Forum Springer Astron. Astrophys.
Forum Whats New Search Orders

Astron. Astrophys. 336, L73-L76 (1998)

Table of Contents
Available formats: HTML | PDF | (gzipped) PostScript

Letter to the Editor

Spiral shocks in the accretion disk of the dwarf nova U Geminorum

V.V. Neustroev 1, 2 and N.V. Borisov 2

1 Department of Astronomy and Mechanics, Udmurt State University, 1, Universitetskaia, 426034, Izhevsk, Russia (e-mail: benj@uni.udm.ru)
2 Special Astrophysical Observatory, Nizhnij Arkhyz, 357147, Karachaevo-Cherkesia, Russia (e-mail: borisov@sao.ru)

Received 27 April 1998 / Accepted 7 July 1998


We present a study of the observable spectral manifestations associated with spiral shocks within quiescent accretion disks and compare them with observations of the dwarf nova U Geminorum. Our results indicate that the orbital behaviour of the hydrogen emission line profile in the spectrum of U Gem can be reproduced via a simple model of the accretion disk with two symmetrically located spiral shocks with the spiral angle [FORMULA] about 60o. This provides for the first time convincing evidence for the existence of spiral shocks in the accretion disk of a cataclysmic variable in quiescence.

Key words: accretion, accretion disks – line: profiles – line: formation – novae, cataclysmic variables – stars: individual: U Gem

Send offprint requests to: V.V. Neustroev (first address)

© European Southern Observatory (ESO) 1998

Online publication: July 27, 1998