J/A+A/644/A64 CO observations of the IC443 SNR (Dell'Ova+, 2020)
Interstellar anatomy of the TeV gamma-ray peak in the IC443 supernova remnant.
Dell'Ova P., Gusdorf A., Gerin M., Riquelme D., Gusten R.,
Noriega-Crespo A., Tram L.N., Houde M., Guillard P., Lehmann A.,
Lesaffre P., Louvet F., Marcowith A., Padovani M.
<Astron. Astrophys. 644, A64 (2020)>
=2020A&A...644A..64D 2020A&A...644A..64D (SIMBAD/NED BibCode)
ADC_Keywords: Supernova remnants ; Interstellar medium ; Carbon monoxide
Keywords: ISM: supernova remnants - ISM: individual objects: IC443 -
ISM: kinematics and dynamics - cosmic rays - stars: formation
Abstract:
Supernova remnants (SNRs) represent a major feedback source from stars
in the interstellar medium of galaxies. During the latest stage of
supernova explosions, shock waves produced by the initial blast modify
the chemistry of gas and dust, inject kinetic energy into the
surroundings, and may alter star formation characteristics.
Simultaneously, gamma-ray emission is generated by the interaction
between the ambient medium and cosmic rays (CRs), including those
accelerated in the early stages of the explosion.
We study the stellar and interstellar contents of IC443, an evolved
shell-type SNR at a distance of 1.9kpc with an estimated age of 30kyr.
We aim to measure the mass of the gas and characterize the nature of
infrared point sources within the extended G region, which corresponds
to the peak of gamma-ray emission detected by VERITAS and Fermi.
We performed 10'x10' mapped observations of 12CO, 13CO J=1-0,
J=2-1, and J=3-2 pure rotational lines, as well as C18O J=1-0
and J=2-1 obtained with the IRAM 30m and APEX telescopes over the
extent of the gamma-ray peak to reveal the molecular structure of the
region. We first compared our data with local thermodynamic
equilibrium models. We estimated the optical depth of each line from
the emission of the isotopologs 13CO and C18O. We used the
population diagram and large velocity gradient assumption to measure
the column density, mass, and kinetic temperature of the gas using
12CO and 13CO lines. We used complementary data (stars, gas, and
dust at multiple wavelengths) and infrared point source catalogs to
search for protostar candidates.
Our observations reveal four molecular structures: a shocked molecular
clump associated with emission lines extending between -31 and 16km/s,
a quiescent, dark cloudlet associated with a line width of ∼2km/s, a
narrow ring-like structure associated with a line width of ∼1.5km/s,
and a shocked knot. We measured a total mass of ∼230, ∼90, ∼210, and
∼4M☉, respectively, for the cloudlet, ring-like structure,
shocked clump, and shocked knot. We measured a mass of ∼1100M☉
throughout the rest of the field of observations where an ambient
cloud is detected. We found 144 protostar candidates in the region.
Our results emphasize how the mass associated with the ring-like
structure and the cloudlet cannot be overlooked when quantifying the
interaction of CRs with the dense local medium. Additionally, the
presence of numerous possible protostars in the region might represent
a fresh source of CRs, which must also be taken into account in the
interpretation of gamma-ray observations in this region.
Description:
This data set contains CO observations of the IC443 SNR performed in a
10'x10' field of observations with the IRAM-30m and APEX telescope.
The J=1-0, J=2-1 and J=3-2 transitions were observed for the
isotopologues 12CO and 13CO, as well as the transitions J=1-0 and
J=2-1 for C18O.
Objects:
--------------------------------------------------
RA (2000) DE Designation(s)
--------------------------------------------------
06 18 02.7 +22 39 36 IC 443 = SNR G189.1+03.0
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 134 9 List of datacubes
fits/* . 9 Individual datacubes
tableg1.dat 90 65 Infrared photometric magnitudes of YSO candidates
detected by WISE in the extended G region
tableg2.dat 74 79 Infrared photometric magnitudes of YSO candidates
detected by 2MASS in the extended G region
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See also:
J/A+A/279/541 : Sub-mm observations of SNR IC 443 (van Dishoeck+ 1993)
J/ApJ/788/122 : IR photometry of YSO candidates toward SNR IC 443 (Su+, 2014)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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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- 31 I4 --- Nz Number of pixels along Z-axis
33- 39 I7 m/s bVRAD Lower value of VRAD interval
41- 46 I6 m/s BVRAD Upper value of VRAD interval
48- 54 F7.3 m/s dVRAD VRAD resolution
56- 60 I5 Kibyte size Size of FITS file
62- 84 A23 --- FileName Name of FITS file, in subdirectory fits
86-134 A49 --- Title Title of the FITS file
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Byte-by-byte Description of file: tableg1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- ID [1/65] Sequential number
4- 22 A19 --- Name Catalog name (JHHMMSS.ss+DDMMSS.s)
24- 29 F6.3 mag W1mag Wise W1 (3.4um) magnitude
31- 35 F5.3 mag e_W1mag Wise W1 (3.4um) magnitude error
37- 42 F6.3 mag W2mag Wise W2 (4.6um) magnitude
44- 48 F5.3 mag e_W2mag Wise W2 (4.6um) magnitude error
50- 55 F6.3 mag W3mag Wise W3 (12um) magnitude
57- 61 F5.3 mag e_W3mag Wise W3 (12um) magnitude error
63- 67 F5.3 mag W4mag Wise W4 (22um) magnitude
69- 73 F5.3 mag e_W4mag ? Wise W4( 22um) magnitude error
75- 82 A8 --- Label Figure 13 label (Class I or Class II) (1)
84- 88 F5.2 --- alpha Spectral index alpha,
α=dlog(λFλ)dlogλ
90 I1 --- Flag [0/5] Flag (G1)
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Note (1): Label as follows:
Class I = α≥3
Class II = -1.6≤α≤-0.3
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Byte-by-byte Description of file: tableg2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- ID [1/79] Sequential number
4 I1 h RAh Right ascension (J2000)
6- 7 I2 min RAm Right ascension (J2000)
9- 13 F5.2 s RAs Right ascension (J2000)
15 A1 --- DE- Declination sign (J2000)
16- 17 I2 deg DEd Declination (J2000)
19- 20 I2 arcmin DEm Declination (J2000)
22- 26 F5.2 arcsec DEs Declination (J2000)
28- 33 F6.3 mag Jmag 2MASS J (1.25um) magnitude
35- 39 F5.3 mag e_Jmag 2MASS J (1.25um) magnitude error
41- 46 F6.3 mag Hmag 2MASS H (1.65um) magnitude
48- 52 F5.3 mag e_Hmag 2MASS H (1.65um) magnitude error
54- 59 F6.3 mag Kmag 2MASS K (2.17um) magnitude
61- 65 F5.3 mag e_Kmag 2MASS K (2.17um) magnitude error
67- 71 A5 --- Label Figure 13 label (YSO, CTTS or HAeBe)
74 I1 --- Flag [0/2] Flag (G1)
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Global notes:
Note (G1): ext_flg flag different than "0" are indicated as extended sources.
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Acknowledgements:
Pierre Dell'Ova, pierre.dellova(at)obspm.fr
History:
* 01-Dec-2020: on-line version
* 12-Feb-2021: tables G1 anf G2 added, from electronic version
(End) Patricia Vannier [CDS] 21-Oct-2020