scholarly journals Infall in Protostellar Envelopes

2004 ◽  
Vol 221 ◽  
pp. 75-82
Author(s):  
Nagayoshi Ohashi
Keyword(s):  
Observational Studies ◽  
Recent Progress ◽  
Angular Resolution ◽  
Protoplanetary Disks ◽  
Great Emphasis ◽  
High Angular Resolution ◽  
Compact Disks

We summarize recent progress of observational studies of infall in protostellar envelopes, with great emphasis on results obtained using millimeter and submillimeter interferometers. Interferometric observations allow us to spatially resolve kinematical structures of protostellar envelopes, enabling us to detect infalling motions in the envelope directly. High angular resolution observations of infalling envelopes having compact disks sufficiently bright in continuum show inverse P-Cygni profiles, which are the least ambiguous evidence for infall. Observations of infalling envelopes using the Submillimeter Array (SMA) may allow us to study the innermost infalling envelopes, where infalling motions most probably transform to Keplerian motions, leading to formation of Keplerian or protoplanetary disks around protostars.

scholarly journals Magnetic Fields in Molecular Clouds

2004 ◽  
Vol 221 ◽  
pp. 83-96
Author(s):  
Tyler L. Bourke ◽  
Alyssa A. Goodman
Keyword(s):  
Star Formation ◽  
Magnetic Fields ◽  
Observational Data ◽  
Observational Studies ◽  
Molecular Clouds ◽  
Large Scale ◽  
Angular Resolution ◽  
Protoplanetary Disks ◽  
High Angular Resolution ◽  
Dense Cores

Magnetic fields are believed to play an important role in the evolution of molecular clouds, from their large scale structure to dense cores, protostellar envelopes, and protoplanetary disks. How important is unclear, and whether magnetic fields are the dominant force driving star formation at any scale is also unclear. In this review we examine the observational data which address these questions, with particular emphasis on high angular resolution observations. Unfortunately the data do not clarify the situation. It is clear that the fields are important, but to what degree we don't yet know. Observations to date have been limited by the sensitivity of available telescopes and instrumentation. In the future ALMA and the SKA in particular should provide great advances in observational studies of magnetic fields, and we discuss which observations are most desirable when they become available.

scholarly journals The Disk Substructures at High Angular Resolution Project (DSHARP). VI. Dust Trapping in Thin-ringed Protoplanetary Disks

2018 ◽  
Vol 869 (2) ◽  
pp. L46 ◽  
Author(s):  
Cornelis P. Dullemond ◽  
Tilman Birnstiel ◽  
Jane Huang ◽  
Nicolás T. Kurtovic ◽  
Sean M. Andrews ◽  
...  
Keyword(s):  
Angular Resolution ◽  
Protoplanetary Disks ◽  
High Angular Resolution ◽  
Dust Trapping

scholarly journals Searching for kinematic evidence of Keplerian disks around Class 0 protostars with CALYPSO

2020 ◽  
Vol 635 ◽  
pp. A15 ◽  
Author(s):  
S. Maret ◽  
A. J. Maury ◽  
A. Belloche ◽  
M. Gaudel ◽  
Ph. André ◽  
...  
Keyword(s):  
Optical Thickness ◽  
Angular Resolution ◽  
Line Emission ◽  
Protoplanetary Disks ◽  
High Angular Resolution ◽  
Moment Maps ◽  
Large Program ◽  
Jet Axis

The formation of protoplanetary disks is not well understood. To understand how and when these disks are formed, it is crucial to characterize the kinematics of the youngest protostars at a high angular resolution. Here we study a sample of 16 Class 0 protostars to measure their rotation profile at scales from 50 to 500 au and search for Keplerian rotation. We used high-angular-resolution line observations obtained with the Plateau de Bure Interferometer as part of the CALYPSO large program. From 13CO (J = 2−1), C18O (J = 2−1) and SO (Nj = 56−45) moment maps, we find that seven sources show rotation about the jet axis at a few hundred au scales: SerpS-MM18, L1448-C, L1448-NB, L1527, NGC 1333-IRAS 2A, NGC 1333-IRAS 4B, and SVS13-B. We analyzed the kinematics of these sources in the uv plane to derive the rotation profiles down to 50 au scales. We find evidence for Keplerian rotation in only two sources, L1527 and L1448-C. Overall, this suggests that Keplerian disks larger than 50 au are uncommon around Class 0 protostars. However, in some of the sources, the line emission could be optically thick and dominated by the envelope emission. Due to the optical thickness of these envelopes, some of the disks could have remained undetected in our observations.

scholarly journals Herbig Ae/Be Star Disks at High Angular Resolution

2004 ◽  
Vol 221 ◽  
pp. 389-394
Author(s):  
C. P. Dullemond ◽  
C. Dominik ◽  
R. van Boekel ◽  
R. Waters ◽  
M. van den Ancker
Keyword(s):  
Angular Resolution ◽  
Protoplanetary Disks ◽  
Spectral Energy ◽  
High Angular Resolution ◽  
Be Stars ◽  
Spectral Energy Distributions ◽  
Energy Distributions ◽  
Spatially Resolved ◽  
Be Star ◽  
Geometric Picture

We show that there exists a simple geometric picture for the geometries of protoplanetary disks around Herbig Ae/Be stars that explains the two main kinds of spectral energy distributions found for these objects, and that makes predictions that are qualitatively in agreement with currently available spatially resolved images and/or interferometric measurements. Also it qualitatively explains the phenomenon of UX Orionis variability.

scholarly journals Molecules with ALMA at Planet-forming Scales (MAPS). X. Studying Deuteration at High Angular Resolution toward Protoplanetary Disks

2021 ◽  
Vol 257 (1) ◽  
pp. 10 ◽  
Author(s):  
Gianni Cataldi ◽  
Yoshihide Yamato ◽  
Yuri Aikawa ◽  
Jennifer B. Bergner ◽  
Kenji Furuya ◽  
...  
Keyword(s):  
Angular Resolution ◽  
Protoplanetary Disks ◽  
High Angular Resolution

scholarly journals Ubiquitous Disks in AGN

1997 ◽  
Vol 163 ◽  
pp. 152-161
Author(s):  
Gary D. Schmidt
Keyword(s):  
Optical Imaging ◽  
Entire Range ◽  
Recent Progress ◽  
Angular Resolution ◽  
High Angular Resolution ◽  
Great Success ◽  
Nuclear Activity

AbstractDisk-like structures have been inferred to exist in the nuclei of galaxies over the entire range in nuclear activity. These form the essence of the Unified Scheme, which has had great success in accounting for AGN of a wide variety of perceived types. Recent progress along this front is summarized, including new polarimetric results, high-angular resolution optical imaging, and interferometry at radio wavelengths.

scholarly journals First Results from ATCA at Millimetre Wavelengths

2004 ◽  
Vol 221 ◽  
pp. 275-282
Author(s):  
Vincent Minier
Keyword(s):  
Star Formation ◽  
Angular Resolution ◽  
Galactic Plane ◽  
Dust Emission ◽  
Protoplanetary Disks ◽  
High Angular Resolution ◽  
Star Forming ◽  
Star Forming Regions ◽  
First Results ◽  
Excellent Tool

The newly upgraded Australia Telescope Compact Array (ATCA) at millimetre wavelengths is the first millimetre interferometer to be built in the Southern Hemisphere. The full array will be operational in 2004-2005 and will provide arcsec angular resolution at 3 mm and 12 mm. This will be a unique instrument to study at high angular resolution the interstellar chemistry and more generally the star formation process, especially in the bulk of the galactic plane and in the Magellanic Clouds. The upgraded ATCA will also be an excellent tool to detect dust emission from nearby protoplanetary disks. In this paper I will present the first results from the upgraded ATCA at 3 mm and 12 mm. The result review will cover the topics of massive star formation and hot molecular cores dust emission from star-forming regions and detection of protoplanetary disks.

scholarly journals The Disk Substructures at High Angular Resolution Project (DSHARP). V. Interpreting ALMA Maps of Protoplanetary Disks in Terms of a Dust Model

2018 ◽  
Vol 869 (2) ◽  
pp. L45 ◽  
Author(s):  
Tilman Birnstiel ◽  
Cornelis P. Dullemond ◽  
Zhaohuan Zhu ◽  
Sean M. Andrews ◽  
Xue-Ning Bai ◽  
...  
Keyword(s):  
Angular Resolution ◽  
Protoplanetary Disks ◽  
High Angular Resolution

scholarly journals Radio Interferometry Observations of the Hallmarks of Planet Formation

2013 ◽  
Vol 8 (S299) ◽  
pp. 80-89
Author(s):  
Sean M. Andrews
Keyword(s):  
Planet Formation ◽  
Angular Resolution ◽  
Planetary System ◽  
Planetary Systems ◽  
Protoplanetary Disks ◽  
Circumstellar Disks ◽  
High Angular Resolution ◽  
Radio Interferometry ◽  
New Directions ◽  
And Migration

AbstractSome of the fundamental processes involved in the evolution of circumstellar disks and the assembly of planetary systems are just now becoming accessible to astronomical observations. The new promise of observational work in the field of planet formation makes for a very dynamic research scenario, which is certain to be amplified in the coming years as the revolutionary Atacama Large Millimeter/submillimeter Array (ALMA) facility ramps up to full operations. To highlight the new directions being explored in these fields, this brief review will describe how high angular resolution measurements at millimeter/radio wavelengths are being used to study several crucial aspects of the formation and early evolution of planetary systems, including: the gas and dust structures of protoplanetary disks, the growth and migration of disk solids, and the interactions between a young planetary system and its natal, gas-rich disk.

Formation and Evolution of Protoplanetary Disks: Observations and Modeling of Jets, Disks, and Disk Substructures

2018 ◽  
Vol 14 (S345) ◽  
pp. 96-101
Author(s):  
Laura M. Pérez
Keyword(s):  
Planet Formation ◽  
Angular Resolution ◽  
Planetary System ◽  
Protoplanetary Disks ◽  
Solid Particles ◽  
High Angular Resolution ◽  
Rapid Progress ◽  
Disk Evolution ◽  
Formation And Evolution ◽  
Dusty Disks

AbstractPlanet formation takes place in the gaseous and dusty disks that surround young stars, known as protoplanetary disks. With the advent of sensitive observations and together with developments in theory, our field is making rapid progress in understanding how the evolution of protoplanetary disks takes place, from its inception to the end result of a fully-formed planetary system. In this review, I discuss how observations that trace both the dust and gas components of these systems inform us about their evolution, mass budget, and chemistry. Particularly, the process of disk evolution and planet formation will leave an imprint on the distribution of solid particles at different locations in a protoplanetary disk, and I focus on recent observational results at high angular resolution in the sub-millimeter regime, which have revealed a variety of substructures present in these objects.

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