J/A+A/582/A118 OH-streamer in SgrA at 1665 and 1667MHz (Karlsson+, 2015)
The OH-streamer in Sagittarius A revisited: analysis of hydroxyl absorption with
in 10 pc from the Galactic centre.
Karlsson R., Sandqvist Aa., Fathi K., Martin S.
<Astron. Astrophys. 582, A118 (2015)>
=2015A&A...582A.118K 2015A&A...582A.118K (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Interstellar medium ; Molecular clouds
Keywords: Galaxy: centre - ISM: individual objects: Sagittarius A -
ISM: molecules - ISM: clouds
Abstract:
We study the structure and kinematics of the OH-streamer and the
+80km/s cloud and their interactions with the circumnuclear disk
(CND) and with other molecular clouds in the vicinity of the Galactic
centre (GC), and we map OH absorption at about 6" resolution at
R≤10pc from the GC, with about 9km/s of velocity resolution.
The VLA was used to map OH line absorption at the 1665 and 1667MHz
lambda doublet main lines of the 2{PI}3/2 state towards the
Sagittarius A complex.
Description:
The VLA was used to map OH line absorption at the 1665 and 1667MHz
lambda doublet main lines of the 2Π3/2 state towards the
Sagittarius A complex. Strong OH absorption was found in the
OH-streamer, the southern streamer (SS), the +20, +50, and +80km/s
molecular clouds, the molecular belt, the CND, the expanding molecular
ring (EMR), and the high negative velocity gas (HNVG).
Data cubes of VLA observations of the Sgr A complex at 1667- and
1665MHz OH-absorption at 7"x5" angular and 8.8km/s velocity
resolution in 63 spectral channels centered at -38km/s (LSR).
OH-absorption is defined as "continuum flux minus line flux". The
continuum is taken as the average of 1665 and 1667 MHz maps of line
free channels. Observations with the VLA in BnA and DnC arrays have
been concatenated with AIPS, and data were calibrated and CLEANed with
NRAO AIPS standard procedures.
Objects:
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RA (2000) DE Designation(s)
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17 45 40.04 -29 00 28.2 Sgr A = NAME Sgr A*
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 147 3 List of fits files
fits/* . 3 Individual fits files
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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- 28 I4 --- Ny Number of pixels along Y-axis
30- 31 I2 --- Nz ? Number of slices for data cubes
33- 42 A10 "date" Date Observation date
44- 54 E11.5 Hz bFreq Frequency or lower value of frequency interval
56- 61 I6 Hz BFreq ? Upper value of frequency interval
63- 69 F7.2 Hz dFreq ? Frequency resolution
71- 76 I6 Kibyte size Size of FITS file
78-101 A24 --- FileName Name of FITS file, in subdirectory fits
103-147 A45 --- Title Title of the FITS file
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Acknowledgements:
Roland Karlsson, rkrolandk(at)gmail.com
(End) Patricia Vannier [CDS] 21-Oct-2015