J/A+A/691/A289 CO (6-5) spectra of 10 galaxies (Israel+, 2024)
Central molecular zones in galaxies:
13 CO(6-5) and molecular gas conditions in bright nearby galaxies.
Israel F.P., Guesten R., Lundgren A.
<Astron. Astrophys. 691, A289 (2024)>
=2024A&A...691A.289I 2024A&A...691A.289I (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra ; Carbon monoxide ; Radio lines
Keywords: ISM: molecules - galaxies: ISM - galaxies: nuclei
Abstract:
This paper summarizes all presently available Jupp≥5 13CO and
accompanying 12CO measurements of galaxy centers including new J=6-5
13CO and 12CO observations of eleven galaxies with the Atacama
Pathfinder EXperiment (APEX) telescope and also Herschel high-J
measurements of both species in five galaxies. The observed
J=6-5/J=1-0 12CO integrated temperature ratios range from 0.10 to
0.45 in matching beams. Multi-aperture data indicate that the emission
of 13CO(6-5) is more centrally concentrated than that of
12CO(6-5). The intensities of 12CO(6-5) suggest a correlation with
those of HCO+ but not with those of HCN. The new data are essential in
refining and constraining the parameters of the observed galaxy center
molecular gas in a simple two-phase model to approximate its complex
multi-phase structure. In all galaxies except the Seyfert galaxy NGC
1068, high-J emission from the center is dominated by a dense
(n∼105cm-3) and relatively cool (20-60K) high-pressure gas. In
contrast, the low-J lines are dominated by low-pressure gas of a
moderate density (n∼103cm-3) and more elevated temperature
(60-150K) in most galaxies. The three exceptions with significant
high-pressure gas contributions to the low-J emission are all
associated with active central star formation.
Description:
The observations are part of two separate programs with the Atacama
Pathfinder EXperiment telescope (APEX) at the Llano de Chajnantor
high-elevation site in the Chilean Andes. The first series of
observations was carried out with the Carbon Heterodyne Array of the
MPIfR (CHAMP+) receiver in guaranteed observing time between 2008 and
2012 (projects X-081.F-1002-2008, E-085.B-0094B-2010,
E-088.B-0075A.2011, and X-089.F-0007-2012). The second series of 120
observations was carried out with the Swedish-ESO PI instrument for
APEX (SEPIA) receiver in 2019 guaranteed observing time and in 2021
regular European southern observatory (ESO) time (projects
E-0104.B-0034A-2019 and E-0108.C-0586A.2021). At the observing
frequencies of 661.067GHz (13CO(6-5)), 691.473GHz (12CO(6-5)) and
806.651/809.350GHz (12CO(7-6)/ [CI](2-1)) the APEX full-width half
maximum (FWHM) beam sizes are 9.3", 8.9" and 7.7" according to
the on-line data sheets.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 42 13 Sample galaxies
list.dat 139 22 List of fits 12CO(6-5) and 13CO(6-5) spectra
fits/* . 22 Individual fits spectra
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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 A1 --- Code [NL] N for Newly observed galaxies,
L for Galaxies from the literature
3- 9 A7 --- Name Galaxy name
10 A1 --- n_Name [*] * for Active galaxy nuclei (AGNs)
12- 13 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
18- 21 F4.1 s RAs Right ascension (J2000)
23 A1 --- DE- Declination sign (J2000)
24- 25 I2 deg DEd Declination (J2000)
27- 28 I2 arcmin DEm Declination (J2000)
30- 31 I2 arcsec DEs Declination (J2000)
33- 36 I4 km/s VLSR LSR velocity
38- 42 F5.1 Mpc Dist Distance
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 23 I4 --- Nx Number of pixels along X-axis
25- 47 A23 "datime" Obs.date Observation date
49- 60 E12.6 Hz BFreq Upper value of frequency interval
62- 73 E12.6 Hz bFreq Lower value of frequency interval
75- 85 E11.6 Hz dFreq Frequency resolution
87- 88 I2 Kibyte size Size of FITS file
90-108 A19 --- FileName Name of FITS file, in subdirectory fits
110-139 A30 --- Title Title of the FITS file
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Acknowledgements:
Frank Israel, israel(at)strw.leidenuniv.nl
(End) Patricia Vannier [CDS] 11-Oct-2024