J/other/ApSS/361.191 High-mass star forming clumps from MALT90 (Zhang+, 2016)
The global chemical properties of high-mass star forming clumps at different
evolutionary stages
Zhang Y.-J., Zhou J.-J., Esimbek J., He Y.-X., Li D.-L., Tang X.-D.,
Ji W.-G., Yuan Y., Guo W.-H.
<Astrophys. Space Sci. 361, 191 (2016)>
=2016Ap&SS.361..191Z 2016Ap&SS.361..191Z (SIMBAD/NED BibCode)
ADC_Keywords: Abundances; Molecular clouds; Star Forming Region;
Interstellar medium; Molecular data; Radio lines
Keywords: Astrochemistry; ISM: clouds; ISM: molecules; ISM: abundances;
Stars: formation
Abstract:
A total of 197 relatively isolated high-mass star-forming clumps were
selected from the Millimeter Astronomy Legacy Team 90GHz (MALT90)
survey data and their global chemical evolution investigated using
four molecular lines, N2H+(1-0), HCO+(1-0), HCN(1-0), and
HNC(1-0). The results suggest that the global averaged integrated
intensity ratios I(HCO+)/I(HNC), I(HCN)/I(HNC), I(N2H+)/I(HCO+),
and I(N2H+)/ I(HCN) are promising tracers for evolution of
high-mass star-forming clumps. The global averaged column densities
and abundances of N2H+, HCO+, HCN, and HNC increase as clumps
evolve. The global averaged abundance ratios X(HCN)/X(HNC) could be
used to trace evolution of high-mass star forming clumps,
X(HCO+)/X(HNC) is more suitable for distinguishing high-mass
star-forming clumps in prestellar (stage A) from those in protostellar
(stage B) and HII/PDR region (stage C). These results suggest that the
global averaged integrated intensity ratios between HCN(1-0),
HNC(1-0), HCO+(1-0) and N2H+(1-0) are more suitable for tracing
the evolution of high-mass star forming clumps. We also studied the
chemical properties of the target high-mass star-forming clumps in
each spiral arm of the Galaxy, and got results very different from
those above. This is probably due to the relatively small sample in
each spiral arm. For high-mass star-forming clumps in Sagittarius arm
and Norma-Outer arm, comparing two groups located on one arm with
different Galactocentric distances, the clumps near the Galactic
Center appear to be younger than those far from the Galactic center,
which may be due to more dense gas concentrated near the Galactic
Center, and hence more massive stars being formed there.
Description:
The Millimeter Astronomy Legacy Team 90GHz (MALT90) survey is a large
international project that exploited the fast-mapping capability of
the ATNF Mopra 22m telescope and obtained 16 molecular line maps near
90GHz for 2012 sources to characterize physical and chemical
conditions of high-mass star formation regions over a wide range of
evolutionary states (from Pre-stellar cores, to Proto-stellar cores,
and H II regions). The sample of this survey is a subsample of the
ATLASGAL catalog (Schuller+ 2009A&A...504..415S 2009A&A...504..415S), with angular and
spectral resolution approximately 36" and 0.11km/s.
In this paper, we selected 197 relatively isolated high-mass clumps at
different evolutionary stages from all the MALT90 survey data obtained
from the online archive.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 57 197 Source information
table2.dat 70 197 Integrated intensities and integrated intensity ratio
table5.dat 68 197 Molecular abundances and abundance ratio
table7.dat 31 162 *Kinematic distances of 162 clumps
--------------------------------------------------------------------------------
Note on table7.dat: The kinematic distances of clumps located within the
direction -3°≤GLON≤3° were not derived due to large errors.
--------------------------------------------------------------------------------
See also:
II/293 : GLIMPSE Source Catalog (I + II + 3D) (IPAC 2008)
J/A+A/291/943 : Protostellar cores (Ossenkopf+, 1994)
J/AJ/136/2391 : GLIMPSE Extended Green Objects catalog (Cyganowski+, 2008)
J/A+A/527/A88 : Chemistry in infrared dark clouds (Vasyunina+, 2011)
J/ApJ/756/60 : A 3mm line survey in 37 IR dark clouds (Sanhueza+, 2012)
J/ApJ/777/157 : 90GHz obs. of high-mass star-forming regions (Hoq+, 2013)
J/A+A/549/A45 : ATLASGAL Compact Source Catalog: 330<l<21 (Contreras+, 2013)
J/A+A/563/A97 : IRAM 30m reduced spectra of 59 sources (Gerner+, 2014)
J/A+A/568/A41 : ATLASGAL Compact Source Catalog: 280<l<60 (Urquhart+, 2014)
J/MNRAS/443/1555 : ATLASGAL massive star forming clumps (Urquhart+, 2014)
J/AJ/149/64 : MIPSGAL 24µm point source catalog (Gutermuth+, 2015)
J/ApJ/815/130 : High-mass molecular clumps from MALT90 (Guzman+, 2015)
J/ApJ/824/29 : ATLASGAL clumps with IRAS flux & MALT90 data (Stephens+, 2016)
J/other/PASA/33.30 : MALT90 Catalogue (Rathborne+, 2016)
J/AJ/154/140 : MALT90 kinematic distances to clumps (Whitaker+, 2017)
J/ApJS/231/11 : High-mass starless clump candidates from ATLASGAL (Yuan+, 2017)
J/ApJ/839/113 : GLIMPSE/MIPSGAL data of molecular clouds (Retes-Romero+, 2017)
J/MNRAS/473/1059 : Complete sample of Galactic clumps (Urquhart+, 2018)
http://www3.mpifr-bonn.mpg.de/div/atlasgal/ : ATLASGAL home page
http://malt90.bu.edu/ : MALT90 home page
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Source name (GLLL.lll+BB.bbb)
17- 23 F7.3 deg GLON Galactic longitude
25- 31 F7.3 deg GLAT [-1.1/1.1] Galactic latitude
33 A1 --- Stage Evolutionary stage (G1)
35- 41 F7.2 km/s FWHM [-121.1/154] Full line width at half maximum
(FWHM) of N2H+(1-0) (ΔV(N2H+))
43- 46 F4.2 km/s e_FWHM [0.01/0.6] dVN2H uncertainty
48- 52 F5.2 km/s Vlsr [0.4/24.4] LSR velocity of N2H+(1-0)
54- 57 F4.2 km/s e_Vlsr [0.02/1.2] Vlsr uncertainty
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Source name (GLLL.lll+BB.bbb)
17- 20 F4.2 K.km/s IN2H [1/8.7] N2H+ integrated intensity
22- 25 F4.2 K.km/s IHCO [1/8.7] HCO+ integrated intensity
27- 30 F4.2 K.km/s IHCN [0.9/10] HCN integrated intensity
32- 35 F4.2 K.km/s IHNC [1/7.3] HNC integrated intensity
37- 41 F5.2 --- IN2H/HCO [0.03/20] N2H+ to HCO+ integrated
intensity ratio
43- 47 F5.2 --- IN2H/HCN [0.03/53] N2H+ to HCN integrated
intensity ratio
49- 53 F5.2 --- IN2H/HNC [0.09/14] N2H+ to HNC integrated
intensity ratio
55- 59 F5.2 --- IHCO/HCN [0.04/16] HCO+ to HCN integrated
intensity ratio
61- 65 F5.2 --- IHCO/HNC [0.07/15] HCO+ to HNC integrated
intensity ratio
67- 70 F4.2 --- IHCN/HNC [0.02/8] HCN to HNC integrated
intensity ratio
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Source name (GLLL.lll+BB.bbb)
17- 20 F4.2 10-9 N2H [0.05/1.1] Abundance of N2H+(1-0)
22- 25 F4.2 10-9 HCO [0.01/1.5] Abundance of HCO+(1-0)
27- 30 F4.2 10-9 HCN [0.04/5] Abundance of HCN(1-0)
32- 35 F4.2 10-9 HNC [0.02/0.8] Abundance of HNC(1-0)
37- 41 F5.2 --- N2H/HCO [0.2/10.2] N2H+ to HCO+ abundance ratio
43- 46 F4.2 --- N2H/HCN [0.06/4.3] N2H+ to HCN abundance ratio
48- 52 F5.2 --- N2H/HNC [0.3/17.5] N2H+ to HNC abundance ratio
54- 57 F4.2 --- HCO/HCN [0.02/3] HCO+ to HCN abundance ratio
59- 62 F4.2 --- HCO/HNC [0.2/5.5] HCO+ to HNC abundance ratio
64- 68 F5.2 --- HCN/HNC [0.2/27.7] HCN to HNC abundance ratio
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Source name (GLLL.lll+BB.bbb)
17 A1 --- Stage Evolutionary stage (G1)
19- 23 F5.2 kpc Dist [0.6/25.3] Kinematic distance
25- 29 F5.2 kpc Rgc [3/16.8] Distance from the Galactic Center
of the source
31 I1 --- Arm [1/4] Spiral arm (1)
--------------------------------------------------------------------------------
Note (1): The high-mass star forming clumps were identified on the Galactic
plane, and the spiral arm positions were taken from Cordes and Lazio
(2002astro.ph..7156C 2002astro.ph..7156C) (Fig. 8). The Sagittarius, Scutum-Centaurus,
Perseus, and Norma spiral are hereafter called spiral arm 1, 2, 3, and
4, respectively.
--------------------------------------------------------------------------------
Global notes:
Note (G1): Table 6 Median values of derived clump properties for each
evolutionary stage:
----------------------------------------------------------------------------
Property Stage A Stage B Stage C
----------------------------------------------------------------------------
Integrated intensity (K.kms/s)
I(N2H+) 1.99 2.10 2.38
I(HCO+) 1.52 1.86 2.38
I(HCN) 1.51 1.66 2.32
I(HNC) 1.61 1.67 1.91
Integrated intensity ratios
I(N2H+)/I(HCO+) 0.96 0.57 0.45
I(HCO+)/I(HNC) 0.89 1.66 1.95
I(HCO+)/I(HCN) 1.30 1.20 0.98
I(N2H+)/I(HNC) 0.96 1.02 0.82
I(N2H+)/I(HCN) 1.24 0.95 0.46
I(HCN)/I(HNC) 0.81 1.21 1.98
Column densities (1013cm-2)
NN2H+ 1.2 1.5 2.4
NHCO+ 0.4 0.5 0.9
NHCN 1.1 1.5 2.9
NHNC 0.6 0.7 1.1
Molecular abundance (10-9)
X(N2H+) 0.16 0.31 0.43
X(HCO+) 0.08 0.17 0.30
X(HCN) 0.31 0.46 1.01
X(HNC) 0.10 0.16 0.27
Abundance ratios
X(N2H+)/X(HCO+) 2.12 1.82 1.49
X(N2H+)/X(HCN) 0.50 0.70 0.45
X(N2H+)/X(HNC) 1.61 1.89 1.60
X(HCO+)/X(HCN) 0.33 0.39 0.29
X(HCO+)/X(HNC) 0.73 1.05 1.11
X(HCN)/X(HNC) 2.18 2.84 3.76
----------------------------------------------------------------------------
This table list the summary median values of derived clump properties
for each evolutionary stage. Column 1 list the properties of the sources;
Columns 2 to 4 list the median values of each evolutionary stages.
----------------------------------------------------------------------------
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 12-Dec-2019