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.

We announce the initial release of data from the Ohio State University Bright Spiral Galaxy Survey, a BV RJHK imaging survey of a well-defined sample of 205 bright, nearby spiral galaxies. We present H-band morphological classification on the Hubble sequence for the OSU Survey sample. We compare the H-band classification to B-band classification from our own images and from standard galaxy catalogs. Our B-band classifications match well with those of the standard catalogs. On average, galaxies with optical classifications -2from Sa through Scd appear about one T-type earlier in the H-band than in the B-band, but with large scatter. This result does not support recent claims made in the literature that the optical and near-IR morphologies of spiral galaxies are uncorrelated. We present detailed descriptions of the H-band morphologies of our entire sample, as well as B-and H-band images for a set of 17 galaxies chosen as type examples, and BRH color-composite images of six galaxies chosen to demonstrate the range in morphological variation as a function of wavelength. Data from the survey are accessible at

We have performed a multiparametric analysis of luminosity data for a sample of 234 normal spiral and irregular galaxies observed in X-rays with the Einstein Observatory. This sample is representative of S and Irr galaxies, with a good coverage of morphological types and absolute magnitudes. In addition to X-ray and optical data, we have compiled H-band magnitudes, IRAS near-and far-infrared, and 6cm radio continuum observations for the sample from the literature. We have also performed a careful compilation of distance estimates. We have explored the effect of morphology by dividing the sample into early (S0/a-Sab), intermediate (Sb-Sbc), and late-type (Sc-Irr) subsamples. The data were analysed with bivariate and multivariate survival analysis techniques that make full use of all the information available in both detections and limits. We find that most pairs of luminosities are correlated when considered individually, and this is not due to a distance bias. Different luminosity-luminosity correlations follow different power-law relations. Contrary to previous reports, the L X − L B correlation follows a power-law with exponent larger than 1. Both the significances of some correlations and their power-law relations are morphology dependent. Our analysis confirms the 'representative' nature of our sample, by returning well known results derived from previous analyses of independent samples of galaxies (e.g., the L B − L H , L 12 − L F IR , L F IR − L 6cm correlations). Our multivariate analysis suggests that there are -2two fundamentally strong correlations, regardless of galaxy morphology, when all the wavebands are analyzed together with conditional probability methods. These are the L B − L H and the L 12 − L F IR correlations. As it is well known, the former links stellar emission processes, and points to a basic connection between the IMF of low-mass and intermediate-to-high-mass stars. The latter may be related to the heating of small and larger size dust grains by the same UV photon field. Other highly significant 'fundamental' correlations exist, but are morphology-dependent. In particular, in the late sample (Sc-Irr) we see an overall connection of mid-, far-IR, and radio-continuum emission, which could be related to the presence of star-forming activity in these galaxies, while in early-type spirals (S0/a-Sab), we find no strong direct link of FIR and radio continuum. This paper gives a compilation of both input data and results of our systematic statistical analysis, as well as a discussion of potential biases. Results relevant to both X-ray and multiwavelength emission properties are analyzed futher and discussed in Paper II.

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