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We use a gravitational bar torque method to compare bar strengths (the maximum tangential force normalized by radial force) in B and H-band images of 152 galaxies from the Ohio State University Bright Spiral Galaxy Survey. Our main motivation is to check how much the difference in the rest-frame wavelength could affect comparisons of bar strengths in low and high redshift observations. Between these two bands we find an average bar strength ratio Q_B/H= 1.25 which factor is nearly independent of the morphological type. We show that Q_B/H > 1 is mostly due to reduced bulge dilution of radial forces in the B-band. The bar torque method needs an estimate for the vertical scale height of the galaxy, based on the radial scale length of the disk and the galaxys morphological type. Since these two might not always be possible to determine at high redshifts in a reliable manner, we also checked that similar results are obtained with vertical scale heights estimated from the radii corresponding to the K-band surface brightness of 20 mag/arcsec^2. Also, we made a simple test of the usability of the bar torque method at high redshifts by checking the effects of image degradation (nearest neighbour sampling without any adjustment of noise levels): we found that the estimated bar strengths varied by +/- 10% at most as long as the total extent of the bar was at least 10 pixels. Overall, we show that the gravitational bar torque method should provide a proficient tool for quantifying bar strengths also at high redshifts.
We present electron collision strengths and their thermally averaged values for the forbidden lines of the astronomically abundant doubly-ionized oxygen ion, O^{2+}, in an intermediate coupling scheme using the Breit-Pauli relativistic terms as imple
We have used the LONGSP spectrometer on the 1.5-m TIRGO telescope to obtain long slit spectra in the J, H, and K wavelength bands towards two positions along the Orion bar. These data have been supplemented with images made using the ARNICA camera mo
An imaging survey of the {em IRAS} 1-Jy sample of 118 ultraluminous infrared galaxies was conducted at optical (R) and near-infrared (K) wavelengths using the University of Hawaii 2.2m telescope. The methods of observation and data reduction are desc
The present paper discusses the results from an analysis of the images presented in Paper I (astro-ph/0207373) supplemented with new spectroscopic data obtained at Keck. All but one object in the 1-Jy sample show signs of a strong tidal interaction/m
We report on the archival optical and near-infrared observations of 6 low mass X-ray binaries situated in the Galactic bulge. We processed several recent Chandra and XMM-Newton as well as Einstein datasets of a binary systems suspected to be ultracom