VIII/8A Parkes High-Latitude H I Survey (Cleary+ 1979)
The Parkes High-Latitude H I Survey
Cleary M.N., Heiles C., and Haslam C.G.T.
<Astron. & Astrophys. Suppl., 36, 95 (1979)>
=1979A&AS...36...95C 1979A&AS...36...95C
ADC_Keywords: Radio sources ; Surveys ; Radio lines ; H I data
Description:
This survey consists of HI 21-cm spectra covering the southern sky
with absolute galactic latitude |b|≥10 degrees and declination
dec≤-30 degrees. The observations were made with the Parkes Radio
Observatory (CSIRO) 60-foot telescope. The receiver back end was the
Parkes 64-channel spectrometer. The velocity resolution was 7km/s
(33kHz) and the beamwidth (HPBW) was 48arcmin. Drift scans at constant
declination were used with continuous integration in right ascension
for -80≤declination≤-30 degrees. For declination←80 degrees a grid
of positions spaced 1 degree apart in declination and one beam-width
apart in right ascension were observed. The survey was made in two
parts. Part 1 included b≥-25 degrees, |b|≥10 degrees and declination
dec≤-30 degrees. Part 2 included b≤-25 degrees and dec≤-30 degrees.
The scans in Part 1 were spaced at 1 degree intervals in declination
and the velocity coverage was from -148 to +300km/s. The scans in Part
2 were spaced at 2 degrees and the velocity coverage was from -230 to
+218km/s. Each spectrum or record consists of a header followed by 64
antenna temperatures. The header contains the galactic longitude,
galactic latitude, right ascension, declination, central velocity
(LSR), and quality factor. The catalog contains a total of 9891
spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 420 9891 The southern sky 21cm survey data
software.for 80 459 Two Fortran main codes and several subroutines
lbmap.fit 2880 55 Velocity-integrated map of the whole plane
fits.dat 20 293 Summary of velocity/latitude maps
fits/* . 293 FITS maps of velocity/latitude
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Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 6 I6 0.001deg mGLON Galactic longitude in units of milli-degrees
7- 12 I6 0.001deg mGLAT Galactic latitude in units of milli-degrees
13- 14 I2 h RAh Right ascension (B1950)
15- 16 I2 min RAm RA in minutes
17- 18 I2 s RAs [0,60] RA in seconds
19 A1 --- DE- Sign of Declination
20- 21 I2 deg DEd Declination in degrees (B1950)
22- 23 I2 arcmin DEm DEC in arcminutes
24- 25 I2 arcsec DEs DEC in arcseconds
26- 32 I7 m/s Vo *Velocity if first measure (Local Standard of Rest)
33- 35 I3 --- Qual *Unexplained Quality factor
37-420 64I6 0.01K TA *Antenna temperature in each channel
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Note on Vo, TA:
The velocity Vo corresponds to the first cell of the TA array, and the
channels are separated by 33kHz (6.99km/s). The VLSRs of each channel
can also be computed by the following FORTRAN statements:
cvel = real(icv)/1000.
do i = 1,64
vlsr(i) = cvel + real(i-1)*6.99
enddo
Note on Qual:
The value does not seem to be correlated with the appearance of the
spectra, see the "History" section below.
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Byte-by-byte Description of file: fits.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- FITSfile Name of FITS file, in "fits" subdirectory
14 A1 --- NS [S] Galactic hemisphere (South)
16- 20 F5.1 deg GaLon Galactic longitude of map
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Brief description of software.for:
FORTRAN codes for use in extracting spectra from the H I surveys of
Heiles and Habing (VIII/7), this catalog (VIII/8), Argentina (VIII/9),
Bell Labs (VIII/10), and Weaver and Williams (VIII/11)
History:
* The catalog was received at ADC in 1992; a brief introduction
was added at CDS (Francois Ochsenbein).
* March 1977: A FITS version of the survey was derived at the
Astrophysics Data Facility (NASA/GSFC) from the original catalog of
spectra. Of the 9891 spectra in the catalog, 59 were rejected for
having spikes, ridges, or bad baselines. (The 'quality' flag in the
original catalog is undocumented and its value does not seem to be
correlated with the appearance of the spectra; it was ignored). The
remaining 9832 spectra were interpolated in frequency to a uniform
central velocity, then interpolated spatially onto a regular grid in
Galactic coordinates. For the latter interpolation, the cos(b)
corrections for longitude offsets were taken into account. Owing to
the sparse sampling, especially at high latitudes, interpolation over
several degrees was frequently required. The effective angular
resolution of the FITS maps varies from about 1 degree to at least 3
degrees. Latitude-velocity slices were written in FITS format for each
30 arcmin of longitude. Longitude ranges containing no spectra were
not written. A longitude- latitude map, integrated over all
velocities, was also written in FITS format to illustrate the coverage
of the individual latitude-velocity slices. Note that in many spectra
the emission extends beyond the velocity coverage of the spectrometer.
High-velocity emission, in particular parts of the Magellanic Stream,
may have been missed in the observations; see Mathewson et al.
(1974ApJ...190..291M 1974ApJ...190..291M and 1977ApJ...217L...5M 1977ApJ...217L...5M).
* November 2003: this ReadMe file was completed with the description
of the catalog (Francois Ochsenbein, CDS)
Acknowledgements:
The General Information on High-latitude 21-cm Line Surveys by Carl
Heiles (1988), University of California, Berkeley was used to create
this ReadMe file.
References:
Mathewson, D. S., Cleary, M. N., and Murray, J. D. 1974, ApJ, 190, 291
Mathewson, D. S., Schwarz, M. P., and Murray, J. D. 1977, ApJ, 217, L5
(End) Seth Digel & C.-H. Joseph Lyu [Hughes STX/NASA] 24-Mar-1997