HALOGAS: Observations and Modeling of the Nearby Edge-on Spiral Galaxy NGC 4565

We present models of the distribution and kinematics of HI in NGC 4565, a nearby spiral galaxy observed as part of the Westerbork Hydrogen Accretion in LOcal GAlaxieS (HALOGAS) survey. These models focus on the potential existence of extraplanar gas in the form of a halo as well as the presence of a negative gradient in rotational velocity upward from the plane of the disk (a lag). Insight concerning such information helps to better understand the prevalence as well as origins of halos in spiral galaxies, specifically whether they are a result of outflow from the disk, accretion from external sources, or a combination of the two. The modeling process utilizes a recently developed semi-automated Tilted Ring Fitting Code (TiRiFiC), which applies a chi-square minimization. Current models indicate a thin HI layer, which flares at large radii.