J/A+A/622/A91 Herschel/HIFI and IRAM 30m images of OMC1 (Goicoechea+, 2019)
Molecular tracers of radiative feedback in Orion (OMC-1).
Widespread CH+ (J=1-0), CO (10-9), HCN (6-5), and HCO+ (6-5) emission.
Goicoechea J.R., Santa-Maria M.G., Bron E., Teyssier D., Marcelino N.,
Cernicharo J., Cuadrado S.
<Astron. Astrophys. 622, A91 (2019)>
=2019A&A...622A..91G 2019A&A...622A..91G (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Molecular clouds
Keywords: planetary nebulae: general - ISM: clouds - infrared: galaxies -
galaxies: ISM
Abstract:
Young massive stars regulate the physical conditions, ionization, and
fate of their natal molecular cloud. It is important to find tracers
that help quantifying the stellar feedback processes that take place
at different scales. We present ∼85arcmin2 velocity-resolved maps of
several submm molecular lines toward the closest high-mass
star-forming region, OMC-1. The observed rotational lines include
probes of warm and dense molecular gas that are difficult to detect
from ground-based telescopes: CH+ (1-0), CO (10-9), HCO+ (6-5),
and HCN (6-5). These lines trace an extended but thin layer of
molecular gas at high thermal pressure, Pth∼107-109K/cm3,
associated with the FUV-irradiated surface of OMC-1. The intense FUV
field, emerging from massive stars in the Trapezium cluster, heats,
compresses and photoevaporates the cloud edge. It also triggers the
formation of reactive molecules such as CH+. The CH+ (1-0)
emission spatially correlates with the flux of FUV photons impinging
the cloud: G_0 from 1e3 to 1e5. This correlation is supported by
isobaric PDR models in the parameter space
Pth/G0~[5*103-8*104]K/cm3 where many PDRs seem to lie. The
CH+ (1-0) emission correlates with the extended emission from
vibrationally excited H2, and with that of [CII]158um and CO 10-9,
all emerging from FUV-irradiated gas. These correlations link the
presence of CH+ to the availability of C+ ions and of FUV-pumped
H2(v>0) molecules. The parsec-scale CH+ emission and narrow-line
(dv∼3 km/s) mid-J CO emission arises from extended PDRs and not from
fast shocks. PDR line tracers are the smoking gun of the stellar
feedback from young massive stars. The PDR component in OMC-1
represents 5 to 10 % of the total gas mass, however, it dominates the
emitted line luminosity. These results provide insights into the
source of submm CH+ and mid-J CO emission from distant star-forming
galaxies.
Description:
The FITS files contain the following line surface brightness images:
- CH+ (1-0), CO (10-9), H2O (312-221), and C18O (2-1)
shown in Fig. 2.
- CH (1,3/2-1,1/2), CO (2-1), CH3OH, and 13CO (2-1) shown in Fig. B.1.
- HCO+ (3-2), HCO+ (6-5), HCN (13-12), and HCN (6-5) shown in Fig. B.2.
The intensity scale is in units of 10-8W/m2/sr.
Objects:
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RA (2000) DE Designation(s)
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05 35 17.0 -05 22 33.7 OMC1 = NAME OMC-1
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 107 12 List of fits images
fits/* . 12 Individual fits images
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See also:
J/A+A/466/949 : Velocities of OMC-1 flows (Nissen+, 2007)
J/A+A/533/A38 : Extinction map of OMC-1 (Scandariato+, 2011)
J/A+A/587/A47 : SMA 1.3mm image of OMC 1 North (Teixeira+, 2016)
J/ApJ/826/16 : ALMA and GeMS observations of the OMC1 region (Eisner+, 2016)
J/A+A/609/A16 : OMC 1 reduced H2CO(3-2) datacubes (Tang+, 2018)
Byte-by-byte Description of file: list.dat
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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- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 33 I4 Kibyte size Size of FITS file
35- 68 A34 --- FileName Name of FITS file, in subdirectory fits
70-107 A38 --- Title Title of the FITS file
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Acknowledgements:
Javier R. Goicoechea, javier.r.goicoechea(at)csic.es
References:
Goicoechea et al., 2015ApJ...812...75G 2015ApJ...812...75G, Velocity-resolved [CII] emission
and [CII]/FIR mapping along Orion with Herschel
(End) Javier Goicoehcea [CSIC, Spain], Patricia Vannier [CDS] 07-Dec-2018