PREDNASAJUCI / LECTURER :

Yusuke Tampo

(1) Department of Astronomy, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan

NAZOV / TITLE : 

Impact of disk wind on the optical spectra of dwarf nova outbursts

ABSTRAKT / ABSTRACT : 

Dwarf novae are an interacting binary with an accretion disk around a primary white dwarf, 
and they exhibit recurrent outbursts triggered by disk instability.
While the simplicity of dwarf novae has benefited various studies of accretion disks, 
the outflow in dwarf novae remains relatively unexplored.

In this talk,  we present the probable detection of a disk wind in dwarf nova V455 And 
based on our intensive, time-resolved, and mid-to-high-resolution optical spectroscopic observations.
Around its outburst maximum, the spectra showed strong emission lines of the Balmer series and He II.
Interestingly, their peak separation and line width were considerably narrower 
than the expectation from a Keplerian accretion disk.
However, as the outburst evolved, the peak separation gradually increased, 
eventually reaching a width consistent with the accretion disk after two weeks.
This finding suggests that the observed emission profile can be attributed to the disk wind.

We will also introduce an ongoing numerical simulation project 
to reproduce the observed spectra with the emission from a disk wind.
These findings will contribute to a better understanding of disk wind in dwarf novae, 
especially in terms of their time evolution and diversity across systems.