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The massive stellar content of the Hii region NGC 604 and its evolutionary state
Pérez, Enrique; González Delgado, Rosa M.
This paper analyses the integrated ultraviolet spectra taken with the International Ultraviolet Explorer (IUE) and optical ground-based spectra taken with the William Herschel Telescope (WHT) of the giant Hii region NGC 604. These data are complemented with ultraviolet (WFPC2 through F170W) and Hα (WFPC2 through F656N) images retrieved from the Hu…
The European Large Area ISO Survey - III. 90-µm extragalactic source counts
Genzel, R.; Danese, L.; Puget, J. -L. +17 more
We present results and source counts at 90µm extracted from the preliminary analysis of the European Large Area ISO Survey (ELAIS). The survey covered about 12deg2 of the sky in four main areas and was carried out with the ISOPHOT instrument onboard the Infrared Space Observatory (ISO). The survey is at least an order of magnitude…
Hubble Space Telescope imaging and ground-based spectroscopy of old nova shells - I. FH Ser, V533 Her, BT Mon, DK Lac and V476 Cyg
O'Brien, T. J.; Gill, C. D.
In this paper we report on the first five out of eleven observations in our programme of Hubble Space Telescope (HST) imaging of old nova shells. We present new WFPC2 images of the shells around FH Ser and V533 Her taken in the F656N (Hα+[Nii]) filter. We also show long-slit spectra taken using the William Herschel Telescope on La Palma for these …
The discovery of a low-mass, pre-main-sequence stellar association around γ Velorum
Jeffries, R. D.; Naylor, T.; Pozzo, M. +3 more
We report the serendipitous discovery of a population of low-mass, pre-main-sequence (PMS) stars in the direction of the Wolf-Rayet/O-star binary system γ2Vel and the Vela OB2 association. We argue that γ2Vel and the low-mass stars are truly associated and approximately coeval, and that both are at distances between 360 and 4…
Circumnuclear regions in barred spiral galaxies - I. Near-infrared imaging
Knapen, J. H.; Pérez-Ramírez, D.; Peletier, R. F. +3 more
We present subarcsecond-resolution, ground-based, near-infrared images of the central regions of a sample of 12 barred galaxies with circumnuclear star formation activity, which is organized in ring-like regions typically 1kpc in diameter. We also present Hubble Space Telescope near-infrared images of 10 of our sample galaxies, and compare them wi…
A strategy for finding gravitationally lensed distant supernovae
Ellis, Richard; Smail, Ian; Madau, Piero +2 more
Distant Type Ia and II supernovae (SNe) can serve as valuable probes of the history of the cosmic expansion and star formation, and provide important information on their progenitor models. At present, however, there are few observational constraints on the abundance of SNe at high redshifts. A major science driver for the Next Generation Space Te…
Deep spectroscopy of distant 3CR radio galaxies: the data
Röttgering, H. J. A.; Best, P. N.; Longair, M. S.
Deep long-slit spectroscopic data are presented for a sample of 14 3CR radio galaxies at redshift z~1, previously studied in detail using the Hubble Space Telescope, the Very Large Array, and the UK Infrared Telescope (UKIRT). Analysis of the [Oii] 3727 emission-line structures at ~5Å spectral resolution is carried out to derive the kinematic prop…
Two-dimensional modelling of optical Hubble Space Telescope and infrared tip-tilt images of quasar host galaxies
McLure, R. J.; Dunlop, J. S.; Kukula, M. J.
A description is given of the method used to extract quasar host-galaxy parameters from the deep Hubble Space Telescope (HST) quasar images presented by McLure, Dunlop and co-workers. We then give the results of extensive testing of this technique on a wide range of simulated quasar+host combinations spanning the redshift range of our HST study (0…
A moving group of young stars in Carina-Vela
Makarov, Valeri V.; Urban, Sean
Accurate two-colour photometry and proper motions of 7096 young X-ray stars in the ROSAT All-Sky Survey Bright Star Catalogue, version 1RXS, are extracted from the Tycho-2 Catalogue. The sample is dominated by red main-sequence and possibly pre-main-sequence stars. On a global proper motion convergence map, two features are very prominent: the nea…
Absolute magnitudes of OB and Be stars based on Hipparcos parallaxes
Wegner, W.
Absolute visual magnitudes of OB stars are determined from Hipparcos parallaxes using a sample of 1207 unreddened and 441 reddened stars of luminosity classes V-IV, III, Ia and Iab-Ib-II. The value of total-to-selective extinction R for reddened stars was calculated from near-infrared photometry. The new MV calibration is compared with …