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G11.92-0.61 MM 1: A fragmented Keplerian disk surrounding a Proto-O star

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Title: G11.92-0.61 MM 1: A fragmented Keplerian disk surrounding a Proto-O star
Authors: Ilee, JD
Cyganowski, CJ
Brogan, CL
Hunter, TR
Forgan, DH
Haworth, TJ
Clarke, CJ
Harries, TJ
Item Type: Journal Article
Abstract: We present high-resolution (~300 au) Atacama Large Millimeter/submillimeter Array observations of the massive young stellar object G11.92–0.61 MM 1. We resolve the immediate circumstellar environment of MM 1 in 1.3 mm continuum emission and CH3CN emission for the first time. The object divides into two main sources—MM 1a, which is the source of a bipolar molecular outflow, and MM 1b, located 0farcs57 (1920 au) to the southeast. The main component of MM 1a is an elongated continuum structure, perpendicular to the bipolar outflow, with a size of 0farcs141 × 0farcs050 (480 × 170 au). The gas kinematics toward MM 1a probed via CH3CN trace a variety of scales. The lower energy J = 12–11 K = 3 line traces extended, rotating gas within the outflow cavity, while the v8 = 1 line shows a clearly resolved Keplerian rotation signature. Analysis of the gas kinematics and dust emission shows that the total enclosed mass in MM 1a is 40 ± 5 M ⊙ (where between 2.2 and 5.8 M ⊙ is attributed to the disk), while MM 1b is <0.6 M ⊙. The extreme mass ratio and orbital properties of MM 1a and MM 1b suggest that MM 1b is one of the first observed examples of the formation of a binary star via disk fragmentation around a massive young (proto)star.
Issue Date: 20-Dec-2018
Date of Acceptance: 9-Nov-2018
URI: http://hdl.handle.net/10044/1/65505
DOI: https://dx.doi.org/10.3847/2041-8213/aaeffc
ISSN: 2041-8205
Publisher: American Astronomical Society
Journal / Book Title: Astrophysical Journal Letters
Volume: 869
Issue: 2
Copyright Statement: © 2018 The American Astronomical Society. All rights reserved.
Keywords: Science & Technology
Physical Sciences
Astronomy & Astrophysics
accretion, accretion disks
ISM: individual objects (G11.92-0.61)
stars: formation
stars: protostars
submillimeter: ISM
0201 Astronomical And Space Sciences
Publication Status: Published
Open Access location: https://arxiv.org/pdf/1811.05267.pdf
Article Number: L24
Online Publication Date: 2018-12-14
Appears in Collections:Physics