Spiral structure in IP Pegasi; how persistent is it?
| Autor: | T. R. Marsh, I. Billington, L. Morales-Rueda |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Physics
Astrophysics::High Energy Astrophysical Phenomena Astrophysics (astro-ph) Cataclysmic variable star Astronomy Balmer series FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Light curve Wavelength symbols.namesake Intermediate polar Space and Planetary Science symbols Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Emission spectrum Spectroscopy Dwarf nova Astrophysics::Galaxy Astrophysics |
| DOI: | 10.48550/arxiv.astro-ph/9911088 |
| Popis: | We present spectroscopy of the dwarf nova IP Pegasi taken during two consecutive nights, 5 and 6 days after the start of an outburst. Even this late in the outburst, Doppler maps show marked spiral structure in the accretion disc, at least as strongly as seen earlier in other outbursts of IP Peg. The spiral shocks are present on both nights with no diminution in strength from one night to the next. The light curves of the lines show an offset to earlier phases, with the mid-eclipse of the emission lines displaced to phases between -0.015 +- 0.001 and -0.045 +- 0.009. This cannot be explained by the presence of the accretion shocks. As well as the fixed spiral pattern, the disc shows strong flaring in the Balmer and HeII lines. Irradiation-induced emission is seen from the companion star in the Balmer, HeI, HeII, MgII, CII, and other lines. The emission is located near the poles of the companion star, suggesting that the accretion disc shields the companion star substantially and thus has an effective H/R of order 0.2 at EUV wavelengths. The Balmer emission is distinctly broader than the other lines consistent with non-Doppler broadening. Comment: 7 pages, 8 figures, accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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