How well should the DENIS Survey probe through the Galactic Plane?

Abstract

The DENIS 2 micron survey is described. It's ability to probe galaxies at very low galactic latitudes is computed using simulated images. This analysis indicates that DENIS will be able to separate galaxies from stars, right through the Galactic Plane, for galactic longitudes $45^\circ \leq \ell \leq 315^\circ$, with a maximum loss in the magnitude limit for reliable extraction of $\simeq 1.2$ magnitude relative to that at the Galactic Pole (where the 92\% reliability limit is $K' = 13.2$ for star/elliptical galaxy separation, and fainter for other morphological types). Extinction corrected magnitude limits are substantially worse, but for $|b| \geq 2^\circ$, they are within one magnitude from that of the Galactic Poles. Thus, confusion by stars will not prevent the establishment of a reliable galaxy catalog right through the Galactic Plane. However, extinction will produce galaxies of lower surface brightness, which will be more difficult to detect.