J/ApJ/878/44 13CO clumps toward the Cassiopeia A supernova remnant (Ma+, 2019)
A large-field J=1-0 survey of CO and its isotopologues toward the Cassiopeia A
supernova remnant.
Ma Y., Wang H., Zhang M., Li C., Yang J.
<Astrophys. J., 878, 44 (2019)>
=2019ApJ...878...44M 2019ApJ...878...44M
ADC_Keywords: Supernova remnants; Molecular clouds; Interstellar medium;
Carbon monoxide; Surveys
Keywords: ISM: clouds; ISM: individual objects (Cas A); ISM: supernova remnants;
stars: formation; surveys
Abstract:
We have conducted a large-field simultaneous survey of 12CO, 13CO,
and C18O J=1-0 emission toward the Cassiopeia A (Cas A) supernova
remnant (SNR), which covers a sky area of 3.5°x3.1°. The Cas
giant molecular cloud (GMC) mainly consists of three individual clouds
with masses on the order of 104-105M☉. The total mass
derived from the 13CO emission of the GMC is 2.1x105M☉ and
is 9.5x105M☉ from the 12CO emission. Two regions with
broadened (6-7km/s) or asymmetric 12CO line profiles are found in
the vicinity (within a 10'x10' region) of the Cas A SNR, indicating
possible interactions between the SNR and the GMC. Using the
GAUSSCLUMPS algorithm, 547 13CO clumps are identified in the GMC,
54% of which are supercritical (i.e., αvir<2). The mass
spectrum of the molecular clumps follows a power-law distribution with
an exponent of -2.20. The pixel-by-pixel column density of the GMC can
be fitted with a log-normal probability distribution function (N-PDF).
The median column density of molecular hydrogen in the GMC is
1.6x1021cm-2 and half the mass of the GMC is contained in regions
with H2 column density lower than 3x1021cm-2, which is well
below the threshold of star formation. The distribution of the YSO
candidates in the region shows no agglomeration.
Description:
In this work, we present a large-scale (3.5°x3.1°) survey of
molecular gas toward the Cas A supernova remnant (SNR), as part of the
Milky Way Imaging Scroll Painting (MWISP) project
(Su+ 2019ApJS..240....9S 2019ApJS..240....9S).
The observations were taken using the Purple Mountain Observatory
(PMO) 13.7m millimeter-wavelength telescope located at Delingha in
China during two observational seasons from 2015 October to 2016 April
and 2016 October to 2017 April. The 12CO J=1-0, 13CO J=1-0, and
C18O J=1-0 line emission data were obtained simultaneously through
the nine-beam Superconducting Spectroscopic Array Receiver mounted on
the telescope. The pointing of the telescope has an accuracy of about 5".
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 121 547 Properties of 13CO clumps
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See also:
VII/278 : A Catalogue of Galactic Supernova Remnants (Green 2017)
J/ApJ/428/693 : Rosette Nebula & Maddalena structures (Williams+ 1994)
J/A+A/368/267 : Spatially resolved spectroscopy of Cas A (Maccarone+, 2001)
J/ApJ/551/852 : FCRAO CO survey of the outer Galaxy (Heyer+, 2001)
J/ApJ/613/343 : Cas A knot and filament proper motions (Delaney+, 2004)
J/ApJS/179/195 : A catalog of outer ejecta knots in Cas A (Hammell+, 2008)
J/ApJ/699/1092 : Giant molecular clouds (SRBY) (Heyer+, 2009)
J/MNRAS/431/1752 : ATLASGAL 6.7GHz methanol masers (Urquhart+, 2013)
J/ApJS/212/1 : The WISE catalog of Galactic HII regions (Anderson+, 2014)
J/ApJ/783/130 : Parallaxes of high mass star forming regions (Reid+, 2014)
J/ApJS/217/2 : Refined associations of Fermi/LAT sources (Massaro+, 2015)
J/A+A/588/A104 : Molecular clouds and star formation (Gong+, 2016)
J/ApJ/837/118 : NIR knots in the Cas A supernova remnant (Lee+, 2017)
J/ApJ/866/139 : Knots in the deep [FeII]+[SiI] image of Cas A (Koo+, 2018)
J/A+A/612/A110 : Cas A LOFAR and VLA images (Arias+, 2018)
http://www.radioast.nsdc.cn/mwisp.php : MWISP home page
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [MWISP]
7- 28 A22 --- MWISP MWISP project source identifier
(GLLL.lll-BB.bbb-NNN.NN; with NNN.NN=Vlsr;
in Simbad)
30- 36 F7.3 deg GLON [109.7/113.2] Galactic Longitude, centroid
38- 43 F6.3 deg GLAT [-4.21/-1.18] Galactic Latitude, centroid
45- 47 I3 arcsec amaj [50/324] FWHM of the major axis
49- 51 I3 arcsec bmin [56/326] FWHM of the minor axis
53- 55 I3 deg PA [-74/178] Position Angle
57- 62 F6.2 km/s Vlsr [-57/-27] Local Standard of Rest velocity
64- 66 F3.1 K Tpeak [1.5/7.3] Peak intensity of 13CO emission
68- 71 F4.2 km/s DeltaV [0.4/4.2] FWHM line width
73- 75 F3.1 pc Rad [0.5/2] Effective Radius
77- 80 F4.1 K Tex [6.5/18.8] Excitation temperature
82- 84 F3.1 --- Tau [0.2/1.1] Optical depth
86- 92 E7.1 cm-2 NH2 [5.5e+20/1.5e+22] Peak column density
94-100 E7.1 Msun MLTE [23/2800] LTE mass
102-108 E7.1 Msun/pc2 Sigma [29/750] Mass surface density
110-116 E7.1 cm-3 n [420/14000] Number density
118-121 F4.2 --- aVir [0.26/6.2] Virial parameter αvir
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 03-Dec-2020