Results 1 to 10 of about 9,121 (217)
Modelling emission lines in star-forming galaxies [PDF]
Monthly Notices of the Royal Astronomical Society, 2021 ABSTRACT We present a new model to compute the luminosity of emission lines in star-forming galaxies and apply this in the semi-analytical galaxy formation code galform. The model combines a pre-computed grid of H II region models with an empirical determination of how the properties of H II regions depend on the macroscopic properties ...
C M Baugh +3 more
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The Weak Emission Line Stars [PDF]
Symposium - International Astronomical Union, 2003 In this paper, we study the evolution of the weak emission line central stars of planetary nebula (WELS), which are similar to the H-deficient Wolf-Rayet central stars except for systematically weaker emission lines. Our attempts at finding an evolutionary sequence for the WELS similar to what was established for Wolf-Rayet central stars, were ...
Jeffrey Fogel +2 more
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A photometric catalogue of southern emission-line stars [PDF]
Astronomy & Astrophysics, 2001 We present a catalogue of previously unpublished optical and infrared photometry for a sample of 162 emission-line objects and shell stars visible from the southern hemisphere. The data were obtained between 1978 and 1997 in the Walraven (WULBV), Johnson/Cousins (UBV(RI)_c) and ESO and SAAO near-infrared (JHKLM) photometric systems.
de Winter, D. +7 more
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Rapid Variability of H α Emission Line in Be Stars [PDF]
Symposium - International Astronomical Union, 1994 We have initiated an observational campaign on some bright Be stars in order to investigate the rapid variability in emission lines using a Fabry-Perot spectrometer(λ/δλ = 104; FSR = 21.3Å) at the Nasmyth focus of the 1.22 m JRO telescope at Hyderabad, India. The PMT dark counts were 1 – 2sec-1. Here we report our first observations on four stars.
B. G. Anandarao +3 more
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The atypical emission-line star Hen 3-209 [PDF]
Monthly Notices of the Royal Astronomical Society, 2006 6p, 5 fig, accepted for publication in MNRAS (www.blackwell-synergy.com)
Nazé, Yaël +5 more
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Measurement of Interstellar Extinction in Emission Line Stars [PDF]
Symposium - International Astronomical Union, 1970 Usually selective interstellar extinction is derived by comparing the spectrum of a reddened star with an unreddened nearby star, preferably of the same spectral type. But in many cases this comparison is not possible, so that new methods have to be used.A direct measure of this quantity is possible when a spectrum shows a number of emission lines as ...
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EUV Emission Lines in the Atmospheres of Cool Stars [PDF]
Physica Scripta, 1987 High resolution far ultraviolet (1200-2000 A) spectra of 17 cool giant and supergiant stars have been obtained using the IUE satellite of ESA, NASA and UK. We have measured the line intensities, wavelengths and widths of approximately 200 EUV emission lines in these spectra, using a least squares gaussian fitting technique. Line identification has been
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Super star clusters and their emission lines [PDF]
Proceedings of the International Astronomical Union, 2009 AbstractSuper star clusters (SSCs) are young massive objects typically observed in starburst galaxies. They consist of millions of stars occupying volumes only several parsecs across. Recent infrared observations of SSCs reveal strong emission lines with moderately supersonic widths (FWHM ~ 50 – 100 km s−1).
Richard Wünsch +4 more
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Profiles of Emission Lines in be Stars
The Astrophysical Journal, 1972 Study of the broadening functions resulting from a gaseous ring in circular motion around a star according to Kepler's law. When the distribution in the gaseous ring has a circular symmetry in the equatorial plane, the broadening profile is related to the surface density distribution along the radius by an integral equation which can be transformed ...
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Orbits and outflows of emission-line stars
, 2021 The optical spectra of some stars exhibit spectral lines in emission, which is characteristic of them having powerful radiatively driven winds. These stars are known as emission-line stars. In this thesis, I study the orbits and outflows of the most luminous and massive emission-line stars: Luminous Blue Variables and Wolf-Rayet stars.
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