J/ApJS/264/48 HC3N & N2H+ obs. toward 61 ultracompact HII regions (Wang+, 2023)
A possible chemical clock in high-mass star-forming regions: N(HC3N)/N(N2H+)?
Wang Y.X., Zhang J.S., Yu H.Z., Wang Y., Yan Y.T., Chen J.L., Zhao J.Y.,
Zou Y.P.
<Astrophys. J. Suppl. Ser., 264, 48 (2023)>
=2023ApJS..264...48W 2023ApJS..264...48W
ADC_Keywords: H II regions; Radio lines; Interstellar medium; Masers;
Space velocities; Molecular data
Keywords: Astrochemistry ; Star formation ; Interstellar medium ;
Interstellar molecules
Abstract:
We conducted observations of multiple HC3N (J=10-9, 12-11, and
16-15) lines and the N2H+ (J=1-0) line toward a large sample of
61 ultracompact (UC) HII regions, through the Institut de
Radioastronomie Millmetrique 30 m and the Arizona Radio Observatory
12m telescopes. The N2H+ J=1-0 line is detected in 60 sources and
HC3N is detected in 59 sources, including 40 sources with three lines,
9 sources with two lines, and 10 sources with one line. Using the
rotational diagram, the rotational temperature and column density of
HC3N were estimated toward sources with at least two HC3N lines. For
10 sources with only one HC3N line, their parameters were estimated,
taking one average value of Trot. For N2H+, we estimated the
optical depth of the N2H+ J=1-0 line, based on the line intensity
ratio of its hyperfine structure lines. Then the excitation
temperature and column density were calculated. When combining our
results in UC HII regions and previous observation results on
high-mass starless cores, the N(HC3N)/N(N2H+) ratio clearly increases
from the region stage. This means that the abundance ratio changes
with the evolution of high-mass star-forming regions (HMSFRs).
Moreover, positive correlations between the ratio and other
evolutionary indicators (dust temperature, bolometric luminosity, and
luminosity-to-mass ratio) are found. Thus we propose the ratio of
N(HC3N)/N(N2H+) as a reliable chemical clock of HMSFRs.
Description:
The observations of the HC3N (J=10-9 and 16-15) and N2H+ (J=1-0)
lines were carried out toward our 61 ultracompact (UC) HII region
sample with the Institut de Radioastronomie Millimetrique (IRAM) 30m
telescope during 2020 August 18-24 within project 022-20 (PI Hongzhi Yu).
The Eight Mixer Receiver (EMIR) heterodyne receivers (E090 and E150)
were employed covering the frequency ranges of 90.5-98.2GHz and
138.3-146GHz.
Toward those 49 sources with detections of both HC3N lines (J=10-9
and 16-15) lines by the IRAM 30m telescope, we performed complementary
observations on their HC3N J=12-11 line in 2021 May, using the
Arizona Radio Observatory (ARO) 12m telescope (Yu20A1, PI, Hongzhi Yu).
Using the N2H+ (J=1-0) data of the Nobeyama 45m telescope with a
beam size of 17" in high-mass starless cores (HMSCs) and high-mass
protostellar cores (HMPOs) from Taniguchi+ (2019ApJ...872..154T 2019ApJ...872..154T), and
following the procedure and equations in Section 3.3.2, we
recalculated N(N2H+) of HMSCs and HMPOs (see details in Table 7
and Section 4.1).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 62 61 Detailed information of our ultracompact (UC)
HII region sample
table3.dat 81 200 Spectral line parameters of HC3N
table4.dat 85 167 Spectral line parameters of N2H+
table5.dat 29 23 Outflow and maser information of sources with
line wings
table6.dat 77 61 Derived parameters of HC3N and N2H+ in UC HII regions
table7.dat 65 36 Physical parameters of HC3N and N2H+ in high-mass
starless cores (HMSCs) and high-mass protostellar
cores (HMPOs)
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See also:
J/ApJ/566/945 : Massive star forming regions at 1.2mm (Beuther+, 2002)
J/A+A/426/503 : Catalog of high velocity molecular outflows (Wu+ 2004)
J/AJ/129/348 : Radio compact HII regions in the Milky Way (Giveon+, 2005)
J/AJ/130/156 : Galactic radio compact HII regions at 1.4GHz (Giveon+, 2005)
J/A+A/434/613 : Water maser survey of methanol masers (Szymczak+, 2005)
J/ApJ/641/389 : Millimetric observations of IRDC cores (Rathborne+, 2006)
J/A+A/453/1003 : SCUBA ultracompact HII regions (Thompson+, 2006)
J/A+A/461/11 : Radio observations of MYSO candidates (Urquhart+, 2007)
J/AJ/136/2391 : GLIMPSE Extended Green Objects catalog (Cyganowski+, 2008)
J/A+A/498/147 : High mass protostellar objects parameters (Grave+, 2009)
J/A+A/501/539 : RMS survey. 6cm observations of YSOs (Urquhart+, 2009)
J/MNRAS/416/178 : 1.2-mm dust clumps with luminous water masers (Breen+, 2011)
J/ApJS/197/25 : MALT90 pilot survey (Foster+, 2011)
J/ApJS/206/22 : Newly EGOs from GLIMPSE II survey. II. MoC (Chen+, 2013)
J/ApJ/764/61 : H2O maser & NH3 survey of GLIMPSE EGOs (Cyganowski+, 2013)
J/ApJ/777/157 : 90GHz obs. of high-mass star-forming regions (Hoq+, 2013)
J/ApJS/205/1 : CORNISH project. II. Source catalog (Purcell+, 2013)
J/MNRAS/435/400 : ATLASGAL. Compact HII regions (Urquhart+, 2013)
J/A+A/565/A75 : ATLASGAL: dust condensations in Gal. plane (Csengeri+, 2014)
J/A+A/563/A97 : IRAM 30m reduced spectra of 59 sources (Gerner+, 2014)
J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)
J/A+A/579/A71 : Infrared emission of young HII regions (Cesaroni+, 2015)
J/A+A/579/A80 : Star-forming regions deuteration (Gerner+, 2015)
J/MNRAS/453/645 : Massive molecular outflows (Maud+, 2015)
J/ApJ/833/18 : Ultra-compact HII regions & methanol masers. I. (Hu+, 2016)
J/AJ/152/92 : NH3 & CO outflow around 6.7GHz methanol masers (Li+, 2016)
J/ApJS/231/20 : A new 95GHz methanol maser catalog. I. (Yang+, 2017)
J/ApJS/231/11 : High-mass starless clump cand. from ATLASGAL (Yuan+, 2017)
J/A+A/606/A74 : IRC +10216 13.3GHz-18.5GHz spectrum (Zhang+, 2017)
J/A+A/615/A103 : CORNISH project. III. UCHII region catalog (Kalcheva+, 2018)
J/ApJ/867/167 : High-mass outflows from the COHRS CO(3-2) survey (Li+, 2018)
J/MNRAS/473/1059 : Galactic clump properties (Urquhart+, 2018)
J/ApJS/235/3 : Outflows associated with ATLASGAL clumps (Yang+, 2018)
J/MNRAS/487/1057 : Massive SFR beyond the solar circle (Djordjevic+, 2019)
J/ApJ/885/131 : ∼200 high-mass SFR plx & PM with VLBI (Reid+, 2019)
J/MNRAS/484/4444 : ATLASGAL dense clumps Molecular parameters (Urquhart+, 2019)
J/ApJ/899/145 : Sulfur isotopes in SFR with 12m ARO and 30m IRAM (Yu+, 2020)
J/A+A/637/A40 : HMSCs classification and physical parameters (Zhang+, 2020)
J/MNRAS/510/3389 : High-mass star formation evolution (Urquhart+, 2022)
J/A+A/663/A177 : High-mass star-forming regions cyanopolyyne (Wang+, 2022)
J/A+A/658/A160 : SEDIGISM survey, search for molecular outflows (Yang+, 2022)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Source name (GLLL.ll+BB.bb)
15- 16 I2 h RAh [17/22] Hour of Right Ascension (J2000)
18- 19 I2 min RAm Minute of Right Ascension (J2000)
21- 25 F5.2 s RAs Second of Right Ascension (J2000)
27- 27 A1 --- DE- Sign of the Declination
28- 29 I2 deg DEd Degree of Declination (J2000)
31- 32 I2 arcmin DEm Arcminute of Declination (J2000)
34- 38 F5.2 arcsec DEs Arcsecond of Declination (J2000)
40- 44 F5.2 kpc Dist [0.8/20.5] Heliocentric distance (1)
46- 46 A1 --- CH3OHII CH3OH Class II Maser?
48- 48 A1 --- CH3OHI CH3OH Class I Maser?
50- 50 A1 --- H2O H2O Maser?
52- 52 A1 --- OH OH Maser?
54- 60 A7 --- Evol Evolutionary stage (always "UC H II")
62 I1 --- Ref Reference (2)
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Note (1): Heliocentric distances from Reid+ (2014, J/ApJ/783/130 and
2019, J/ApJ/885/131)
Note (2): References as follows:
1 = Hu et al. 2016, J/ApJ/833/18
2 = Giveon et al. 2005, J/AJ/129/348
3 = Kalcheva et al. 2018, J/A+A/615/A103
4 = Urquhart et al. 2009, J/A+A/501/539
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Source name (GLLL.ll+BB.bb)
15- 22 A8 --- Tel Telescope name (1)
24- 32 A9 --- Tr HC3N Transition
34- 38 F5.1 min Exp [3.8/210] Integration time
40- 43 F4.2 K rms [0.01/0.12] Root mean square value
45- 50 F6.2 km/s vlsr [-72.6/110.7]? Local standard of rest velocity
52- 55 F4.2 km/s e_vlsr [0.01/0.3]? Uncertainty in vlsr
57- 60 F4.2 km/s dv [1.3/7.8]? Full width at half maximum (FHWM)
62- 65 F4.2 km/s e_dv [0.01/0.6]? Uncertainty in dv
67- 71 F5.2 K.km/s I [0.03/23.6]? Integrated line intensity
73- 76 F4.2 K.km/s e_I [0.01/0.2]? Uncertainty in I
78- 81 F4.2 K Tmb [0.07/3.7]? Peak Tmb value
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Note (1): Telescope as follows:
IRAM 30m = the Institut de Radioastronomie Millimetrique (122 occurrences)
ARO 12m = the Arizona Radio Observatory (78 occurrences)
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Source name (GLLL.ll+BB.bb)
15- 35 A21 --- Tr NH2+ Transition
37- 41 F5.1 min Exp [3.8/120] Integration time
43- 46 F4.2 K rms [0.01/0.08] Root mean square value
48- 53 F6.2 km/s vlsr [-81/116]? Local standard of rest velocity
55- 58 F4.2 km/s e_vlsr [0.01/0.7]? Uncertainty in vlsr
60- 63 F4.2 km/s dv [0.7/5.6]? Full width at half maximum (FHWM)
65- 68 F4.2 km/s e_dv [0.01/0.8]? Uncertainty in dv
70- 74 F5.2 K.km/s I [0.2/65.2]? Integrated line intensity
76- 79 F4.2 K.km/s e_I [0.01/2.5]? Uncertainty in I
81- 85 F5.2 K Tmb [0.08/10.3]? Peak Tmb value
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Source name (GLLL.ll+BB.bb)
15 A1 --- Blue Blue wing?
17 A1 --- Red Red wing?
19 A1 --- Outflow Dipolar CO Outflow?
21 I1 --- r_Outflow ? Reference for Outflow (1)
23 A1 --- H2O H2O maser?
25 A1 --- r_H2O Reference for H2O (1)
27 A1 --- CH3OHI Class I CH3OH maser?
29 A1 --- r_CH3OHI Reference for CH3OHI (1)
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Note (1): References as follows:
1 = Yang et al. 2022, J/A+A/658/A160
2 = Li et al. 2016, J/AJ/152/92
3 = Wu et al. 2004, J/A+A/426/503
4 = Yang et al. 2018, J/ApJS/235/3
5 = Li et al. 2018, J/ApJ/867/167
6 = Cyganowski et al. 2008, J/AJ/136/2391
7 = Maud et al. 2015, J/MNRAS/453/645
a = Breen et al. 2010MNRAS.406.1487B 2010MNRAS.406.1487B
b = Titmarsh et al. 2014MNRAS.443.2923T 2014MNRAS.443.2923T
c = Ladeyschikov et al. 2022AJ....163..124L 2022AJ....163..124L
d = Breen & Ellingsen 2011, J/MNRAS/416/178
e = Xi et al. 2015MNRAS.453.4203X 2015MNRAS.453.4203X
f = Szymczak et al. 2005, J/A+A/434/613
g = Kim et al. 2019ApJS..244....2K 2019ApJS..244....2K
h = Cyganowski et al. 2013, J/ApJ/764/61
y = Yang et al. 2017, J/ApJS/231/20
z = Kim et al. 2019ApJS..244....2K 2019ApJS..244....2K
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Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Source name (GLLL.ll+BB.bb)
15- 19 F5.2 arcsec Size [29.18/67.1]? Source size (HC3N J=10-9)
21- 25 F5.2 K Trot [19.5/60.7]? Rotational Temperature, HC3N
27- 31 F5.2 K e_Trot [0.2/36]? Uncertainty in Trot
33- 33 I1 --- f_Trot [1/2]? Flag on Trot (3)
35- 38 F4.2 10+13cm-2 NHC3N [0.14/9.9]? Column density, HC3N
40- 43 F4.2 10+13cm-2 e_NHC3N [0.01/1.6]? Uncertainty in N-HC3N
45- 45 I1 --- f_NHC3N [1/2]? Flag on HC3N (3)
47- 50 F4.2 --- tau [0.08/4.1]? Optical depth from N2H+
52- 55 F4.2 --- e_tau [0.02/1.2]? Uncertainty on tau
57- 61 F5.2 K Tex [3/20.1]? Excitation temperature, N2H+
63- 66 F4.2 K e_Tex [0.01/1.8]? Uncertainty on Tex
68- 72 F5.2 10+13cm-2 NN2H+ [0.4/20.9]? Column density, N2H+
74- 77 F4.2 10+13cm-2 e_NN2H+ [0.01/0.9]? Uncertainty on N-N2H+
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Note (3): Flags on HC3N calculations as follows:
1 = Trot and N-HC3N are calculated by the rotational diagram with two
HC3N (10-9 & 16-15) lines data;
2 = Trot and N represent the average vaule of Trot of HC3N and the
corresponding column density of HC3N.
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Stage Evolutionary stage ("HPMO":high-mass
protostellar core; or "HMSC": high-mass
starless core)
6- 18 A13 --- Source Source name
20- 24 F5.2 kpc Dist [1/11] Heliocentric distance (1)
26- 29 F4.2 10+13cm-2 NHC3N [0.05/2.3]? Column density, HC3N (2)
31- 34 F4.2 10+13cm-2 e_NHC3N [0.01/0.7]? Uncertainty in N-HC3N (2)
36- 39 F4.2 --- tau [0.4/3.9] optical depth from N2H+ (3)
41- 44 F4.2 --- e_tau [0.03/1.2] Uncertainty on tau (3)
46- 49 F4.2 K Tex [2.8/8.4] excitation temperature, N2H+ (3)
51- 54 F4.2 K e_Tex [0/0.5] Uncertainty on Tex (3)
56- 60 F5.2 10+13cm-2 NN2H+ [0.9/14.8] Column density, N2H+ (3)
62- 65 F4.2 10+13cm-2 e_NN2H+ [0.05/0.5] Uncertainty on N-N2H+ (3)
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Note (1): Determined from the latest parallax-based distance calculator V2.
Note (2): Taken from Taniguchi+ 2019ApJ...872..154T 2019ApJ...872..154T
Note (3): Derived with the N2H+ (J=1-0) data of Taniguchi+ 2019ApJ...872..154T 2019ApJ...872..154T
and the method of Purcell+ 2009MNRAS.394..323P 2009MNRAS.394..323P
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 10-Mar-2023