A COUNTERROTATING BULGE IN THE SB GALAXY NGC-7331

We have found that the bulge of the large, nearby Sb galaxy NGC 7331 r otates retrograde to its disk. Analysis of spectra in the region of th e near-IR Ca II triplet along the major axis shows that, in the radial range between 5 '' and similar to 20 '', the line-of-sight velocity d istribution of the absorption lines has two distinct peaks and can be decomposed into a fast-rotating component with nu/sigma > 3, and a slo wer rotating, retrograde component with nu/sigma similar to 1-15 The r adial surface brightness profile of the counterrotating component foll ows that of the bulge, obtained from a two-dimensional bulge-disk deco mposition of a near-infrared K-band image, while the fast-rotating com ponent follows the disk. At the radius at which the disk starts to dom inate, the isophotes change from being considerably boxy to being very disky. Although a number of spiral galaxies have been found that cont ain cold, counterrotating disks, this is the first galaxy known to hav e a boxy, probably triaxial, fairly warm, counterrotating component, w hich is dominating in the central regions. If it is a bar seen end-on, this bar has to be thicker than the disk. We find that NGC 7331, even though it is a fairly early-type spiral, does not have a conventional , corotating bulge. The fact that the inner component is retrograde ma kes us believe that it was formed from infalling material in either st ellar or gaseous form (see, e.g. Balcells Br Quinn). Another possibili ty, however, is that the structure has been there since the formation of the galaxy. In this case, it will be a challenge to explain the lar ge change in orientation of the angular momentum when going outward ra dially.