HALOGAS: HI Observations and Modeling of the Nearby Edge-on Spiral
  Galaxy NGC 4244
  We present 21-cm observations and models of the HI kinematics and
distribution of NGC 4244, a nearby edge-on Scd galaxy observed as part of the
Westerbork Hydrogen Accretion in LOcal GAlaxieS (HALOGAS) survey. Our models
give insight into the HI kinematics and distribution with an emphasis on the
potential existence of extra-planar gas as well as a negative gradient in
rotational velocity with height above the plane of the disk (a lag). Our models
yield strong evidence against a significantly extended halo and instead favor a
warp component along the line of sight as an explanation for some of the
observed thickening of the disk. Based on these models, we detect a lag of -9
+3/-2 km s-1 kpc-1 in the approaching half and -9 +/-2 km s-1 kpc-1 in the
receding half. This lag decreases in magnitude to -5+/-2 km s-1 kpc-1 and
-4+/-2 km s-1 kpc-1 near a radius of 10 kpc in the approaching and receding
halves respectively. Additionally, we detect several distinct morphological and
kinematic features including a shell that is probably driven by star formation
within the disk.
