J/A+A/568/A65 NGC 7129 FIRS 2 interferometric 1-D spectrum (Fuente+, 2014)
The hot core towards the intermediate mass protostar NGC 7129 FIRS 2:
Chemical similarities with Orion KL.
Fuente A., Cernicharo J., Caselli P., McCoey C., Johnstone D., Fich M.,
van Kempen T., Palau Aina , Yildiz U.A., Tercero B., Lopez A.
<Astron. Astrophys. 568, A65 (2014)>
=2014A&A...568A..65F 2014A&A...568A..65F
ADC_Keywords: YSOs ; Spectroscopy ; Radio sources ; Interferometry
Keywords: astrochemistry - stars: formation - ISM: molecules -
ISM: individual (NGC 7129 FIRS 2)
Abstract:
NGC 7129 FIRS 2 (hereafter FIRS 2) is an intermediate-mass (2 to
8M☉) protostar located at a distance of 1250pc. High spatial
resolution observations are required to resolve the hot core at its
center. We present a molecular survey from 218200MHz to 221800MHz
carried out with the IRAM Plateau de Bure Interferometer. These
observations were complemented with a long integration single-dish
spectrum taken with the IRAM 30m telescope. We used a Local
Thermodynamic Equilibrium (LTE) single temperature code to model the
whole dataset. The interferometric spectrum is crowded with a total of
∼300 lines from which a few dozens remain unidentified yet. The
spectrum has been modeled with a total of 20 species and their
isomers, isotopologues and deuterated compounds. Complex molecules
like methyl formate (CH3OCHO), ethanol (CH3CH2OH),g
lycolaldehyde (CH2OHCHO), acetone (CH3COCH3), dimethyl ether
(CH3OCH3), ethyl cyanide (CH3CH2CN) and the aGg' conformer of
ethylene glycol (aGg'-(CH2OH)2) are among the detected species.
The detection of vibrationally excited lines of CH3CN, CH3OCHO,
CH3OH, OCS, HC3N and CH3CHO proves the existence of gas and dust
at high temperatures. In fact, the gas kinetic temperature estimated
from the vibrational lines of CH3CN, ∼405K, is similar to that
measured in massive hot cores. Our data allow an extensive comparison
of the chemistry in FIRS 2 and the Orion hot core. We find a quite
similar chemistry in FIRS 2 and Orion. Most of the studied fractional
molecular abundances agree within a factor of 5. Larger differences
are only found for the deuterated compounds D2CO and CH2DOH and a
few molecules (CH3CH2CN, SO2, HNCO and CH3CHO). Since the
physical conditions are similar in both hot cores, only different
initial conditions (warmer pre-collapse phase in the case of Orion)
and/or different crossing time of the gas in the hot core can explain
this behavior.
Description:
Interferometric 1-D spectrum towards NGC 7129 FIRS 2 (RA=21:43:01.7,
Dec=+66:03:23.6 J2000). The X-axis is frequency in MHz and the Y-axis
is intensity in temperature units (K). The spectrum was observed with
the IRAM Plateau de Bure Interferometer in CD configuration providing
a synthesized beam of 1.43"x1.26" PA 144. The adopted source velocity
is v=-10km/s.
Objects:
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RA (2000) DE Designation(s)
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21 43 01.7 +66 03 23.6 NGC 7129 FIRS 2 = Name NGC 7129 FIRS 2
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table.dat 29 1843 Interferometric 1-D spectrum towards NGC 7129 FIRS 2
table.fits 2880 5 Spectrum as FITS file
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Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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4- 13 F10.3 MHz Freq [218046/221685] Frequency
19- 29 E11.5 K Int Intensity, in temperature units
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Acknowledgements:
Asuncion Fuente, a.fuente(at)oan.es
(End) Patricia Vannier [CDS] 22-May-2014