J/ApJ/884/100 Astrochemical study along M83 circumnuclear ring (Harada+, 2019)
Chemical evolution along the circumnuclear ring of M83.
Harada N., Sakamoto K., Martin S., Watanabe Y., Aladro R., Riquelme D.,
Hirota A.
<Astrophys. J., 884, 100 (2019)>
=2019ApJ...884..100H 2019ApJ...884..100H
ADC_Keywords: Molecular data; Interstellar medium; Radio lines; Galaxies, nearby
Keywords: astrochemistry; galaxies: individual (M83); galaxies: star formation;
ISM: abundances; ISM: clouds; ISM: molecules
Abstract:
We report an astrochemical study on the evolution of interstellar
molecular clouds and consequent star formation in the center of the
barred spiral galaxy M83. We used the Atacama Large
Millimeter/submillimeter Array (ALMA) to image molecular species
indicative of shocks (SiO and CH3OH), dense cores (N2H+), and
photodissociation regions (CN and CCH), as well as a radio
recombination line (H41α) tracing active star-forming regions.
M83 has a circumnuclear gas ring that is joined at two intersections
by gas streams from the leading- edge gas lanes on the bar. We found
elevated abundances of the shock and dense-core tracers in one of the
orbit-intersecting areas, and found peaks of CN and H41α
downstream. In the other orbit-intersection area, we found a similar
enhancement of the shock tracers, but less variation of other tracers,
and no sign of active star formation in the stream. We propose that
the observed chemical variation or lack of it is due to the presence
or absence of collision-induced evolution of molecular clouds and
induced star formation. This work presents the clearest case of the
chemical evolution in the circumnuclear rings of barred galaxies
thanks to the ALMA resolution and sensitivity.
Description:
Our observations cover six tunings and were conducted during ALMA
cycle 4 (2016 Oct-2017 Mar) using both the 12m and the 7m array
(project code: 2016.1.00164.S; PI: Harada). We targeted the entire
circumnuclear ring, and we mosaicked the area of 25"x25 for Bands 6
and 7, whose primary beam sizes are smaller than our targeted area. We
supplemented our data with ALMA archival data 2012.1.00762.S
(PI: Hirota -- 2013 Jun-2015 Jan) for CN(N=1-0) and
2015.1.01177.S (PI: Longmore -- 2016 Apr-Sep) for the CCH(N=1-0) and
SiO(2-1) lines.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 29 12 Coordinates of analyzed positions
table7.dat 62 384 Observed peak intensities and velocity-integrated
intensities for detected lines
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See also:
J/A+A/361/1079 : HNCO in massive galactic dense cores (Zinchenko, 2000)
J/AJ/122/3046 : HST photometry of star clusters in NGC 5236 (Harris+, 2001)
J/A+A/455/971 : Organic molecules in the Gal. center (Requena-Torres+, 2006)
J/ApJS/174/337 : Star formation in nuclear rings (Mazzuca+, 2008)
J/ApJ/703/517 : The Spitzer Local Volume Legacy: IR photometry (Dale+, 2009)
J/ApJ/699/1092 : Giant molecular clouds (SRBY) (Heyer+, 2009)
J/MNRAS/421/2786 : Modelling of shock waves mol. line emission (Flower+ 2012)
J/A+A/549/A39 : A 3mm molecular line survey of NGC1068 (Aladro+, 2013)
J/A+A/563/L6 : CIG 638 CCH, HCN. HOC and HNC spectra (Martin+, 2014)
J/A+A/579/A101 : 3mm molecular line survey of 8 AGN (Aladro+, 2015)
J/ApJ/845/116 : 3mm survey toward W51 (Watanabe+, 2017)
J/ApJ/855/49 : ALMA astrochemical obs. of NGC 3256 (Harada+, 2018)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- Pos Position
4- 5 I2 h RAh Hour of right ascension (ICRS)
7- 8 I2 min RAm Minute of right ascension (ICRS)
10- 15 F6.3 s RAs Second of right ascension (ICRS)
17 A1 --- DE- Sign of declination (ICRS)
18- 19 I2 deg DEd Degree of declination (ICRS)
21- 22 I2 arcmin DEm Arcminute of declination (ICRS)
24- 29 F6.3 arcsec DEs Arcsecond of declination (ICRS)
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 21 A21 --- Trans Transition
23- 24 A2 --- Pos Position
26- 26 A1 --- l_Ipeak Limit flag on Ipeak (1)
28- 34 E7.1 mK Ipeak [5.8/2200] Peak intensity (2)
36- 42 E7.1 mK e_Ipeak [2/64]? Uncertainty for Ipeak
44- 44 A1 --- l_IdV Limit flag on IdV (1)
46- 52 E7.1 K.km/s IdV [0.2/120] Velocity-integrated Intensity (2)
54- 60 E7.1 K.km/s e_IdV [0.06/4]? Uncertainty on IdV
62- 62 A1 --- Flag Error Flag (3)
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Note (1): For transitions undetected, upper limit values of 3σ are shown.
Note (2): Peak intensities are taken from a channel smoothed to 10km/s.
We show intensities of data smoothed to the beam size of 2.8".
The absolute flux calibration has accuracy of about 10%.
Note (3):
* = Asterisks are added to values for CS(6-5) at S1 to indicate that
these values seem to show more errors than what are theoretically
predicted from the primary beam correction, and they need to be taken
with caution.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 22-Mar-2021