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{
"abstracts": [
{
"content": "We present Atacama Large Millimeter/submillimeter Array (ALMA) line and\ncontinuum observations at 1.2mm with ~0.3\" resolution that uncover a\nKeplerian-like disk around the forming O-type star AFGL 4176. The continuum\nemission from the disk at 1.21 mm (source mm1) has a deconvolved size of\n870+/-110 AU x 330+/-300 AU and arises from a structure ~8 M_sun in mass,\ncalculated assuming a dust temperature of 190 K. The first-moment maps,\npixel-to-pixel line modeling, assuming local thermodynamic equilibrium (LTE),\nand position-velocity diagrams of the CH3CN J=13-12 K-line emission all show a\nvelocity gradient along the major axis of the source, coupled with an increase\nin velocity at small radii, consistent with Keplerian-like rotation. The LTE\nline modeling shows that where CH3CN J=13-12 is excited, the temperatures in\nthe disk range from ~70 to at least 300 K and that the H2 column density peaks\nat 2.8x10^24 cm^-2. In addition, we present Atacama Pathfinder Experiment\n(APEX) 12CO observations which show a large-scale outflow from AFGL 4176\nperpendicular to the major axis of mm1, supporting the disk interpretation.\nFinally, we present a radiative transfer model of a Keplerian disk surrounding\nan O7 star, with a disk mass and radius of 12 M_sun and 2000 AU, that\nreproduces the line and continuum data, further supporting our conclusion that\nour observations have uncovered a Keplerian disk around an O-type star.",
"lang": "en",
"mimetype": "text/plain",
"sha1": "0d0ccb2d947e54076c8e2762f072d51a919c486a"
}
],
"contribs": [
{
"index": 0,
"raw_name": "Katharine G. Johnston",
"role": "author"
},
{
"index": 1,
"raw_name": "Thomas P. Robitaille",
"role": "author"
},
{
"index": 2,
"raw_name": "Henrik Beuther",
"role": "author"
},
{
"index": 3,
"raw_name": "Hendrik\n Linz",
"role": "author"
},
{
"index": 4,
"raw_name": "Paul Boley",
"role": "author"
},
{
"index": 5,
"raw_name": "Rolf Kuiper",
"role": "author"
},
{
"index": 6,
"raw_name": "Eric Keto",
"role": "author"
},
{
"index": 7,
"raw_name": "Melvin G. Hoare",
"role": "author"
},
{
"index": 8,
"raw_name": "Roy van Boekel",
"role": "author"
}
],
"ext_ids": {
"arxiv": "1509.08469v1"
},
"extra": {
"arxiv": {
"base_id": "1509.08469",
"categories": [
"astro-ph.SR"
],
"comments": "6 pages, 4 figures, accepted for publication in ApJL"
}
},
"ident": "5hzpesjrjrdrzaoahvihorp7eq",
"language": "en",
"license_slug": "ARXIV-1.0",
"refs": [],
"release_date": "2015-09-28",
"release_stage": "submitted",
"release_type": "article",
"release_year": 2015,
"revision": "29d2a48a-6e57-48bf-be55-6d30ef405365",
"state": "active",
"title": "A Keplerian-like disk around the forming O-type star AFGL 4176",
"version": "v1",
"work_id": "afmgjv5gijd3xkn65hvuqlfewa"
}
|