The Frequency of Barred Spiral Galaxies in the Near-IR

Paul B. Eskridge, Jay A. Frogel, Richard W. Pogge, Alice C. Quillen, Roger L. Davies, D. L. DePoy, Mark L. Houdashelt, Leslie E. Kuchinski, Solange V. Ramirez, K. Sellgren, Donald M. Terndrup, Glenn P. Tiede

Published 1999-10-26Version 1

We have determined the fraction of barred galaxies in the H-band for a statistically well-defined sample of 186 spirals drawn from the Ohio State University Bright Spiral Galaxy survey. We find 56% of our sample to be strongly barred at H, while another 16% is weakly barred. Only 27% of our sample is unbarred in the near-infrared. The RC3 and the Carnegie Atlas of Galaxies both classify only about 30% of our sample as strongly barred. Thus strong bars are nearly twice as prevalent in the near-infrared as in the optical. The frequency of genuine optically hidden bars is significant, but lower than many claims in the literature: 40% of the galaxies in our sample that are classified as unbarred in the RC3 show evidence for a bar in the H-band, while for the Carnegie Atlas this fraction is 66%. Our data reveal no significant trend in bar fraction as a function of morphology in either the optical or H-band. Optical surveys of high redshift galaxies may be strongly biased against finding bars, as bars are increasingly difficult to detect at bluer rest wavelengths.