ADC/CDS Standard Document for Catalog:
/journal_tables/AJ/105/393/

1. Use the ADC Data Viewer Suite to visualize the data.
2. Get the data files via anonymous FTP. (See Note.)

J/AJ/105/393      Small Drift Scan Survey Galaxies Northern Sky (Kent+ 1993)
================================================================================
A Small Drift Scan Survey for Galaxies in the Northern Sky
      Kent S.M., Ramella M., Nonino M.
     <Astron. J. 105, 393 (1993)>
     =1993AJ....105..393K
===============================================================================
ADC_Keywords: Galaxy catalogs ; Magnitudes ; Selected areas

Abstract:
  The file is an ASCII text file containing data for 1053 galaxies
  brighter than 18.0 mag. in the filter used. The effective wavelength
  of this filter for objects that have the color of galaxies closely
  matches that of Thuan and Gunn r filter. The strip covered in the
  survey is 12 arcmin wide by 60 degree long. The observations were
  carried out on the night of 23 May 1990, using the drift scanning
  technique, with the 24 inch telescope of the Whipple Observatory.
  The effective integration time was 57 s.

Introduction:
  One key problem of galaxy surveys using photographic plates is an
  accurate magnitude calibration. Moreover sensitivity and vignetting
  variations across the plate, need to be removed. The drift-scan
  technique is a viable alternative: in this observing mode the
  telescope tracking is stopped and the CCD is clocked at the sidereal
  rate. CCD columns are aligned in the east-west direction. The CCD is
  read continuously, building up an image of a strip of the sky.

  Data were reduced in the standard manner, but replacing bias with
  drift dark (CCD is operating in drift scan mode with the shutter
  closed). Flatfields were  obtained from median averaging sets of data
  frames. Astrometry was done using stars whose position was known from
  the Guide Star Catalog. The galaxy-star classification was done using
  the east-west FWHM. Then every candidate galaxy was visually
  inspected.

Important Notice:
  The published coordinates have errors (up to 6" in the worst case):
  this is due to a charge smearing problem, which correlates with
  magnitude. The coordinates in this version are the corrected ones.

File Summary:
-------------------------------------------------------------------------------
 FileName     Lrecl      Records        Explanations
------------------------------------------------------------------------------
ReadMe           80             .        This file
table.dat        42          1053       *The galaxy catalog
-------------------------------------------------------------------------------
Note on table.dat: Galaxy number 357 has been removed in the
     electronic table.
-------------------------------------------------------------------------------

Byte-by-byte Description of file: table.dat
--------------------------------------------------------------------------------
   Bytes Format Units   Label     Explanations
--------------------------------------------------------------------------------
   1-  4  I4    ---     ID       *[1/1054]+ Number as in the published version
   6-  7  I2    h       RAh       [11/16]+= 1950 Right Ascension
   9- 10  I2    min     RAm       1950 Right Ascension  minutes
  12- 17  F6.3  s       RAs       1950 Right Ascension  seconds
  20- 21  I2    deg     DEd       [29/29] 1950 Declination degrees
  23- 24  I2    arcmin  DEm       1950 Declination minutes of arc
  26- 30  F5.2  arcsec  DEs       1950 Declination seconds of arc
  32- 36  F5.2  mag     Mag       Magnitude
      37  A1    ---     u_Mag     Uncertainty Flag on Magnitude
  38- 42  F5.1  arcsec  Ap        Aperture radius used to compute Mag
--------------------------------------------------------------------------------
Note on ID: the galaxy number 357 is missing in the electronic table:
            galaxies 357 and 358 seem identical in the printed table.
--------------------------------------------------------------------------------

History:
  * July 1994: the first version was prepared by N. Paul. M. Kuin [NSSDC/ADC]
    and M. Nonino [Trieste].
  * December 1996: the ID number was added at CDS (P. Dubois)


Acknowledgements:
 This work has been supported by NSF Grant No. AST 8451724, Nato Grant No.
 CRG 901016, and a donation from the Digital Equipment Corporation
================================================================================
(End)         N. Paul. M. Kuin [NSSDC/ADC] and M. Nonino [Trieste]   05-Dec-1996