observatory, covering the spectral regions 3400-5150 Å and 5700-6700 Å . Ultraviolet IUE observations were also analyzed. The spectru…

A Multifrequency Catalog of LINERs

Masegosa, J.; Dultzin-Hacyan, D.; Carrillo, R. +1 more

Spectroscopy and Direct Imaging of the Planetary Nebula IC 4593.

Olguín, L.; Bohigas, J.

Spectroscopy of the planetary nebula IC 4593 leads to helium, oxygen, carbon, sulfur and argon abundances which are typical of non-type I planetaries. Nitrogen abundance is normal when UV data is used. Neon might be underabundant by a factor of 2. Images in various emission lines show that the nebula is composed of two internal structures dominate…

The Spatial Intensity Distribution of the UV Light in HH Objects. Revisited

Raga, A. C.; Noriega-Crespo, A.; Moro-Martin, A. +1 more

Simple kinematical bow shock models have successfully explained many of the observed features in Herbig-Haro objects. It is shown that similar models can be applied to the spatial intensity distribution of the UV lines observed by IUE. Archival IUE spectra have been used for the HH 1, HH 2(H+A^'), HH 2(G+B), HH 24A, HH 32A, HH 43(A+B+C),…

LM1-64: a high excitation planetary nebula with WR nucleus in the LMC.

Torres-Peimbert, S.; Ruiz, M. T.; Peña, M. +1 more

The authors present optical and UV spectra of the planetary nebula LM1-64 in the LMC. This is a high excitation planetary nebula which shows evidence of having a WC central star. Broad and complex stellar emission at λ4650 (due to C III and C IV) is detected in the optical spectrum. The authors have measured all the emission line fluxes available …