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特異新星 V838 Mon の電波観測、その後。. 出口修至 (国立天文台野辺山) 、 松永典之、福士比奈子 ( 東大天文セ ) Kaminski (N. Kopernicus Center, Poland). Nova ( d =-3° ) 2002/01 erupted Light echo Spectra->M supergiant TiO, metal 4 m m SiO. Abs em. New type of Nova 7.5+0.5Msun merger 何年続くか?. V838 Monocerotis ?. SAAO 1m.
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特異新星V838 Monの電波観測、その後。 出口修至(国立天文台野辺山)、 松永典之、福士比奈子(東大天文セ) Kaminski (N. Kopernicus Center, Poland)
Nova(d=-3°) 2002/01 erupted Light echo Spectra->M supergiant TiO, metal 4 mm SiO. Absem. New type of Nova 7.5+0.5Msun merger 何年続くか? V838 Monocerotis? SAAO 1m
Conclusion (2005) • 1. V838 Mon emits SiO Masers, approving a cool mass-losing star • 2. Vlsr: distance 7 kpc • 3. --> Eruptive formation of M-supergiant : living example of stellar merger
45-m telescope 6-element 10-m mm-wave interferometer Solar Heliograph (80cm x84 elements) 22-115 GHz Beam 40” at 43 GHz Tsys=200 K (2GHz bandwidth) Nobeyama Radio Observatory
SiO J=1-0 v=1/2 at 43 GHz on 2005/02/23 2005/04/24 again (J=2-1 v=1 negative) 2005/05/23 H2O maser at 22GHz negative SiO Maser?(NRO45m)
Further Observations(Dec. 17, 2005) • SiO at ~43 GHz • SiO at 86 GHz • CO 115 GHz • H2O at ~22 GHz
爆発前の観測 2MASS blue star >13 K=4-5 mag IRAS 07015-0346 (F12=0.25 Jy) No MSX obj. F10= 10 Jy at present Projenitor is not M-gaint 7.5+0.5 Main sq. stars. 何年つずくか? M-supergiant created? (120” x120”)
Nova in 1994 Feb Early M0-M5 star SiO J=1-0 v=1/2 H2O at Nobeyama both negative Same type, V4332 Sgr (+ M31 RV)
Vlsr=54 km/s Optical Vlsr=42-52 km/s(P Cyg) --> Dkin=7 kpc Munari 2002 ~1kpc Bond 2003 >6.4 kpc Munari 2004 8-10 kpc Mass losing star Nova rate 1 in 10 yr SiO life ? 2000 yr Half is 100 objects ~1500 SiO sources 100/1500 ~6.6 % 10 kpc 1 in every 1 kpc (bright) Implication of this discovery
V838 Mon conference2006/05/16-19 at La Palma, Spain Munari, Goranski, Bond, Henden
Distance • Echo (naive) 0.7 kpc 10 kpc • [Munari 2002, 2005] • Kinematic (Vlsr=55 km/s) 7 kpc [Deguchi et al. 2005] • Echo Polarization 6.1±0.6 kpc [Sparks et al. 2008] • Cluster (luminosity) 6.2±1.2 kpc [Afsar & Bond 2007]
B3V companion eclipse • 2006 short dip • 2008 long
CO mapping (2008) • Deguchi, 2007 • Poland: Kaminski
SiO Maser • J=1-0 weakening • J=2-1 appearing (86.243GHZ) • How long ?
Shell structure ? • Fast flow (~200 km/s) • Slow flow(~20 km/s) • SiO not fast flow
Conclusion • 1. V838 Mon emits SiO Masers, approving a cool mass-losing star • 2. Vlsr: distance 7 kpc • 3. --> Eruptive formation of M-supergiant : living example of stellar merger • How long does it continue ?
Hayashi phase (1961) proto-star PASJ 13, 450 (roll of convection) SPH calc. MS-MS Lombardi et al. 2003 (references) Structure of a Merged star
Tk=1000-3000 K r=1--2 x1014 cm 8 micron foundamental 4 micron first overtone H2O maser T=300--600K. SiO maser a probe of inner envelope near photosphere SiO maser lines in vibrational states
Nova Per 1901 (GK Per) Discovered on Feb. 21, 1901(first nova in 20c) by Thomas Anderson, an Edinburgh Amature Max 0.2 Mag ->4th in 2w then oscillate 6 mo. later light echo With rapid expansion >c Kapteyn 1902 explained Historical Light Echo Ever Observed
Where is the dust ? van Loon circumstellar origin ejected material from AGB phase Tylenda interstellar Light Echo
Born Again Hypo. Post-AGB + MS ? He-shell flash T. Kato 2004 (V4334 Sgr Sakurai obj.) Merger Hypo. MS+dwarf binaries Tylenda 2004/5 Globular cluster SiO maser objects PN/OH/SiO/IR = V1018 Sco (Cohen et al. 2005) Eruptive Formation of M-Supergiants