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J/ApJS/177/515     6cm and 20cm survey of Galactic Center           (Law+, 2008)

A wide-area VLA continuum survey near the galactic center at 6 and 20 cm wavelengths. Law C.J., Yusef-Zadeh F., Cotton W.D. <Astrophys. J. Suppl. Ser., 177, 515-545 (2008)> =2008ApJS..177..515L
ADC_Keywords: Radio continuum ; Surveys ; Radio sources Keywords: Galaxy: center - radio continuum: general - surveys Abstract: We describe the results of a millijansky sensitivity VLA survey of roughly 1deg2 near the Galactic center at 6 and 20cm. Catalogs of compact and filamentary structures are given and compared to previous surveys of the region. Eight of the unusual nonthermal radio filaments are detected in 6cm polarized emission; three of these are the first such detections, confirming their nonthermal nature. This survey found emission from a filament at (l,b)=(359.1,0.75), or a projected distance from Sgr A* of 200pc, greatly extending the latitude range observed with such features. There is also new evidence for spatial gradients in the 6/20cm spectral indices of some filaments, and we discuss models for these gradients. In studying compact sources, the combination of spectral index and polarization information allows us to identify pulsar candidates and compact HII regions in the survey. There is also some evidence that the flux measurements of compact sources may be affected by electron scattering from the interstellar medium in the central few hundred parsecs of the Galaxy. Description: Observations with the Very Large Array (VLA) at 6cm (2004 June) and 20cm (2004 January-August) were designed to have similar sensitivities, resolutions, and uv coverage, allowing unbiased spectral index measurements to be made. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table4.dat 63 93 *Compact sources in 6cm survey table5.dat 63 48 *Compact sources in 20cm survey table67.dat 59 9 Point sources with 6 and 20cm polarization (table 6 and 7 of the paper) table8.dat 58 33 *Compact sources in both 6 and 20cm catalogs table9.dat 28 60 Compact sources in 6cm catalog only match.dat 66 35 Sources matching other catalogs
Note on table4.dat: Sources have greater than 5σ peak brightness significance according to SFIND and better than ∼3σ confidence according to the AIPS SAD/JMFIT routines. Note on table5.dat: Sources have greater than 5σ peak brightness significance according to the AIPS SAD/JMFIT routines. Note on table8.dat: Comparing all sources with greater than 3σ confidence according to the AIPS SAD/JMFIT routines.
See also: J/ApJS/91/347 : A 5-GHz VLA Survey of the Galactic Plane (Becker+ 1994) J/ApJS/118/201 : Galactic Center 6 and 20cm survey (Lazio+, 1998) J/ApJS/155/421 : Survey of Galactic Center region at 20cm (Yusef-Zadeh+, 2004) J/ApJS/174/481 : 2LC Compact Radio Sources in the galactic center (Lazio+ 2008) Byte-by-byte Description of file: table[45].dat
Bytes Format Units Label Explanations
1- 2 I2 h RAh Hour of right ascension (J2000) (1) 4- 5 I2 min RAm Minute of right ascension (J2000) 7- 11 F5.2 s RAs Second of right ascension (J2000) 13 A1 --- DE- Declination sign (J2000) (1) 14- 15 I2 deg DEd Degree of declination (J2000) 17- 18 I2 arcmin DEm Arcminute of declination (J2000) 20- 23 F4.1 arcsec DEs Arcsecond of declination (J2000) 25- 29 F5.2 mJy Fp Peak flux in mJy/beam at 6 or 20cm 30 A1 --- f_Fp [b] Assumed source size (G2) 32- 35 F4.2 mJy e_Fp Error on peak flux in mJy/beam 37- 42 F6.2 mJy FSi Integrated flux 44- 47 F4.2 mJy e_FSi Error on FSi at 6 or 20cm 49- 52 F4.1 arcsec Maj Major axis of the source 54- 57 F4.1 arcsec Min Minor axis of the source 59- 63 F5.1 deg PA [-180/180] Position angle of the source (3)
Note (1): Position of 6cm sources for table 4 and 20cm sources for table 5. Note (3): Position angle increases to the east from celestial north.
Byte-by-byte Description of file: table67.dat
Bytes Format Units Label Explanations
1- 2 I2 h RAh Hour of right ascension (J2000) 4- 5 I2 min RAm Minute of right ascension (J2000) 7- 11 F5.2 s RAs Second of right ascension (J2000) 13 A1 --- DE- Declination sign (J2000) 14- 15 I2 deg DEd Degree of declination (J2000) 17- 18 I2 arcmin DEm Arcminute of declination (J2000) 20- 23 F4.1 arcsec DEs Arcsecond of declination (J2000) 25- 26 I2 cm cm Wavelength (6 or 20) 28- 32 F5.1 mJy FSi Integrated flux at 6 or 20cm 34- 36 F3.1 mJy e_FSi Error on FSi 38- 41 F4.1 mJy FPSi Integrated polarized flux at 6 or 20cm 42 A1 --- f_FPSi [b] Assumed source size (G2) 44- 47 F4.2 mJy e_FPSi Error on FPSi 49- 53 F5.3 --- Fpol Polarization fraction 55- 59 F5.3 --- e_Fpol Error on Fpol
Byte-by-byte Description of file: table8.dat
Bytes Format Units Label Explanations
1- 2 I2 h RAh 6cm source hour of right ascension (J2000) 4- 5 I2 min RAm 6cm source minute of right ascension (J2000) 7- 11 F5.2 s RAs 6cm source second of right ascension (J2000) 13 A1 --- DE- 6cm source declination sign (J2000) 14- 15 I2 deg DEd 6cm source degree of declination (J2000) 17- 18 I2 arcmin DEm 6cm source arcminute of declination (J2000) 20- 23 F4.1 arcsec DEs 6cm source arcsecond of declination (J2000) 25- 26 I2 h RA2h 20cm source hour of right ascension (J2000) 28- 29 I2 min RA2m 20cm source minute of right ascension (J2000) 31- 35 F5.2 s RA2s 20cm source second of right ascension (J2000) 37 A1 --- DE2- 20cm source declination sign (J2000) 38- 39 I2 deg DE2d 20cm source degree of declination (J2000) 41- 42 I2 arcmin DE2m 20cm source arcminute of declination (J2000) 44- 47 F4.1 arcsec DE2s 20cm source arcsecond of declination (J2000) 49- 53 F5.2 --- alpha 6/20cm spectral index from the integrated flux of the source (G1) 55- 58 F4.2 --- e_alpha Error on 6/20cm spectral index
Byte-by-byte Description of file: table9.dat
Bytes Format Units Label Explanations
1- 2 I2 h RAh 6cm source hour of right ascension (J2000) 4- 5 I2 min RAm 6cm source minute of right ascension (J2000) 7- 11 F5.2 s RAs 6cm source second of right ascension (J2000) 13 A1 --- DE- 6cm source declination sign (J2000) 14- 15 I2 deg DEd 6cm source degree of declination (J2000) 17- 18 I2 arcmin DEm 6cm source arcminute of declination (J2000) 20- 23 F4.1 arcsec DEs 6cm source arcsecond of declination (J2000) 25- 28 F4.1 --- alpha Limit on the 6/20cm spectral index (G1)
Byte-by-byte Description of file: match.dat
Bytes Format Units Label Explanations
1- 2 I2 h RAh Hour of right ascension (J2000) (1) 4- 5 I2 min RAm Minute of right ascension (J2000) 7- 11 F5.2 s RAs Second of right ascension (J2000) 12 A1 --- D [a] two sources unresolved in Becker et al. (1994, Cat. J/ApJS/91/347) 13 A1 --- DE- Declination sign (J2000) (1) 14- 15 I2 deg DEd Degree of declination (J2000) 17- 18 I2 arcmin DEm Arcminute of declination (J2000) 20- 23 F4.1 arcsec DEs Arcsecond of declination (J2000) 25- 29 F5.1 mJy FSi Integrated flux at 6 or 20cm (1) 31- 33 F3.1 mJy e_FSi Error on FSi 35- 36 I2 --- Ref Number of original table in the paper (2) 38- 50 A13 --- Name Previous name of the source in the catalog from Ref 52- 56 F5.1 mJy FS Integrated flux at 6 or 20cm from Ref 58- 60 F3.1 mJy e_FS ? Error on FS 62- 66 F5.1 mJy FS1281 ? Integrated flux measured in the second band from Ref
Note (1): Position and integrated fluxes of the 6cm sources for ref=12, 20cm sources otherwise. Note (2): References as follows: 10 = 20cm source matching the Catalog of Paper I (Yusef-Zadeh et al. 2004, Cat. J/ApJS/155/421 ; <[YHC2004] GLLL.ll+B.bb> in Simbad) 11 = 20cm source matching the Catalog of Lazio & Cordes (1998, Cat. J/ApJS/118/201 ; <1LC LLL.lll+B.bbb> in Simbad) ; integrated fluxes are measured in two bands near 20cm: 1658 and 1281MHz. 12 = 6cm source matching the Catalog of Becker et al. (1994, Cat. J/ApJS/91/347 ; <GPSR5 LLL.lll+B.bbb> in Simbad)
Global Notes: Note (G1): The spectral index α assumes Sν∝να. Note (G2): b = Source parameters found by fixing the source size to the beam size of 14" by 9". This assumption may result in the peak brightness being overestimated by about 50%.
Nomenclature note: Tables 4-5: <[LYC2008b] JHHMMSS.ss+DDMMSS.s> in Simbad. History: From electronic version of the journal
(End) Emmanuelle Perret [CDS] 10-Sep-2009
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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