Comparison of the Spectral Evolution in WZ Sge, GW Lib, and V455 And in Superoutburst Daisaku 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 II

At first… We presented a talk in the 8 th 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/ ).

4. Evolution of the disk in the course of the outburst GW Lib V455 And wind flaring disk Temperature inversion layer? quiescence Rising phase Outburst maximum Plateau phase PLEASE FORGET THIS!

WZ SgeGW LibV455 And Orb. Per.82 min77 min81 min Inclination~75 deg~11 deg~75 deg

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

Rising phase: Balmer & He I in absorption Maximum: H , He II, CIII/NIII double-peaked emission lines, other Balmer lines in absorption Spiral structure Halpha He II Early superhumps?

~1 week after the maximum: still double-peaked emission lines of H , He II, CIII/NIII At 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 mag 27 days Plateau phase Fading tail, still brighter than by 1-2 mag in quiescence Hiroi et al., PASJ, submitted

The first spectrum during the rising Blue continuum + Balmer absorption

The same spectrum, but normalized at the continuum level : pure absorption lines FWHM ~3000km/s

: absorption + emission core (FWZI<20 Å ) High excitation lines: He II, CIII/NIII, CIV? Normalized spectrum at the very maximum

During the outburst plateau phase At the fading tail after the rapid decline Balmer emission lines emission core of high excitation lines the other Balmer absorptions became strong.

Rapid variability? At the maximum During the plateau No significant detection! Nearly pole-on

V455 And: Outburst light curve and Observation date ~7.8mag ~28days 5 night obs. During the fading tail Mid- to high-resolution time-resolved spectra

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

Short-term variabilities in the emission-line profile just after the maximum He II 4686 Orbital phase Halpha: 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 lines Swell concentrated around Vx,y~0, in Halpha, beta Depression on a swell around Vx,y~0, in He II, Hgamma Not reliable

Spectral evolution during the plateau phase 2007/09/05(before the max) 2007/09/06(at the maximum) 2007/09/ /09/19 Gettinging weaker Becoming double- peaked Peak separation <1000 km/s

Spectra during the fading tail Around max. Near the end of the plateau Fading tail Balmer emission lines and He I lines became strong with time. No sign of highly excited lines.

Spectral evolution I 1.Before the maximum: Balmer absorption lines (all) 2.Around the maximum: H , He I&II, CIII/NIII emission line (all) double peak (WZ Sge, spiral st.) single peak (V455 And?, GW Lib) H ,.. absorption (WZ Sge, GW Lib) single-peaked emission (V455 And)

Spectral evolution II During the plateau phase: He II, CIII/NIII soon getting weaker (all) H  slightly getting weaker (WZ Sge) + double-peaked (V455 And) getting weaker to absorption (GW Lib) H ,.. 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 outburst GW Lib WZ Sge, V455 And quiescence Rising phase Outburst maximum Optically thick disk Flaring disk + photo ionization emission lines Fading tail Plateau phase Disk + P.I. are settled down. Geometrical effect? (emi. vs abs.)

The next CV meeting will be held at Kyoto, Japan in July 2010! おいでやす、京都へ。 Contact: Daisaku Nogami