The thick disk in the galaxy NGC 4244 from S4G imaging
  If thick disks are ubiquitous and a natural product of disk galaxy formation
and/or evolution processes, all undisturbed galaxies which have evolved during
a significant fraction of a Hubble time should have a thick disk. The late-type
spiral galaxy NGC 4244 has been reported as the only nearby edge-on galaxy
without a confirmed thick disk. Using data from the Spitzer Survey of Stellar
Structure in Galaxies (S4G) we have identified signs of two disk components in
this galaxy. The asymmetries between the light profiles on both sides of the
mid-plane of NGC 4244 can be explained by a combination of the galaxy not being
perfectly edge-on and a certain degree of opacity of the thin disk. We argue
that the subtlety of the thick disk is a consequence of either a limited
secular evolution in NGC 4244, a small fraction of stellar material in the
fragments which built the galaxy, or a high amount of gaseous accretion after
the formation of the galaxy.
