ALMA2019: Science Results and Cross-Facility Synergies

Session

Circumstellar Disks

IV

15 Oct 2019, 11:30

T-Hotel Cagliari

Description

Chair of the session:

39. The puzzle of protoplanetary disk masses

Dr Anna Miotello

15/10/2019, 11:30

Invited talk

Abstract:
"Thanks to the advent of the Atacama Large Millimeter/submillimeter Array (ALMA), large surveys of protoplanetary disks in different star forming regions have been carried out to study the gas and dust components simultaneously. Carbon monoxide (CO) and its less abundant isotopologues have been observed to trace the bulk of the gas, while the dust was traced by the...

41. The demographical properties of brown dwarf disks

Dr Leonardo Testi

15/10/2019, 11:55

Contributed talk

Abstract:
"The study of the properties of disks around young brown dwarfs can provide important clues on the formation of these very low-mass objects and on the possibility of forming planetary systems around them. We will report on the systematic ALMA search for cold dust around extinction limited samples of young brown dwarfs with infrared excess in the Lupus, Ophiuchus and...

42. Time-Domain Astrochemistry During Planet Formation

Dr Ilse Cleeves

15/10/2019, 12:10

Invited talk

Abstract:
"The chemistry of protoplanetary disks sets the initial composition of newly formed planets and may regulate the efficiency by which planets form. Disk chemical abundances typically evolve over timescales spanning thousands if not millions of years. Consequently, it was a surprise when ALMA observations taken over the course of a single year showed significantly...

43. Probing Snow Surfaces/Lines in Protoplanetary Disks

Dr Chunhua Qi

15/10/2019, 12:25

Contributed talk

Abstract:
"Protoplanetary disk radial and vertical thermal temperature gradients result in 2D snow surfaces, or condensation fronts. These are analogous to 1D snowlines, which are located where snow surfaces intersect with the disk midplane. CO and N2 are two of the most abundant disk molecules, and their snow surface locations could provide disk temperature structure...

65. Small-Scale Substructures in Protoplanetary Disks

Dr Sean Andrews

17/10/2019, 11:40

Invited talk

Abstract:
The Disk Substructures at High Angular Resolution Project (DSHARP) observed 20 nearby protoplanetary disks in the 240 GHz continuum and 12CO J=2-1 spectral line with the Atacama Large Millimeter/submillimeter Array (ALMA) at a resolution of 35 milli-arcseconds (5 au). This talk will describe the motivation for this project and highlight the initial DSHARP results. We...

66. A path to planets: youngest known ringed structures in a protostellar disk

Dr Dominique Segura-Cox

17/10/2019, 12:05

Contributed talk

Abstract:
Circumstellar disks are fundamental to the low-mass star and planet formation processes, yet their properties are only beginning to be unveiled in detail during the earliest Class 0 and I phases due to the dense gas and dust envelopes present at early times. ALMA observations of the older Class II protostar HL Tau exposed dark gaps and dust rings in the disk,...

67. How small molecules betray dust evolution in planet forming disks

Dr Michiel Hogerheijde

17/10/2019, 12:20

Contributed talk

Abstract:
ALMA observations of planet forming disks over the past several years have firmly established that the grains responsible for the millimeter wavelength continuum emission have undergone a significant evolution in their radial and size distribution. Many disks show clear signs of both radial drift of grains and accumulation in rings. This grain evolution is...

68. Organic Molecules in Protoplanetary Disks

Dr Jeong-Eun Lee

17/10/2019, 15:00

Invited talk

Abstract:
Earth-like planets form mostly from dry refractory materials in the inner regions of protoplanetary disks; however, they might become habitable if water and organic molecules are delivered to their surfaces and atmospheres by planetesimals formed beyond the sublimation front of water. Complex organic molecules (COMs), which are the seeds of prebiotic material and...

69. Observing the first phases of planet formation: measuring vertical dust settling in a sample of Edge

Dr François Ménard

17/10/2019, 15:25

Contributed talk

Abstract:
Planets form in Protoplanetary disks. New instruments like ALMA and VLT / SPHERE are revealing features in young disks that may be the traces of these planets: rings, gaps, spirals. The direct detection of forming planets still located inside their disk remains, however, very challenging. The consequence is that direct observational constraints on the formation...

70. Radial variations of grain sizes and dust scale heights on the protoplanetary disk of HD 163296

Dr Satoshi Ohashi

17/10/2019, 15:40

Contributed talk

Abstract:
HD 163296 is one of the best examples of the ring and gap structured protoplanetary disks. In addition, this disk is the only target where the ring and gap are spatially resolved in millimeter-wave polarization as well. By performing radiative transfer calculations of self-scattering polarization, we find that grain size and the dust scale height are the key...

71. ALMA Studies the Origin and Impact of Flares in Planetary Systems

Dr Rachel Osten

17/10/2019, 15:55

Contributed talk

Abstract:
The unanticipated detection of mm flaring in Proxima Cen by ALMA has spurred follow-on observations to understand the origin and nature of stellar flaring and its impact in planetary systems. In April through June of 2019, a coordinated observing campaign took place to further these investigations
and learn more about the relationship between particle acceleration...

74. Hydrogen Radio Recombination Line Masers observed with ALMA: Imaging of Warped Disks and Photo-evapo

Dr Izaskun Jimenez-Serra

17/10/2019, 16:10

Contributed talk

Abstract:
Hydrogen radio recombination lines (or RRLs) are excellent probes of the kinematics and physical conditions of the ionised gas in the ISM. The lines at sub-/millimeter wavelengths are particularly especial since they may present maser amplification. This is a rare effect that has been observed only toward a handful of objects. However, in the cases where maser RRLs...

40. Revolutionizing Our View of Protostellar Disk and Multiplicity: The VLA/ALMA Nascent Disk and Multiplicity Survey"

Dr John Tobin

Contributed talk

Abstract:
"We have conducted a large survey of 328 protostars in the Orion star forming regions at ~40 AU (0.1"") resolution, using ALMA (0.87 mm) and the VLA (9 mm). This large sample was derived from Spitzer and Herschel surveys and constitutes the majority of the protostars in Orion, providing a statistical characterization of the protostellar disk and multiplicity...