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
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:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 128 1789 List of 1789 scintillating radio sources
Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
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)
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) 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.
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
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