ALMA Fellow Report: ALMA Study of Disk Formation around Protostars - - PowerPoint PPT Presentation

ALMA Fellow Report: ALMA Study of Disk Formation around Protostars

Shigehisa Takakuwa & Nicolas Salinas (Kagoshima University)

Introduction

• 1. Evidence for Magnetic Fields in Disk Formation ?

̶> Counter Rotation between the Envelopes and Disk in IRAS 04169+2702.

How the precursors of planets, protoplanetary disks, form ? ̶> Still Controversial.

̶> ALMA Observations of Protostellar Envelopes and the Forming Disks around Protostars.

• 2. Sign of Planet Formation in Protostellar Disks ?

̶> Our follow-up HL Tau observations.

Class I Protostar IRAS 04169+2702

Tbol ~133 K; Lbol ~0.76 Lsolar; in the B213 Cloud

6.0 6.3 DECLINATION (B1950) 7.4 RIGHT ASCENSION (B1950) 04 16 56 55 54 53 52 27 03 15 00 02 45 30 15 8.0 5.6 6.7 7.0 7.7

2000 AU

Ohashi et al. (1997) 2200×1100 au Envelope in C18O (1-0) NW (Red) SE (Blue)

Envelope Velocity Gradient

SMA Velocity Features

280 au 70 au Right ascension (J2000.0) a) 13CO (3-2) Blue & Red c) C18O (2-1) Low-Vel. Blue & Red d) b) SO (65-54) Blue & Red

Our Results of IRAS 04169+2702

Infalling and Counter-Rotating Envelope (C18O 1-0, 2-1) SO 65-54 Disk (13CO 3-2) Blueshifted Outflow (12CO 2-1; 1-0) Redshifted Outflow (12CO 2-1; 1-0; 13CO 2-1) ~200 au ~1000 au

Disk and Envelope Rotation Opposite. See Takakuwa et al. 2018, ApJ, 865, 51

Cycle 6 ALMA Observations of IRAS 04169 ̶> C43-5 Executed !!

Right ascension (J2000.0)

280 au beam

The Gas motion controlled by the magnetic field will be unveiled unambiguously with ALMA. Anticipated Model Velocity Channel maps in C18O 3-2

ALMA SV observations of HL Tau

Akiyama et al. 2016 Pinte et al. 2015

80 mas (11 au) 30 mas (4 au) 30 mas (4 au) Resolution:

Hints of HCO+ gas gaps

(a)

• riginal moment 0 map of HCO+ (1-0)

D1 B1 D2 B2 D5 D6 B5 B6 D2 D5 D6 B5 B6

(b)

Azimuthal Averaging Outer Gap Inner Gap

(c)

Image Reconstruction

Yen et al. 2016

Hints of HCO+ gas gaps

(a)

• riginal moment 0 map of HCO+ (1-0)

D1 B1 D2 B2 D5 D6 B5 B6 D2 D5 D6 B5 B6

(b)

Azimuthal Averaging Outer Gap Inner Gap

(c)

Image Reconstruction

Yen et al. 2016 (a) (b)

HCO+ (3-2) HCO+ (4-3)

HCO+ (1-0) HCO+ (3-2) HCO+ (4-3)

Prediction

Summary: ALMA Study of Disk Formation around Protostars

Gas Motion controlled by the Magnetic Field in the Process of Disk Formation. Search for Sign of Planet Formation in the Disks around Protostars.

New Hiring Unfortunately, Nicolas left Kagoshima for his personal issue. We are going to hire another one.