Access to Astronomical Catalogues

B/merlin           The MERLIN Archive                  (MERLIN 1992-)
The MERLIN Achive
    MERLIN Staff
   <MERLIN/VLBI National Facility, JBO, University of Manchester, UK. (1992-)>
ADC_Keywords: Observatory log ; Radio sources


Description:
    This database contains a log of MERLIN archive data since 1992 which
    have been partially reduced and are electronically available. It is
    managed and updated by the MERLIN staff. All data are taken using a
    single IF and correlated using 2-bit digitisation.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
merlin.dat       369     3839   Log of MERLIN archive data


See also:
  http://www.merlin.ac.uk/archive/ : for more information and for the
  full list of sources observed but not yet electronically archived.


Byte-by-byte Description of file: merlin.dat

   Bytes Format  Units   Label       Explanations

   1-  2  I2     h       RAh         Pointing position R.A. J2000 (hr)
   4-  5  I2     min     RAm         Pointing position R.A. J2000 (min)
   7- 15  F9.6   s       RAs         Pointing position R.A. J2000 (sec)
      17  A1     ---     DE-         Pointing position Dec. J2000 (sign)
  18- 19  I2     deg     DEd         Pointing position Dec. J2000 (degrees)
  21- 22  I2     arcmin  DEm         Pointing position Dec. J2000 (arcmin)
  24- 31  F8.5   arcsec  DEs         Pointing position Dec. J2000 (arcsec)
  33- 49  A17    ---     Name        Source name
  51- 68  A18    ---     Observ      Observatory Name
  70- 87  A18    ---     Station     Antennas potentially present (1)
  89- 98  A10    ---     DataID      Data processing block ID
 100-103  I4     yr      begDATE.Y   Block start date (year) (2)
 104-105  I2     "month" begDATE.M   Block start date (month) (2)
 106-107  I2     d       begDATE.D   Block start date (day) (2)
 109-112  I4     yr      endDATE.Y   Block end date (year) (2)
 113-114  I2     "month" endDATE.M   Block end date (month) (2)
 115-116  I2     d       endDATE.D   Block end date (day) (2)
 118-127  F10.3  MHz     Freq        Frequency in central channel (3)
 129-136  F8.6   MHz     Chanwidth   Channel width in raw data
 138-143  F6.3   MHz     Bandwidth   Bandwidth of raw data
 145-152  A8     ---     Stokes      Polarisation products potentially available
 154-159  F6.4   mas     pixRA       Pixel size in R.A. direction (4)
 161-166  F6.4   mas     pixDE       Pixel size in Dec. direction (4)
 168-175  I8     ---     Nvisib      Number of visibilities on source
 177-184  A8     ---     Type        Source type (5)
 186-202  A17    ---     Assoc       Associated source(5)
 204-210  A7     ---     AssocType   Associated source type (5)
 212-224  A13    ---     AMPCAL      Amplitude calibration source
 226-234  F9.3   Jy      AmpFlux     Flux density assigned to AMPCAL (6)
 236-247  A12    ---     PropID      Proposal code
 249-278  A30    ---     PIname      Principle Investigator
 280-359  A80    ---     Comments    Factors affecting data quality
 361-369  I9     ---     DataNo      Link to MERLIN Archive web page
                                      for more details.

Note (1): Two-letter codes for antennas present for all or part of the block.

Note (2): Each source was observed for one or more periods during this block.

Note (3): If the LSR correction is applied FREQ is in the source rest-frame.

Note (4): The pixel size is chosen during mapping and can be changed.
          Resolution is determined by the beam size and signal-to-noise ratio.
Note (5): Source type can be
          TARGET,
          PHICAL (phase calibration source),
          TARX (non-phase-referenced target),
          AMPCAL (amplitude calibration source),
          POLCAL (polarisation calibration source) or
          PACAL (polarisation angle calibration source).
Note (6): The AMPCAL flux on MERLIN scales is derived wrt 3C286 (Baars 1977).



History:
  This file is updated as more MERLIN archive data becomes available on-line.

Acknowledgements:
  We warmly thank the CDS staff for assistance in making these data accessible.
(End)            Anita M. S. Richards [JBO]                          14-Oct-2002