Review of Cataclysmic Review of Cataclysmic Variables : Variables : Unification model Unification model for various types of for various types of variations variations Makoto Uemura Makoto Uemura (Kyoto University : VSNET (Kyoto University : VSNET team) team)
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Review of Cataclysmic Variables : Unification model for various types of variations Makoto Uemura (Kyoto University : VSNET team)
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Review of Cataclysmic Review of Cataclysmic Variables : Variables :
Unification model Unification model for various types of for various types of
variationsvariationsMakoto Uemura Makoto Uemura
(Kyoto University : VSNET (Kyoto University : VSNET team)team)
ContentsContents
Recent works of the VSNET teamRecent works of the VSNET team Various types of variations in CVsVarious types of variations in CVs Unification model for the CV Unification model for the CV
activityactivity To “see” accretion disksTo “see” accretion disks SummarySummary
Recent works 1 : GRB Recent works 1 : GRB 010222010222
Left : CCD images of GRB 010222 taken at Kyoto University (Rc=19.3). The right image is from DSS.
Characteristics of sub-Characteristics of sub-classesclasses SS Cyg : (normal) outburstSS Cyg : (normal) outburst Z Cam : standstill Z Cam : standstill SU UMa : superoutburst + SU UMa : superoutburst +
Unification model of CVs : Unification model of CVs : 1. Thermal instability of 1. Thermal instability of accretion diskaccretion disk
Low temperature “Quiescence”
High temperature “Outburst”
Unification model of CVs :Unification model of CVs :2. Tidal instability model2. Tidal instability model
Psuperhump ~ 1.03 Porbital
(SPH simulation by Murray)
PPorb orb – Mv relation – Mv relation
Dwarf nova
Novalike
Z Cam
SS CygSU UMa
Thermal instability
Tidal instabilit
y
(Osaki 1996)
Observation of “disks”Observation of “disks”
Observation
Eclipse mapping
Examples of eclipse mapping: Examples of eclipse mapping: IY UMaIY UMa
Superoutburst on 2000 January
Early phase with fully-grown superhumps
Late phase with late superhumps
Examples of eclipse mapping: Examples of eclipse mapping: DV UMaDV UMa
Superoutburst Superoutburst on 1999 on 1999
DecemberDecember
Rapid Rapid evolution of evolution of an accretion an accretion disk during disk during the very early the very early phase of the phase of the superoutburssuperoutburstt
Summary Summary Various types of variations in CVs can basiVarious types of variations in CVs can basi
cally be interpreted with two instabilities wically be interpreted with two instabilities within accretion disks.thin accretion disks.
The eclipse mapping method is a strong toThe eclipse mapping method is a strong tool to study accretion disks. For investigatiol to study accretion disks. For investigation of continuous evolution of disks, multi-lon of continuous evolution of disks, multi-longitude observations are essential.ongitude observations are essential.
VSNET serves a number of information on VSNET serves a number of information on variable stars through e-mails, ftp, and wevariable stars through e-mails, ftp, and web. Let’s enjoy the world of VSNET ! b. Let’s enjoy the world of VSNET ! (http://v(http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/index.html)snet.kusastro.kyoto-u.ac.jp/vsnet/index.html)