J/ApJ/833/248 Chemical properties of red MSX sources (RMSs) (Yu+, 2016)
Chemical evolution of red MSX sources in the southern sky.
Yu N., Xu J.
<Astrophys. J., 833, 248-248 (2016)>
=2016ApJ...833..248Y 2016ApJ...833..248Y (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Radio lines ; Surveys ; H II regions ;
YSOs ; Millimetric/submm sources ; Abundances
Keywords: evolution; H II regions; ISM: abundances; ISM: clouds; ISM: molecules;
stars: formation
Abstract:
Red Midcourse Space Experiment (MSX) Sources (RMSs) are regarded as
excellent candidates of massive star-forming regions. In order to
characterize the chemical properties of massive star formation, we
made a systematic study of 87 RMSs in the southern sky, using archival
data taken from the Atacama Pathfinder Experiment Telescope Large Area
Survey of the Galaxy (ATLASGAL), the Australia Telescope Compact
Array, and the Millimetre Astronomy Legacy Team Survey at 90GHz
(MALT90). According to previous multiwavelength observations, our
sample could be divided into two groups: massive young stellar objects
and HII regions. Combined with the MALT90 data, we calculated the
column densities of N2H+, C2H, HC3N, and HNC and found that
they are not much different from previous studies made in other
massive star-forming regions. However, their abundances are relatively
low compared to infrared dark clouds (IRDCs). The abundances of
N2H+ and HNC in our sample are at least 1mag lower than those
found in IRDCs, indicating chemical depletions in the relatively hot
gas. Besides, the fractional abundances of N2H+, C2H, and HC3N
seem to decrease as a function of their Lyman continuum fluxes (NL),
indicating that these molecules could be destroyed by UV photons when
HII regions have formed inside. We also find that the C2H abundance
decreases faster than HC3N with respect to NL. The abundance of
HNC has a tight correlation with that of N2H+, indicating that it
may be also preferentially formed in cold gas. We regard our RMSs as
being in a relatively late evolutionary stage of massive star
formation.
Description:
Our molecular line data come from the Millimetre Astronomy Legacy Team
Survey at 90GHz (MALT90) (e.g., Foster+ 2011, J/ApJS/197/25; Jackson+
2013PASA...30...57J 2013PASA...30...57J). This project is performed with Mopra, a 22m
single-dish radio telescope located near Coonabarabran in New South
Wales, Australia.
The angular resolution of Mopra is 38", with a beam efficiency between
0.49 at 86GHz and 0.42 at 115GHz. The pointing accuracy of the main
MALT90 maps is about 8", and the absolute flux uncertainty is in the
range of 10%-17% depending on the transition in question.
The target clumps of this survey are selected from the 870um Atacama
Pathfinder Experiment (APEX) Telescope Large Area Survey of the Galaxy
(ATLASGAL; Schuller+ 2009A&A...504..415S 2009A&A...504..415S; Contreras+ 2013, J/A+A/549/A45;
superseded by J/A+A/568/A41).
Using Australia Telescope Compact Array (ATCA), Urquhart+ (2007,
J/A+A/461/11) observed radio emissions of 826 Red Midcourse Space
Experiment (MSX) Sources (RMSs) in the southern sky. We also have
checked our sources with the data taken from the Sydney University
Molonglo Sky Survey (SUMSS) carried out at 843MHz with the Molonglo
Observatory Synthesis Telescope (MOST; Mauch+ 2003, VIII/81).
See section 2 for further explanations.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 56 87 List of Red Midcourse Space Experiment (MSX)
Sources (RMSs)
table2.dat 86 87 Integrated intensities of N2H+, C2H, HC3N, HN13C
table3.dat 52 87 Peak intensities of N2H+, C2H, HC3N, HN13C
table4.dat 64 87 Column densities of N2H+, C2H, HC3N, HNC
table5.dat 63 87 Abundances of N2H+, C2H, HC3N, HNC
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See also:
V/114 : MSX6C Infrared Point Source Catalog (Egan+ 2003)
VIII/81 : Sydney University Molonglo Sky Survey (SUMSS V2.1) (Mauch+ 2008)
J/ApJ/815/130 : High-mass molecular clumps from MALT90 (Guzman+, 2015)
J/MNRAS/452/4029 : RMS survey (Urquhart+, 2015)
J/MNRAS/452/637 : Distance-limited sample of MYSOs (Maud+, 2015)
J/MNRAS/437/1791 : RMS survey: molecular observations (Urquhart+, 2014)
J/A+A/568/A41 : ATLASGAL Compact Source Catalog: 280<l<60 (Urquhart+, 2014)
J/ApJ/777/157 : 90GHz obs. of high-mass star-forming regions (Hoq+, 2013)
J/ApJS/208/11 : The Red MSX Source Survey: massive protostars (Lumsden+, 2013)
J/ApJS/206/22 : Newly EGOs from GLIMPSE II survey. II. MoC (Chen+, 2013)
J/A+A/549/A45 : ATLASGAL Compact Source Catalog: 330<l<21 (Contreras+, 2013)
J/MNRAS/430/1125 : RMS survey: NIR spectroscopy of massive YSOs (Cooper+, 2013)
J/ApJ/756/60 : A 3mm line survey in 37 IR dark clouds (Sanhueza+, 2012)
J/MNRAS/420/1656 : RMS compact HII regions distances (Urquhart+, 2012)
J/MNRAS/410/1237 : Red MSX survey (RMS) massive young stars (Urquhart+, 2011)
J/ApJS/197/25 : MALT90 pilot survey (Foster+, 2011)
J/A+A/527/A88 : Chemistry in infrared dark clouds (Vasyunina+, 2011)
J/A+A/525/A149 : Red MSX Survey (RMS): YSO bolometric fluxes (Mottram+, 2011)
J/A+A/510/A89 : RMS survey of young massive stars in far-IR (Mottram+, 2010)
J/ApJ/716/1315 : Hyperfine levels of N2H+ (Keto+, 2010)
J/A+A/507/795 : The RMS survey: water masers of YSOs (Urquhart+, 2009)
J/A+A/505/405 : A catalogue of Spitzer dark clouds (Peretto+, 2009)
J/A+A/501/539 : RMS survey. 6cm observations of YSOs (Urquhart+, 2009)
J/A+A/487/253 : The RMS survey: 13CO observations of YSOs (Urquhart+ 2008)
J/A+A/482/179 : Interferometric study of SgrB2(N) (Belloche+, 2008)
J/A+A/476/1019 : RMS survey of southern candidate massive YSOs (Mottram+, 2007)
J/A+A/461/11 : Radio observations of MYSO candidates (Urquhart+, 2007)
J/AJ/126/1423 : MSX 8.3um fluxes of star-forming regions (Kraemer+, 2003)
http://atlasgal.mpifr-bonn.mpg.de/cgi-bin/ATLASGAL_DATABASE.cgi : ATLASGAL
database server
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Sample Urquhart+ (2007, J/A+A/461/11) Group (G1)
7- 23 A17 --- MSX6C RMS (MSX) field name (GLLL.llll+BB.bbbb)
25- 28 F4.1 kpc Dist [1.6/15] Distance from Urquhart+
(2008, J/A+A/487/253)
30- 33 F4.1 K Td [17.6/40] Dust temperature from Guzman+
(2015, J/ApJ/815/130)
35- 38 F4.1 K e_Td [0.4/11] Uncertainty in Td
40- 44 F5.2 [s-1] logNL [45/49.1]? log Lyman continuum flux estimate
46- 50 F5.2 10+22cm-2 NH2 [2.9/67] H2 column density from Guzman+
(2015, J/ApJ/815/130)
52- 56 F5.2 10+22cm-2 e_NH2 [0.1/11] Uncertainty in NH2
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Sample Urquhart+ (2007, J/A+A/461/11) Group (G1)
6- 22 A17 --- MSX6C RMS (MSX) field name (GLLL.llll+BB.bbbb)
24- 27 F4.2 K.km/s iN2H-1 [0.3/9]? N2H+ Group 1 integrated intensity
(G2)
29- 32 F4.2 K.km/s e_iN2H-1 [0.09/0.4]? Uncertainty in N2H-1
34- 38 F5.2 K.km/s iN2H-2 [1.5/41]? N2H+ Group 2 integrated intensity
(G2)
40- 43 F4.2 K.km/s e_iN2H-2 [0.1/1.1]? Uncertainty in N2H-2
45- 49 F5.2 K.km/s iC2H [1.4/11.6]? C2H, F=2-1 integrated intensity
51- 54 F4.2 K.km/s e_iC2H [0.1/1.3]? Uncertainty in C2H
56- 60 F5.2 K.km/s iHC3N [0.8/10.5]? HC3N, J=10-9 integrated intensity
62- 65 F4.2 K.km/s e_iHC3N [0.1/0.4]? Uncertainty in HC3N
67- 70 F4.2 K.km/s iHN13C [0.9/4.2]? HN13C, J=1-0 integrated intensity
72- 75 F4.2 K.km/s e_iHN13C [0.1/0.3]? Uncertainty in HN13C
77- 81 F5.2 K.km/s iHNC [1.5/36]? HNC, J=1-0 integrated intensity
83- 86 F4.2 K.km/s e_iHNC [0.1/2.4]? Uncertainty in HNC
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Sample Urquhart+ (2007, J/A+A/461/11) Group (G1)
6- 22 A17 --- MSX6C RMS (MSX) field name (GLLL.llll+BB.bbbb)
24- 27 F4.2 K pN2H-2 [0.2/6]? N2H+ Group 2 peak intensities (G2)
29- 32 F4.2 K pC2H-1 [0.2/1.2]? C2H, F=1-0 peak intensities
34- 37 F4.2 K pC2H-2 [0.3/2.3]? C2H, F=2-1 peak intensities
39- 42 F4.2 K pHC3N [0.3/2]? HC3N, J=10-9 peak intensities
44- 47 F4.2 K pHN13C [0.3/1]? HN13C, J=1-0 peak intensities
49- 52 F4.2 K pHNC [0.4/5.2]? HNC, J=1-0 peak intensities
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Sample Urquhart+ (2007, J/A+A/461/11) Group (G1)
6- 22 A17 --- MSX6C RMS (MSX) field name (GLLL.llll+BB.bbbb)
24- 27 F4.2 10+13cm-2 dN2H [0.3/7.8]? N2H+ column density
29- 32 F4.2 10+13cm-2 e_dN2H [0.03/1]? Uncertainty in dN2H
34- 38 F5.2 10+14cm-2 dC2H [1.3/17]? C2H column density
40- 43 F4.2 10+14cm-2 e_dC2H [0.1/6]? Uncertainty in dC2H
45- 48 F4.2 10+13cm-2 dHC3N [0.3/4.3]? HC3N column density
50- 53 F4.2 10+13cm-2 e_dHC3N [0.03/0.4]? Uncertainty in dHC3N
55- 59 F5.2 10+14cm-2 dHNC [1.9/11.5]? HNC column density
61- 64 F4.2 10+14cm-2 e_dHNC [0.07/4]? Uncertainty in dHNC
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Sample Urquhart+ (2007, J/A+A/461/11) Group (G1)
6- 22 A17 --- MSX6C RMS (MSX) field name (GLLL.llll+BB.bbbb)
25- 28 F4.2 10-9 aN2H [0.03/0.9]? N2H+ abundance
30- 33 F4.2 10-9 e_aN2H [0.01/0.3]? Uncertainty in aN2H
35- 38 F4.2 10-8 aC2H [0.09/2]? C2H abundance
40- 43 F4.2 10-8 e_aC2H [0.02/0.8]? Uncertainty in aC2H
45- 48 F4.2 10-10 aHC3N [0.4/1.7]? HC3N abundance
50- 53 F4.2 10-10 e_aHC3N [0.05/0.5]? Uncertainty in aHC3N
55- 58 F4.2 10-8 aHNC [0.05/0.6]? HNC abundance
60- 63 F4.2 10-8 e_aHNC [0.01/0.3]? Uncertainty in aHNC
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Global note:
Note (G1): Australia Telescope Compact Array (ATCA) group as follows:
HII = HII region (59 instances)
MYSO = massive young stellar object (28 instances)
Note (G2): See equation section 3.2 for an explanation about
group 1/group 2 defined in Purcell+, 2009MNRAS.394..323P 2009MNRAS.394..323P
(Figure 2).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 09-May-2017