Search Publications
ISO-SWS observations of Herbig Ae/Be stars: HI recombination lines in MWC1080 and CoD -42d 11721
Benedettini, M.; Lorenzetti, D.; Nisini, B. +4 more
ISO-SWS grating spectra are obtained towards the two Herbig Ae/Be stars MWC1080 and CoD -42(deg) 11721, showing hydrogen recombination lines of the Brackett, Pfund and Humphreys series. The observed line decrements in each spectral series are consistent with emission from ionized winds, as expected from these early-type stars. We compare the obser…
The strange mid-infrared spectrum of M 31: ISOCAM observations
Sauvage, M.; Pagani, L.; Lequeux, J. +3 more
We present observations of the mid-IR spectrum of 4 small regions of M 31. The spectrum of the central 3\arcmin is characterized by a strong, broad unidentified emission band (UIB) at 11.3 mu m while the other usual UIBs at 6.2, 7.7 and 8.6 mu m are absent or very faint. We present a map of this area in the 11.3 mu m band and compare it with optic…
An Ultraviolet Spectral Atlas of 10 Lacertae Obtained with the Goddard High Resolution Spectrograph on the Hubble Space Telescope
Savage, B. D.; Ebbets, D. C.; Carpenter, K. G. +16 more
Observations of the narrow-lined O-type star 10 Lacertae taken with the Goddard High Resolution Spectrograph in 1992 November are presented. The spectra cover the wavelength range 1181-1777 Å with a resolution of 15 km s^-1 and signal-to-noise ratio greater than 100:1. Absorption lines arising in the interstellar medium, the photosphere, and the s…
Probing nuclear starburst activity in a sample of nearby spiral galaxies
Alloin, D.; Pastoriza, M. G.; Bonatto, C. +1 more
As part of a systematic study of the UV properties of galaxies in the IUE library, we present in this paper an analysis of nuclear stellar populations in spiral galaxies with radial velocity <= 5000 km/s. In this sample of 60 galaxies the IUE aperture probes a mean 1.0 kpc x 2.1 kpc area. Prior to any comparison of galaxy spectra in the range c…
Spectral decomposition by genetic forward modelling
Judge, P. G.; Brown, J. C.; Charbonneau, P. +3 more
We discuss the analysis of real and simulated line spectra using a genetic forward modelling technique. We show that this Genetic Algorithm (GA) based technique experiences none of the user bias or systematic problems that arise when faced with poorly sampled or noisy data. An important feature of this technique is the ease with which rigid a prio…
Detection of the lensing galaxy for the double QSO HE 1104-1805
Surdej, J.; Grundahl, F.; Hjorth, J. +5 more
High angular resolution ground-based direct imaging ( V, R, Ic) of the double QSO HE 1104-1805 has been obtained with the NOT and NTT telescopes. Analysis of these data led to the first detection of the lensing galaxy. Direct imaging of HE 1104-1805 has subsequently been carried out with the Planetary Camera (WFPC2) through the F555W (n…
A test of Hipparcos parallaxes on multiple stars
Tokovinin, A. A.; Shatskii, N. I.
The dynamical parallaxes of visual binary stars with reliable orbits selected from the multiple star catalog are compared with their Hipparcos trigonometric parallaxes. 141 objects with errors in the Hipparcos parallaxes no larger than 2.5 mas are divided into three groups by the quality of their orbits and by the reliability of the Hipparcos comp…
Illumination in Symbiotic Binary Stars: Non-LTE Photoionization Models. II. WIND Case
Raymond, John C.; Kenyon, Scott J.; Proga, Daniel
We describe a non-LTE photoionization code to calculate the wind structure and emergent spectrum of a red giant wind illuminated by the hot component of a symbiotic binary system. We consider spherically symmetric winds with several different velocity and temperature laws and derive predicted line fluxes as a function of the red giant mass-loss ra…
The molecular cloud core M17-North: ISO spectroscopy and IR/mm continuum mapping
Henning, Th.; Lemke, D.; Launhardt, R. +2 more
We present the first complete infrared spectrum of a molecular cloud core covering the wavelength region from 2.4 up to 200mu m together with a map at 1.3mm wavelength and near-infrared (NIR) images. The core is located in the northern part of
X-ray spectroscopy of the active giant beta Ceti: the SAX LECS view
Peres, G.; Favata, F.; Sciortino, S. +1 more
We present an X-ray observation of the active giant beta Cet, performed with the Low Energy Concentrator Spectrometer (LECS) on-board the SAX satellite. The resulting X-ray spectrum is well fit by an optically-thin plasma model with two discrete temperatures, and the inferred coronal metallicity is compatible both with the abundances derived from …