A NEUTRAL HYDROGEN SURVEY OF POLAR-RING GALAXIES .1. GREEN BANK OBSERVATIONS OF THE NORTHERN SAMPLE

We present the results of a neutral hydrogen survey conducted with the Green Bank 140 foot radio telescope of 47 northern objects in the pol ar-ring galaxy atlas of Whitmore et al. [AJ, 100, 1489 (1990)]. We det ected 39 of these above our detection limit of 1.7 Jy km s-1; the aver age measured flux of 21 Jy km s-1 corresponds to an average neutral hy drogen mass of 5.3 X 10(9) M. for a Hubble constant of H-0=75 km s-1 M pc-1. For the polar-ring galaxies in our sample that have also been ob served with radio arrays, we find that the 21'(FWHM) Green Bank beam o ften includes much more flux than found by the synthesis instruments f or the polar rings alone; some of these galaxies are known to have gas -rich companions. We compare the neutral hydrogen content of the sampl e to the blue luminosity and IRAS fluxes. The H I-mass-to-blue-light r atios of the confirmed and probable polar rings are around unity in so lar units, indicating that polar-ring galaxies (or their environments) are as gas-rich as typical irregular galaxies. For their blue luminos ity, the confirmed polar rings are underluminous in the far infrared, as compared with the rest of the sample. They are also FIR underlumino us for their H I masses, which suggests that most of the gas in the ri ng may be in stable orbits, rather than flowing inward to trigger star formation in the central galaxy. The more disordered class of ''relat ed objects,'' which includes a number of obvious mergers, is highly lu minous in the far infrared. Detailed notes for each galaxy, including information about companions within the GB 140' beam that may contribu te to the total H I line integral and its width, are contained in the Appendix.