J/AJ/168/52 Infall motion in molecular clumps. V. HCO+ & HCN obs. (Yu+, 2024)
In search of infall motion in molecular clumps.
V. HCO+ (1-0) and HCN (1-0) observations toward 210 infall candidates.
Yu S., Jiang Z., Chen Z., Yang Y., Feng H.
<Astron. J., 168, 52 (2024)>
=2024AJ....168...52Y 2024AJ....168...52Y
ADC_Keywords: Molecular clouds; Radio lines; Interstellar medium;
Space velocities
Keywords: Star formation ; Interstellar medium ; Molecular clouds ;
Collapsing clouds
Abstract:
We have carried out HCO+(J=1-0) and HCN(J=1-0) line observations
towards 210 infall candidates selected from the CO blue-profile
catalog by Jiang+ 2023RAA....23g5001J 2023RAA....23g5001J, using the Purple Mountain
Observatory 13.7m telescope. Out of the 210 targets, 42 sources are
further confirmed to have infall signatures in HCO+ and/or HCN lines,
with a confirmation rate of ∼20%. According to the line profiles, we
classify them into two categories: double-peaked and peak-shoulder.
Some physical properties are estimated through profile fitting using
the RATRAN model. We find that the two types are separated in
parameter space, indicating they may be of different properties. The
median values of kinetic temperature, infall velocity, and mass infall
rate for the two types are 10.5K and 40.8K, 0.40km/s and 1.00km/s, and
4.6x10-5M☉/yr and 3.5x10-4M☉/yr, respectively. The
infall velocities and mass-infall rates of peak-shoulder sources are
slightly larger than those of double-peaked ones, suggesting they tend
to form more massive stars. We also discuss the association of the
42 confirmed sources with other star formation activities such as
maser and outflow, which supports this result.
Description:
We select 210 objects out of those by Jiang+ 2023RAA....23g5001J 2023RAA....23g5001J,
without overlapping with those observed by Yang+ (2020, J/ApJS/248/18),
and use HCO+(1-0) and HCN(1-0) to probe with higher-density line
profiles of the candidates.
The facility used for our observations is the Purple Mountain
Observatory (PMO) 13.7m radio telescope located in Delingha, Qinghai
Province, China (project code 19A001). Its observable frequency range
is 85-115GHz. The all-sky pointing accuracy of the telescope is
reported to be ≲5". The rest frequency of HCO+(1-0) and HCN(1-0) are
89.2GHz and 88.6GHz.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 38 99 Line parameters and profiles of 99 infall
candidates with HCO+ and HCN emission
table4.dat 87 42 Star-forming regions, masers, and outflows
associated with further confirmed infall candidates
tablea1.dat 45 210 List of all 210 observed infall candidates
refs.dat 74 67 References
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See also:
VII/7 : Lynds' Catalogue of Dark Nebulae (LDN) (Lynds 1962)
J/A+AS/58/197 : 11cm survey, 357.4≤l≤76, -1.5≤b≤1.5 (Reich+, 1984)
J/A+AS/101/153 : Galactic H2O masers (Palagi+ 1993)
J/MNRAS/276/57 : IRAS Galactic star-forming regions. II. (Codella+ 1995)
J/ApJ/463/205 : CS and NH3 Survey of H2O Maser Emission (Anglada+ 1996)
J/ApJS/110/21 : Molecular clouds in Cepheus & Cassiopeia (Yonekura+ 1997)
J/A+AS/132/211 : Interstellar SiO sources (Harju+ 1998)
J/ApJ/526/788 : Infall motions toward starless cores (Lee+, 1999)
J/A+AS/143/269 : 6.7GHz methanol maser emission survey (Szymczak+, 2000)
J/A+A/368/845 : Arcetri Cat. of H2O maser sources. (Valdettaro+, 2001)
J/A+A/413/233 : 12.2 GHz methanol survey (Blaszkiewicz+, 2004)
J/A+A/458/789 : ISOCAM survey of Serpens/G3-G6 (Djupvik+, 2006)
J/A+A/453/911 : VLA and IR obs. of the S235A-B region (Felli+, 2006)
J/PASJ/59/1185 : Water maser in galactic IRAS sources (Sunada+, 2007)
J/A+A/487/993 : MAMBO Mapping of c2d Clouds and Cores (Kauffmann+, 2008)
J/ApJS/184/18 : Spitzer survey of young stellar cl. (Gutermuth+, 2009)
J/ApJ/714/L285 : YSO candidates in M17 SWex (Povich+, 2010)
J/PASJ/63/S1 : Atlas & cat. of dark clouds from 2MASS (Dobashi+, 2011)
J/MNRAS/418/1689 : Red MSX water maser & ammonia emissions (Urquhart+, 2011)
J/ApJ/750/125 : Spitzer imaging of Cepheus OB3b cluster (Allen+, 2012)
J/MNRAS/431/1752 : ATLASGAL 6.7GHz methanol masers (Urquhart+, 2013)
J/MNRAS/435/400 : ATLASGAL. Compact HII regions (Urquhart+, 2013)
J/MNRAS/439/3719 : Embedded clusters infrared photometry (Chavarria+, 2014)
J/MNRAS/450/1926 : Infall motions in massive star-forming regions (He+, 2015)
J/MNRAS/461/2288 : Infall motions in massive star-forming regions (He+, 2016)
J/ApJ/833/18 : Compact HII regions & methanol masers. I. (Hu+, 2016)
J/A+A/590/A72 : Herschel counterparts of SDC (Peretto+, 2016)
J/A+A/594/A28 : Planck Cat. of Galactic cold clumps (PGCC) (Planck+, 2016)
J/ApJ/838/80 : JHK polarimetry of stars behind bubble N4 (Chen+, 2017)
J/ApJS/231/20 : A new 95GHz methanol maser catalog. I. (Yang+, 2017)
J/A+A/620/A158 : IR-dark clumps MALT90 molecular content (Saral+, 2018)
J/A+A/628/A90 : OH maser emission in THOR survey (Beuther+, 2019)
J/MNRAS/490/2779 : Dust clumps associated with masers (Billington+, 2019)
J/MNRAS/485/2895 : The SCOPE 850um compact source catalogue (Eden+, 2019)
J/ApJ/884/4 : KEYSTONE: ammonia structures in Gal. GMCs (Keown+, 2019)
J/ApJ/885/131 : High-mass SFR plx & proper motion with VLBI (Reid+, 2019)
J/A+A/632/A58 : Physical properties of CHIMPS clumps (Rigby+, 2019)
J/ApJS/241/18 : 6.7GHz methanol maser survey. II. |b|<2° (Yang+, 2019)
J/MNRAS/492/1335 : Star formation and 6.7GHz methanol masers (Paulson+, 2020)
J/ApJS/248/18 : 44 and 95GHz obs. of class I methanol masers (Yang+, 2020)
J/other/RAA/20.115 : Molecular clumps CO, HCO and HCN data (Yang+, 2020)
J/A+A/633/A51 : Distances to molecular clouds in SFR (Zucker+, 2020)
J/A+A/666/A59 : GLOSTAR GPS. 6.7GHz Methanol Maser Catalog (Nguyen+, 2022)
J/MNRAS/510/3389 : High-mass star formation evolut. trends (Urquhart+, 2022)
J/AJ/167/220 : Molecular clouds dist. measurements; MWISP (Zhang+, 2024)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Source name (GLLL.ll+B.bb)
14 A1 --- f_Name [*] *: confirmed to have infall signature
16- 19 F4.2 K THCO [0.13/5]? HCO+ peak intensity
21- 24 F4.2 K THCN [0.09/4.8]? HCN peak intensity
26- 29 F4.2 km/s DelVHCO [0.5/5.2]? HCO+ line width
31- 34 F4.2 km/s DelVHCN [0.2/6.4]? HCN line width
36- 38 A3 --- Prof Type of line profile for HCO+(1-0) and
HCN(1-0) respectively (R=red; B=blue)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/42] Running sequence number
4- 15 A12 --- Name Source name (GLLL.ll+B.bb)
17- 35 A19 --- SFR Star forming region
37 A1 --- HII HII region?
39 A1 --- I CH3OH maser class I?
41 A1 --- II CH3OH maser class II?
43 A1 --- H2O H2O maser?
45 A1 --- OH OH maser?
47 A1 --- Out Outflow?
49- 60 A12 --- Evol Evolution (1)
62- 87 A26 --- Ref Reference(s) (see refs.dat file)
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Note (1): The match result of evolutionary stage obtained from
Elia+ (2021MNRAS.504.2742E 2021MNRAS.504.2742E) and Urquhart+ (2022, J/MNRAS/510/3389).
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/210] Running sequence number
5- 16 A12 --- Name Source name (GLLL.ll+B.bb) identified
by 12CO and 13CO unless flagged
18 A1 --- f_Name Flag on Name (1)
20- 21 I2 h RAh Hour of right ascension (J2000)
23- 24 I2 min RAm Minute of right ascension (J2000)
26- 29 F4.1 s RAs Second of right ascension (J2000)
31 A1 --- DE- Sign of declination (J2000)
32- 33 I2 deg DEd Degree of declination (J2000)
35- 36 I2 arcmin DEm Arcminute of declination (J2000)
38- 39 I2 arcsec DEs Arcsecond of declination (J2000)
41- 45 F5.1 km/s Vlsr [-49.6/47.1] LSR velocity
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Note (1): Flag as follows:
d = this source is initially identified by the line pair 13CO and C18O
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Ref [1/67] Reference code
5- 31 A27 --- Auth First author's name(s)
34- 52 A19 --- BibCode Bibcode of the reference
54- 74 A21 --- Cat VizieR catalog reference
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 16-Sep-2024