NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-17 T10:16:25 PDT
Help | Comment | NED Home

For refcode 1995MNRAS.274..769M:
Retrieve 155 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by Royal Astronomical Society. 1995MNRAS.274..769M CCD galaxy photometry and the calibration of photographic surveys N. Metcalfe, R. Fong and T. Shanks Physics Department, University of Durham, South Road, Durham DHl 3LE Accepted 1994 December 22. Received 1994 November 12; in original form 1994 February 28 ABSTRACT We present CCD UBVRI aperture photometry and total B-band magnitudes for a sample of 155 galaxies with B <~ 18 covering 14 UK Schmidt fields. The data, taken on a variety of telescopes, have been acquired in order to calibrate photographic photometry on these fields. Using these data, we discuss the calibration of photographic galaxy surveys at these magnitudes, and show that the accuracy of such photometry is potentially better than +/-0.05 mag. However, data from both the COSMOS and APM automatic plate measuring machines show strong surface-brightness- dependent systematic errors, which primarily manifest themselves as a much increased scatter (~ +/-0:25 mag). The cause of these effects is almost certainly related to the limited dynamic range of the automated machines. They have the potential to introduce scale errors of up to ~0.1 mag per magnitude into the photographic magnitudes, and we discuss the implications of this for bright galaxy number-magnitude counts. We show evidence for a scale error in the APM galaxy survey magnitudes. Our revised APM magnitudes allow a standard, non-evolving cosmological model to fit the APM galaxy counts in the range 17 < B < 20, although this model continues to overpredict the galaxy count at brighter magnitudes. Key words: methods: data analysis - surveys - galaxies: evolution - galaxies: photometry - cosmology: miscellaneous.
Retrieve 155 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home