A Keplerian-Like Disk Around the Forming O-Type Star Afgl 4176

Johnston, K. G.; Robitaille, Thomas; Beuther, H.; Linz, H.; Boley, Paul A.; Kuiper, Rolf; Keto, Eric; Hoare, M. G.; Boekel, R. van

doi:10.1088/2041-8205/813/1/l19

Cited by 149 publications

(207 citation statements)

References 49 publications

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“…However, it is still a matter of debate whether the most massive stars are ever associated with accretion disks. Most of the reported accretion disks around massive stars are mostly associated with early Btype protostars (Cesaroni et al 2005;Patel et al 2005;Franco-Hernández et al 2009;Fernández-López et al 2011a;Wang et al 2012;Sanchez-Monge et al 2013;Beltrán & de Wit 2016), although there are some evidence of disks around O-type stars (Johnston et al 2015;Ilee et al 2016).…”

Section: Introductionmentioning

confidence: 99%

The Circumestellar Disk of the B0 Protostar Powering the HH 80-81 Radio Jet

Girart

Estalella

Fernández-López

et al. 2017

ApJ

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We present subarcsecond angular resolution observations carried out with the Submillimeter Array (SMA) at 880 µm centered at the B0-type protostar GGD27 MM1, the driving source of the parsec scale HH 80-81 jet. We constrain its polarized continuum emission to be 0.8% at this wavelength. Its submm spectrum is dominated by sulfur-bearing species tracing a rotating disk-like structure (SO and SO 2 isotopologues mainly), but also shows HCN-bearing and CH 3 OH lines, which trace the disk and the outflow cavity walls excavated by the HH 80-81 jet. The presence of many sulfurated lines could indicate the presence of shocked gas at the disk's centrifugal barrier or that MM1 is a hot core at an evolved stage. The resolved SO 2 emission traces very well the disk kinematics and we fit the SMA observations using a thin-disk Keplerian model, which gives the inclination (47 • ), the inner ( 170 AU) and outer (∼ 950 − 1300 AU) radii and the disk's rotation velocity (3.4 km s −1 at a putative radius of 1700 AU). We roughly estimate a protostellar dynamical mass of 4-18 M ⊙ . MM2 and WMC cores show, comparatively, an almost empty spectra suggesting that they are associated with extended emission detected in previous low-angular resolution observations, and therefore indicating youth (MM2) or the presence of a less massive object (WMC).

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Section: Introductionmentioning

confidence: 99%

The Circumestellar Disk of the B0 Protostar Powering the HH 80-81 Radio Jet

Girart

Estalella

Fernández-López

et al. 2017

ApJ

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“…These are central questions for high-mass star formation research (e.g., Henning et al 2000;Kratter & Matzner 2006;Beuther et al 2009;Cesaroni et al 2007;Vaidya et al 2009;Kraus et al 2010Kraus et al , 2016Beltrán et al 2011;Ilee et al 2013;Boley et al 2013Boley et al , 2016Sánchez-Monge et al 2014;Johnston et al 2015). The main indirect evidence stems from observations of massive and collimated outflows that are qualitatively similar to low-mass jets (e.g., Beuther et al 2002;Zhang et al 2005;Arce et al 2007;López-Sepulcre et al 2009;Duarte-Cabral et al 2013).…”

Section: Introductionmentioning

confidence: 99%

Multiplicity and disks within the high-mass core NGC 7538IRS1

Beuther

Linz

Henning

et al. 2017

A&A

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Context. High-mass stars have a high degree of multiplicity and most likely form via disk accretion processes. The detailed physics of the binary and disk formation are still poorly constrained. Aims. We seek to resolve the central substructures of the prototypical high-mass star-forming region NGC7538IRS1 at the highest possible spatial resolution line and continuum emission to investigate the protostellar environment and kinematics. Methods. Using the Karl G. Jansky Very Large Array (VLA) in its most extended configuration at ∼24 GHz has allowed us to study the NH 3 and thermal CH 3 OH emission and absorption as well as the cm continuum emission at an unprecedented spatial resolution of 0.06 × 0.05 , corresponding to a linear resolution of ∼150 AU at a distance of 2.7 kpc. Results. A comparison of these new cm continuum data with previous VLA observations from 23 yrs ago reveals no recognizable proper motions. If the emission were caused by a protostellar jet, proper motion signatures should have been easily identified. In combination with the high spectral indices S ∝ ν α (α between 1 and 2), this allows us to conclude that the continuum emission is from two hypercompact Hii regions separated in projection by about 430 AU. The NH 3 spectral line data reveal a common rotating envelope indicating a bound high-mass binary system. In addition to this, the thermal CH 3 OH data show two separate velocity gradients across the two hypercompact Hii regions. This indicates two disk-like structures within the same rotating circumbinary envelope. Disk and envelope structures are inclined by ∼33• , which can be explained by initially varying angular momentum distributions within the natal, turbulent cloud. Conclusions. Studying high-mass star formation at sub-0.1 resolution allows us to isolate multiple sources as well as to separate circumbinary from disk-like rotating structures. These data show also the limitations in molecular line studies in investigating the disk kinematics when the central source is already ionizing a hypercompact Hii region. Recombination line studies will be required for sources such as NGC7538IRS1 to investigate the gas kinematics even closer to the protostars.

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“…We find that the disc is in Keplerian rotation (see Figure 5). We note that Ilee et al (2016), Johnston et al (2015) and Chen et al (2016) identify Keplerian rotation in their observations of massive discs. However the observational measurements of the disc kinematics are complicated by the fact that they are obtained from molecular line tracers that may also simultaneously probe the rotating and infalling envelopes (for example Hunter et al (2014) observed a combination of Keplerian rotation and infall).…”

Section: Disc Mass and Radiusmentioning

confidence: 66%

Radiation-hydrodynamical simulations of massive star formation using Monte Carlo radiative transfer – II. The formation of a 25 solar-mass star

Harries

Douglas

Ali

2017

Monthly Notices of the Royal Astronomical Society

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We present a numerical simulation of the formation of a massive star using MonteCarlo-based radiation hydrodynamics (RHD). The star forms via stochastic disc accretion and produces fast, radiation-driven bipolar cavities. We find that the evolution of the infall rate (considered to be the mass flux across a 1500 au spherical boundary), and the accretion rate onto the protostar, are broadly consistent with observational constraints. After 35 kyr the star has a mass of 25 M and is surrounded by a disc of mass 7 M and 1500 au radius, and we find that the velocity field of the disc is close to Keplerian. Once again these results are consistent with those from recent high-resolution studies of discs around forming massive stars. Synthetic imaging of the RHD model shows good agreement with observations in the near-and far-IR, but may be in conflict with observations that suggests that MYSOs are typically circularly symmetric on the sky at 24.5 µm. Molecular line simulations of a CH 3 CN transition compare well with observations in terms of surface brightness and line width, and indicate that it should be possible to reliably extract the protostellar mass from such observations.

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A Keplerian-Like Disk Around the Forming O-Type Star Afgl 4176

Cited by 149 publications

References 49 publications

The Circumestellar Disk of the B0 Protostar Powering the HH 80-81 Radio Jet

The Circumestellar Disk of the B0 Protostar Powering the HH 80-81 Radio Jet

Multiplicity and disks within the high-mass core NGC 7538IRS1

Radiation-hydrodynamical simulations of massive star formation using Monte Carlo radiative transfer – II. The formation of a 25 solar-mass star

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