Search Publications
Far infrared mapping of the gas cooling along the L1448 outflow
Codella, C.; Benedettini, M.; Lorenzetti, D. +4 more
The molecular outflows associated with the two Class 0 sources L1448-mm and L1448-IRS3 have been mapped with the spectrometers on board the ISO satellite allowing to study in detail the physical and chemical structure of the shocked gas. The far infrared cooling is mainly due to the emission from pure rotational lines of CO, H2O and H
Multi-colour PL-relations of Cepheids in the bt HIPPARCOS catalogue and the distance to the LMC
Groenewegen, M. A. T.; Oudmaijer, R. D.
We analyse a sample of 236 Cepheids from the hipparcos catalog, using the method of ``reduced parallaxes'' in V, I, K and the reddening-free ``Wesenheit-index''. We compare our sample to those considered by Feast & Catchpole (1997) and Lanoix et al. (1999), and argue that our sample is the most carefully selected one with respect to completene…
Non-LTE analysis of neutral magnesium in cool stars
Zhao, G.; Gehren, T.
Calculations of the statistical equilibrium of magnesium in the solar photosphere have shown that NLTE populations hardly affect Mg line formation in the Sun. However, in metal-poor dwarfs and giants the influence of electron collisions is reduced, and the ultraviolet radiation field, enhanced due to reduced background line opacity, results in mor…
Monte Carlo predictions of far-infrared emission from spiral galaxies
Bianchi, S.; Davies, J. I.; Alton, P. B.
We present simulations of Far Infrared (FIR) emission by dust in spiral galaxies, based on the Monte Carlo radiative transfer code of \citet*{BianchiApJ1996}. The radiative transfer is carried out at several wavelength in the Ultraviolet (UV), optical and Near Infrared (NIR), to cover the range of the stellar Spectral Energy Distribution (SED). To…
Stellar dynamics observations of a double nucleus in M 83
Genzel, R.; Thatte, N.; Tecza, M.
We report on the discovery of a double nucleus in M 83, based on measurements of the line of sight velocity distribution of stars observed at near infrared wavelengths with the VLT ISAAC spectrograph. We observe two peaks separated by 2\farcs 7 in the velocity dispersion profile of light from late-type stars measured along a slit 0\farcs 6 wide, c…
ISO-SWS spectra of the carbon stars TX Psc, V460 Cyg, and TT Cyg
Jørgensen, U. G.; Hron, J.; Loidl, R.
During our open and discretionary time ISO programs we have observed a number of carbon-rich and oxygen-rich AGB stars. We present here a hydrostatic analysis of 3 carbon rich stars, TX Psc, V460 Cyg, and TT Cyg, which show only modest variability. We identify absorption features of the molecules C_2, CN, CH, CO, CS, HCN, C_2H_2, and C_3 in the th…
New forbidden and fluorescent Fe III lines identified in HST spectra of eta Carinae
Davidson, K.; Johansson, S.; Hartman, H. +4 more
We discuss the origin of eight emission lines in the spectra of gas blobs close to the central star of eta Carinae. The spectra have been obtained with the Goddard High Resolution Spectrograph (GHRS) and the Space Telescope Imaging Spectrograph (STIS) onboard the Hubble Space Telescope. Between 2400 and 2500 Å five narrow lines are identified as n…
Determination of asteroid masses --- I. (1) Ceres, (2) Pallas and (4) Vesta
Michalak, G.
The masses of the three largest asteroids: (1) Ceres, (2) Pallas and (4) Vesta were determined from gravitational perturbations exerted on respectively 25, 2, and 26 selected asteroids. These masses were calculated by means of the least-squares method as weighted means of the values obtained separately from the perturbations on single asteroids. S…
The distance to the nearest star-forming clouds: MBM12 and MBM20
Neuhäuser, R.; Alcalá, J. M.; Covino, E. +2 more
We present high-resolution spectra (R ~ 49,000) of stars that have parallax measurements from the Hipparcos satellite and are projected along the line of sight to the two nearest known star forming clouds to the Sun: MBM12 and MBM20. The spectra were obtained with the FOCES Echelle Spectrograph at the 2.2 meter telescope in Calar Alto, Spain and t…
The morphology of extremely red objects
Cimatti, A.; Daddi, E.; Moriondo, G.
We present a quantitative study of the morphology of 41 Extremely Red Objects (EROs). The analysis is based on deep otical and near-infrared images from the Hubble Space Telescope public archive, and performed by fitting to each galaxy image a PSF-convolved bi-dimensional model brightness distribution. Relying both on the visual inspection of the …