The Redshift-Distance Relation. I. Angular Diameter of First Ranked Cluster Galaxies as a Function of Redshift: the Aperture Correction to Magnitudes

view Abstract Citations (227) References (29) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Redshift-Distance Relation. I. Angular Diameter of First Ranked Cluster Galaxies as a Function of Redshift: the Aperture Correction to Magnitudes Sandage, Allan Abstract Micrometric estimates of the apparent angular diameters of first-ranked elliptical galaxies in clusters, obtained from a homogeneous series of plates taken with the Palomar 48-inch (122 cm) Schmidt and the Hale reflector, are tightly correlated with redshift, such that 0 z '. The cosmic dispersion about the mean correlation is a(A log 0) 0.07, which is close to `5 (AV), where AV is the deviation of apparent magnitude of these same galaxies from the Rubble diagram. This relation suggests constant mean surface brightness for first-ranked ellipticals, as does correlation of the individual magnitude and diameter residuals. The theoretical 0 = J(z, qo) relations derived for Friedmann models shows that qo may eventually be found from accurate microphotometry of such plates (or direct photoelectric area scanning). The predicted differences in the diameter function for various qo values are adequately large compared with the intrinsic dispersion (T(A log 0) for test galaxies at z > 0.4 to make such a program feasible. The growth curve of magnitude with measuring aperture is obtained from new photoelectric data listed in Papers II and III. The aperture correction follows from this formulation as a function of z and qo alone for first-ranked ellipticals. A method for differential correction of the aperture function is developed that takes account of cosmic differences in intrinsic diameters and different qo values Publication: The Astrophysical Journal Pub Date: May 1972 DOI: 10.1086/151440 Bibcode: 1972ApJ...173..485S full text sources ADS | data products NED (76) Related Materials (9) Part 2: 1972ApJ...178....1S Part 3: 1972ApJ...178...25S Part 4: 1973ApJ...180..687S Part 5: 1973ApJ...183..711S Part 6: 1973ApJ...183..731S Part 7: 1973ApJ...183..743S Part 8: 1975ApJ...202..563S Part 9: 1986ApJ...307....1S Part 10: 1987ApJ...317..557S