J/ApJ/862/63 Massive starless clump candidates from BGPS (Calahan+, 2018)
Searching for inflow toward massive starless clump candidates identified
in the Bolocam Galactic Plane Survey.
Calahan J.K., Shirley Y.L., Svoboda B.E., Ivanov E.A., Schmid J.R.,
Pulley A., Lautenbach J., Zawadzki N., Bullivant C., Cook C.W., Gray L.,
Henrici A., Pascale M., Bosse C., Chance Q., Choi S., Dunn M.,
Jaime-Frias R., Kearsley I., Kelledy J., Lewin C., Mahmood Q., Mckinley S.,
Mitchell A.M., Robinson D.R.
<Astrophys. J., 862, 63-63 (2018)>
=2018ApJ...862...63C 2018ApJ...862...63C (SIMBAD/NED BibCode)
ADC_Keywords: Radio lines; Interstellar medium; Galactic plane
Keywords: ISM: clouds; ISM: molecules; ISM: structure; stars: formation
Abstract:
Recent Galactic plane surveys of dust continuum emission at long
wavelengths have identified a population of dense, massive clumps with
no evidence for ongoing star formation. These massive starless clump
candidates are excellent sites to search for the initial phases of
massive star formation before the feedback from massive star formation
affects the clump. In this study, we search for the spectroscopic
signature of inflowing gas toward starless clumps, some of which are
massive enough to form a massive star. We observed 101 starless clump
candidates identified in the Bolocam Galactic Plane Survey (BGPS) in
HCO+J=1-0 using the 12m Arizona Radio Observatory telescope. We
find a small blue excess of E=(Nblue-Nred)/Ntotal=0.03 for the
complete survey. We identified six clumps that are good candidates for
inflow motion and used a radiative transfer model to calculate mass
inflow rates that range from 500 to 2000M☉/Myr. If the observed
line profiles are indeed due to large-scale inflow motions, then these
clumps will typically double their mass on a freefall time. Our survey
finds that massive BGPS starless clump candidates with inflow
signatures in HCO+J=1-0 are rare throughout our Galaxy.
Description:
We observed at the Arizona Radio Observatory (ARO) 12m radio telescope
on Kitt Peak for 19 observing shifts between 2015-Sept and 2016-Apr.
We tuned to the J=1-0 transition of HCO+ at 89,188.5250MHz.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 68 101 Starless clump candidates
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See also:
J/ApJS/208/14 : BGPS. IX. Data release 2. (Ginsburg+, 2013)
J/ApJ/777/157 : 90GHz obs. of high-mass star-forming regions (Hoq+, 2013)
J/ApJS/209/2 : The BGPS. X. Dense molecular gas (Shirley+, 2013)
J/A+A/568/A41 : ATLASGAL Compact Source Catalog: 280<l<60 (Urquhart+, 2014)
J/ApJ/799/29 : BGPS. XII. DR2 distance catalog (Ellsworth-Bowers+, 2015)
J/MNRAS/450/1926 : Infall motions in massive star-forming regions (He+, 2015)
J/ApJ/822/59 : BGPS. XIV. Molecular cloud clumps GBT obs. (Svoboda+, 2016)
J/ApJS/224/43 : Planck cold clumps & cores in 2nd quadrant (Zhang+, 2016)
J/A+A/592/A21 : Are infrared dark clouds really quiescent? (Feng+, 2016)
J/MNRAS/461/2288 : Infall motions in massive star-forming regions (He+, 2016)
J/MNRAS/469/2163 : JCMT Plane Survey. first complete data release (Eden+, 2017)
J/ApJ/846/144 : Virial analysis of the dense cores in Orion A (Kirk+, 2017)
J/MNRAS/471/100 : Hi-GAL compact source catalog. -71.0<l<67.0 (Elia+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [BGPS]
6- 9 I4 --- BGPSv2 BGPS v.2.0.1 catalog index number
(Ginsburg+ 2013, J/ApJS/208/14)
11- 12 I2 h RAh Hour of right ascension (J2000)
14- 15 I2 min RAm Minute of right ascension (J2000)
17- 21 F5.2 s RAs Second of right ascension (J2000)
23 A1 --- DE- Sign of declination (J2000)
24- 25 I2 deg DEd Degree of declination (J2000)
27- 28 I2 arcmin DEm Arcminute of declination (J2000)
30- 34 F5.2 arcsec DEs Arcsecond of declination (J2000)
36- 41 F6.3 kpc Dist [1.17/11.8] Distance (1)
43- 49 F7.3 km/s Vlsr [-1.5/114.4]? Local Standard of Rest
velocity for the HCO+ peak
51- 55 F5.3 km/s e_Vlsr [0.003/0.3]? vlsr uncertainty
57- 62 F6.3 --- Delv [-4.3/3.5]? The FWHM line width, δv
64- 68 F5.3 --- e_Delv [0.005/0.3]? Delv uncertainty
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Note (1): Distances are the maximum likelihood distance of the distance
probability density function (DPDF) in Svoboda+ (2016, J/ApJ/822/59).
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 29-Sep-2023