AnIUESpectroscopic Study of the Ultra–Short‐Period Dwarf Nova T Leonis in Outburst
| Autor: | Dirk Fabian, Kunegunda Belle, Q. Nguyen, Edward M. Sion, M. Huang |
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| Rok vydání: | 1998 |
| Předmět: |
Physics
Energy distribution Astrophysics::High Energy Astrophysical Phenomena White dwarf Astronomy Astronomy and Astrophysics Astrophysics Accretion (astrophysics) Wind speed Spectral line Intermediate polar Accretion disc Space and Planetary Science Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Dwarf nova Astrophysics::Galaxy Astrophysics |
| Zdroj: | Publications of the Astronomical Society of the Pacific. 110:47-52 |
| ISSN: | 1538-3873 0004-6280 |
| DOI: | 10.1086/316113 |
| Popis: | The IUE archive contains numerous low‐resolution spectra of dwarf novae in outburst but relatively little synthetic spectral analyses of them using realistic accretion disk models with spectral lines. We have examined a series of previously unstudied archival IUE low‐resolution short‐wavelength prime spectra of the SU UMa–type ultra–short‐period dwarf nova T Leonis, obtained continuously through a single dwarf nova outburst. We describe its outburst spectra, characterizing its metallic absorption‐line spectrum and the shape of its energy distribution. We estimate a terminal wind velocity of 2500 km s−1 and report possible evidence of wind variability on timescales of roughly 2 hr, although orbital phase variations cannot be ruled out. We have constructed a grid of optically thick accretion disk models for white dwarf masses 0.6 and 1.0 M⊙, accretion rates 10−11–10−7 M⊙ yr−1, and disk inclination angles of 40° and 80°. We carry out preliminary synthetic accretion disk spectral fitting of T Leo and present the results. Our best‐fitting model to a co‐addition of three spectra with similar S/N yields MWD = 0.6 M⊙, i 40°, M 10-9M⊙ yr−1 with an inner disk temperature of 30,000 K and an outer disk temperature of 14,000 K. These results compare favorably with analyses of optical spectra of T Leo in outburst, suggesting that a similar application to other far‐UV spectra of dwarf novae in outburst, with a finer grid of disk models, should prove profitable. |
| Databáze: | OpenAIRE |
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