J/A+A/663/A177 High-mass star-forming regions cyanopolyyne (Wang+, 2022)
Cyanopolyyne line survey towards high-mass star-forming regions with TMRT.
Wang Y.X., Zhang J.S., Yan Y.T., Qiu J.J., Chen J.L., Zhao J.Y., Zou Y.P.,
Wu X.C., He X.L., Gong Y.B., Cai J.H.
<Astron. Astrophys., 663, A177 (2022)>
=2022A&A...663A.177W 2022A&A...663A.177W (SIMBAD/NED BibCode)
ADC_Keywords: Star Forming Region ; Photometry, millimetric/submm ;
Abundances ; Masers
Keywords: astrochemistry - stars: formation - ISM: clouds - ISM: molecules
Abstract:
Cyanopolyynes (HC2n+1N, n=1,2,3), which are the linear carbon
chain molecules, are precursors for the prebiotic synthesis of simple
amino acids. They are important for understanding prebiotic chemistry
and may be good tracers of the star formation sequence.
We aim to search for cyanopolyynes in high-mass star-forming regions
(HMSFRs) at possibly different evolutionary stages, investigate the
evolution of HC3N and its relation with shock tracers, and detect
the existence of HC5N and HC7N in HMSFRs with a formed protostar.
We carried out a cyanopolyyne line survey towards a large sample of
HMSFRs using the Shanghai Tian Ma 65m Radio Telescope (TMRT). Our
sample consisted of 123 targets taken from the TMRT C band line
survey. It included three kinds of sources, namely those with
detection of the 6.7GHz CH3OH maser alone, with detection of the
radio recombination line (RRL) alone, and with detection of both
(hereafter referred to as Maser-only, RRL-only, and Maser-RRL sources,
respectively). For our sample with detection of cyanopolyynes, their
column densities were derived using the rotational temperature
measured from the NH3 lines. We constructed and fitted the
far-infrared (FIR) spectral energy distributions (SED; obtained from
the Herschel FIR data and the Atacama Pathfinder Experiment data at
870 um) of our HC3N sources. Moreover, by analysing the relation
between HC3N and other shock tracers, we also investigate whether
HC3N is a good tracer of shocks.
We detected HC3N in 38 sources, HC5N in 11 sources, and HC7N in
G24.790+0.084, with the highest detection rate being found for
Maser-RRL sources and a very low detection rate found for RRL-only
sources. The mean column density of HC3N was found to be
(1.75±0.42)x1013, (2.84±0.47)x1013, and
(0.82±0.15)x1013cm-2 for Maser-only, Maser-RRL, and RRL-only
sources, respectively. Based on a fit of the FIR SED, we derive their
dust temperatures, H2 column densities, and abundances of
cyanopolyynes relative to H2. The mean relative abundance of HC3N
was found to be (1.22±0.52)x10-10 for Maser-only,
(5.40±1.45)x10-10 for Maser-RRL, and (1.65±1.50)x10-10 for
RRL-only sources, respectively.
The detection rate, the column density, and the relative abundance of
HC3N increase from Maser-only to Maser-RRL sources and decrease from
Maser-RRL to RRL-only sources. This trend is consistent with the
proposed evolutionary trend of HC3N under the assumption that our
Maser-only, Maser-RRL, and RRL-only sources correspond to massive
young stellar objects, ultracompact HII regions, and normal classical
HII regions, respectively. Our detections enlarge the sample of HC3N
in HMSFRs and support the idea that unsaturated complex organic
molecules can exist in HMSFRs with a formed protostar. Furthermore, a
statistical analysis of the integrated line intensity and column
density of HC3N and shock-tracing molecules (SiO, H2CO) enabled us
to find positive correlations between them. This suggests that HC3N
may be another tracer of shocks, and should therefore be the subject
of further observations and corresponding chemical simulations. Our
results indirectly support the idea that the neutral-neutral reaction
between C2H2 and CN is the dominant formation pathway of HC3N.
Description:
We present a cyanopolyyne (HC2n+1N) line survey in the Ku band
(12-18GHz) towards a large sample of 123 HMSFRs using the TMRT. The
sample was divided into 29 sources with detection of the 6.7GHz
CH3OH maser alone (Maser-only), 44 sources with detection of RRL
alone (RRL-only), and 50 sources with both maser and RRL (Maser-RRL).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 121 21 Far infrared properties of our HC3N sources
tableb1.dat 101 41 The HC3N (J = 2-1) transitions detected with
the TMRT
tableb2.dat 91 12 The HC5N (J=3-2) and HC7N (J=15-14)
transitions detected with TMRT
tableb3.dat 103 38 The column density and the relative abundance
for HC3N, HC5N, and HC7N.
tableb4.dat 63 23 The integrated line intensities of other
molecules
tablec1.dat 53 85 Sources without HC3N (J=2-1) detection
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See also:
J/A+A/568/A41 : ATLASGAL Compact Source Catalog: 280<l<60 (Urquhart+, 2014)
J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)
J/A+A/586/A149 : SiO in ATLASGAL-selected massive clumps (Csengeri+, 2016)
J/MNRAS/473/1059 : Complete sample of Galactic clump properties
(Urquhart+, 2018)
J/ApJ/885/131 : ∼200 high-mass SFR plx + proper motion with VLBI
(Reid+, 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Class Classifications
12- 24 A13 --- Name Source name, GLL.lll+B.bbb
26- 29 I4 Jy F70 Herschel flux density at 70um
31- 33 I3 Jy e_F70 Herschel flux density at 70um error
35- 38 I4 Jy F160 Herschel flux density at 160um
40- 42 I3 Jy e_F160 Herschel flux density at 160um error
44- 47 I4 Jy F250 Herschel flux density at 250um
49- 51 I3 Jy e_F250 Herschel flux density at 250um error
53- 55 I3 Jy F350 Herschel flux density at 350um
57- 59 I3 Jy e_F350 Herschel flux density at 350um error
61- 63 I3 Jy F500 Herschel flux density at 500um
65- 67 I3 Jy e_F500 Herschel flux density at 500um error
69- 70 I2 Jy F870 APEX flux density at 870um (1)
72 I1 Jy e_F870 APEX flux density at 870um error (1)
74- 75 I2 arcsec Reff Effective radius of sources at 870um (1)
77- 79 I3 --- gamma Gas-to-dust ratio
81- 85 F5.2 K Tdust Dust temperature
87- 90 F4.2 K e_Tdust Dust temperature error
92- 95 I4 Msun M Total (gas + dust) core mass
97-100 I4 Msun e_M Total (gas + dust) core mass error
102-105 F4.1 K T0dust Dust temperature from Urquhart et al.
(2018MNRAS.473.1059U 2018MNRAS.473.1059U, Cat. J/MNRAS/473/1059)
107-110 I4 Msun Ma Total mass from Urquhart et al.
(2018MNRAS.473.1059U 2018MNRAS.473.1059U, Cat. J/MNRAS/473/1059)
112-116 F5.2 10+23cm-2 N(H2) Column density of H2
118-121 F4.2 10+23cm-2 e_N(H2) Column density of H2 error
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Note (1): Flux density and effective radius of sources at 870um from APEX
telescope, which are given by Urquhart et al. (2014A&A...568A..41U 2014A&A...568A..41U,
Cat. J/A+A/568/A41).
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Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Source Name (GLLL.lll+B.bbb)
17- 18 I2 h RAh Right ascension (J2000)
20- 21 I2 min RAm Right ascension (J2000)
23- 27 F5.2 s RAs Right ascension (J2000)
29 A1 --- DE- Declination sign (J2000)
30- 31 I2 deg DEd Declination (J2000)
33- 34 I2 arcmin DEm Declination (J2000)
36- 39 F4.1 arcsec DEs Declination (J2000)
41- 46 F6.2 km/s Vlsr LSR velocity
48- 51 F4.2 km/s e_Vlsr LSR velocity error
53- 56 F4.2 km/s Deltanu Full width at half maximum
58- 61 F4.2 km/s e_Deltanu Full width at half maximum error
63- 65 I3 mK Tmb Peak mean brigthness temperature value
67- 68 I2 mK rms ?=- rms noise value
70- 73 F4.2 K.km/s IntTmbdv Integrated line intensity
75- 78 F4.2 K.km/s e_IntTmbdv Integrated line intensity error
80- 83 F4.2 kpc Dist ? Heliocentric distance D is taken from the
trigonometric parallax measurements (1)
84 A1 --- n_Dist [*] * for Dist obtained from the latest
Parallax-based Distance Calculator V2
86- 90 F5.2 kpc Dgc ? Galactocentric distance
92-101 A10 --- Class Classifications
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Note (1): from Reid et al., 2014ApJ...783..130R 2014ApJ...783..130R, Cat. J/ApJ/783/130,
2019ApJ...885..131R 2019ApJ...885..131R, Cat. J/ApJ/885/131.
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Byte-by-byte Description of file: tableb2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Mol Molecule species
6- 18 A13 --- Name Source Name (GLL.lll+B.bbb)
20- 21 I2 h RAh Right ascension (J2000)
23- 24 I2 min RAm Right ascension (J2000)
26- 30 F5.2 s RAs Right ascension (J2000)
32 A1 --- DE- Declination sign (J2000)
33- 34 I2 deg DEd Declination (J2000)
36- 37 I2 arcmin DEm Declination (J2000)
39- 42 F4.1 arcsec DEs Declination (J2000)
44- 49 F6.2 km/s Vlsr LSR velocity
51- 54 F4.2 km/s e_Vlsr LSR velocity error
56- 59 F4.2 km/s Deltanu Full width at half maximum
61- 64 F4.2 km/s e_Deltanu Full width at half maximum error
66- 67 I2 mK Tmb Peak mean brightness temperature value
69- 70 I2 mK rms ?=- rms noise value
72- 75 F4.2 K.km/s IntTmbdv Integrated line intensity
77- 80 F4.2 K.km/s e_IntTmbdv Integrated line intensity error
82- 91 A10 --- Class Classifications
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Byte-by-byte Description of file: tableb3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Class Classifications
12- 26 A15 --- Name Source Name (GLLL.lll+BB.bbb)
28- 32 F5.2 K Trot Rotational temperature of NH3
33 A1 --- n_Trot [*] Note on Trot (1)
35- 39 F5.2 10+13cm-2 N(HC3N) Column density of HC3N
41- 44 F4.2 10+13cm-2 e_N(HC3N) Column density of HC3N error
46- 50 F5.2 10+10 X(HC3N) ?=- Relative abundance of HC3N
52- 55 F4.2 10+10 e_X(HC3N) ?=- Relative abundance of HC3N
error
57- 60 F4.2 10+13cm-2 N(HC5N) ?=- Column density of HC5N
62- 65 F4.2 10+13cm-2 e_N(HC5N) ?=- Column density of HC5N error
67- 70 F4.2 10+10 X(HC5N) ?=- Relative abundance of HC5N
72- 75 F4.2 10+10 e_X(HC5N) ?=- Relative abundance of HC5N
error
77- 80 F4.2 10+13cm-2 N(HC7N) ?=- Column density of HC7N
82- 85 F4.2 10+13cm-2 e_N(HC7N) ?=- Column density of HC7N error
87- 90 F4.2 10+10 X(HC7N) ?=- Relative abundance of HC7N
92- 95 F4.2 10+10 e_X(HC7N) ?=- Relative abundance of HC7N
error
97-101 F5.2 --- N(HC3N)/N(HC5N) ?=- Abundance ratio of
N(HC3N)/N(HC5N)
103 I1 --- r_Trot ?=- Reference (2)
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Note (1): * for mean Trot of each type.
Note (2): Rotational temperature references as follows:
1 = Yang et al. in prep.
2 = Wienen et al., 2012A&A...544A.146W 2012A&A...544A.146W, Cat. J/A+A/544/A146
3 = Urquhart et al., 2011MNRAS.418.1689U 2011MNRAS.418.1689U, Cat. J/MNRAS/418/1689
4 = Li et al., 2016AJ....152...92L 2016AJ....152...92L, Cat. J/AJ/152/92
5 = Cyganowski et al., 2013ApJ...764...61C 2013ApJ...764...61C, Cat. J/ApJ/764/61
6 = Svoboda et al., 2016ApJ...822...59S 2016ApJ...822...59S, Cat. J/ApJ/822/59
7 = Chira et al., 2013A&A...552A..40C 2013A&A...552A..40C, Cat. J/A+A/552/A40
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Byte-by-byte Description of file: tableb4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Class Classifications
12- 26 A15 --- Name Source Name (GLLL.lll+BB.bbb)Source name
27- 31 F5.2 K.km/s IH2CO ?=- Integrated line intensity of H2CO
(taken from TMRT C band survey)
33- 36 F4.2 K.km/s e_IH2CO ?=- Integrated line intensity of H2CO error
38- 42 F5.2 10+13cm-2 NH2C ?=- Column density of H2CO, which is
derived as done for cyanopolyynes in
Sect. 3.1
44- 47 F4.2 10+13cm-2 e_NH2C ?=- Column density of H2CO error
49- 53 F5.2 K.km/s ISiO ?=- Integrated line intensity of SiO, taken
from Csengeri et al. (2016A&A...586A.149C 2016A&A...586A.149C,
Cat. J/A+A/586/A149)
55- 58 F4.2 K.km/s e_ISiO ?=- Integrated line intensity of SiO error
60- 63 F4.2 10+13cm-2 NSiO ?=- Column density of SiO
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Byte-by-byte Description of file: tablec1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Source Name (GLLL.lll+BB.bbb)
17- 18 I2 h RAh Right ascension (J2000)
20- 21 I2 min RAm Right ascension (J2000)
23- 27 F5.2 s RAs Right ascension (J2000)
29 A1 --- DE- Declination sign (J2000)
30- 31 I2 deg DEd Declination (J2000)
33- 34 I2 arcmin DEm Declination (J2000)
36- 39 F4.1 arcsec DEs Declination (J2000)
41- 50 A10 --- Class Classifications
52- 53 I2 --- rms rms noise value
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 24-Nov-2022