J/A+A/605/A57 SOLIS. I. OMC2-FIR4 HC3N and HC5N images (Fontani+, 2017)
Seeds of Life in Space (SOLIS).
I. Carbon-chain growth in the Solar-type protocluster OMC2-FIR4.
Fontani F., Ceccarelli C., Favre C., Caselli P. Neri R., Sims I.R.,
Kahane C., Alves F., Balucani N., Bianchi E., Caux E., Jaber Al-Edhari A.,
Lopez-Sepulcre A., Pineda J., Bachiller R., BIzzocchi L., Bottinelli S.,
Chacon-Tanarro A., Choudhury R., Codella C., Coutens A., Dulieu F., Feng S.,
Rimola A., Hily-Blant P., Holdship J., Jimenez-Serra I., Laas J.,
Lefloch B., Oya Y., Podio L., Pon A., Punanova A., Quenard D., Sakai N.,
Spezzano S., Taquet V., Testi L., Theule P., Ugliengo P., Vastel C.,
<Astron. Astrophys. 605, A57 (2017)>
=2017A&A...605A..57F 2017A&A...605A..57F (SIMBAD/NED BibCode)
ADC_Keywords: Infrared sources ; Interstellar medium
Keywords: radio lines: ISM - stars: formation - ISM: molecules
Abstract:
The interstellar delivery of carbon atoms locked into molecules might
be one of the key ingredients for the emergence of life. Cyanopolyynes
are carbon chains delimited at their two extremities by an atom of
hydrogen and a cyano group, meaning that they could be excellent
reservoirs of carbon. The simplest member, HC3N, is ubiquitous in
the galactic interstellar medium and found also in external galaxies.
Thus, understanding the growth of cyanopolyynes in regions forming
stars similar to our Sun, and what affects them, is particularly
relevant.
In the framework of the IRAM/NOEMA Large Program SOLIS (Seeds Of Life
In Space), we have obtained a map of two cyanopolyynes, HC3N and
HC5N, in the protocluster OMC-2 FIR4. Because our Sun is thought to
be born in a rich cluster, OMC-2 FIR4 is one of the closest and best
known representatives of the environment in which the Sun may have
been born. We find a HC3N/HC5N abundance ratio across the source
in the range ∼1-30, with the smallest values (<10) in FIR5 and in the
Eastern region of FIR4.
The ratios ≤10 can be reproduced by chemical models only if:
(1) the cosmic-ray ionisation rate z is ∼4x10-14s-1; (2) the
gaseous elemental ratio C/O is close to unity; and (3) oxygen and
carbon are largely depleted. The large z is comparable to that
measured in FIR4 by previous works and was interpreted as due to a
flux of energetic (>10MeV) particles from embedded sources. We
suggest that these sources could lie East of FIR4 and FIR5.
Description:
IRAM-NOEMA Interferometer, 3mm receiver, Widex and Narrow-band
correlators.
Observations with the IRAM NOEMA Interferometer of HC3N (9-8) and
HC5N (31-30), at rest frequencies 81.881468GHz and 82.539039GHz ,
respectively, towards OMC-2 FIR4 have been carried out over 5 days
between the 5th and the 19th of August, 2015.
The HC3N line was observed in the Widex band correlator, providing a
resolution in velocity of ∼7.15km/s, while the HC5N line was
observed also in the Narrow band correlator with a resolution in
velocity of ∼0.57km/s.
Objects:
---------------------------------------------------------------
RA (2000) DE Designation(s)
---------------------------------------------------------------
05 35 26.97 -05 09 54.5 OMC2-FIR4 = [MWZ90] OMC-2 FIR 4
---------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 113 4 List of fits images
fits/* . 4 Individual fits images
--------------------------------------------------------------------------------
See also:
J/A+A/556/A57 : Transitions in OMC-2 FIR 4 in the far-IR (Kama+, 2013)
J/A+A/596/A26 : OMC-2 FIR 3 and FIR 4 [OI] maps (Gonzalez-Garcia+, 2016)
J/A+A/605/L3 : SOLIS. I. L1157-B1 NH2CHO image (Codella+, 2017)
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 39 E12.6 m/s RV Radial velocity
41- 42 I2 Kibyte size Size of FITS file
44- 67 A24 --- FileName Name of FITS file, in subdirectory fits
69-113 A45 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Acknowledgements:
Francesco Fontani, fontani(at)arcetri.astro.it
References:
Codella et al., Paper II 2017A&A...605L...3C 2017A&A...605L...3C, Cat J/A+A/605/L3
(End) Francesco Fontani [INAF-OAA, Italy], Patricia Vannier [CDS] 17-Aug-2017