J/MNRAS/229/589 Interplanetary Scintillation Survey at 81.5 MHz (Purvis+ 1987)
The Cambridge IPS Survey at 81.5 MHz
Purvis A., Tappin S.J., Rees W.G., Hewish A., Duffett-Smith P.J.
<Mon. Not. R. Astron. Soc. 229, 589 (1987)>
=1987MNRAS.229..589P 1987MNRAS.229..589P
ADC_Keywords: Radio sources; Pulsars; Galaxies, radio; QSOs
Description:
A catalog of 1789 radio sources which exhibit interplanetary
scintillation (IPS) at 81.5 MHz is presented. The angular diameters of
scintillating components in the range 0.2-2 arcsec are listed together
with values of the scintillating flux density at a solar elongation of
90 deg. IPS selects those sources which are highly compact, such as
pulsars and some unusual extragalactic sources, or those in which
energy is being released from active beams in the outer lobes of
intrinsically powerful radio galaxies and quasars.
The survey was made with the 3.6-hectare array at Cambridge and covers
the area of sky between declinations -10 deg and +83 deg at all values
of right ascension. The array was operated as a north-south
phase-switching interferometer observing sources near meridian
transit. Sixteen declination beams were produced covering the observed
declination range. The half-power width of a declination beam is 5.5
sec(52.16-DEC) degrees, where DEC is the declination of peak beam
response. The half-power beam width in right ascension is 107
sec(delta) s for a source at declination delta. The faintest sources
in the catalogue have scintillating flux densities of about 0.3 Jy rms
at a solar elongation of 90 deg, and total flux densities of about 5
Jy at 81.5 MHz. The sensitivity of the survey is not uniform over the
sky, being determined largely by the galactic background emission. The
flux density corresponding to one source per beam area in this survey
is about 2.3 Jy at 81.5 MHz so that confusion errors are likely to be
significant for total flux density S ≤ 20 Jy.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 128 1789 List of 1789 scintillating radio sources
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Source Name
11- 12 I2 h RAh Right Ascension (1950)
14- 15 I2 min RAm Right Ascension (1950)
17- 18 I2 s RAs Right Ascension (1950) (1)
21 A1 --- DE- ?Declination sign (1950)
22- 23 I2 deg DEd Declination (1950)
25- 26 I2 arcmin DEm Declination (1950)
28 A1 --- n_DEd Note on declination (2)
30- 35 F6.2 Jy dS_90 Scintillating flux density at solar elongation
of 90 degrees (3)
38- 42 F5.2 arcsec Diam ?Angular diameter (4)
45- 48 F4.2 arcsec Dmin ?One sigma error limit on Diam
50- 53 F4.2 arcsec Dmax ?One sigma error limit on Diam
55 A1 --- n_Diam ?Note on Diam (5)
59- 62 F4.1 Jy Sc ?Compact flux density for scintillating
component (4)
65- 68 F4.1 Jy Sc_min ?One sigma error limit on Sc
69- 73 F5.1 Jy Sc_max ?One sigma error limit on Sc
79-128 A50 --- Ident ?Possible contributing sources (6)
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Note (1): Correct within ± 5 s of time.
Note (2): I: determined by computer algorithm, typical error 30 arcmin.
H: determined by hand, typical error 30 arcmin.
C: source is confused, central declination of the beam is listed,
error ∼1/2 of declination beamwidth.
N: insufficient data to determine declination, central declination
of the beam is listed, error ∼1 declination beamwidth.
B: adjacent beam record apparently contradictory, central declination
of the beam is listed, error ∼1/2 of declination beamwidth.
Note (3): The median scintillating flux density in the elongation range 80-100
degrees. Scintillating flux density is the rms variation of total
flux density.
Note (4): Derived by fitting theoretical curves from the model of Readhead
et al. (1978MNRAS.185..207R 1978MNRAS.185..207R) to the data between elongations 40 and
90 degrees.
Note (5): +: Estimate of Diam is not reliable because data is sparse.
S: Very sparse data, Diam value not given.
P: Pulsar like curve, Diam value not given.
H: High ecliptic latitude source, Diam value not given.
Note (6): The antenna pattern was too broad for reliable identifications in
most cases, so several possible contributing sources may be listed.
^1 following a source name indicates it makes only a minor
contribution to the measured signal.
^2 indicates confusion by a system artefact.
* indicates a 4C source for which positional agreement would be
improved by lobe shifting.
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History:
An electronic version of the data table was obtained from
http://www.mrao.cam.ac.uk/surveys/ips/index.html .
H. Andernach informed ADC of minor differences between the MRAO web
version and the published version of the data table. The version here
is in agreement with the published version.
(End) N. Odegard [SSDOO/ADC] 01-Nov-1999