J/MNRAS/452/3969 ATCA Survey of Sagittarius B2 at 7mm (Corby+, 2015)
An ATCA survey of Sagittarius B2 at 7 mm:
chemical complexity meets broad-band interferometry.
Corby J.F., Jones P.A., Cunningham M.R., Remijan A.J., Menten K.M.,
Belloche A., Schwab F., Walsh A., Balnozan E., Bronfman L., Lo N.
<Mon. Not. R. Astron. Soc. 452, 3969 (2015)>
=2015MNRAS.452.3969C 2015MNRAS.452.3969C
ADC_Keywords: Molecular clouds ; Radio lines ; Radio continuum ; Spectroscopy ;
H II regions ; Nebulae
Keywords: astrochemistry - line: identification - H II regions -
ISM: molecules - photodissociation region (PDR) - radio lines: ISM
Abstract:
We present a 30-50GHz survey of Sagittarius B2(N) conducted with the
Australia Telescope Compact Array (ATCA) with 5 - 10 arcsec
resolution. We analyze the spectra towards three HII regions that have
foreground molecular gas in Sgr B2. Towards the most line-dense
region, we detect >500 spectral line components, >90% of which are
assigned to H and He recombination lines and 53 firmly identified
molecular species (not including isotopologues). The data reveal
extremely subthermally excited molecular gas in Sgr B2 absorbing
against the continuum background, as well as molecular line emission
from two hot cores in Sgr B2(N). They also also contain line-of-sight
absorption by ∼15 molecules observed in translucent gas in the
Galactic Center, bar, and intervening spiral arm clouds, revealing the
complex chemistry and clumpy structure of this gas. Formamide
(NH2CHO) is detected for the first time in a translucent cloud.
Description:
The FITS files include 12 baseline-subtracted data cubes that are not
corrected for the primary beam. The data cover the full frequency
range from 29.8-50.2GHz with 1MHz channels and three continuum images.
The data were taken towards a single pointing position towards Sgr
B2(N). The continuum images are all generated from a 7.5GHz bandwidth,
and the three images are centered on 33.4GHz, 40.2GHz, and 46.5GHz.
Objects:
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RA (2000) DE Designation(s)
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17 47 20.4 -28 22 12 Sgr B2 = NAME SGR B2
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 234 15 List of fits images and data cubes
fits/* . 15 Individual fits data cubes
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See also:
J/ApJS/117/427 : Sgr B2 spectral survey (Nummelin+, 1998)
J/ApJS/158/188 : Detection of glycolaldehyde toward Sgr B2 (Widicus+, 2005)
J/A+A/559/A47 : Sgr B2(N) and Sgr B2(M) IRAM 30m line survey (Belloche+, 2013)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 19 A19 "datime" ObsDate Observation date
21- 29 F9.5 deg RAdeg Right Ascension of center (J2000)
30- 38 F9.5 deg DEdeg Declination of center (J2000)
39- 41 F3.1 arcsec/pix Scale [1/2] Scale of the image
43- 45 I3 --- Nx [160/256] Number of pixels along X-axis
47- 49 I3 --- Ny [160/256] Number of pixels along Y-axis
51- 54 I4 --- Nz [1/1948] Number of slides or channels
56- 60 I5 MHz nu.min [29776/48276] Lower value of Frequency
62- 66 I5 MHz nu.max [31724/50224] Upper value of Frequency
68- 70 F3.1 MHz dnu [1.0] Frequency resolution [MHz]
72- 78 F7.3 Mbyte size [0.121/488] Size of FITS file
80-110 A31 --- FileName Name of FITS file, in "fits" subdirectory
112-234 A123 --- Title Title of the file
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Acknowledgements:
Joanna Corby, jfc2113(at)gmail.com
Paul Jones, paulcojones(at)gmail.com
National Radio Astronomy Observatory;
Australia Telescope National Facility of the CSIRO, Australia
(End) Patricia Vannier [CDS] 29-May-2015