J/ApJS/177/255 GBT multiwavelength survey of Galactic center (Law+, 2008)
Green bank telescope multiwavelength survey of the Galactic Center region.
Law C.J., Yusef-Zadeh F., Cotton W.D., Maddalena R.J.
<Astrophys. J. Suppl. Ser., 177, 255-274 (2008)>
=2008ApJS..177..255L 2008ApJS..177..255L
ADC_Keywords: Radio sources ; Surveys
Keywords: Galaxy: center - radio continuum: general - surveys
Abstract:
We describe the results of a radio continuum survey of the central
4°x1° with the 100m Green Bank Telescope (GBT) at wavelengths
of 3.5, 6, 20, and 90cm. The 3.5 and 6cm surveys are the most
sensitive and highest resolution single-dish surveys made of the
central degrees of our Galaxy. We present catalogs of compact and
extended sources in the central 4° of our Galaxy, including
detailed spectral index studies of all sources. The analysis covers
star-forming regions such as Sgr B and Sgr C, where we find evidence
of a mixture of thermal and nonthermal emission. The analysis
quantifies the relative contribution of thermal and nonthermal
processes to the radio continuum flux density toward the Galactic
center (GC) region. In the central 4°x1° of the GC, the
thermal and nonthermal flux fractions for all compact and diffuse
sources are 28%/72% at 3.5cm and 19%/81% at 6cm. The total flux
densities from these sources are 783±52 and 1063±93Jy at 3.5 and
6cm, respectively, excluding the contribution of Galactic synchrotron
emission.
Description:
Observations were conducted over five days in August of 2002 for a
total observing time of 30hr.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
compact.dat 98 46 3.5cm compact source catalog for GC region and
6cm compact source catalog for GC region (table
2 (3.5cm) and table 3 (6cm) of the paper)
extended.dat 113 28 Extended source catalog for 3.5 and 6cm GBT
observations of GC region (table 5 of the paper)
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See also:
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 : Compact Galactic Center Radio Sources (Lazio+, 2008)
Byte-by-byte Description of file: compact.dat
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Bytes Format Units Label Explanations
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1- 3 A3 cm cm [3.5 6] Wavelength
7- 8 I2 --- [LYC2008] Number designation (G1)
10- 16 F7.3 deg GLON Galactic longitude
18- 23 F6.3 deg GLAT Galactic latitude
25- 26 I2 h RAh Hour of right ascension (J2000)
28- 29 I2 min RAm Minute of right ascension (J2000)
31- 35 F5.2 s RAs Second of right ascension (J2000)
37 A1 --- DE- Declination sign (J2000)
38- 39 I2 deg DEd Degree of declination (J2000)
41- 42 I2 arcmin DEm Arcminute of declination (J2000)
44- 47 F4.1 arcsec DEs Arcsecond of declination (J2000)
49- 53 F5.2 Jy Sp Source peak brightness at 3.5cm or 6cm
in Jansky/beam (1)
55- 60 E6.2 Jy e_Sp Error on Sp in Jansky/beam (1)
62- 66 F5.2 Jy Si Source flux density at 3.5cm or 6cm
68- 73 E6.2 Jy e_Si Error on Si
75- 79 F5.1 arcsec maj Major axis of the best-fit Gaussian to source
81- 85 F5.1 arcsec min Minor axis
87- 89 I3 deg PA Position angle
91- 95 F5.2 Jy SH92 ? Flux density at 3.5cm given in
Haynes et al. (1992A&A...264..500H 1992A&A...264..500H)
97- 98 I2 % e_SH92 ? Error on SH92
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Note (1): GBT beam FWHM at 3.5cm is 88" for table 2 and 153" at 6cm.
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Byte-by-byte Description of file: extended.dat
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Bytes Format Units Label Explanations
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1- 16 A16 --- Name Designation (G1)
17 A1 --- n_Name [ab] Thermal or non-thermal emission (1)
19- 24 F6.2 deg GLON Galactic longitude
26- 30 F5.2 deg GLAT Galactic latitude
32- 33 I2 h RAh Hour of right ascension (J2000)
35- 36 I2 min RAm Minute of right ascension (J2000)
38- 41 F4.1 s RAs Second of right ascension (J2000)
43 A1 --- DE- Declination sign (J2000)
44- 45 I2 deg DEd Degree of declination (J2000)
47- 48 I2 arcmin DEm Arcminute of declination (J2000)
50- 51 I2 arcsec DEs Arcsecond of declination (J2000)
53- 56 F4.1 arcmin Reff Effective radius
58- 63 F6.2 Jy S3.5r 3.5cm raw source flux density
64 A1 --- n_S3.5r [cd] Source included ion background (2)
66- 71 E6.2 Jy e_S3.5r rms uncertainty on S3.5r measured in a
background region in Jansky/beam
73- 79 F7.3 Jy S3.5i Background-subtracted flux density at 3.5cm
81- 85 F5.2 Jy e_S3.5i Error on S3.5i
87- 92 F6.2 Jy S6.0r 6cm raw source flux density
93 A1 --- n_S6.0r [cd] Source included ion background (2)
95-100 E6.2 Jy e_S6.0r rms uncertainty on S6.0r measured in a
background region in Jansky/beam
102-107 F6.2 Jy S6.0i Background-subtracted flux density at 6cm
109-113 F5.2 Jy e_S6.0i Error on FSi6
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Note (1): Flag as follows:
a = The "th" appended to the source name emphasizes that the source region
is defined for the thermal-emitting part of the complex.
b = The "nt" appended to the source name emphasizes that the source region
is defined for the nonthermal-emitting part of the complex.
Note (2): Flag as follows:
c = Flux includes Arched filaments extended source, which is subtracted
with the background.
d = Flux includes the Sgr B2 point source, which is subtracted with the
background.
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Global notes:
Note (G1): Designations in Simbad:
compact = <[LYC2008] 3.5cm NN> and <[LYC2008] 6cm NN>
extended = <[LYC2008] GLLL.l+B.b aa>.
History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 31-Aug-2009