Lack of Interaction between the Dust Grains and the Anomalous Radio Jet
  in the Nearby Spiral Galaxy NGC 4258
  We obtained Spitzer/IRAC 3.6-8 micron images of the nearby spiral galaxy NGC
4258 to study possible interactions between dust and the radio jet. In our
analysis we also included high-resolution radio continuum, H-alpha, CO, and
X-ray data. Our data reveal that the 8 micron emission, believed to originate
largely from PAH molecules and hot dust, is an excellent tracer of the normal
spiral structure in NGC 4258, and hence it originates from the galactic plane.
We investigated the possibility of dust destruction by the radio jet by
calculating correlation coefficients between the 8 micron and radio continuum
emissions along the jet in two independent ways, namely (i) from
wavelet-transformed maps of the original images at different spatial scales,
and (ii) from one-dimensional intensity cuts perpendicular to the projected
path of the radio jet on the sky. No definitive sign of a correlation (or
anticorrelation) was detected on relevant spatial scales with either approach,
implying that any dust destruction must take place at spatial scales that are
not resolved by our observations.
