Kinematics and stability of high-mass protostellar disk candidates at sub-arcsecond resolution -- Insights from the IRAM NOEMA large program CORE

Abstract

The fragmentation mode of high-mass molecular clumps and the accretion processes that form the most massive stars ($M\gtrsim 8M_{\odot }$) are still not well understood. To this end, we have undertaken a large observational program (CORE) making use of interferometric observations from the Northern Extended Millimetre Array (NOEMA) for a sample of 20 luminous ($L>10^4{L}_{\odot }$) protostellar objects in the 1.37 mm wavelength regime in both continuum and line emission, reaching $\sim$0.4" resolution (800 au at 2 kpc). Using the dense gas tracer CH${}_3$CN, we find velocity gradients across 13 cores perpendicular to the directions of bipolar molecular outflows, making them excellent disk candidates. Specific angular momentum ($j$) radial profiles are on average $\sim 10^{-3}$ km /s pc and follow $j\propto r^{1.7}$, consistent with a poorly resolved rotating and infalling envelope/disk model. Fitting the velocity profiles with a Keplerian model, we find protostellar masses in the range of $\sim 10-25$ $M_{\odot }$. Modelling the level population of CH${}_3$CN lines, we present temperature maps and find median gas temperatures in the range $70-210$ K. We create Toomre $Q$ maps to study the stability of the disks and find almost all (11 of 13) disk candidates to be prone to fragmentation due to gravitational instabilities at the scales probed by our observations. In particular, disks with masses greater than $\sim 10-20\%$ of the mass of their host (proto)stars are Toomre unstable, and more luminous protostellar objects tend to have disks that are more massive and hence more prone to fragmentation. Our finings show that most disks around high-mass protostars are prone to disk fragmentation early in their formation due to their high disk to stellar mass ratio. This impacts the accretion evolution of high-mass protostars which will have significant implications for the formation of the most massive stars.

27 pages, 12 figures, 6 appendices - accepted for publication in Astronomy and Astrophysics

References in corpus (41)

• Binary interaction dominates the evolution of massive stars
• Trigonometric Parallaxes Of High-Mass Star Forming Regions: Our View Of The Milky Way
• MAMBO Mapping of Spitzer c2d Small Clouds and Cores
• Southern Massive Stars at High Angular Resolution: Observational Campaign and Companion Detection
• The earliest phases of high-mass star formation: a 3 square degree millimeter continuum mapping of Cygnus X
• Circumventing the radiation pressure barrier in the formation of massive stars via disk accretion
• Three-dimensional simulation of massive star formation in the disk accretion scenario
• Water maser motions in W3(OH) and a determination of its distance
• Limiting Accretion onto Massive Stars by Fragmentation-Induced Starvation
• Fragmentation of Massive Protostellar Disks
• Magnetic processes in a collapsing dense core. II Fragmentation. Is there a fragmentation crisis ?
• A hot compact dust disk around a massive young stellar object
• G11.92-0.61 MM1: A Keplerian disc around a massive young proto-O star
• Trigonometric Parallaxes of Star Forming Regions in the Perseus Spiral Arm
• pyspeckit: A spectroscopic analysis and plotting package
• The Role of Magnetic Fields in Protostellar Outflows and Star Formation
• Forming spectroscopic massive proto-binaries by disk fragmentation
• A necklace of dense cores in the high-mass star forming region G35.20-0.74N: ALMA observations
• The local spiral structure of the Milky Way
• Protostellar Outflows and Radiative Feedback from Massive Stars. II. Feedback, Star Formation Efficiency, and Outflow Broadening
• Substructures in the Keplerian disc around the O-type (proto)star G17.64+0.16
• Protostellar Outflows and Radiative Feedback from Massive Stars
• Spiral arms and instability within the AFGL 4176 mm1 disc
• Chemical complexity in high-mass star formation: An observational and modeling case study of the AFGL 2591 VLA 3 hot core
• Collapse of turbulent massive cores with ambipolar diffusion and hybrid radiative transfer I. Accretion and multiplicity
• A multiple system of high-mass YSOs surrounded by disks in NGC7538 IRS1
• An Asymmetric Keplerian Disk Surrounding the O-type Protostar IRAS16547$-$4247
• NGC7538 IRS1 - an ionized jet powered by accretion
• ALMA reveals a candidate hot and compact disk around the O-type protostar IRAS 16547$-$4247
• Salt, Hot Water, and Silicon Compounds Tracing Massive Twin Disks
• Disk Kinematics and Stability in High-Mass Star Formation: Linking Simulations and Observations
• Massive binaries in high-mass star-forming regions: A multi-epoch radial velocity survey of embedded O-stars
• A pilot survey of the binarity of Massive Young Stellar Objects with $K$ band adaptive optics
• A relation between the radial velocity dispersion of young clusters and their age: Evidence for hardening as the formation scenario of massive close binaries
• Multi-scale view of star formation in IRAS 21078+5211: From clump fragmentation to disk wind
• Multiplicity and disks within the high-mass core NGC7538IRS1: Resolving cm line and continuum emission at ~0.06"x0.05" resolution
• Hot Ammonia around O-type Young Stars. I. JVLA imaging of Ammonia (6,6) to (14,14) in NGC7538 IRS1
• IRAS23385+6053: An embedded massive cluster in the making
• Non-circular Motions in the Outer Perseus Spiral Arm
• A 10-$M_{\odot }$ YSO with a Keplerian disk and a nonthermal radio jet
• Disk fragmentation in high-mass star formation. High-resolution observations towards AFGL 2591-VLA 3

Cited by in corpus (11)

• JOYS: Disentangling the warm and cold material in the high-mass IRAS 23385+6053 cluster
• The accretion burst of the massive young stellar object G323.46 -0.08
• PRODIGE -- envelope to disk with NOEMA. IV. An infalling gas bridge surrounding two Class 0/I systems in L1448N
• The Role of Thermal Instability in Accretion Outbursts in High-Mass Stars
• Gas infall via accretion disk feeding Cepheus A HW2
• Resolved Gas Temperatures and 12C/13C ratios in SVS13A from ALMA Observations of CH3CN and CH3-13-CN
• Digging into the Interior of Hot Cores with ALMA (DIHCA). VII. Disk candidates around high-mass stars and evidence of anisotropic infall
• Episodic accretion in high-mass star formation: An analysis of thermal instability for axially symmetric disks
• Surveys of clumps, cores, and condensations in Cygnus-X: Searching for Keplerian disks on the scale of 500 au
• ngVLA Synthetic Observations of Ionized Gas in Massive Protostars
• Unlocking accretion rate diagnostics for high-mass protostars using JWST/MIRI HI lines