Asymmetric mid-plane gas in ALMA images of HD~100546

Abstract

In this paper we present new ALMA observations towards the proto-planet hosting transitional disc of Herbig Ae/Be star HD 100546. This includes resolved 1.3 mm continuum, ${}^{13}$CO and the first detection of C${}^{18}$O in this disc, which displays azimuthal asymmetry in regions spatially coincident with structures previously identified in HST images related to spiral arms. The lower limit on the mass of the dust disc is calculated to be 9.6x10${}^{-4}$M${}_{\odot }$. A firm lower-limit on the total gas mass calculated from optically thin, mid-plane tracing C${}^{18}$O (2-1) emission is 0.018M${}_{\odot }$ assuming ISM abundances. These mass estimates provide an estimate of gas-to-dust ratio in the disc of 19, the ratio will increase if C${}^{18}$O is relatively under-abundant in the disc compared to CO and H2. Through deprojection and azimuthal averaging of the image plane we detect 1.3 mm continuum emission out to 290+/-10 au,${}^{13}$CO to 390+/-10 au and C${}^{18}$O to 300+/-10au. We measure a radially increasing millimetre spectral index between wavelengths of 867$\mu$m and 1.3 mm, which shows that grain sizes increase towards the star, with solid particles growing to cm scales in the inner disc.

References in corpus (22)

• Coagulation, fragmentation and radial motion of solid particles in protoplanetary disks
• Ring shaped dust accumulation in transition disks
• Dust size distributions in coagulation/fragmentation equilibrium: Numerical solutions and analytical fits
• Lupus disks with faint CO isotopologues: low gas/dust or large carbon depletion?
• Protoplanetary disk masses from CO isotopologues line emission
• Different dust and gas radial extents in protoplanetary disks: consistent models of grain growth and CO emission
• ALMA hints at the presence of two companions in the disk around HD 100546
• Testing the theory of grain growth and fragmentation by millimeter observations of protoplanetary disks
• An ALMA Survey of CO isotopologue emission from Protoplanetary Disks in Chamaeleon I
• Five steps in the evolution from protoplanetary to debris disk
• CO gas inside the protoplanetary disk cavity in HD 142527: disk structure from ALMA
• A Resolved Molecular Gas Disk around the Nearby A Star 49 Ceti
• NIR Spectroscopy of the HAeBe Star HD 100546: III. Further Evidence of an Orbiting Companion?
• CO mass upper limits in the Fomalhaut ring - the importance of NLTE excitation in debris discs and future prospects with ALMA
• HD100546 Multi-Epoch Scattered-Light Observations
• Chemistry in Protoplanetary Disks: the gas-phase CO/H2 ratio and the Carbon reservoir
• Millimetre spectral indices of transition disks and their relation to the cavity radius
• CO emission tracing a warp or radial flow within $\lesssim$ 100 au in the HD 100546 protoplanetary disk
• ALMA observations of a misaligned binary protoplanetary disk system in Orion
• Spiral arms in thermally stratified protoplanetary discs
• The protoplanetary system HD 100546 in H$\alpha$ polarized light from SPHERE/ZIMPOL. A bar-like structure across the disk gap?
• Effects of disc midplane evolution on CO snowline location

Cited by in corpus (17)

• Photoevaporative Dispersal of Protoplanetary Disks around Evolving Intermediate-mass Stars
• Sulphur monoxide emission tracing an embedded planet in the HD 100546 protoplanetary disk
• AB Aur, a Rosetta stone for studies of planet formation (I): chemical study of a planet-forming disk
• Gemini-LIGHTS: Herbig Ae/Be and massive T-Tauri protoplanetary disks imaged with Gemini Planet Imager
• Herbig Stars: A Quarter Century of Progress
• ALMA 870 $\mu$m continuum observations of HD 100546. Evidence of a giant planet on a wide orbit
• Photoevaporation of Grain-Depleted Protoplanetary Disks around Intermediate-Mass Stars: Investigating Possibility of Gas-Rich Debris Disks as Protoplanetary Remnants
• The Origin of the Doppler-flip in HD 100546: a large scale spiral arm generated by an inner binary companion
• ALMA reveals thermal and non-thermal desorption of methanol ice in the HD 100546 protoplanetary disk
• An SMA Survey of Chemistry in Disks around Herbig AeBe Stars
• Detection of Substructures in Young Transition Disk WL 17
• Spatial distribution of the aromatic and aliphatic carbonaceous nano-grain features in the protoplanetary disk around HD 100546
• New Mid-Infrared Imaging Constraints on Companions and Protoplanetary Disks around six Young Stars
• Radial distribution of the carbonaceous nano-grains in the protoplanetary disk around HD 169142
• Nearby Young Stars and Young Moving Groups
• Planet formation in intermediate-separation binary systems
• HD 44892: The youngest (or oldest?) gas-harbouring debris disc around an intermediate mass star