J/A+A/642/A136 Sources detected at 325 and 610 MHz in Cygnus (Benaglia+ 2020)
Cygnus survey with the Giant Metrewave Radio Telescope at 325 and 610 MHz:
the catalog.
Benaglia P., Ishwara-Chandra C.H., Intema H., Colazo M.E., Gaikwad M.
<Astron. Astrophys. 642, A136 (2020)>
=2020A&A...642A.136B 2020A&A...642A.136B (SIMBAD/NED BibCode)
ADC_Keywords: Radio continuum ; Radio sources ; Regional catalog
Keywords: catalogs - radio continuum: general -
open clusters and associations: individual: Cyg OB2 -
open clusters and associations: individual: Cyg OB8 -
open clusters and associations: individual: Cyg OB9
Abstract:
Observations at the radio continuum band below the gigahertz band are
key when the nature and properties of non-thermal sources are
investigated because their radio radiation is strongest at these
frequencies. The low radio frequency range is therefore the best to
spot possible counterparts to very high-energy (VHE) sources:
relativistic particles of the same population are likely to be involved
in radio and high-energy radiation processes. Some of these
counterparts to VHE sources can be stellar sources.
The Cygnus region in the northern sky is one of the richest in this
type of sources that are potential counterparts to VHEsources. We
surveyed the central ∼15 sq deg of the Cygnus constellation at the
325 and 610MHz bands with angular resolutions and sensitivities of
10" and 6", and 0.5 and 0.2mJy/beam, respectively.
The data were collected during 172 hours in 2013-2017, using the
Giant Metrewave Radio Telescope (GMRT) with 32MHz bandwidth, and were
calibrated using the SPAM routines. The source extraction was carried
out with the PyBDSF tool,followed by verification through visual
inspection of every putative catalog candidate source in order to
determine its reliability.
In this first paper we present the catalog of sources, consisting of
1048 sources at 325MHz and 2796 sources at 610MHz. By cross-matching
the sources from both frequencies with the objects of the SIMBAD
database, we found possible counterparts for 143 of them. Most of the
sources from the 325MHz catalog (993) were detected at the 610MHz
band, and their spectral index alpha was computed adopting
S(nu)∝nualpha. The maximum of the spectral index
distribution is at alpha=-1, which is characteristic of
non-thermal emitters and might indicate an extragalactic population.
Description:
Position, sizes and radio fluxes of 1048 sources detected at 325MHz
and 2796 sources detected at 610MHz, in the central part of Cygnus,
and spectral index values for 993 of them.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 122 1048 Detected sources at 325MHz above 7sigma
table4.dat 122 2796 Detected sources at 610MHz above 7sigma
table5.dat 87 993 Spectral index of sources detected at both bands
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See also:
J/AJ/107/1433 : Cygnus OB2 polarimetry (Kobulnicky+, 1994)
J/ApJ/643/238 : Chandra/2MASS sources in Cygnus OB2 (Butt+, 2006)
J/A+A/464/211 : Cyg OB2 Chandra and near-IR obs. (Albacete Colombo+, 2007)
J/A+A/472/557 : Cygnus OB2 region 610MHz sources (Marti+, 2007)
J/ApJS/184/84 : X-ray sources in Cyg OB2 region (Wright+, 2009)
J/ApJ/713/871 : X-ray sources in star-forming region Cyg-OB2 (Wright+, 2012)
J/ApJS/202/19 : riz photometry in Cyg OB2 (Guarcello+, 2012)
J/MNRAS/460/2593 : Cygnus OB2 DANCe: Proper motion study (Wright+, 2016)
J/A+A/603/A106 : Rotational periods in Cygnus OB2 (Roquette+, 2017)
J/A+A/612/A50 : New massive members of Cygnus OB2 (Berlanas+, 2018)
J/MNRAS/484/1838 : Spatial substructure of Cygnus OB2 (Berlanas+, 2019)
J/A+A/637/A64 : Cygnus OB2 e-MERLIN 21cm survey (COBRaS) (Morford+, 2020)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Source325 Source Designation for 325MHz, BIC325-NNNN
13- 14 I2 h RAh Right ascension (J2000)
16- 17 I2 min RAm Right ascension (J2000)
19- 23 F5.2 s RAs Right ascension (J2000)
25- 31 F7.3 arcsec e_RAs Error on RAs
32 A1 --- DE- Declination sign (J2000)
33- 34 I2 deg DEd Declination (J2000)
36- 37 I2 arcmin DEm Declination (J2000)
39- 43 F5.2 arcsec DEs Declination (J2000)
45- 51 F7.2 arcsec e_DEs Error on DEs
53- 58 F6.1 mJy FTot Integrated flux at 325MHz
60- 65 F6.2 mJy e_FTot Error on integrated flux at 325MHz
67- 72 F6.1 mJy/beam FPeak Peak flux at 325MHz
74- 79 F6.2 mJy/beam e_FPeak Error on peak flux at 325MHz
81- 86 F6.1 arcsec Maj Major axis at 325MHz
88- 93 F6.2 arcsec e_Maj Error on major axis at 325MHz
95-100 F6.1 arcsec Min Minor axis at 325MHz
102-107 F6.2 arcsec e_Min Error on minor axis at 325MHz
109-115 F7.1 deg PA Position angle at 325MHz
117-122 F6.2 deg e_PA Error on position angle at 325MHz
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Source610 Source Designation for 610MHz, BIC610-NNNN
13- 14 I2 h RAh Right ascension (J2000)
16- 17 I2 min RAm Right ascension (J2000)
19- 23 F5.2 s RAs Right ascension (J2000)
25- 31 F7.3 arcsec e_RAs Error on RAs
32 A1 --- DE- Declination sign (J2000)
33- 34 I2 deg DEd Declination (J2000)
36- 37 I2 arcmin DEm Declination (J2000)
39- 43 F5.2 arcsec DEs Declination (J2000)
45- 51 F7.2 arcsec e_DEs Error on DEs
53- 58 F6.1 mJy FTot Integrated flux at 610MHz
60- 65 F6.2 mJy e_FTot Error on integrated flux at 610MHz
67- 72 F6.1 mJy/beam FPeak Peak flux at 610MHz
74- 79 F6.2 mJy/beam e_FPeak Error on peak flux at 610MHz
81- 86 F6.1 arcsec Maj Major axis at 610MHz
88- 93 F6.2 arcsec e_Maj Error on major axis at 610MHz
95-100 F6.1 arcsec Min Minor axis at 610MHz
102-107 F6.2 arcsec e_Min Error on minor axis at 610MHz
109-115 F7.1 deg PA Position angle at 610MHz
117-122 F6.2 deg e_PA Error on position angle at 610MHz
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Source325 Source Designation for 325MHz, BIC325-NNNN
13- 14 I2 h RAh Right Ascension (J2000)
16- 17 I2 min RAm Right Ascension (J2000)
19- 23 F5.2 s RAs Right Ascension (J2000)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 35 F5.2 arcsec DEs Declination (J2000)
37- 71 A35 --- Source610 Source Designation(s) for 610MHz,
BIC610-NNNN
73- 79 F7.1 --- Sp+Index Spectral index 325/610
81- 87 F7.2 --- e_Sp+Index Error on Spectral index
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Acknowledgements:
Paula Benaglia, paula(at)iar-conicet.gov.ar
(End) Paula Benaglia [IAR, Argentina], Patricia Vannier [CDS] 03-Sep-2020