J/ApJS/136/265 Monitoring compact radio sources at 2.5 + 8.2GHz (Lazio+, 2001)
A dual-frequency, multiyear monitoring program of compact radio sources.
Lazio T.J.W., Waltman E.B., Ghigo F.D., Fiedler R.L., Foster R.S.,
Johnston K.J.
<Astrophys. J. Suppl. Ser. 136, 265 (2001)>
=2001ApJS..136..265L 2001ApJS..136..265L
ADC_Keywords: Radio sources ; Redshifts
Keywords: radio continuum: general - scattering - surveys
Abstract:
We present light curves for 149 sources monitored with the Green Bank
Interferometer. The light curves are at two radio frequencies
(approximately 2.5 and 8.2GHz) and range from 3 to 15yr in length,
covering the interval 1979-1996, and have a typical sampling of one
flux density measurement every 2 days.
Observations were made on a 2.4km baseline. Dual circular
polarization was recorded over a 35MHz bandwidth at two frequencies
in the S and X frequency bands. Until 1989 August (1989.7), the
frequencies were 2.7GHz (S band) and 8.1GHz (X band); in 1989
September cryogenic receivers were installed, and the frequencies
changed to 2.25GHz (S band) and 8.3GHz (X band).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 168 149 Sources Monitored with the Green Bank Interferometer
gbi/* 78 149 Fluxes observed (time series)
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See also:
J/ApJS/128/17 : VLBA obs. of radio reference frame sources. III. (Fey+, 2000)
http://ese.nrl.navy.mil/GBI : Navy's Extragalactic Source Monitoring Program
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Source name (5)
10 A1 --- f_Name Name variation (5)
11- 13 I3 deg GLON Galactic longitude
15- 17 I3 deg GLAT Galactic latitude
19- 24 F6.1 yr Obs0 Start of the observation
26- 31 F6.1 yr Obs1 End of the observation
33- 37 F5.2 Jy S2GHz Mean 2.5GHz flux density (1)
39- 43 F5.2 Jy S8GHz Mean 8.2GHz flux density (1)
45- 48 A4 --- Type Source identification: Quasar (Q), Galaxy (G),
BL Lac object (BL), star (*)
50- 54 A5 --- SF Structure indices (3)
56- 60 F5.3 --- z ? Redshift
61 A1 --- u_z [?] Indicates an uncertain redshift
63- 66 F4.1 mag Vmag ? The apparent V band magnitude
68 A1 --- --- [i]
69- 70 I2 --- r_Name ? References for identification (4)
71 A1 --- --- [s]
72- 73 I2 --- r_S2GHz ? References for VLBI structure (4)
74 A1 --- --- [z]
75- 76 I2 --- r_z ? References for redshift (4)
77 A1 --- --- [m]
78- 79 I2 --- r_Vmag ? References for optical magnitude (4)
81-168 A88 --- AName Alternate name
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Note (1): Over the interval 1989.7-1994.
Note (3): Measure of how compact the source is on milliarcsecond scales
and defined by Charlot (1990AJ.....99.1309C 1990AJ.....99.1309C). A source with a
structure index of 1 is relatively compact, having 90% or more of its
flux density in a single component, while a structure index of 4
indicates a relatively extended source, typically having two or more
components of approximately equal flux density. Structure indices are
taken from Fey & Charlot (1997ApJS..111...95F 1997ApJS..111...95F) and Fey & Charlot
(2000, Cat. J/ApJS/128/17), who determined the structure indices
from the contribution of the sources' structures to interferometric
group delays in VLBI observations.
Note (4): References as follows:
0 = Condon et al. (1983AJ.....88...20C 1983AJ.....88...20C)
1 = Hewitt & Burbidge (1991ApJS...75..297H 1991ApJS...75..297H, Cat. VII/178)
2 = Hewitt & Burbidge (1993ApJS...87..451H 1993ApJS...87..451H, Cat. VII/158)
3 = Stickel & Kuhr (1994A&AS..103..349S 1994A&AS..103..349S, Cat. III/175)
4 = Stickel, Meisenheimer, Kuhr (1994, Cat. J/A+AS/105/211)
5 = Stickel & Kuhr (1996, Cat. J/A+AS/115/1)
6 = Drinkwater et al. (1996A&AS..115....1S 1996A&AS..115....1S, Cat. VIII/34)
7 = Fey & Charlot (1997ApJS..111...95F 1997ApJS..111...95F)
8 = Veron-Cetty & Veron (2000ESOSR..19....1V 2000ESOSR..19....1V, see cat. VII/224)
9 = Fey & Charlot (2000, Cat. J/ApJS/128/17)
10 = de Vries et al. (2000A&AS..143..181D 2000A&AS..143..181D)
11 = Spinrad et al. (1985, Cat. J/PASP/97/932)
12 = Zacharias et al. (1999AJ....118.2511Z 1999AJ....118.2511Z)
Note (5): 4 sources (marked with the '*') have a name slighlty different
in the sub-directory gdb. These names are flagged with an asterisk
in byte 10 (added at CDS) and concern:
1038+528A/1038+528 ; 1547+507/1547+508;
2007+777/2007+776 ; 2307+106/2307+107
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Byte-by-byte Description of file: gbi/*
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Bytes Format Units Label Explanations
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4- 12 F9.3 d MJD Epoch of observation (JD-2400000.0 or 2400000.5?)
15- 22 F8.3 yr Epoch Epoch of observation (Besselian year)
27- 32 F6.3 --- LHA Unexplained parameter
37- 42 F6.3 Jy S2GHz ?=-1 Flux observed at 2GHz
(2.7GHz before 1989.7, 2.25GHz after)
47- 52 F6.3 Jy S8GHz ?=-1 Flux observed at 8GHz
(8.1GHz before 1989.7, 8.3GHz after)
57- 62 F6.2 --- SI ?=-10 Spectral index between 2 and 8GHz
(S(ν)∝να
65- 70 F6.3 Jy e_S2GHz ?=0 Mean error on S2GHz
73- 78 F6.3 Jy e_S8GHz ?=0 Mean error on S8GHz
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History:
* 14-Jan-2002: From electronic version of the journal
* 01-Dec-2010: Added time series subdirectory,
from http://ese.nrl.navy.mil/GBI/
References:
Fiedler et al., Paper I 1987ApJS...65..319F 1987ApJS...65..319F
Waltman et al., 1991ApJS...77..379W 1991ApJS...77..379W
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 14-Jan-2002