Deep intermediate-band surface photometry of NGC 907

Intrigued by the initial report of an extended luminosity distribution perp endicular to the disk of the edge-on Sc galaxy NGC 5907, we have obtained v ery deep exposures of this galaxy with a Schmidt telescope, large-format CC D, and intermediate-band filters centered at 6660 Angstrom and 8020 Angstro m. These two filters, part of a 15-filter set, are custom designed to avoid the brightest (and most variable) night skylines. As a result, our images are able to go deeper with lower sky noise than those taken with broadband filters at similar effective wavelengths: e.g., 0.6 e(-) arcsec(-2) s(-1) f or our observations versus 7.4 e(-) arcsec(-2) s(-1) for the R-band measure s of Morrison et al. In our assessment of both random and systematic errors , we show that the flux level where the errors of observation reach 1 mag a rcsec(-2) are 29.00 mag arcsec(-2) in the 6660 Angstrom image (correspondin g to 28.7 in the R band) and 27.4 mag arcsec(-2) in the 8020 Angstrom image (essentially on the I-band system). In a previous paper we have shown that NGC 5907 has a luminous ring around it, most plausibly caused by the tidal disruption of a dwarf spheroidal gal axy by the much more massive spiral. Here we show that, for values fainter than 27 R mag arcsec(-2), the surface brightness around NGC 5907 is strongl y asymmetric, being mostly brighter on the northwest (ring) side of the gal actic midplane. This asymmetry rules out a halo as the cause of the faint s urface brightness we see. We find this asymmetry is likely an artifact resu lting from a combination of ring light and residual surface brightness at f aint levels from stars that our star-masking procedure cannot completely el iminate. The possible existence of an optical face-on warp in NGC 5907, sug gested by our Very Large Array H I observations, is too confused with foreg round star contamination to be independently studied. Good agreement with t he surface photometry of NGC 5907 by other observers leads us to conclude t hat their data are similarly affected at faint levels by ring light and the residual effects of star masking procedures. Inspection of published image s confirm this to be the case. Thus, we conclude that NGC 5907 does not hav e a faint extended halo.