J/A+A/651/A86 GLOSTAR Galactic plane survey. II. SNR. (Dokara+, 2021)
A global view on star formation: The GLOSTAR Galactic plane survey.
II. Supernova remnants in the first quadrant of the Milky Way
Dokara R., Brunthaler A., Menten K.M., Dzib S.A., Reich W., Cotton W.D.,
Anderson L.D., Chen C.-H.R., Gong Y., Medina S.-N.X., Ortiz-Leon G.N.,
Rugel M., Urquhart J.S., Wyrowski F., Yang A.Y., Beuther H.,
Billington S.J., Csengeri T., Carrasco-Gonzalez C., Roy N.
<Astron. Astrophys. 651, A86 (2021)>
=2021A&A...651A..86D 2021A&A...651A..86D (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Galactic plane ; Supernova remnants ; Radio sources ;
Polarization
Keywords: ISM: supernova remnants - radio continuum: ISM - polarization -
H II regions - surveys
Abstract:
The properties of the population of Galactic supernova remnants (SNRs)
are essential to our understanding of the dynamics of the interstellar
medium (ISM) in the Milky Way. However, the completeness of the
catalog of Galactic SNRs is expected to be only ∼30%, with on order
700 SNRs yet to be detected. Deep interferometric radio continuum
surveys of the Galactic plane help in rectifying this apparent
deficiency by identifying low surface brightness SNRs and compact SNRs
that have not been detected in previous surveys. However, SNRs are
routinely confused with HII regions, which can have similar radio
morphologies. Radio spectral index, polarization, and emission at
mid-infrared (MIR) wavelengths can help distinguish between SNRs and
HII regions.
We aim to identify SNR candidates using continuum images from the Karl
G. Jansky Very Large Array GLObal view of the STAR formation in the
Milky Way (GLOSTAR) survey.
GLOSTAR is a C-band (4-8GHz) radio wavelength survey of the Galactic
plane covering 358°≥l≤60°, |b|≤1°. The continuum images
from this survey, which resulted from observations with the most
compact configuration of the array, have an angular resolution of
18''. We searched for SNRs in these images to identify known SNRs,
previously identified SNR candidates, and new SNR candidates. We study
these objects in MIR surveys and the GLOSTAR polarization data to
classify their emission as thermal or nonthermal.
We identify 157 SNR candidates, of which 80 are new. Polarization
measurements provide evidence of nonthermal emission from 9 of these
candidates. We find that two previously identified candidates are
filaments. We also detect emission from 91 of the 94 known SNRs in the
survey region. Four of these are reclassified as HII regions following
detection in MIR surveys.
The better sensitivity and resolution of the GLOSTAR data have led to
the identification of 157 SNR candidates, along with the
reclassification of several misidentified objects. We show that the
polarization measurements can identify nonthermal emission, despite
the diffuse Galactic synchrotron emission. These results underscore
the importance of higher resolution and higher sensitivity radio
continuum data in identifying and confirming SNRs.
Description:
We list the details of various objects that were searched for and
studied in this paper. The flux densities we report here are as
measured by the Very Large Array interferometer, and do not have
single-dish data added - hence they should be interpreted as lower
limits unless the objects are of small angular size. Table 2 contains
the properties of SNRs listed in Green's catalog of Galactic SNRs
(Green, 2019JApA...40...36G 2019JApA...40...36G, Cat. VII/284, G19). Tables 3 and 4 are
for newly identified and previously identified SNR candidates
respectively.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 160 94 *Green (2019, Cat. VII/284) SNRs identified in
the GLOSTAR-VLA images
table3.dat 157 80 *Newly identified SNR candidates in the
GLOSTAR-VLA data
table4.dat 189 77 *Previously identified SNR candidates with
counterparts in the GLOSTAR-VLA data
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Note on table2.dat, table3.dat, table4.dat: We note that the quoted Stokes I
flux densities should be considered as only lower limits due to missing short
spacing data (see sections 2.1 and 4.2.1 of the paper).
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See also:
VII/284 : A Catalogue of Galactic Supernova Remnants (Green, 2019)
J/A+A/627/A175 : GLOSTAR. Radio Source Catalogue I (Medina+ 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Name of the source
12- 18 F7.3 deg GLON [0.0/359.12] Galactic longitude
20- 25 F6.3 deg GLAT [-1.11/1.0] Galactic latitude
27- 30 F4.1 arcmin Radius [1.3/36.5] Radius of the circle encompassing
all emission of the source
32- 33 A2 --- Type Type of the source (G1)
35-106 A72 --- Remarks Some remarks on the source
108-115 F8.5 Jy Sint [0.0/5.78]? 5.8GHz integrated flux density
117-124 F8.5 Jy e_Sint [0.0/0.04]? Error in the 5.8GHz integrated
flux density
126-133 F8.5 Jy Lint [0.0/0.63]? 5.8GHz integrated linearly
polarized flux density
135-140 E6.1 Jy e_Lint [0.0/0.11]? Error in the 5.8GHz integrated
linearly polarized flux density
142-149 F8.5 --- p [0.0/0.43]? Degree of linear polarization
151-158 F8.5 --- e_p [0.0/0.11]? Error in the degree of linear
polarization
160 A1 --- l_p [Y] Linear polarization upper limit flag.
=Y if it is an upper limit.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Name of the source
16- 22 F7.3 deg GLON [1.94/359.18] Galactic longitude
24- 29 F6.3 deg GLAT [-0.98/0.82] Galactic latitude
31- 34 F4.1 arcmin Radius [1.0/27.0] Radius of the circle
encompassing all emission of the source
36- 37 A2 --- Type Type of the source (G1)
39-103 A65 --- Det-in Previous surveys in which the source
can be identified (2)
105-112 F8.5 Jy Sint [0.0/0.23]? 5.8GHz integrated flux
density
114-121 F8.5 Jy e_Sint [0.0/0.02]? Error in the 5.8GHz
integrated flux density
123-130 F8.5 Jy Lint [0.0/0.02]? 5.8GHz integrated linearly
polarized flux density
132-137 E6.1 Jy e_Lint [0.0/0.01]? Error in the 5.8GHz
integrated linearly polarized flux
density
139-146 F8.5 --- p [0.0/0.48]? Degree of linear polarization
148-155 F8.5 --- e_p [0.0/0.21]? Error in the degree of
linear polarization
157 A1 --- l_p [Y] Linear polarization upper limit flag
(=Y if it is an upper limit)
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Note (2): The candidates that have at least a faint counterpart in lower
frequency surveys have been marked as follows:
TV = 20cm THOR+VGPS
M20 = 20cm MAGPIS
M90 = 90cm MAGPIS
G150 = 150cm GLEAM
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Name of the source
17- 23 F7.3 deg GLON [3.1/359.56] Galactic longitude
25- 30 F6.3 deg GLAT [-0.86/0.9] Galactic latitude
32- 36 F5.2 arcmin Radius [0.6/20.0] Radius of the circle
encompassing all emission of the source
38- 39 A2 --- Type Type of the source (G1)
41-112 A72 --- Remarks Some remarks on the source
114-135 A22 --- Refs Previous studies on this object (2)
137-144 F8.5 Jy Sint [0.0/1.06]? 5.8GHz integrated flux density
146-153 F8.5 Jy e_Sint [0.0/0.02]? Error in the 5.8GHz
integrated flux density
155-162 F8.5 Jy Lint [0.0/0.09]? 5.8GHz integrated linearly
polarized flux density
164-169 E6.1 Jy e_Lint [0.0/0.02]? Error in the 5.8GHz
integrated linearly polarized flux density
171-178 F8.5 --- p [0.0/0.71]? Degree of linear polarization
180-187 F8.5 --- e_p [0.0/0.4]? Error in the degree of linear
polarization
189 A1 --- l_p [Y] Linear polarization upper limit flag
(=Y if it is an upper limit)
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Note (2): References are labeled as below:
1 = Gray, 1994MNRAS.270..847G 1994MNRAS.270..847G
2 = Trushkin, 2001ESASP.459..109T 2001ESASP.459..109T
3 = Brogan et al., 2006ApJ...639L..25B 2006ApJ...639L..25B
4 = Helfand et al., 2006AJ....131.2525H 2006AJ....131.2525H, Cat. J/AJ/131/2525
5 = Anderson et al., 2017A&A...605A..58A 2017A&A...605A..58A
6 = Hurley-Walker et al., 2019PASA...36...45H 2019PASA...36...45H
7 = Maxted et al., 2019ApJ...885..129M 2019ApJ...885..129M
8 = Bamba et al., 2003ApJ...589..253B 2003ApJ...589..253B
9 = Dokara et al., 2018ApJ...866...61D 2018ApJ...866...61D
10 = Hurley-Walker et al., 2019PASA...36...48H 2019PASA...36...48H
11 = Castelletti et al., 2017A&A...602A..31C 2017A&A...602A..31C, Cat. J/A+A/602/A31
12 = Petriella, 2019A&A...626A..65P 2019A&A...626A..65P
13 = Sidorin et al., 2014A&A...565A...6S 2014A&A...565A...6S
14 = Driessen et al., 2018ApJ...860..133D 2018ApJ...860..133D
15 = Supan et al., 2018A&A...616A..98S 2018A&A...616A..98S
16 = Larosa et al., 2000AJ....119..207L 2000AJ....119..207L
17 = Nakashima et al., 2010PASJ...62..971N 2010PASJ...62..971N
18 = Ponti et al., 2015MNRAS.453..172P 2015MNRAS.453..172P
19 = Marti et al., 2007A&A...462.1065M 2007A&A...462.1065M
* = Discussed in the text of this paper
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Global notes:
Note (G1): Type as follows (taken from Green, 2019, Cat. VII/284):
S = shell
S? = shell, uncertain
C = composite
C? = composite, uncertain
F = filled
F? = filled, uncertain
? = uncertain
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Acknowledgements:
Rohit Dokara, rdokara(at)mpifr-bonn.mpg.de
History:
22-Jul-2021: Original tables
16-Aug-2021: Updated tables (from author)
(End)