FAUST. XXVIII. High-Resolution ALMA Observations of Class 0/I Disks: Structure, Optical Depths, and Temperatures

Abstract

We present high-resolution (~7.5 au) ALMA observations at 1.3 and 3 mm of 16 disks around Class 0/I protostars across multiple star-forming regions and a variety of multiplicities, showing a range of disk sizes (~2-100 au) and including circumbinary disks (CBDs) in binaries with separations <100 au. The disk properties show similarities to Class II disks, including (a) low spectral index (SI) values (alpha=2.1) that increase with disk radius, (b) 3 mm disk sizes only marginally smaller than at 1.3 mm (<10%), and (c) radial intensity profiles well described by modified self-similar profiles. We also find key differences: (i) SI values increasing with radius, but exceeding 2 only at the disk edge (ii) higher brightness temperatures Tb, in some cases higher than the predicted temperatures due to irradiation, and (iii) ~10x higher luminosity at a given size compared to the Class II disks. These results confirm significant optical depth in the observed Class 0/I disks, at both 1.3 and 3 mm, helping to explain their higher luminosities, but higher temperatures are also required for the most compact (< 40 au) disks, suggesting additional viscous heating. Considering optical depth, most disk dust masses are estimated in the range 30-900 Mearth (0.01-0.3 Msun in gas), resulting in some disks reaching marginal gravitational instability. The median location of the water iceline is ~3 au, but it can extend beyond 10-20 au for the hottest disks. CBDs exhibit lower optical depths at both wavelengths and hence higher SI values (alpha=3.0), dust masses of 100 Mearth, and beta~1.5 (2 Class 0 CBDs) and beta~1 (1 Class I CBD), suggesting substantial grain growth only in the more evolved CBD. The inferred high optical depths provide a compelling explanation for the apparent scarcity of dust substructures in the younger disks at ~ 1 mm, despite mounting evidence for early planet formation (ABRIDGED).

31 pages, 15 figures, Accepted for publication in A&A

References in corpus (63)

• CASA, the Common Astronomy Software Applications for Radio Astronomy
• The ALMA Protostellar Interferometric Line Survey (PILS): First results from an unbiased submillimeter wavelength line survey of the Class 0 protostellar binary IRAS 16293-2422 with ALMA
• On the diversity and statistical properties of protostellar discs
• The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. A Statistical Characterization of Class 0 and I Protostellar Disks
• Identifying the Low Luminosity Population of Embedded Protostars in the c2d Observations of Clouds and Cores
• A Circumplanetary Disk Around PDS70c
• One Solution to the Mass Budget Problem for Planet Formation: Optically Thick Disks with Dust Scattering
• Dust masses of young disks: constraining the initial solid reservoir for planet formation
• The Radial Distribution of Dust Particles in the HL Tau Disk from ALMA and VLA Observations
• Early Planet Formation in Embedded Disks (eDisk). I. Overview of the Program and First Results
• The anomalously low (sub)millimeter spectral indices of some protoplanetary disks may be explained by dust self-scattering
• Dust growth and evolution in protoplanetary disks
• The Ophiuchus DIsc Survey Employing ALMA (ODISEA)-III: the evolution of substructures in massive discs at 3-5 au resolution
• Thermal desorption of circumstellar and cometary ice analogs
• Characterizing the dust content of disk substructures in TW Hya
• The statistical properties of stars and their dependence on metallicity
• The time evolution of dusty protoplanetary disc radii: observed and physical radii differ
• Complex organics in IRAS 4A revisited with ALMA and PdBI: Striking contrast between two neighbouring protostellar cores
• Brown dwarf disks with ALMA: evidence for truncated dust disks in Ophiuchus
• Low dust emissivities and radial variations in the envelopes of Class 0 protostars: a signature of early grain growth?
• SMA observations of young disks: separating envelope, disk, and stellar masses in class I YSOs
• The protoplanetary disk population in the rho-Ophiuchi region L1688 and the time evolution of Class II YSOs
• Hot Corinos Chemical Diversity: Myth or Reality?
• A new planet candidate detected in a dust gap of the disc around HD 163296 through localised kinematic signatures. An observational validation of the Discminer
• Distribution of solids in the rings of the HD 163296 disk: a multiwavelength study
• Radial-velocity discovery of a second planet in the TOI-1338/BEBOP-1 circumbinary system
• Corona-Australis DANCe. I. Revisiting the census of stars with Gaia-DR2 data
• Orbital and mass constraints of the young binary system IRAS 16293-2422 A
• Protostellar collapse: the conditions to form dust rich protoplanetary disks
• Protoplanetary disk birth in massive star forming clumps: the essential role of the magnetic field
• FAUST I. The hot corino at the heart of the prototypical Class I protostar L1551 IRS5
• Demographics of disks around young very low-mass stars and brown dwarfs in Lupus
• Formation and evolution of protostellar accretion discs. II. From 3D simulation to a simple semi-analytic model of Class 0/I discs
• ALMA chemical survey of disk-outflow sources in Taurus (ALMA-DOT) V: Sample, overview, and demography of disk molecular emission
• The Mass Accretion Rate and Stellar Properties in Class I Protostars
• Implications of a hot atmosphere/corino from ALMA observations towards NGC1333 IRAS 4A1
• ALMA-IMF II -- investigating the origin of stellar masses: Continuum Images and Data Processing
• Early Planet Formation in Embedded Disks (eDisk). IV. The Ringed and Warped Structure of the Disk around the Class I Protostar L1489 IRS
• Substructure Formation in a Protostellar Disk of L1527 IRS
• Population Synthesis Models Indicate a Need for Early and Ubiquitous Disk Substructures
• FAUST III. Misaligned rotations of the envelope, outflow, and disks in the multiple protostellar system of VLA 1623$-$2417
• Revealing the dust grain size in the inner envelope of the Class I protostar Per-emb-50
• The young protostellar disk in IRAS16293-2422 B is hot and shows signatures of gravitational instability
• Disc population synthesis: Decrease in the solid mass reservoir through pebble drift
• Extension of HOPS Out to 500 ParSecs (eHOPS). I. Identification and Modeling of Protostars in the Aquila Molecular Clouds
• Testing a New Model of Embedded Protostellar Disks Against Observation: The Majority of Orion Class 0/I Disks Are Likely Warm, Massive, and Gravitationally Unstable
• FAUST VIII. The protostellar disk of VLA 1623-2417 W and its streamers imaged by ALMA
• Into the thick of it: ALMA 0.45 mm observations of HL Tau at 2 au resolution
• Dust hot spots at 10 au scales around the Class 0 binary IRAS 16293-2422 A: a departure from the passive irradiation model
• Photodesorption of water ice from dust grains and thermal desorption of cometary ices studied by the INSIDE experiment
• Formation of dust clumps with sub-Jupiter mass and cold shadowed region in gravitationally unstable disk around Class 0/I protostar in L1527 IRS
• FAUST XVII: Super deuteration in the planet forming system IRS 63 where the streamer strikes the disk
• The centimeter emission from planet-forming disks in Taurus
• IRAS4A1: Multi-wavelength continuum analysis of a very flared Class 0 disk
• FAUST. XVIII. Evidence for annular substructure in a very young Class 0 disk
• On the frequencies of circumbinary discs in protostellar systems
• CAMPOS II. The onset of protostellar disk substructures and planet formation
• Dust mass in protoplanetary disks with porous dust opacities
• FAUST XXVI. The dust opacity spectral indices of protostellar envelopes bridge the gap between interstellar medium and disks
• Multi-frequency observations of PDS 70c: Radio emission mechanisms in the circum-planetary environment
• HD 163296 and its Giant Planets: Creation of Exo-comets, Interstellar Objects and Transport of Volatile Material
• Resolved Gas Temperatures and 12C/13C ratios in SVS13A from ALMA Observations of CH3CN and CH3-13-CN
• The evolution of the flux-size relationship in protoplanetary discs by viscous evolution and radial pebble drift

Cited by in corpus (1)

• A Dual-Band Centimetre Continuum Monitoring Survey of Young Stellar Objects in the Coronet Cluster