Astronomy and Astrophysics – Astronomy
Scientific paper
Apr 1995
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995apj...443..329w&link_type=abstract
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 443, no. 1, p. 329-340
Astronomy and Astrophysics
Astronomy
16
Atomic Energy Levels, Binary Stars, Far Ultraviolet Radiation, Line Spectra, Periodic Variations, Spectral Line Width, Ultraviolet Astronomy, Astronomical Photometry, Error Detection Codes, High Resolution, Hubble Space Telescope, Iue
Scientific paper
We have reanalyzed the numerous high-resolution, far-ultraviolet observations of Capella made by the International Ultraviolet Explorer (IUE) in its 16 yr lifetime. Our purpose was to search for long-term profile variations in Capella's ultraviolet emission lines and to complement the analysis of Goddard High Resolution Spectrograph (GHRS) observations of Capella, discussed in a companion paper (Linsky et al. 1995). We implemented a state-of-the-art photometric correction and spectral extraction procedure to improve S/N and control potential sources for systematic errors. Nevertheless, we were unable to find compelling evidence for any significant long-term profile variations. Previous work has shown that the G8 primary star is only a minor contributor to the high-excitation transition region lines but is a significant contributor to the low-excitation chromospheric lines. We have found exceptions to this rule, however. We find that the G8 star is responsible for a significant portion of Capella's N V lambda lambda 1239, 1243 emission, but is not a large contributor to the S I lambda 1296, Cl I lambda 1352, and O lambda 1356 lines. We suggest possible explanations for these behaviors. We also find evidence that the He II lambda 1640 emission from the G1 star is from the transition region, while the He II lambda 1640 emission from the G8 star is chromospheric, consistent with the findings of Linsky et al. (1994). The C II lambda 1336 line shows a weak central reversal. It is blueshifted by about 9 km/s with respect to the centroid of the emission from the G1 star. While the central reversal of the C II line is blueshifted by about 9 km/s with respect to the centroid of the emission from the G1 star. While the central reversal of the C II line is blueshifted, the central reversal of the Si III lambda 1207 line discussed by Linsky et al. (1994) is not.
Ayres Thomas R.
Wood Brian E.
No associations
LandOfFree
A reanalysis of the SWP-HI IUE observations of Capella does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A reanalysis of the SWP-HI IUE observations of Capella, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A reanalysis of the SWP-HI IUE observations of Capella will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1828627