J/A+A/694/A235 CO-CHANGES II. (Jiang+, 2025)
CO-CHANGES. II: Spatially resolved IRAM 30M CO line observations of
23 nearby edge-on spiral galaxies.
Jiang Y., Li J.-T., Tan Q.-H., Ji L., Bregman J.N., Wang Q.D., Wang J.-F.,
Lu L.-Y., Jiang X.-J.
<Astron. Astrophys. 694, A235 (2025)>
=2025A&A...694A.235J 2025A&A...694A.235J (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Galaxy catalogs ; Carbon monoxide ;
Interstellar medium ; Radio sources
Keywords: ISM: molecules - galaxies: ISM - galaxies: spiral -
galaxies: star formation
Abstract:
Molecular gas, as the fuel for star formation, and its relationship
with atomic gas are crucial for understanding how galaxies regulate
their star forming (SF) activities. We conducted IRAM 30m observations
of 23 nearby spiral galaxies from the CHANG-ES project to investigated
the distribution of molecular gas and the Kennicutt-Schmidt law.
Combining these results with atomic gas masses from previous studies,
we aim to investigate the scaling relations that connect the molecular
and atomic gas masses with stellar masses and the baryonic
Tully-Fisher relation. Based on spatially resolved observations of the
three CO lines, we calculated the total molecular gas masses, the
ratios between different CO lines, and derived physical parameters
such as temperature and optical depth. The median line ratios for
nuclear/disk regions are 8.6/6.1 (12CO/13CO(1-0)) and 0.53/0.39
(12CO(2-1/1-0)). Molecular gas mass derived from 13CO is
correlated but systematically lower than that from 12CO. Most
galaxies follow the spatially resolved SF scaling relation with a
median gas depletion timescale of approximately 1Gyr, while a few
exhibit shorter timescales of approximately 0.1Gyr. The
molecular-to-atomic gas mass ratio correlates strongly with stellar
mass, consistent with previous studies. Galaxies with lower stellar
masses show an excess of atomic gas, indicating less efficient
conversion to molecular gas. Most galaxies tightly follow the baryonic
Tully-Fisher relation, but NGC 2992 and NGC 4594 deviate from the
relation due to different physical factors. We find that the ratio of
the cold gas (comprising molecular and atomic gas) to the total baryon
mass decreases with the gravitational potential of the galaxy, as
traced by rotation velocity, which could be due to gas consumption in
SF or being heated to the hot phase.
Description:
These tables correspond to the two long tables (Table 2 and Table 3)
in the paper. Table 2 is the observation log for 22 galaxies in the
CO-CHANGES sample. For each galaxy, we selected 3 to 13 single- point
observation positions. The table 3 contains the integrated intensities
of the three CO spectra at each position, the fitted line center
velocities, and the physical parameters corrected for beam dilution,
including molecular line ratios, kinematic temperatures, and optical
depths calculated under the LTE assumption. NGC 4594 is not included
in those tables, there are in CO-CHANGES Paper I (Jiang et al.,
2024MNRAS.528.4160J 2024MNRAS.528.4160J).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 77 23 Parameters of the sample galaxies
table2.dat 113 157 IRAM 30m observation log
table3.dat 174 157 Observed and derived parameters of the CO lines
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Galaxy Galaxy name
10- 14 F5.2 Mpc Dist Distance is obtained from Vargas et al.
(2019ApJ...881...26V 2019ApJ...881...26V)
16- 19 F4.1 --- Mtype The morphological type code (1)
21- 23 F3.1 --- e_Mtype The morphological type code error
25- 29 F5.1 km/s Vrot The maximum atomic gas rotation
velocity (2)
31- 35 F5.2 kpc Diam Diameter derived from 22um data by
Wiegert et al. (2015AJ....150...81W 2015AJ....150...81W,
Cat. J/AJ/150/81)
37- 42 F6.3 10+10Msun M* The stellar mass (3)
44- 48 F5.3 10+10Msun e_M* The stellar mass error
50- 54 F5.3 10+10Msun MHI The total atomic gas mass (4)
55 A1 --- r_MHI The source of the HI flux, the detailed
calculation methods are summarized in
Sect. 4.1. (5)
57- 61 F5.2 Msun/yr SFR ?=- The revised star formation rate (6)
63- 66 F4.2 Msun/yr e_SFR ? The revised star formation rate error
68- 72 F5.2 10-3Msun/yr/kpc2 SSFR ?=- The surface density of SFR (7)
74- 77 F4.2 10-3Msun/yr/kpc2 e_SSFR ? The surface density of SFR error
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Note (1): from de Vaucouleurs et al. (1991, Cat. VII/155), except for NGC 3448,
which is from Huchra et al. (2012ApJS..199...26H 2012ApJS..199...26H, Cat. J/ApJS/199/26).
Note (2): corrected for inclination obtained from HyperLeda
(http://leda.univ-lyon1.fr/), as also noted in Makarov et al.
(2014A&A...570A..13M 2014A&A...570A..13M).
Note (3): from Li et al. (2016MNRAS.456.1723L 2016MNRAS.456.1723L), which is derived from the 2MASS
K-band apparent magnitude (Skrutskie et al., 2006, Cat. VII/233).
Note (4): is directly available for 14 galaxies from Zheng et al.
(2022MNRAS.513.1329Z 2022MNRAS.513.1329Z).
Note (5): References and corresponding observational instruments are as follows:
a = Chaves & Irwin (2001ApJ...557..646C 2001ApJ...557..646C) with VLA L-band CnB-array
b = Zheng et al. (2022MNRAS.513.1329Z 2022MNRAS.513.1329Z) with VLA L-band C-array
c = Courtois & Tully (2015MNRAS.447.1531C 2015MNRAS.447.1531C, Cat. J/MNRAS/447/1531), who
uniformly processed data from various telescope (NGC 2820 and NGC 3735
from Green Bank 42m; NGC 3432, NGC 4244 and NGC 4594 from Robert C.
Byrd Green Bank Telescope; NGC 4845 from Arecibo with line feed system.)
d = Huchtmeier (1982A&A...110..121H 1982A&A...110..121H) with NRAO 91m;
e = Davis & Seaquist (1983ApJS...53..269D 1983ApJS...53..269D) with NRAO 91m.
Note (6): from Vargas et al. (2019ApJ...881...26V 2019ApJ...881...26V), calculated using a
combination of Hα and 22um data.
Note (7): and calculated using the 22um diameter and obtained from
Vargas et al. (2019ApJ...881...26V 2019ApJ...881...26V)
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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- 10 A10 --- Name Name, NGCNNNN-NN or UGCNNNNN-NN (1)
12- 13 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
18- 22 F5.2 s RAs Right ascension (J2000)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 36 F6.3 arcsec DEs Declination (J2000)
38- 47 A10 "date" Date1 Observation date
48 A1 --- --- [,]
50- 59 A10 "date" Date2 Observation date
60 A1 --- --- [,]
62- 71 A10 "date" Date3 Observation date
73- 76 F4.2 --- tau225GHz The average opacity at 225GHz during
observation dates
78 I1 --- Nobs The total number of observation scans at each
position, each scan having an effective
on-source integration time of 9.8 minutes
80- 84 F5.2 min Texp12CO The total on-source integration time at each
position for the 12CO(1-0) (2)
86- 90 F5.2 min Texp13CO The total on-source integration time at each
position for the 13CO(1-0) (2)
92- 96 F5.2 min TexpCO21 The total on-source integration time at each
position for the 12CO(2-1) (2)
98-102 F5.2 mk rms12CO The root mean square for the 12CO(1-0) (2)
104-107 F4.2 mk rms13CO The root mean square for the 13CO(1-0) (2)
109-113 F5.2 mk rmsCO21 The root mean square for the 12CO(2-1) (2)
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Note (1): Some observation positions are not on the galaxy disk; the location
may correspond to a companion galaxy or a non-disk point (possibly located
halfway to the companion galaxy).
Note (2): Those time and rms including both vertical and horizontal polarization
components.
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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- 10 A10 --- Name Name, NGCNNNN-NN or UGCNNNNN-NN
12- 16 F5.1 kpc Dist ?=- The projection distance to the
minor axis of the galaxy
18 A1 --- l_I12CO Limit flag on I12CO
19- 22 F4.1 K.km/s I12CO The integrated line intensity of
12CO(1-0) (1)
24- 26 F3.1 K.km/s e_I12CO ? The integrated line intensity of
12CO(1-0) error (1)
28- 33 F6.1 km/s v012CO ?=- The centroid velocity of 12CO(1-0)
35- 38 F4.1 km/s E_v012CO ? The centroid velocity of 12CO(1-0)
error (upper value)
41- 44 F4.1 km/s e_v012CO ? The centroid velocity of 12CO(1-0)
error (lower value)
46 A1 --- l_I13CO Limit file on I13CO
47- 49 F3.1 K.km/s I13CO The integrated line intensity of
13CO(1-0) (1)
51- 53 F3.1 K.km/s e_I13CO ? The integrated line intensity of
13CO(1-0) error (1)
55- 60 F6.1 km/s v013CO ?=- The centroid velocity of 13CO(1-0)
62- 65 F4.1 km/s E_v013CO ? The centroid velocity of 13CO(1-0)
error (upper value)
68- 71 F4.1 km/s e_v013CO ? The centroid velocity of 13CO(1-0)
error (lower value)
73 A1 --- l_ICO21 Limit flag on ICO21
74- 78 F5.1 K.km/s ICO21 The integrated line intensity of
12CO(2-1) (1)
80- 82 F3.1 K.km/s e_ICO21 ? The integrated line intensity of
12CO(2-1) error (1)
85- 90 F6.1 km/s v0CO21 ?=- The centroid velocity of 12CO(2-1)
92- 95 F4.1 km/s E_v0CO21 ? The centroid velocity of 12CO(2-1)
error (upper value)
98-101 F4.1 km/s e_v0CO21 ? The centroid velocity of 12CO(2-1)
error (lower value)
104 A1 --- l_R12CO/13CO Limit flag on R12CO/13CO
105-108 F4.1 --- R12CO/13CO ?=- The intensity line ratios of
12CO/13CO(1-0) (2)
110-112 F3.1 --- E_R12CO/13CO ? The intensity line ratios of
12CO/13CO (1-0) error (upper value) (2)
115-117 F3.1 --- e_R12CO/13CO ? The intensity line ratios of
12CO/13CO (1-0) error (lower value) (2)
119 A1 --- l_RCO21/CO10 Limit flag on RCO21/CO10
120-124 F5.3 --- RCO21/CO10 ?=- The intensity line ratio of
12CO(2-1)/12CO(1-0) (2)
126-130 F5.3 --- E_RCO21/CO10 ?=- The intensity line ratio of
12CO(2-1)/12CO(1-0)
error (upper value) (2)
132-136 F5.3 --- e_RCO21/CO10 ?=- The intensity line ratio of
12CO(2-1)/12CO(1-0)
error (lower value) (2)
138 A1 --- l_Tau13CO Limit flag on Tau13co
139-143 F5.3 --- Tau13CO ?=- The optical depth derived under LTE
145-149 F5.3 --- E_Tau13CO ?=- The optical depth derived under LTE
error (upper value)
151-155 F5.3 --- e_Tau13CO ?=- The optical depth derived under LTE
error (lower value)
158-162 F5.1 K Tkin ?=- The kinetic temperature derived under
LTE
164-168 F5.1 K E_Tkin ?=- The kinetic temperature derived under
LTE error (upper value)
171-174 F4.1 K e_Tkin ?=- The kinetic temperature derived under
LTE error (lower value)
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Note (1): All intensity have been corrected for the main beam and forward
efficiencies.
Note (2): Those ratio are corrected for beam dilution.
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Acknowledgements:
Yan Jiang, astroyanjiang(at)gmail.com
References:
Jiang et al., Paper I 2024MNRAS.528.4160J 2024MNRAS.528.4160J
(End) Patricia Vannier [CDS] 19-Dec-2024