Lamarr
L. Parsons
llp4 at cornell dot
edu
Cornell
University
|
A Mid-Infrared Search for Galaxies in
the
"Zone of Avoidance"
|
Using
an IDL program I created, I plotted all of my galaxies as a function of
Galactic Longitude and Latitude. The three graphs below represent a
single block of GLIMPSE 3D data.It is important to note that in these
graphs, the sizes of the ellipses were
enlargened for easier viewing . These galaxies are really not
that
big!
Conclusions
- Twelve square degrees of GLIMPSE 3-D data were searched for
galaxies, resulting in 114 galaxy candidates (9.5 per square
degree) and 159 other interesting objects.
- We note that in our galaxy position graphs, we observe a
galaxy detection gradient. As we move away from the galactic equator,
we find more galaxies. So Galaxy detection is dependent on galactic
latitude increasing from 4 per square degrees at b=1º to 12 per square
degrees at b =3º.
- A silimar survey was conducted on 2MASS data. In comparison to
their detection rate of 1-2 galaxies per square degree for galaxies
brighter than 12.1 mag, our detection rate is two to four times as many
galaxies per unit area.
- The 8 micron band was very intrusmental in finding these
galaxies. Without it, I would approximate that we would have found only
50% of our current galaxy candidates. In future observations,
only the 3.6 and 4.5 micron bands will be at work. These bands may be
able to recover some galaxies, but as we have discovered, galaxies tend
to be most distinct in the 8 micron band.
- Automated searches for galaxies may not yield as many galaxies as
was found by hand. We found that the process involved scaling the sky
search segments several times, in an effort to reveal any hidden
galaxies. We also had to make many judgement calls to differentiate
galaxy candidates and other objects such as stars. Without the human
factor, and automated galaxy search would yield irrelevant data.
Advisor: Bob
Benjamin
Useful Links:
GLIMPSE
University of Wisconsin-Madison