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. =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_{sun}_) 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 (CH_3_OCHO), ethanol (CH_3_CH_2_OH),g lycolaldehyde (CH_2_OHCHO), acetone (CH_3_COCH_3_), dimethyl ether (CH_3_OCH_3_), ethyl cyanide (CH_3_CH_2_CN) and the aGg' conformer of ethylene glycol (aGg'-(CH_2_OH)_2_) are among the detected species. The detection of vibrationally excited lines of CH_3_CN, CH_3_OCHO, CH_3_OH, OCS, HC_3_N and CH_3_CHO proves the existence of gas and dust at high temperatures. In fact, the gas kinetic temperature estimated from the vibrational lines of CH_3_CN, ~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 D_2_CO and CH_2_DOH and a few molecules (CH_3_CH_2_CN, SO_2_, HNCO and CH_3_CHO). 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: --------------------------------------------------------------- RA (2000) DE Designation(s) --------------------------------------------------------------- 21 43 01.7 +66 03 23.6 NGC 7129 FIRS 2 = Name NGC 7129 FIRS 2 --------------------------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- Byte-by-byte Description of file: table.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 4- 13 F10.3 MHz Freq [218046/221685] Frequency 19- 29 E11.5 K Int Intensity, in temperature units -------------------------------------------------------------------------------- Acknowledgements: Asuncion Fuente, a.fuente(at)oan.es ================================================================================ (End) Patricia Vannier [CDS] 22-May-2014