NMA SMA ALMA ALMA Observations of Keplerian Disks

NMA SMA ALMA ? ALMA Observations of Keplerian Disks around Protostars: the case of L 1527 Nagayoshi Ohashi (NAOJ) With K. Saigo, Y. Aso, S. -W. Yen, S. Takakuwa, S. Koyamatsu, Y. Aikawa, K. Tomisaka, K. Tomita, M. Machida, M. Saito

Summary • In order to unambiguously identify Keplerian disks around protostars, it is crucial to distinguish between Kepler rotation (VrotµR-0. 5) and rotation conserving angular momentum(VrotµR-1). • ALMA cycle 0 observations of L 1527 IRS shows that • Most of C 18 O 2 -1 emission arises from an infalling envelope. • The C 18 O arising the vicinity of the central star (R < 60 AU) may suggests a Keplerian disk. • SO 65 -54 shows rigid-like rotation at lower velocities (DV = -1 — 1 km/s) • The kinematics of the SO emission seems to be not explained with the same kinematics explaining the C 18 O emission.

Keplerian disks are ubiquitous around PMSs • Keperian disks are formed as by-products of star formation. • It is, however, not well understood when and how disks are formed. • Initial condition of Keprian disks • Dynamical mass of protostars Simon, Dutrey, Guilloteau 2000

Formation of Keplerian disks around protostars: A conventional picture Dynamical Infall region Vinfall > Vrotation NMA Obs Keplerian rotation region Vinfall << Vrotation c. f. Terebey et al. 1984; Basu 1998 Note that B-field could remove angular momentum effectively, preventing disk formation (e. g. , Mellon & Li 2008, 2009; Machida et al. 2011, Dapp et al. 2012)

Previous studies to identify (Keplerian) disks around protostars (The list is NOT complete) • • Arce and Sargent 2006 Brinch et al. 2007 Lommen et al. 2008 Jorgensen et al. 2009 It has been difficult to firmly Identify Keplerian Lee et al. 2009, 2010 disks around protostars. Maury et al. 2010 Tanner and Arce 2011 Tobin et al. 2011, 2012 If I miss your papers please kindly let me know!

Inner regions of the infalling envelope around L 1551 IRS 5 SMA CS 7 -6 Total Intensity NMA C 18 O 1 -0 SMA CS 7 -6 mean velocity Takakauwa, Ohashi + 2004

Infall Rotation NMA C 18 O (1 -0) (Momose et al. 1998) SMA CS 7 -6 mean velocity Infalling motions are dominant on large scales, Takakauwa, Ohashiscales + 2004 while rotating motions are dominant on small

Are Kepler motions identified around L 1551 IRS 5? PV diagram of the SMA CS 7 -6 data • Sign of spin-up motion consistent with Kepler motion. • R-1 dependence cannot be ruled out. R-1 and R-0. 5 dependences have to be carefully distinguished. Takakuwa et al. 2004

L 1527 IRS (IRAS 04368+2557) • Class 0/I protostar • Lbol ~ 1. 9 Lsolar , Tbol ~ 56 K • Wide opening outflow (Tamura et al. 1996) • Infalling envelope of 1000 AU scale (Ohashi et al. 1997) • Inclination~85° Spitzer IRAC Tobin et al. (2008)

NMA C 18 O 1 -0 Infalling Envelope • Elongated envelope perpendicular to the outflow (Ohashi et al 1997). – 2000 AU in radius – Dynamical infall – Vinfall ~ 0. 3 km/s – Vrotation ~0. 05 km/s – d. M/dt ~ 1 x 10 -6 Mo/yr

CARMA 13 CO 2 -1: Keplerian Disk? -1 and R-0. 5 dependences? 18 How NMA to distinguish R C O 1 -0 VrotµR-1 CARMA 13 CO 2 -1 VrotµR-0. 5 Tobin et al. 2012 Nature

Rotation Curve with a logarithmic scale (Yen et al. 2013) R > 500 AU: Gaussian fit to the spectrum at a given position R < 500 AU：Gaussian fit to the intensity profile at each channel Position (arcsec) rotation curve with a logarithmic scale Velocity (km s– 1)

Vekicity (km s– 1) C 18 O 2 -1 with SMA Position (arcsec) (Yen et al. 2013)

Velocity (km s– 1) SMA C 18 O 2 -1 Rotation Curve Radius (AU) Yen et al. 2013

ALMA Cycle 0 Observations • In order to investigate kinematics of circumstellar material in detail (particularly rotation), three protostars, including L 1527 IRS, have been observed with ALMA cycle 0. • 12 CO, C 18 O 2 -1, SO 6 -5 , 220 GHz continuum etc 5 4 • Dq ~ 0. 96” x 0. 73” (PA ~ 11 deg) • DV ~ 0. 17 km/s • L 1527 IRS, TMC 1 A (Aso’s talk), L 1489 IRS c. f. Sakai et al. have observed L 1527 IRS in C 3 H 2, SO, etc. with ALMA cycle 0 as well (submitted)

a compact rotating class 0 protostar! 140 AU DV = – 2. 5 km/s DV = 2. 5 km/s

Rotation Curve N Rotation Velocity (km s– 1) 5 1 0. 5 S Rb ~ 54 ± 0. 44 AU pin~ – 0. 41 ± 0. 24 Pout ~ -1. 16 ± 0. 13 M* ~0. 33 Mo 50 100 Rotation Radius(AU) Rotation Radius

Summary • In order to unambiguously identify Keplerian disks around protostars, it is crucial to distinguish between Kepler rotation (VrotµR-0. 5) and rotation conserving angular momentum(VrotµR-1). • ALMA cycle 0 observations of L 1527 IRS shows that • Most of C 18 O 2 -1 emission arises from an infalling envelope. • The C 18 O arising the vicinity of the central star (R < 60 AU) may suggests a Keplerian disk. • SO 65 -54 shows rigid-like rotation at lower velocities (DV = -1 — 1 km/s) • The kinematics of the SO emission seems to be not explained with the same kinematics explaining the C 18 O emission.