Near-Infrared Photometry of Superthin Edge-on Galaxies
  We perform near-infrared photometry of a large sample of 49 superthin edge-on
galaxies. These galaxies are selected based on optical photometry because of
high radial-to-vertical scale ratio in their stellar disks. The Near Infrared
(NIR) H and K observations were conducted with the cryogenic-cooled camera
ASTRONIRCAM on the 2.5m telescope at the Caucasus Mountain Observatory of
Lomonosov Moscow State University. A majority of galaxies in our sample show
comparable or better photometric depth than the Sloan Digital Sky Survey (SDSS)
optical images. We estimate the structural parameters of stellar disks in the
galaxies and find that the NIR scale height of stellar disks is comparable to
that estimated from the optical, SDSS g, r and i, whereas the H and K scale
length of the stellar disks is significantly shorter than in the g, r and i. We
investigate if a realistic distribution of dust alone can explain the
difference in the scale length and find that in the majority of the galaxies
the radial variation of the stellar population is actually responsible for the
color distribution. The latter suggests a younger age of the disks periphery,
and the inside out building up of stellar disks in the superthin galaxies.
