Intermediate-Band Surface Photometry of the Edge-on Galaxy NGC 4565

We present a deep, 42.79 hr image of the nearby, edge-on galaxy NGC 4565 inthe Beijing-Arizona-Taipei-Connecticut (BATC) 6660A band using the large-formatCCD system on the 0.6m Schmidt telescope at the Xinglong Station of theNational Astronomical Observatories of China (NAOC). we obtain a final image that iscalibrated to an accuracy of 0.02 mag in zero point, and for which we canmeasure galaxy surface brightness to an accuracy of 0.25 mag at a surfacebrightness at 27.5 mag arcsec^-2 at 6660A, corresponding to a distance of 22kpc from the center of the disk. The integrated magnitude of NGC4565 in ourfilter is m6660=8.99 (R magnitude of 9.1) to a surface brightness of 28 magarcsec-2. We analyze the faint outer parts of this galaxy using atwo-dimensional model comprised of three components: an exponential thin disk,an exponential thick disk, and a power-law halo. A total of 12 parameters areincluded in our model. We determine the best values of our model parameters via10,000 random initial values, 3,700 of which converge to final values. The thindisk and thick disk parameters we determine here are consistent with those ofprevious studies of this galaxy. However, our very deep image permits a betterdetermination of the power law fit to the halo, constraining this power law tobe between r^-3.2 and r^-4.0, with a best fit value of r^-3.88. We find theaxis ratio of the halo to be 0.44 and its core radius to be 14.4 kpc (for anadopted distance of 14.5 Mpc).Comment: 34 pages, 11 figures, will appear in March 2002 of A