J/A+A/629/A6 3 starburst galaxies 12C/13C ALMA datacubes (Tang+, 2019)
ALMA view of the 12C/13C isotopic ratio in starburst galaxies.
Tang X.D., Henkel C., Menten K.M., Gong Y., Martin S., Muehle S., Aalto S.,
Muller S., Garcia-Burillo S., Levshakov S., Aladro R., Spaans M., Viti S.,
Asiri H.M., Ao Y.P., Zhang J.S., Zheng X.W., Esimbek J., Zhou J.J.
<Astron. Astrophys. 629, A6 (2019)>
=2019A&A...629A...6T 2019A&A...629A...6T (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Radio lines
Keywords: galaxies: abundances - galaxies: starburst - galaxies: nuclei -
galaxies: ISM - radio lines: ISM
Abstract:
We derive molecular-gas-phase 12C/13C isotope ratios for the
central few hundred parsecs of the three nearby starburst galaxies
NGC253, NGC1068, and NGC4945 making use of the λ∼3mm 12CN and
13CN N=1-0 lines in the ALMA Band 3. The 12C/13C isotopic
ratios derived from the ratios of these lines range from 30 to 67 with
an average of 41.6±0.2 in NGC253, from 24 to 62 with an average of
38.3±0.4 in NGC1068, and from 6 to 44 with an average of 16.9±0.3
in NGC4945. The highest 12C/13C isotopic ratios are determined in
some of the outskirts of the nuclear regions of the three starburst
galaxies. The lowest ratios are associated with the northeastern and
southwestern molecular peaks of NGC253, the northeastern and
southwestern edge of the mapped region in NGC1068, and the very center
of NGC4945. In the case of NGC 1068, the measured ratios suggest
inflow from the outer part of NGC1068 into the circum-nuclear disk
through both the halo and the bar. Low 12C/13C isotopic ratios in
the central regions of these starburst galaxies indicate the presence
of highly processed material.
Description:
Our observations were carried out from 2014 December to 2015 January
with the Atacama Large Millimeter/submillimeter Array (ALMA) in Band 3
(Project: 2013.1.01151.S). During the observations, 36 to 40 12-m
antennas were employed in a compact configuration with baselines
ranging from 15 to 349m. For each source, the observations took about
30 minutes and 1 hour for 12CN and 13CN, respectively.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 83 3 Main properties of the galaxies and
observational parameters
list.dat 156 6 List of fits datacubes
fits/* . 6 Individual fits datacubes
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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 --- Name Galaxy name
10- 11 I2 h RAh Right ascension (J2000)
13- 14 I2 min RAm Right ascension (J2000)
16- 20 F5.2 s RAs Right ascension (J2000)
22 A1 --- DE- Declination sign (J2000)
23- 24 I2 deg DEd Declination (J2000)
26- 27 I2 arcmin DEm Declination (J2000)
29- 32 F4.1 arcsec DEs Declination (J2000)
34- 37 F4.1 Mpc Dist Distance (1)
39- 41 F3.1 arcsec Beam1 Beam size, angular
43- 45 F3.1 arcsec Beam2 Beam size, angular
47 A1 --- l_Beamp1 [~] Limit flag on Beamp1
48- 50 I3 pc Beamp1 Beam size, linear
52- 54 I3 pc Beamp2 Beam size, linear
56- 57 I2 deg PA Position angle
59- 83 A25 --- Type Type (1)
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Note (1): Distances and type were taken from the NASA/IPAC Extragalactic
Database (NED).
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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- 8 A8 --- Name Galaxy name
10- 18 F9.5 deg RAdeg Right Ascension of center (J2000)
19- 27 F9.5 deg DEdeg Declination of center (J2000)
29- 31 I3 --- Nx Number of pixels along X-axis
33- 35 I3 --- Ny Number of pixels along Y-axis
37- 39 I3 --- Nz Number of slices
41- 66 A26 "datime" Obs.date Observation date
68- 74 F7.3 GHz bFreq ? Lower value of frequency interval
76- 82 F7.3 GHz BFreq ? Upper value of frequency interval
84- 94 E11.5 Hz dFreq ? Frequency resolution
95- 98 I4 km/s bVel ? Lower value of velocity interval
100-103 I4 km/s BVel ? Upper value of velocity interval
105-106 I2 km/s dVel ? Velocity resolution
108-113 I6 Kibyte size Size of FITS file
115-131 A17 --- FileName Name of FITS file, in subdirectory fits
133-156 A24 --- Title Title of the FITS file
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Acknowledgements:
Xindi Tang, tangxindi(at)xao.ac.cn
(End) Patricia Vannier [CDS] 25-Jul-2019