Frost, AJ, Oudmaijer, RD orcid.org/0000-0001-7703-3992, de Wit, WJ et al. (1 more author) (2019) A multi-scale exploration of a massive young stellar object: A transition disk around G305.20+0.21? Astronomy & Astrophysics, 625. A44. ISSN 0004-6361
Abstract
Context. The rarity of young massive stars combined with the fact that they are often deeply embedded has limited the understanding of the formation of stars larger than 8 M⊙. Ground based mid-infrared (IR) interferometry is one way of securing the spatial resolution required to probe the circumstellar environments of massive young stellar objects (MYSOs). Given that the spatial-frequency coverage of such observations is often incomplete, direct-imaging can be supplementary to such a dataset. By consolidating these observations with modelling, the features of a massive protostellar environment can be constrained.
Aims. This paper aims to detail the physical characteristics of the protostellar environment of the MYSO G305.20+0.21 at three size-scales by fitting one 2.5D radiative transfer model to three different types of observations simultaneously, providing an extensive view of the accreting regions of the MYSO.
Methods. Interferometry, imaging and a multi-wavelength spectral energy distribution (SED) are combined to study G305.20+0.21. The high-resolution observations were obtained using the Very Large Telescope’s MIDI and VISIR instruments, producing visibilities in the N-band and near-diffraction-limited imaging in the Q-band respectively. By fitting simulated observables, derived from the radiative transfer model, to our observations the properties of the MYSO are constrained.
Results. The VISIR image shows elongation at 100 mas scales and also displays a degree of asymmetry. From the simulated observables derived from the radiative transfer model output we find that a central protostar with a luminosity of ~5 × 104 L⊙ surrounded by a low-density bipolar cavity, a flared 1 M⊙ disk and an envelope is sufficient to fit all three types of observational data for G305.20+0.21. The weak silicate absorption feature within the SED requires low-density envelope cavities to be successfully fit and is an atypical characteristic in comparison to previously studied MYSOs.
Conclusions. The fact that the presence of a dusty disk provides the best fit to the MIDI visibilities implies that this MYSO is following a scaled-up version of the low-mass star formation process. The low density, low extinction environment implies the object is a more evolved MYSO and this combined with large inner radius of the disk suggests that it could be an example of a transitional disk around an MYSO.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © ESO 2019. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | stars: formation; stars: imaging; stars: early-type; stars: individual: G305.20+0.21; techniques: interferometric; infrared: stars |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Astrophysics (Leeds) |
Funding Information: | Funder Grant number PPARC PPA/G/S/2003/00107 PPARC ST/F002092/1 Science & Technology Facilities Council (STFC) ST/F002092/1 Science & Technology Facilities Council (STFC) ST/I001557/1 Science & Technology Facilities Council (STFC) ST/I001557/1 Science & Technology Facilities Council (STFC) ST/L000628/1 Science & Technology Facilities Council (STFC) ST/P00041X/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 05 Jun 2019 14:39 |
Last Modified: | 25 Jun 2023 21:51 |
Status: | Published |
Publisher: | EDP Sciences |
Identification Number: | 10.1051/0004-6361/201834583 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:146872 |