J/ApJS/270/9 ALMA obs. of 11 massive & luminous clumps protoclusters (Xu+, 2024)
The ALMA Survey of Star Formation and Evolution in Massive Protoclusters with
Blue Profiles (ASSEMBLE): core growth, cluster contraction, and primordial mass
segregation.
Xu F., Wang Ke, Liu T., Tang M., Evans II N.J., Palau A., Morii K., He J.,
Sanhueza P., Liu H.-L., Stutz A., Zhang Q., Chen Xi, Li P.S., Gomez G.C.,
Vazquez-Semadeni E., Li S., Mai X., Lu X., Liu M., Chen Li, Li C., Shi H.,
Ren Z., Li Di, Garay G., Bronfman L., Dewangan L., Juvela M., Lee C.W.,
Zhang S., Yue N., Wang C., Ge Y., Jiao W., Luo Q., Zhou J.-W.,
Tatematsu K., Chibueze J.O., Su K., Sun S., Ristorcelli I., Toth L.V.
<Astrophys. J. Suppl. Ser., 270, 9 (2024)>
=2024ApJS..270....9X 2024ApJS..270....9X
ADC_Keywords: Interstellar medium; Star Forming Region; Radio lines;
Millimetric/submm sources; Carbon monoxide; Space velocities
Keywords: Protoclusters ; Star formation ; Massive stars ;
Interstellar medium ; Protostars ; Star forming regions
Abstract:
The Atacama Large Millimeter/submillimeter Array (ALMA) Survey of Star
Formation and Evolution in Massive Protoclusters with Blue Profiles
(ASSEMBLE) aims to investigate the process of mass assembly and its
connection to high-mass star formation theories in protoclusters in a
dynamic view. We observed 11 massive (Mclump≳103M☉),
luminous (Lbol≳104L☉), and blue-profile (infall signature)
clumps by ALMA with resolution of ∼2200-5500au (median value of
3500au) at 350GHz (870µm). We identified 248 dense cores, including
106 cores showing protostellar signatures and 142 prestellar core
candidates. Compared to early stage infrared dark clouds (IRDCs) by
ASHES, the core mass and surface density within the ASSEMBLE clumps
exhibited a significant increment, suggesting concurrent core
accretion during the evolution of the clumps. The maximum mass of
prestellar cores was found to be 2 times larger than that in IRDCs,
indicating that evolved protoclusters have the potential to harbor
massive prestellar cores. The mass relation between clumps and their
most massive core (MMCs) is observed in ASSEMBLE but not in IRDCs,
which is suggested to be regulated by multiscale mass accretion. The
mass correlation between the core clusters and their MMCs has a
steeper slope compared to that observed in stellar clusters, which can
be due to fragmentation of the MMC and stellar multiplicity. We
observe a decrease in core separation and an increase in central
concentration as protoclusters evolve. We confirm primordial mass
segregation in the ASSEMBLE protoclusters, possibly resulting from
gravitational concentration and/or gas accretion.
Description:
The 17-pointing mosaicked observations were carried out with ALMA
using the 12m array in Band 7 during Cycle 5 (Project ID: 2017.1.00545.S;
PI: Tie Liu) from 2018 May 18 to May 23. The observations have been
divided into six executions; 48 antennas were used to obtain a total
of 1128 baselines with lengths ranging from 15 to 313.7m across all
the executions.
The mosaicked observing fields of ALMA are designed to cover the
densest part of the massive clumps traced by the ATLASGAL 870um
continuum emission. The field center of each mosaicking field is shown
in Table 1. Each mosaicked field has a uniform size of ∼46" and a sky
coverage of ∼0.58arcmin2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 117 11 Physical properties of the ASSEMBLE clumps
table3.dat 82 248 Fundamental measurements of core parameters from
getsf
table4.dat 70 248 Calculated properties for the core sample
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See also:
II/125 : IRAS catalogue of Point Sources, Version 2.0 (IPAC 1986)
J/A+A/291/943 : Protostellar cores (Ossenkopf+, 1994)
J/A+AS/115/81 : A CS(2-1) survey of UC HII regions (Bronfman+, 1996)
J/A+A/308/573 : Ammonia on YSOs IRAS sources (Molinari+ 1996)
J/A+A/426/97 : SIMBA survey. 1.2-mm/IRAS sources (Faundez+, 2004)
J/ApJ/641/389 : Millimetric observations of IRDC cores (Rathborne+, 2006)
J/ApJ/651/L125 : Water masers associated with IR cloud cores (Wang+, 2006)
J/AJ/136/2391 : GLIMPSE Extended Green Objects catalog (Cyganowski+, 2008)
J/A+A/505/405 : A catalogue of Spitzer dark clouds (Peretto+, 2009)
J/ApJS/188/123 : The Bolocam Galactic Plane Survey. II. (Rosolowsky+, 2010)
J/MNRAS/418/1689 : Red MSX water maser and ammonia emissions (Urquhart+, 2011)
J/ApJ/756/60 : A 3mm line survey in 37 IR dark clouds (Sanhueza+, 2012)
J/A+A/553/A115 : Millimetric and far-IR maps of IRDC 18310-4 (Beuther+, 2013)
J/A+A/549/A45 : ATLASGAL Compact Source Catalog: 330<l<21 (Contreras+, 2013)
J/A+A/561/A83 : SDC13 infrared dark clouds spectra (Peretto+, 2014)
J/A+A/568/A41 : ATLASGAL Compact Source Catalog: 280<l<60 (Urquhart+, 2014)
J/A+A/577/A30 : SDC335.579-0.292 6, 8, 23 and 25GHz images (Avison+, 2015)
J/MNRAS/450/1926 : Infall motions in massive star-forming regions (He+, 2015)
J/MNRAS/471/100 : Hi-GAL compact source catalog. -71.0<l<67.0 (Elia+, 2017)
J/ApJS/231/11 : High-mass starless clump cand. from ATLASGAL (Yuan+, 2017)
J/ApJ/862/105 : Core mass function across Gal. env. II. (Liu+, 2018)
J/MNRAS/473/1059 : Complete sample of Galactic clumps (Urquhart+, 2018)
J/MNRAS/475/5659 : OB association members (Ward+, 2018)
J/ApJ/885/131 : High-mass SFR plx & proper motion with VLBI (Reid+, 2019)
J/ApJ/886/102 : ALMA obs. of 70um high-mass clumps (ASHES) (Sanhueza+, 2019)
J/MNRAS/496/2790 : ATOMS I and a first look at G9.62+0.19 (Liu+, 2020)
J/ApJ/912/156 : Core kinematics in the Dragon IRDC from ALMA (Kong+, 2021)
J/ApJS/259/36 : Filaments in the inner Gal. plane from ATLASGAL (Ge+, 2022)
J/A+A/657/A30 : W51 North ALMA 1.3 and 3mm images (Tang+, 2022)
J/A+A/674/A75 : W43-MM1 and W43-MM2+MM3 ALMA datacubes (Nony+, 2023)
J/ApJS/264/35 : C18O dense cores in Orion A (Takemura+, 2023)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- IRName IRAS name (IHHMMm+DDMM; B1950)
13- 27 A15 --- AGAL AGAL identifier (GLLL.lll+BB.bbb)
from Urquhart+ (2018, J/MNRAS/473/1059)
29- 30 I2 h RAh Hour of right ascension (J2000) (1)
32- 33 I2 min RAm Minute of right ascension (J2000)
35- 39 F5.2 s RAs Second of right ascension (J2000)
41 A1 --- DE- Sign of declination (J2000) (1)
42- 43 I2 deg DEd Degree of declination (J2000) (1)
45- 46 I2 arcmin DEm Arcminute of declination (J2000)
48- 51 F4.1 arcsec DEs Arcsecond of declination (J2000)
53- 58 F6.2 km/s Vlsr [-95/-17.7] Local Standard of Rest velocity
derived from the CO(4-3) and C17O(3-2)
lines in APEX obs.
(Yue+ 2021RAA....21...14Y 2021RAA....21...14Y)
60- 64 F5.2 km/s e_Vlsr [-0.9/-0.4] Vlsr uncertainty
66- 69 F4.2 kpc Dist [2.5/7.6] Distance (2)
71- 74 F4.2 kpc e_Dist [0.18/0.7] Lower uncertainty on Dist (2)
76- 79 F4.2 kpc E_Dist [0.3/0.7] Upper uncertainty on Dist (2)
81- 84 F4.2 pc Rcl [0.16/0.8] Radius derived from 2D Gaussian
fitting; in parsec (3)
86- 87 I2 arcsec Rad [12/28] Radius derived from 2D Gaussian
fitting; in arcsec (3)
89- 92 F4.1 K Tdust [23/32.2] Clump dust temperature (4)
94- 97 F4.2 [Msun] logM [2.8/4.4] Log of clump mass (4)
99- 102 F4.2 [Lsun] logLbol [4/6] Log of clump bolometric luminosity (4)
104- 105 I2 Lsun/Msun L/M [11/79] Luminosity-to-mass ratio (4)
107- 110 F4.2 g/cm2 Sigma [0.7/6.5] Clump surface density
(Σcl=Mcl/(πRcl2))
112- 117 A6 --- ID Clump ID as in tables 3 and 4;
column added by CDS (IHHMMm)
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Note (1): Field centers of the ALMA mosaic observations which are not always
consistent with the continuum peak but cover most of the emission of
the clump.
Note (2): The distance and its uncertainties are estimated using the latest
rotation curve model of the Milky Way (Reid+ 2019, J/ApJ/885/131)
Note (3): Effective clump radius by Source Extractor
(Urquhart+ 2014, J/A+A/568/A41).
Note (4): From Urquhart+ (2018, J/MNRAS/473/1059)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- ID ASSEMBLE clump (IHHMMm)
8- 9 I2 --- Core [1/37] Core ID (1)
11- 12 I2 h RAh [14/17] Hour of right ascension (J2000) (2)
14- 15 I2 min RAm Minute of right ascension (J2000) (2)
17- 21 F5.2 s RAs Second of right ascension (J2000) (2)
23 A1 --- DE- [-] Sign of declination (J2000)
24- 25 I2 deg DEd [36/60] Degree of declination (J2000) (2)
27- 28 I2 arcmin DEm Arcminute of declination (J2000) (2)
30- 33 F4.1 arcsec DEs Arcsecond of declination (J2000) (2)
35- 40 F6.1 mJy/beam Ipeak [2.8/1970] Peak intensity
42- 46 F5.1 mJy/beam e_Ipeak [0.3/129] Uncertainty on Ipeak
48- 53 F6.1 mJy Flux [7.6/5133] Integrated flux
55- 59 F5.1 mJy e_Flux [0.3/139] Uncertainty on Flux
61- 64 F4.2 arcsec FWHM-maj [0.79/5.4] Fitted FWHM of major axis
convolved with beam
66- 69 F4.2 arcsec FWHM-min [0.5/3.5] Fitted FWHM of minor axis
convolved with beam
71- 75 F5.1 deg PA Position Angle measured anticlockwise from
north
77- 80 F4.2 arcsec FWHM-c [0.7/4.3] Deconvolved FWHM of core size
82 I1 --- Class [0/5] Core classification based on
Section 4.3 (3)
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Note (1): The core IDs are in order from the north to the south.
Note (2): Equatorial coordinate centers of the cores.
Note (3): Core classification:
0 = prestellar candidate (142 occurrences)
1 = only molecular outflow is detected (13 occurrences)
2 = only warm-core line is detected (51 occurrences)
3 = both outflow and warm-core line are detected (6 occurrences)
4 = both outflow and hot-core line are detected (20 occurrences)
5 = only hot-core line is detected (16 occurrences)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- ID ASSEMBLE clump (IHHMMm)
8- 9 I2 --- Core [1/37] Core ID
11- 13 I3 K Tdust [23/183] Dust temperature
15- 16 I2 K e_Tdust [1/27] Uncertainty on Tdust
18- 18 A1 --- Meth Dust temperature estimation method (1)
20- 23 F4.1 Msun Mcore [0.1/53] Mass of core
25- 28 F4.1 Msun e_Mcore [0.1/23] Uncertainty on Mcore
30- 34 I5 au Rcore [1050/14620] Radius of core
36- 41 F6.2 10+6cm-3 nH2 [0.01/352] H2 volume density
43- 48 F6.2 10+6cm-3 e_nH2 [0.01/159] Uncertainty on nH2
50- 54 F5.2 g.cm-2 Sigma [0.1/12] Surface density
56- 59 F4.2 g.cm-2 e_Sigma [0.06/5] Uncertainty on Sigma
61- 65 F5.2 10+23cm-2 Npeak [0.2/25.3] H2 peak column density
67- 70 F4.2 10+23cm-2 e_Npeak [0.1/9] Uncertainty on Npeak
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Note (1): Temperature estimation method:
G = global clump-averaged temperature in col. Tdust of Table 1
H = H2CS rotation temperature
C = CH3OCHO rotation temperature
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 26-Feb-2024