J/A+A/626/A44 Galactic center CO rot-vib absorption lines (Moultaka+, 2019)
High-spectral resolution M-band observations of CO Rot-Vib absorption lines
towards the Galactic center.
Moultaka J., Eckart A., Tikare K., Bajat A.
<Astron. Astrophys. 626, A44 (2019)>
=2019A&A...626A..44M 2019A&A...626A..44M (SIMBAD/NED BibCode)
ADC_Keywords: Galactic center ; Interstellar medium ; Spectra, infrared
Keywords: Galaxy: center - galaxies: nuclei - infrared: ISM
Abstract:
In the near- to mid-infrared wavelength domain, bright continuum
sources in the central parsec of the Galactic center (GC) are subject
to foreground absorption. These sources therefore represent ideal
probes of the intervening material that is responsible for the
absorption along the line of sight.
Our aim is to shed light on the location and physics of the absorbing
clouds. We try to find out which of the gaseous absorbing materials is
intimately associated with the GC and which one is associated with
clouds at a much larger distance.
We used the capabilities of CRIRES spectrograph located at ESO Very
Large Telescope in Chile to obtain absorption spectra of individual
lines at a high spectral resolution of R=65000, that is, 5km/s. We
observed the 12CO R(0), P(1), P(2), P(3), P(4), P(5), P(6), P(7) and
P(9) transition lines, applied standard data reduction, and compared
the results with literature data. Results. We present the results of
CRIRES observations of 13 infrared sources located in the central
parsec of the Galaxy. The data provide direct evidence for a complex
structure of the interstellar medium along the line of sight and in
the close environment of the central sources. In particular we find
four cold foreground clouds at radial velocities vLS R of the order of
-145, -85, -60, and -40+-15km/s that show absorption in the lower
transition lines from R(0) to P(2) and in all the observed spectra.We
also find in all sources an absorption in velocity range of 50-60km/s,
possibly associated with the so-called 50km/s cloud and suggesting an
extension of this cloud in front of the GC. Finally, we detect
individual absorption lines that are probably associated with material
much closer to the center and with the sources themselves, suggesting
the presence of cold gas in the local region.
Description:
Reduced spectra of the Galactic Center infrared sources.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 169 13 List of studied sources
sp/* . 52 Individual spectra
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Name Source name
10- 11 I2 h RAh Simbad Right ascension (J2000)
13- 14 I2 min RAm Simbad Right ascension (J2000)
16- 20 F5.2 s RAs Simbad Right ascension (J2000)
22 A1 --- DE- Simbad Declination sign (J2000)
23- 24 I2 deg DEd Simbad Declination (J2000)
26- 27 I2 arcmin DEm Simbad Declination (J2000)
29- 32 F4.1 arcsec DEs Simbad Declination (J2000)
34- 43 A10 --- SName Simbad name
45- 58 A14 --- SpR0 Name of the file with 12CO R(0) line
transition in subdirectory sp
60- 73 A14 --- SpP1 Name of the file with 12CO P(1) line
transition in subdirectory sp
75- 88 A14 --- SpP2 Name of the file with 12CO P(2) line
transition in subdirectory sp
90-103 A14 --- SpP3 Name of the file with 12CO P(3) line
transition in subdirectory sp
104-116 A13 --- SpP4 Name of the file with 12CO P(4) line
transition in subdirectory sp
117-128 A12 --- SpP5 Name of the file with 12CO P(5) line
transition in subdirectory sp
129-141 A13 --- SpP6 Name of the file with 12CO P(6) line
transition in subdirectory sp
143-155 A13 --- SpP7 Name of the file with 12CO P(7) line
transition in subdirectory sp
157-169 A13 --- SpP9 Name of the file with 12CO P(9) line
transition in subdirectory sp
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Byte-by-byte Description of file: sp/*
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Bytes Format Units Label Explanations
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1- 22 F22.17 km/s Vlsr LSR velocity
29- 50 F22.17 ct Counts Number counts
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Acknowledgements:
Jihane Moultaka, jmoultaka(at)irap.omp.eu
IRAP, Universite de Toulouse, CNRS, CNES, UPS, France
(End) Jihane Moultaka [IRAP, France], Patricia Vannier [CDS] 29-May-2019