J/ApJ/944/26 YSO candidates in 30 Doradus from IR and ALMA obs. (Nayak+, 2023)
Massive star formation in the Tarantula nebula.
Nayak O., Green A., Hirschauer A.S., Indebetouw R., Meixner M., Wong T.,
Chevance M., De Marchi G., Lebouteiller V., Lee M.-Y., Looney L.W.,
Madden S.C., Roman-Duval J., Fukui Y., Hacar A., Jameson K.E., Kalari V.,
Oudshoorn L., Rubio M., Sabbi E.
<Astrophys. J., 944, 26 (2023)>
=2023ApJ...944...26N 2023ApJ...944...26N
ADC_Keywords: YSOs; Interstellar medium; Photometry, infrared;
Photometry, millimetric/submm; Carbon monoxide;
Star Forming Region; Stars, masses; Stars, diameters
Keywords: Star formation ; Interstellar medium ; Young stellar objects
Abstract:
In this work, we present 299 candidate young stellar objects (YSOs) in
30 Doradus discovered using Spitzer and Herschel point-source
catalogs, 276 of which are new. We study the parental giant molecular
clouds in which these YSO candidates form using recently published
Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 7
observations of 12CO and 13CO. The threshold for star formation in
30 Doradus inferred by the LTE-based mass surface density is
178M☉/pc2, 40% higher than the threshold for star formation in
the Milky Way. This increase in star formation threshold in comparison
to the Milky Way and increase in line width seen in clumps 11pc away
in comparison to clumps 45pc away from the R136 super star cluster
could be due to injected turbulent energy, increase in interstellar
medium pressure, and/or local magnetic field strength. Of the 299 YSO
candidates in this work, 62% are not associated with 12CO molecular
gas. This large fraction can be explained by the fact that 75%-97% of
the H2 gas is not traced by CO. We fit a Kroupa initial mass function
to the YSO candidates and find that the total integrated stellar mass
is 18000M☉ and that the region has a star formation rate (SFR)
of 0.18M☉/yr. The initial mass function determined here applies
to the four 150"x150" (37.5pcx37.5pc) subfields and one 150"x75"
(37.5pcx18.8pc) subfield observed with ALMA. The SFR in 30 Doradus has
increased in the past few million years.
Description:
We use the published band-merged Spitzer Survey of the Agents of
Galaxy Evolution (SAGE) point-source catalog to identify point sources
within the ALMA footprint of 30 Doradus. This catalog has been merged
between the InfraRed Survey Facility (IRSF; converted to the Two
Micron All Sky Survey (2MASS)), IRAC, Herschel PACS, and SPIRE bands.
There are 488 point sources from the Spitzer point-source catalog
within the ALMA Cycle 7 observations of 30 Doradus. See Section 2.1.
We use the ALMA Cycle 7 12CO (2-1) and 13CO (2-1) observations
(2019.1.00843.S) taken by Wong+ (2022, J/ApJ/932/47). The ALMA
footprint of 30 Doradus covers the R136 super star cluster (SSC) and
its surrounding molecular gas.
We present a catalog of 488 point sources within the ALMA Cycle 7
footprint of 30 Doradus. From fitting SEDs we determine that 299 of
these point sources are likely YSO candidates, 276 of which are newly
identified protostars.
Objects:
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RA (ICRS) DE Designation(s)
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05 38 35.99 -69 05 11.0 Tarantula Nebula = NAME 30 Dor Nebula
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 143 488 2MASS and IRAC Point Source photometry
table2.dat 123 488 Mid- to far-infrared point source photometry
table3.dat 99 488 Point sources and reduce χ2 fits
table4.dat 64 299 Properties of likely YSOs ranked from most massive
to least massive
table6.dat 86 113 YSO Candidates associated with the smallest
12CO virial mass clump
table7.dat 53 34 YSO candidates associated with the smallest 13CO
clump calculated using the LTE mass
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See also:
II/288 : IRSF Magellanic Clouds Point Source Catalog (Kato+ 2007)
II/305 : SAGE LMC and SMC IRAC Source Catalog (IPAC 2009)
VI/139 : Herschel Observation Log (Herschel Science Centre, 2013)
J/AJ/132/2268 : SAGE calibration stars (Meixner+, 2006)
J/ApJ/686/948 : CO in extragalactic giant molecular clouds (Bolatto+, 2008)
J/AJ/135/726 : Spitzer SAGE observations of LMC PNe (Hora+, 2008)
J/AJ/136/18 : LMC SAGE. New candidate YSOs (Whitney+, 2008)
J/ApJ/705/144 : Molecular and atomic gas in the LMC. II. (Fukui+, 2009)
J/ApJS/184/172 : High- and intermediate-mass YSOs in the LMC (Gruendl+, 2009)
J/ApJ/699/1092 : Giant molecular clouds (SRBY) (Heyer+, 2009)
J/ApJ/699/150 : Spectral classif. of Massive YSOs in LMC (Seale+, 2009)
J/ApJ/723/1019 : Galactic SFR and gas surface densities (Heiderman+, 2010)
J/ApJS/197/16 : CO obs. of LMC molecular clouds (MAGMA). (Wong+, 2011)
J/A+A/542/A66 : YSOs in 9 LMC star forming regions (Carlson+, 2012)
J/ApJ/761/37 : CO obs. in giant molecular clouds of M33 (Miura+, 2012)
J/ApJ/774/73 : ALMA CO observations of 30 Dor (Indebetouw+, 2013)
J/AJ/146/62 : HERschel HERITAGE in Magellanic Clouds (Meixner+, 2013)
J/ApJ/778/15 : SAGE-SMC III. Young stellar objects (Sewilo+, 2013)
J/AJ/148/124 : Herschel key program Heritage (Seale+, 2014)
J/ApJ/803/16 : Giant MCs in NGC4526 based on 12CO (Utomo+, 2015)
J/MNRAS/4/3250 : SAGE LMC point-sources classification (Jones+, 2017)
J/ApJ/857/19 : ALMA view of GMCs in NGC 300 (Faesi+, 2018)
J/ApJ/854/154 : N159 12CO and 13CO (2-1) clumps (Nayak+, 2018)
J/MNRAS/498/4906 : Pressure components in central HII regions (Barnes+, 2020)
J/ApJ/901/L8 : Molecular gas data of 70 PHANGS-ALMA galaxies (Sun+, 2020)
J/ApJS/254/3 : CO obs. of molecular clouds in the MW midplane (Ma+, 2021)
J/ApJ/932/47 : ALMA CO obs. of the 30 Dor MoC complex (Wong+, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Name Source identifier (Y1 to Y488)
6- 14 F9.6 deg RAdeg [84.5/84.83] Right ascension (J2000)
16- 25 F10.6 deg DEdeg [-69.2/-69] Declination (J2000)
27- 34 F8.4 mJy FJ [0.07/341]?=0 2MASS J band flux
36- 41 F6.4 mJy e_FJ [0.01/7]?=0 Error in FJ
43- 50 F8.4 mJy FH [0.1/492]?=0 2MASS H band flux
52- 58 F7.4 mJy e_FH [0.02/20.4]?=0 Error in FH
60- 67 F8.4 mJy FKs [0.1/475]?=0 2MASS Ks band flux
69- 75 F7.4 mJy e_FKs [0.03/14.4]?=0 Error in FKs
77- 84 F8.4 mJy F3.6um [0.03/289]?=0 Spitzer/IRAC 3.6 micron flux
86- 92 F7.4 mJy e_F3.6um [0.005/12.3]?=0 Error in F3.6um
94- 101 F8.4 mJy F4.5um [0.02/196]?=0 Spitzer/IRAC 4.5 micron flux
103- 109 F7.4 mJy e_F4.5um [0.005/14]?=0 Error in F4.5um
111- 118 F8.4 mJy F5.8um [0.07/181]?=0 Spitzer/IRAC 5.8 micron flux
120- 126 F7.4 mJy e_F5.8um [0.02/19]?=0 Error in F5.8um
128- 135 F8.4 mJy F8um [0.1/255]?=0 Spitzer/IRAC 8.0 micron flux
137- 143 F7.4 mJy e_F8um [0.02/30]?=0 Error in F8um
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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 --- Name Source identifier (Y1 to Y488)
6- 12 F7.2 mJy F24um [4.5/6430]?=0 Spitzer/MIPS 24 micron flux
14- 19 F6.2 mJy e_F24um [0.9/529]?=0 Error in F24um
21- 29 F9.2 mJy F70um [197/166000]?=0 Spitzer/MIPS 70 micron flux
31- 38 F8.2 mJy e_F70um [15/16618]?=0 Error in F70um
40- 47 F8.2 mJy F100um [9.3/57800]?=0 Herschel/PACS 100 micron flux
49- 55 F7.2 mJy e_F100um [0.7/5794]?=0 Error in F100um
57- 64 F8.2 mJy F160um [20/43900]?=0 Herschel/PACS 160 micron flux
66- 72 F7.2 mJy e_F160um [1.6/4406]?=0 Error in F160um
74- 81 F8.2 mJy F250um [98/50100]?=0 Herschel/SPIRE 250 micron flux
83- 89 F7.2 mJy e_F250um [9/4028]?=0 Error in F250um
91- 98 F8.2 mJy F350um [197/24200]?=0 Herschel/SPIRE 350 micron flux
100- 106 F7.2 mJy e_F350um [15/1963]?=0 Error in F350um
108- 115 F8.2 mJy F500um [204/17900]?=0 Herschel/SPIRE 500 micron flux
117- 123 F7.2 mJy e_F500um [20/1440]?=0 Error in F500um
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Name Source identifier (Y1 to Y488)
6- 14 F9.6 deg RAdeg [84.5/84.83] Right ascension (J2000)
16- 25 F10.6 deg DEdeg [-69.2/-69] Declination (J2000)
27- 31 F5.2 [-] chi1 [-4.26/4.4] First log reduced χ2 (1)
33- 37 F5.2 [-] chi2 [-6.21/4] Second log reduced χ2 (2)
39- 55 A17 --- Class Classification (3)
57- 67 A11 --- Reason How source was classified (4)
69- 86 A18 --- Ref References of previous studies (5)
88- 99 A12 --- OldClass Previous classification
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Note (1): To the 'spbhmi' Robitaille (2007A&A...600A..11R 2007A&A...600A..11R) model.
Note (2): To the Castelli & Kurucz (2004A&A...419..725C 2004A&A...419..725C)
stellar photospher model.
Note (3): Classification based on SED fits and spectra of sources as follows:
YSO = 299 occurrences
OB star = 59 occurrences
Reflection Nebula = 20 occurrences
We classify all other sources as "other" (110 occurrences).
Note (4): By Spitzer IRS spectra, VLT observations, or SED fits.
Note (5): References as follows:
W08 = Whitney et al. 2008, J/AJ/136/18
G09 = Gruendl & Chu 2009, J/ApJS/184/172
S09 = Seale et al. 2009, J/ApJ/699/150
S14 = Seale et al. 2014, J/AJ/148/124
N16 = Nayak et al. 2016ApJ...831...32N 2016ApJ...831...32N
J17 = Jones et al. 2017, J/MNRAS/470/3250
S18 = Schneider et al. 2018A&A...618A..73S 2018A&A...618A..73S
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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- 4 A4 --- Name Source identifier (nos among Y1 to Y487)
6- 9 F4.1 Rsun Rad [0.9/100] Best-fit source radius
11- 14 F4.1 Rsun e_Rad [0/45] Error in Rad (1)
16- 23 E8.3 K Teff [2260/27300] Best-fit source temperature
25- 32 E8.3 K e_Teff [0/9200] Error in Teff (1)
34- 37 F4.1 Msun Mass [3.9/38.5] Best-fit source mass (2)
39- 42 F4.1 Msun e_Mass [0/10.2] Error in Mass (1)
44- 51 E8.3 Lsun Lum [114/353000] Best-fit source luminosity (3)
53- 60 E8.3 Lsun e_Lum [0/232000] Error in Lum (1)
62 A1 --- 12CO Is YSO is associated with 12CO?
64 A1 --- 13CO Is YSO is associated with 13CO?
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Note (1): An error of 0 indicates that there was only one YSO model that
fit the observed fluxes.
Note (2): Calculated using: L∝M3.5.
Note (3): Calculated using the best-fit radius and best-fit temperature
with the following formula: L=4πr2σTeff4.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Name YSO identifier (nos among Y2 to Y484)
6- 9 F4.1 Msun Myso [3.9/32.8] YSO mass
11- 14 I4 --- 12COID [40/3455] YSO 12CO clump identifier (G1)
16- 23 E8.3 Msun Mvir12CO [15.3/287000] The 12CO clump virial mass
25- 32 E8.3 Msun e_Mvir12CO [0.016/1] Error in Mvir12CO
34- 41 E8.3 Msun/pc2 Mden12CO [23.7/2210] The 12CO virial mass
surface density
43- 50 E8.3 Msun/pc2 e_Mden12CO [0.016/1] Error in Mden12CO
52- 59 E8.3 Msun Mlum12CO [0.46/61100] Luminosity-based mass (G2)(1)
61- 68 E8.3 Msun e_Mlum12CO [0.1/0.3] Error in Mlum12CO
70- 77 E8.3 Msun/pc2 Mlumden [2.12/674] Luminosity-based mass surface
density (G2)
79- 86 E8.3 Msun/pc2 e_Mlumden [0.1/0.3] Error in Mlumden
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Note (1): H2 mass directly from the 12CO integrated intensity
assuming alpha-scale=3.
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Name YSO identifier (nos among Y3 to Y474)
6- 9 F4.1 Msun Myso [4.5/29] YSO mass
11- 13 I3 --- 13COID [10/654] YSO 13CO clump identifier (G1)
15- 23 E9.4 Msun Mlte13CO [11.13/12500] The 13CO LTE mass
25- 33 E9.4 Msun e_Mlte13CO [0.002/0.14] Error in 13CO-Mass
35- 43 E9.4 Msun/pc2 Mden13CO [42.1/2115] The 13CO LTE mass surface
density (G2)
45- 53 E9.4 Msun/pc2 e_Mden13CO [0.002/0.14] Error in 13CO-MassDen
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Global notes:
Note (G1): Identifier from Wong+ 2022, J/ApJ/932/47.
This is the 250m/s feathered mosaic dendrogram output.
Note (G2): Calculated by diving the LTE mass by the size
of the dendrogram leaf.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 17-Jan-2025