High spatial resolution imaging of SO and H2CO in AB Auriga: the first SO image in a transitional disk

Abstract

Transitional disks are structures of dust and gas around young stars with large inner cavities in which planet formation may occur. Lopsided dust distributions are observed in the dust continuum emission at millimeter wavelengths. These asymmetrical structures can be explained as the result of an enhanced gas density vortex where the dust is trapped potentially promoting the rapid growth to the planetesimal scale. AB Aur hosts a transitional disk with a clear horseshoe morphology which strongly suggests the presence of a dust trap. Our goal is to investigate its formation and the possible effects on the gas chemistry. We used the NOEMA interferometer to image the 1mm continuum dust emission and the 13CO J=2->1, C18O J=2->1, SO J=56->45 and H2CO J=303->202 rotational lines. Line integrated intensity ratio images are built to investigate the chemical changes within the disk. We have used a single point (n,T) chemical model to investigate the lifetime of gaseous CO, H2CO and SO in the dust trap. Our model shows that for densities >10^7 cm^-3, the SO molecules are depleted (directly frozen or converted into SO2 and then frozen out) in less than 0.1 Myr. The lower SO abundance towards the dust trap could indicate that a larger fraction of the gas is in a high density environment. Gas dynamics, grain growth and gas chemistry are coupled in the planet formation process. Because of the strong dependence of SO abundance on the gas density, the sulfur chemistry can be used as a chemical diagnostic to detect the birthsites of future planets. However, the large uncertainties inherent to chemical models and the limited knowledge of the disk physical structure and initial conditions are important drawbacks.

References in corpus (24)

• Formation of methyl formate and other organic species in the warm-up phase of hot molecular cores
• A Major Asymmetric Dust Trap in a Transition Disk
• Observations of gas flows inside a protoplanetary gap
• Chemistry of Dark Clouds: Databases, Networks, and Models
• Disk Imaging Survey of Chemistry with SMA: II. Southern Sky Protoplanetary Disk Data and Full Sample Statistics
• Sub-arcsec imaging of the AB Aur molecular disk and envelope at millimeter wavelengths: a non Keplerian disk
• A molecular survey of outflow gas: velocity-dependent shock chemistry and the peculiar composition of the EHV gas
• Lopsided dust rings in transition disks
• The circumstellar disk of AB Aurigae: evidence for envelope accretion at late stages of star formation?
• Formation of simple organic molecules in inner T Tauri disks
• Deuterium chemistry in protoplanetary disks II The inner 30 AU
• The jet and the disk of the HH 212 low-mass protostar imaged by ALMA: SO and SO2 emission
• Testing particle trapping in transition disks with ALMA
• Millimeter observations and modeling of the AB Aurigae system
• A concentration of centimeter-sized grains in the Oph IRS 48 dust trap
• AB Aurigae Resolved: Evidence for Spiral Structure
• Sulphur chemistry and molecular shocks: the case of NGC1333-IRAS2
• Possible Molecular Spiral Arms in the Protoplanetary Disk of AB Aur
• Chemical differentiation along the CepA-East outflows
• An Ionized Outflow from AB Aur, a Herbig Ae Star with a Transitional Disk
• Chemistry in Disks. II. -- Poor molecular content of the AB Aur disk
• Warm formaldehyde in the Oph IRS 48 transitional disk
• Molecular content of the circumstellar disk in AB Aur: First detection of SO in a circumstellar disk
• Chemical composition of the circumstellar disk around AB Aurigae

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• Chemistry in disks. XI. Sulfur-bearing species as tracers of protoplanetary disk physics and chemistry: the DM Tau case
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• AB Aur, a Rosetta stone for studies of planet formation (I): chemical study of a planet-forming disk
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• Mapping the merging zone of late infall in the AB Aur planet-forming system
• The SVS13-A Class I chemical complexity as revealed by S-bearing species. SOLIS XIII
• AB Aur, a Rosetta stone for studies of planet formation (II): H${}_2$S detection and sulfur budget
• A 3mm chemical exploration of small organics in Class I YSOs
• ALMA high-resolution observations unveil planet formation shaping molecular emission in the PDS 70 disk
• Chemical segregation in the young protostars Barnard 1b-N and S: evidence of pseudo-disk rotation in Barnard 1b-S
• The protoplanetary disc around HD 169142: circumstellar or circumbinary?
• Gas accretion within the dust cavity in AB Aur
• SO as shock tracer in protoplanetary disks: the AB Aurigae case
• ALMA chemical survey of disk-outflow sources in Taurus (ALMA-DOT). IV. Thioformaldehyde (H${}_2$CS) in protoplanetary disks: spatial distributions and binding energies
• Constraints on the gas-phase C/O ratio of DR Tau's outer disk from CS, SO, and C${}_2$H observations
• Molecules with ALMA at Planet-forming Scales (MAPS) XII: Inferring the C/O and S/H ratios in Protoplanetary Disks with Sulfur Molecules