ALMA Science Highlights 2018 Low-mass Star Formation and - - PowerPoint PPT Presentation

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Low-mass Star Formation and Protoplanetry Disk

Kazuya Saigo (NAOJ)

ALMA Science Highlights 2018

• Dec. 26 2018

ALMA/45m/ASTE Users Meeting 2018

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DSHARP Protoplanetary Disks

The ALMA Large Program in Cycle 4

Disk Substructures at High Angular Resolution Project High resolution (~0.035” or 5au) survey 240 GHz (1.25 mm) continuum

12CO J=2-1 line emission

from 20 nearby, bright, and large PP disks.

DSHARP I: Andrews, S. M et al. 2018arXiv181204040 II: Huang, J. et al. 2018arXiv181204041 III: Huang, J. et al. 2018 arXiv:1812.04143 IV: Kurtovic N. et al. arXiv:1812.04536 V: Birnstiel, T. et al. 2018arXiv181204043 VI: Dullemond, C. P . et al. 2018arXiv181204044 VII: Zhang, S. al. 2018arXiv181204045 VIII:Guzmán, V. V. et al. 2018arXiv181204046 IX: Isella, A. et al. 2018arXiv181204047 X: Pérez, L. M. et al. 2018arXiv181204049

Almost all PP disks have substructures.

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DSHARP Protoplanetary Disks

Formation models of such substructures

• 1. Dust trapping in radial pressure bumps

Dullemond et al. (2018 paper VI) find all ring structures are consistent with dust trapping model.

• 2. Gravitational interaction with planets

Zhang et al. (2018 paper VII) reproduced the observed ring

• f AS 209 by single planet model.
• 3. Opacity gap by snowlines of major volatiles

Some of the gaps roughly coincide with the location of snowlines of major volatiles. But this model contradicts diversity?

• 4. Gravitational Instability

2D Simulation Single Planet + low viscosity

Formation mechanism is an open question.

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Asymmetries structure in PP Disks

Dong 2018 ApJ, 860, 124 PP Disk around MWC 758

• ff-centered cavity+ 2 clumps + rings + arms

Asymmetric structures are shaped by the gravitational interaction with unseen planets? PP Disk around HD 163296 Ring + asymmetric structure Isella et al. 2018 arXiv181204047 (DSHARP IX) Mayama et al. (2018)： misaligned PP disk around J16042165-2130284 Pérez, L. M. et al. 2018 arXiv181204049: misaligned PP disk around HD143006 ect.

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Kinematic Evidence for Embedded Protoplanets I

Pinte et al. 2018 ApJL, 860, L13P

~15% deviation from Keplerian rotation in the PP disk around HD 163296. Perturbation by ~ 2 MJup mass proto-planet at R ~ 260 au ?

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Kinematic Evidence for Embedded Protoplanets II

Teague et al. 2018 ApJL, 860L, L12T Deviation from Keplerian rotation C18O(2-1) model (3 proto-planets )

Azimuthally averaged velocity structure indicates the embedded three ptoto-planets in the PP disk around HD 163296.

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Sub-structures in Protostellar Disk

Sheehan and Eisner 2017; 2018 Class I protostar GY 91 Class I protostar WL 17 ALMA 3mm

Protostellar disks in the main acretion phase also have sub-structures.

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Discovery of Jupter Mass protostar

Protostar IRAS 15398–3359 Okoda et al. 2018 ApJL, 864, L25

0.007M8

Offset position (arcsec)

ALMA observation of very young objects

M* <~0.2M8 Low Luminosity? or no IR emission Embedded in the cloud core Yen et al. 2018 88 young objects in Lupus Yoko Oya et al. 2018 L483 Tokuda et al. 2018 MC27/L1521F Tien-Hao Hsieh et al. 2018 IRAS 16253-2429(protobrown dwarf?) Aso et al. 2018 Very young protostars in Serpens Main Kawabe et al. 2018 Oph. Sorce A/Source X , ,

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Dust size diagnosis by Polarization

Stephens et al. 2017 (see Kataoka et al. 2016a, 2016b, 2017) HL Tau: 100μm (Stephens et al. 2017) DG Tau: 100μm (Bacciotti et al 2018) CW Tau: 50-70μm (Bacciotti et al 2018) HD142527 Southern Region: <100μm Northern Region: >150μm (Ohashi et al. 2018) Bacciotti et al 2018 Dust grain size

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Magnetic Structure in Protostellar envelopes

Kwon et al. 2018 proto-binary L1448 IRS2 Maury et al. 2018 Class 0 Protostar B335

Polarization observation toward protostars Sadavoy et al. (2018) Class 1 Protobinary IRAS16293-2422 Harris et al. (2018) Class 0 Protobinary VLA1623, Class 1 Protostar L1527 Alves et al. (2018) Class 0 Protobinary BHB07-11 Cox et al. 2018 10 protostars Perseus Molecular Cloud

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Protostellar Jet: Kinematic and Magnetic and Structures

Lee Chin-Fei et al. 2018 ApJ, 865, 9

Protostellar outflow/jet HH211

Line Polarization (SiO) Lee Chin-Fei et al. 2018, Nature Communications

Line polarization is attributed to the Goldreich- Kylafis effect in the presence of magnetic field.

toroidal fields? Very High Resolution Image 0.03 arcsec resolution (∼ 7au)

If this polarization vector is perpendicular to the magnetic field * It depends on physical condition.

Revised 2018 12/26

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Protostellar Jet: Kinematic and Magnetic and Structures

Lee Chin-Fei et al. 2018 ApJ, 865, 9

Protostellar outflow/jet HH211

Line Polarization (SiO) Lee Chin-Fei et al. 2018, Nature Communications

Line polarization is attributed to the Goldreich- Kylafis effect in the presence of magnetic field.

Very High Resolution Image 0.03 arcsec resolution (∼ 7au)

↑ If this polarization vector is perpendicular to the magnetic field. (Note that it depends on physical condition.)

Revised 2018 12/26

toroidal fields?

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Discovery of shock heated filaments in the low mass protstellar core

Tokuda et al. 2018 MC27/L1521F 12CO (2-1) Shock Heated Filament (width <~a few x 10au, T>~60K)

Decay process ? turbulence or internal motions Δv ~ a few km/s => sub-sonic?