特異新星 V838 Mon の電波観測、その後。

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)

V838 Monocerotis？ Nova（ =-3°） 2002/01 erupted Light echo Spectra->M

supergiant TiO, metal 4 m SiO. Abs em. New type of Nova 7.5+0.5Msun merger 　　何年続くか？

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

Nobeyama Radio Observatory

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)

SiO Maser? (NRO45m ）

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

記念写真 (2005/02/23)

Further Observations(Dec. 17, 2005)

SiO at ~43 GHz SiO at 86 GHz CO 115 GHz

H2O at ~22 GHz

M-supergiant created?

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？

(120” x120”)

Same type, V4332 Sgr

(+ M31 RV)

Nova in 1994 Feb Early M0-M5 star

SiO J=1-0 v=1/2 H2O at

Nobeyama both negative

Implication of this discovery

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)

V838 Mon conference 2006/05/16-19 at La Palma, Spain

Munari, Goranski, Bond, Henden

Light Echo その後

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]

Keck Spectrum (Kaminski et al. 2008)

B3VML?

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 ?

Structure of a Merged star Hayashi phase

(1961) proto-star PASJ 13, 450 (roll of convection) SPH calc. MS-MS Lombardi et al.

2003 (references)

Tk=1000-3000 K r=1--2 x1014 cm

8 micron foundamental4 micron first overtone

H2O maser T=300--600K.

SiO maser a probe of innerenvelope near photosphere

J=0 12

34

5

6

V=0

V=1

V=2

28SiO Masers SiO maser lines in vibrational states

Historical Light Echo Ever Observed

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

Light Echo

Where is the dust ? van Loon

circumstellar origin ejected material

from AGB phase Tylenda

interstellar 　

Eruptive Formation of M-Supergiants 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)