VERAによる 近傍星形成領域の位置天文観測 Tomoya Hirota (VERA, NAOJ)

Nearby SFRs project H2O masers in SFRs within 1 kpc from the Sun Orion-Monoceros Molecular Cloud complex Taurus Perseus Ophiuchus Serpens Cepheus-Cassiopeia Distribution of molecular clouds (Dame et al. 1987)

Nearby SFRs project Goal of our project To measure distances to nearby molecular clouds To reveal structure and dynamics of molecular clouds dynamics of Local arm Distribution of molecular clouds (Grabelsky et al. 1988)

Orion-Monoceros complex Nearest GMCs/High-mass SFRs Numbers of H2O masers Distance estimated with various methods 3D-structure of molecular clouds Distribution of molecular clouds (Wilson et al. 2005) and H2O masers (Valdettaro et al. 2001) South Filament (457pc) Northern Filament (393pc) Crossbones (465pc) Orion East (120pc) Mon R2(800pc) Scissors (~150pc) Orion B (387-514pc) NGC2149 (425pc) Orion A (412-521pc)

Orion-Monoceros complex Orion KL region in Orion A molecular clouds Optical image CO(J=1-0) NIR(Subaru)

Orion KL region NIR image (Subaru) H2O masers (VERA)

Masers in Orion KL region H2O masers (VERA) SiO masers (VERA; Kim et al.) Disk? Jet?

Masers in Orion KL region Kinematics not fully understood NW-SE outflow(SiO)+ torus(H2O) Disk + NE-SW outflow (SiO) (Greenhill et al. 1998) (Greenhill et al. 2003) SiO(VLBA) H2O(VLA) SiO(VLBA)

H2O masers in Orion KL NIR image (Subaru) H2O masers (VERA)

H2O masers in Orion KL Hirota et al. 2007, PASJ, in press 　 = 437+/-19 pc Error sources Structure? Zenith delay?

SiO masers in Orion KL Kim et al. in prep. D=401+/-10 pc Higher precision even with 6-month observations!

Proper motion of Orion KL Proper motion of source I (3.5 mas, -4.4 mas; Rodriguez et al. 2005) Absolute proper motion of the maser feature (2.77 mas, -8.97 mas): 19.7 kms-1 Proper motion of the maser feature w.r.t. source I (-0.7 mas, -4.6 mas): 9.7 kms-1 Jet from IRc2/source I? Further analysis for other spots

Perseus complex Nearest cluster forming region Chain of dark clouds and HII regions, and OB associations Distance to dark clouds (Cernis 1993) 　　　　　　　　　　　　　　　　　　　　　　　　　 　　Distribution of molecular clouds = Av map (Ridge et al. 2006) Per OB2 Taurus B1 IC348 NGC1333 PerOB2 HD278942 NGC1333 B1 L1448 B5 IC348 B1E

NGC1333 Nearby low-mass SFR Cluster of YSOs Numbers of HH flows Cernis (1989): extinction --- 220 pc de Zeeuw et al. (1999): HIPPARCOS (Per OB) --- 318+/-27 pc Cluster of YSOs Numbers of HH flows SII and HI image (Bally et al. 1996) HH7-11 10’

H2O masers in NGC1333 Hirota et al. 2008, PASJ, in press 4.25+/-0.32 mas =235+/-18 pc

Proper motion of NGC1333 We measured absolute proper motion of H2O masers Intrinsic proper motion of H2O masers? Galactic rotation: (-0.65, 0.49) mas yr-1 negligible Remove Solar motion of (U,V,W)=(10.00,5.25,7.17) km s-1 Effect of Solar Motion

Proper motion of NGC1333 Proper motion of H2O masers w.r.t. LSR Disk? Jet? Prpper motion of VLA4A w.r.t. LSR =0 ? To be measured with VLA and/or IR?

Proper motion of HH7-11 Optical proper motion of HH7-11 Proper motions w.r.t. reference stars in NGC1333 IR absolute proper motion measurements possible? Proper motion measurements with HST of HH7-11 (Noriega- Crespo & Garnavich 2001)

Other researches H2O masers in IRAS 16293-2422 Distance measured with 1% accuracy (VLBA: Claussen) Radio continuum sources in Taurus 147.6+/-0.6, 132.8+/-0.5, 128.5+/-0.6 pc (VLBA, Loinard et al., Torres et al. ) Radio continuum source in Orion Nebula Cluster 389 +24/-21 pc (Sandstrom et al. 2007) Radio continuum sources in Orion Nebula Cluster 414+/-7 pc (Menten et al. 2007) 3 papers on distance measurements of Orion!

Nearby SFRs project H2O masers in SFRs within 1 kpc from the Sun Orion-Monoceros Molecular Cloud complex Taurus Perseus Ophiuchus Serpens Cepheus-Cassiopeia Structure of Local arm? Distribution of observed maser sources

Summary Annual parallax and proper motion of Orion KL and NGC1333 were successfully measured. We have not yet analyzed the kinematics (jet/disk?) of Orion KL and NGC1333. We aim to reveal structure and dynamics of Local arm. We need absolute proper motion measurements of powering sources of masers to understand the origin of the masers --- IR astrometry!