Search Publications
Local Cloud structure from HST-GHRS
Ferlet, R.; Vidal-Madjar, A.; Lallement, R. +2 more
Echelle spectra at high resolution (λ/{DELTA}λ= 90,000) of the nearby stars α Aql (Altaie r), α Lyr (Vega), α Cen and δ Cas, have been obtained with the Goddard High-Resolution Spectrograph (GHRS) on board the Hubble Space Telescope (HST), during the cycles 1 and 3. In all but one spectra, interstellar Fe II and Mg II absorption lines are detected…
Galactic wind and Lyman α emission in the blue compact galaxy Haro 2 = MKN 33.
Mas-Hesse, J. M.; Kunth, D.; Sargent, W. L. W. +1 more
We have observed with the Goddard High-Resolution Spectrometer on board the Hubble Space Telescope the blue compact galaxy Haro 2 in two wavelength regions around Lyman α and O I 1302A. We have detected redshifted absorptions in those lines as well as in lines of N I, Si II and Si III, in front of the hot stars ionizing the central H II region of …
The interstellar void in the direction to ɛ CMa: local clouds and hot gas.
Ferlet, R.; Vidal-Madjar, A.; Lemoine, M. +2 more
We analyse HST GHRS observations of the interstellar medium in the direction to ɛ CMa, the strongest EUV source in the sky, located in a region deficient in neutral gas. The line of sight contains three main absorption components resolved in the high resolution Ech B observations. Three weak components are also detected. We derive their heliocentr…
Low mass stars in globular clusters. II. The mass function of M15.
Paresce, F.; de Marchi, G.
We have used the WFPC2 on board HST to investigate the stellar population in a field located 4.6' NW of the center of the globular cluster M15 by means of deep imaging in wide bands centered at 606 and 812nm. A total of 7770 stars are accurately classified by two-color photometry to form a color-magnitude diagram extending down to a limiting magni…
The structure and evolution of the Nova V1974 Cygni shell from HST observations.
Paresce, F.; Livio, M.; Korista, K. +1 more
The Faint Object Camera on the refurbished Hubble Space Telescope (HST) observed Nova Cygni 1992 (V1974 Cyg) on three separate occasions in the first five months of 1994 through a series of interference and narrow band filters sensitive to the emission lines of OIII, OII, Hβ, Lyman α, HeII, NeIII, NeV, MgII, and NIV. Two objective prism images in …
Detectability and incidence of E+A galaxies in the distant cluster Cl0939+472 (z=0.41).
Belloni, P.; Bruzual, A. G.; Thimm, G. J. +1 more
We present results of a study of E+A galaxies in the cluster Cl0939+472 (z=0.41). We have used a series of narrow-band filters (FWHM=~90-200A) covering the range from 3800 to 9200A, and broad band B, R, I filters to obtain low resolution spectra for all galaxies brighter than R=22.5mag in a 5x5' cluster field. Two of the narrow-band filters have b…
Possible detection of a diffuse interstellar cloud boundary. II. HST-GHRS observations of Sirius A.
Ferlet, R.; Vidal-Madjar, A.; Lallement, R. +2 more
We present HST-GHRS observations with the G160M grating in the HI Lyman α spectral range toward Sirius A and around the Civ 1550 A doublet toward three lines of sight of the local interstellar medium. The local interstellar cloud (LIC) in which the Sun is embedded and another cloud (BC) are detected toward Sirius A from high spectral resolution Mg…
Low-mass stars in globular clusters. III. The mass function of 47 Tucanae.
Paresce, F.; de Marchi, G.
We have used the WFPC2 on board HST to investigate the stellar population in a field located 4'6 E of the center of the globular cluster 47 Tuc (NGC 104), close to the half-mass radius, through wide band imaging at 606 and 812nm. A total of ~3000 stars are accurately classified by two-color photometry to form a color-magnitude diagram extending do…
Proof of a fast wind in the symbiotic nova AG Pegasi.
Schmutz, W.; Vogel, M.; Nussbaumer, H.
Hubble Space Telescope observations of the symbiotic nova AG Peg reveal a P Cygni profile in N V λl240. This proves that the hot compact object in the binary system loses material through a fast wind. High resolution spectra allow to discern three different emission regions: the wind from the hot compact star, a nebular emission region of relative…
A snapshot of the continuous emission of the active galactic nucleus in NGC 3783 from gamma-ray to radio wavelengths.
Altieri, B.; Glass, I. S.; Malkan, M. A. +21 more
With the aim of better understanding the physical processes that produce the continuous emission in active galactic nuclei (AGNs), a snapshot of the overall continuous energy distribution of NGC 3783, from γ-ray to radio wavelengths, has been obtained within the framework of the World Astronomy Days. The data collected in this campaign are from GR…