J/ApJ/897/53 IR dark clouds parameters in molecular clouds (Retes-Romero+, 2020)
Infrared Dark Clouds and High-mass Star Formation Activity in Galactic Molecular
Clouds.
Retes-Romero R., Mayya Y.D., Luna A., Carrasco L.
<Astrophys. J., 897, 53 (2020)>
=2020ApJ...897...53R 2020ApJ...897...53R
ADC_Keywords: Interstellar medium; Star Forming Region; YSOs; Molecular clouds
Keywords: Interstellar medium ; Infrared dark clouds ; Star formation ;
Young stellar objects ; Protostars ; Protoclusters
Abstract:
Ever since their discovery, infrared dark clouds (IRDCs) are generally
considered to be the sites just at the onset of high-mass (HM) star
formation. In recent years, it has been realized that not all IRDCs
harbor HM young stellar objects (YSOs). Only those IRDCs satisfying a
certain mass-size criterion, or equivalently above a certain threshold
density, are found to contain HMYSOs. In all cases, IRDCs provide
ideal conditions for the formation of stellar clusters. In this paper,
we study the massive stellar content of IRDCs to readdress the
relation between IRDCs and HM star formation. For this purpose, we
have identified all IRDCs associated with a sample of 12 Galactic
molecular clouds (MCs). The selected MCs have been the target of a
systematic search for YSOs in an earlier study. The cataloged
positions of YSOs have been used to search all YSOs embedded in each
identified IRDC. In total, we have found 834 YSOs in 128 IRDCs. The
sample of IRDCs have mean surface densities of 319M☉/pc2, mean
mass of 1062M☉, and a mass function power-law slope -1.8, which
are similar to the corresponding properties for the full sample of
IRDCs and resulting physical properties in previous studies. We find
that all those IRDCs containing at least one intermediate to HM young
star satisfy the often-used mass-size criterion for forming HM stars.
However, not all IRDCs satisfying the mass-size criterion contain HM
stars. We find that the often-used mass-size criterion corresponds to
35% probability of an IRDC forming a massive star. Twenty-five (20%)
of the IRDCs are potential sites of stellar clusters of mass more than
100M☉.
Description:
The sample of infrared dark clouds (IRDCs) in the present study
consists of all those associated with the 12 molecular clouds (MCs)
studied by Retes-Romero+, 2017, J/ApJ/839/113 (R17), and are drawn
from the Peretto & Fuller, 2009, J/A+A/505/405 IRDC catalog (hereafter
PF09).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 80 12 Summary of the properties of the MC sample where
IRDCs have been searched
table2.dat 145 128 Observed and derivated parameters of individual
IRDCs
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See also:
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/AJ/113/1733 : Orion Nebula Cluster population (Hillenbrand 1997)
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/653/1325 : Galactic distribution of infrared dark clouds (Simon+, 2006)
J/A+A/462/L17 : Dense cores in interstellar molecular clouds (Alves+, 2007)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/A+A/505/405 : A catalogue of Spitzer dark clouds (Peretto+, 2009)
J/ApJ/698/324 : Spitzer IRDCs (Ragan+, 2009)
J/ApJ/699/1153 : Kinematic distances GRS molecular clouds (Roman-Duval+, 2009)
J/ApJ/723/1019 : Galactic SFR and gas surface densities (Heiderman+, 2010)
J/A+A/533/A109 : Pisa pre-main sequence tracks and isochrones (Tognelli+, 2011)
J/AJ/144/192 : Spitzer survey of Orion A & B. I. YSO catalog (Megeath+, 2012)
J/A+A/559/A79 : IRDC APEX/SABOCA observations (Ragan+, 2013)
J/A+A/588/A29 : Star formation in massive clumps in Milky Way (Heyer+, 2016)
J/ApJ/822/59 : BGPS. XIV. Molecular cloud clumps GBT obs. (Svoboda+, 2016)
J/ApJ/839/113 : Molecular clouds with GLIMPSE/MIPSGAL (Retes-Romero+, 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 --- MC Name of the molecular cloud
6- 15 A10 --- IRAS Name of the principal IRAS source in the MC
17- 21 F5.2 deg GLON [16.94/50.28] Galactic longitude
23- 27 F5.2 deg GLAT [-0.61/0.15] Galactic latitude
29- 31 F3.1 kpc Dist [1.0/5.4] Kinematical distance (1)
33- 35 F3.1 kpc e_Dist [0.1/0.6] Uncertainty in Dist; 12% of value
37- 41 F5.2 Msun Mass [0.23/13.52] Mass of the MC obtained using
the LTE method
43- 46 F4.2 Msun e_Mass [0.11/6.46] Uncertainty in Mass
48- 50 I3 --- Nyso [14/861] Number, YSOs spatially associated
to the MC
52- 53 I2 --- Nirdc [1/25] Number, IRDCs spatially associated to
the MC
55- 57 I3 Msun/pc2 Sgas [133/816] Surface gas density of the MC
59- 61 I3 Msun/pc2 e_Sgas [60/410] Uncertainty in Sgas
63- 66 F4.1 Msun/Myr/pc2 Ssfr [1.0/26.8] Surface density of star formation
rate of the MC
68- 71 F4.1 Msun/Myr/pc2 e_Ssfr [0.6/13.5] Uncertainty in Ssfr
73- 76 F4.1 % SFE [0.5/11.9] Star formation efficiency in %
units in each cloud.
78- 80 F3.1 % e_SFE [0.1/0.7] Uncertainty in SFE
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Note (1): Kinematical distance (with an error of 12%) to the dense clump
associated to the IRAS source from Faundez+, 2004, J/A+A/426/97.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- MC Name of the molecular cloud
6- 11 A6 --- IRDC IRDC identifier
13- 19 F7.4 deg GLON [16.91/50.43] Galactic longitude, IRDC
centroid (1)
21- 27 F7.4 deg GLAT [-0.69/0.24] Galactic latitude, IRDC
centroid (1)
29- 36 F8.4 arcsec maj [6.0/361.5] Major axis size of IRDC (1)
38- 45 F8.4 arcsec min [4.3/123.4] Minor axis size of IRDC (1)
47- 54 F8.4 deg PA [-88.0/332.0] Position angle of IRDC (1)
56- 61 F6.4 --- tau [0.37/0.85] mean opacity, Spitzer/IRAC
8um band (1)
63- 69 F7.4 pc2 Area [0.006/54.2] Area of IRDC (2)
71- 77 F7.4 pc2 e_Area [0.001/13.6] Uncertainty in Area
79- 84 F6.4 pc Rad [0.04/4.16] Effective radius of IRDC (2)
86- 91 F6.4 pc e_Rad [0.003/0.3] Uncertainty in Rad
93-102 F10.4 Msun Mass [2/19702] Mass of the IRDC (2)
104-112 F9.4 Msun e_Mass [1/2168] Uncertainty in Mass
114-121 F8.4 Msun/pc2 Sgas [236/543] Surface gas density of IRDC (2)
123-129 F7.4 Msun/pc2 e_Sgas [25.99/59.8] Uncertainty in Sgas
131-137 F7.4 Msun/Myr/pc2 Ssfr [0.013/34.8] Surface density of the star
formation rate of the IRDC (2)
139-145 F7.4 Msun/Myr/pc2 e_Ssfr [0.005/13.6] Uncertainty in Ssfr
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Note (1): Values from Peretto & Fuller, 2009, J/A+A/505/405
Note (2): Values derived in this work
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 27-Sep-2021