Comparison of the Spectral Evolution in WZ Sge, GW Lib, and V455 And in SuperoutburstDaisaku Nogami, Kazuo Hiroi, Yuji Suzuki, Yuuki Moritani, Yu'ichi Soejima (Kyoto Univ.), Akira Imada (Kagoshima Univ.), Osamu Hashimoto, Kenzo Kinugasa, Satoshi Honda (Gunma Obs.), Kazuya Ayani (Bisei Obs.), Shinya Narusawa, Hiroyuki Naito, Makoto Sakamoto (Nishi-Harima Obs.), Takashi Iijima (Asiago Obs.), Mitsugu Fujii (Fujii Bisei Obs.), Norio Narita (Univ. of Tokyo)Wild Stars in the Old West II2009/03/19(Thu)@Tucson

At firstWe presented a talk in the 8th Pacific Rim conference on Stellar Astrophysics in May, 2008, based on the same data.And, we have to apologize for the participants, and those who have read our contribution in the proceeding book (astro-ph/0807.2098).

4. Evolution of the disk in the course of the outburstGW LibV455 Andwindflaring diskTemperature inversion layer?quiescenceRising phaseOutburst maximumPlateau phasePLEASE FORGET THIS!

WZ Sge during the 2001 SOBBaba et al. (2002), Nogami et al. (2004)

Rising phase: Balmer & He I in absorptionMaximum: Ha, He II, CIII/NIII double-peaked emission lines, other Balmer lines in absorptionSpiral structureHalphaHe IIEarly superhumps?

~1 week after the maximum: still double-peaked emission lines of Ha, He II, CIII/NIIIAt the end of the plateau phase: strong double-peaked emission lines of the Balmer series.

Light curve of GW Lib during the 2007 superoutburst~8.5 mag27 daysPlateau phaseFading tail, stillbrighter than by 1-2 mag in quiescenceHiroi et al., PASJ, submitted

The first spectrum during the risingBlue continuum +Balmer absorption

The same spectrum, but normalized at the continuum level

Normalized spectrum at the very maximum

During the outburst plateau phaseAt the fading tail after the rapid declineBalmer emission lines

Rapid variability?At the maximumDuring the plateauNearly pole-on

V455 And: Outburst light curve and Observation date~7.8mag~28days5 night obs.During the fading tailMid- to high-resolution time-resolved spectra

R~600Blue continuum +Single-peak emission lines of the Balmer series, and He I +Strong He IIR~600

Short-term variabilities in the emission-line profile just after the maximumHe II 4686Orbital phaseHalpha: single peak, He II 4686: double peak (Peak sep. ~300 km/s )No prominent radial velocity variation?The shape was slightly changing, but not periodic on the orbital period.

Doppler maps of Balmer & He II linesSwell concentrated around Vx,y~0, in Halpha, betaDepression on a swell around Vx,y~0, in He II, HgammaNot reliable

450050005500600065007000Spectral evolution during the plateau phase2007/09/05(before the max)2007/09/06(at the maximum)2007/09/122007/09/19Gettinging weakerBecoming double-peakedPeak separation

Spectra during the fading tailAround max.Near the end of the plateauFading tailBalmer emission lines and He I lines became strong with time.

No sign of highly excited lines.

Spectral evolution IBefore the maximum: Balmer absorption lines (all)Around the maximum: Ha, He I&II, CIII/NIII emission line (all) double peak (WZ Sge, spiral st.) single peak (V455 And?, GW Lib) Hb,g,.. absorption (WZ Sge, GW Lib) single-peaked emission (V455 And)

Spectral evolution IIDuring the plateau phase: He II, CIII/NIII soon getting weaker (all) Ha slightly getting weaker (WZ Sge) + double-peaked (V455 And) getting weaker to absorption (GW Lib) Hb,g,.. absorption to emission (WZ Sge) continuously emission (V455 And) continuously absorption (GW Lib)During the fading tail: similar to quiescence (all)

Evolution of the disk in the course of the outburstGW LibWZ Sge, V455 AndquiescenceRising phaseOutburst maximumOptically thick diskFlaring disk + photo ionization emission linesFading tailPlateau phaseDisk + P.I. are settled down.Geometrical effect? (emi. vs abs.)

The next CV meeting will be held at Kyoto, Japanin July 2010!Contact: Daisaku Nogami (nogami@kwasan.kyoto-u.ac.jp)