What is different about LINER Galaxies

Sandy Faber has several First-Year Project ideas, some in connection with the
DEEP survey, others in connection with Sloan data. All are related to galaxy
formation, and all get you working with data and teach you useful tools. All of
them are GUARANTEED to yield a published paper. Finally, all are a good
introduction to future work on galaxy evolution, if that topic interests you.
2) "What is different about LINER galaxies?"
- A major question in galaxy evolution is what
controls the star formation histories of galaxies.
We observe that the "red sequence" (i.e., ellipticals
and S0's) have very low star formation rates and
stand apart from normal, blue, star-forming galaxies.
Also that the number of RS galaxies is increasing
with time, and hence that galaxies are "going out".
Why? There are many theories, ranging from dark
halo mass going over some critical threshold to
feedback from star bursts to feedback from AGNs
to the gas supply simply running out.
- LINERS are enigmatic objects on the RS that
exhibit weak emission. This does not come from
H II regions but rather from heating by some very
hot objects, perhaps (in part) AGNs. LINERS may
represent some "dying-down" phase of AGN activity
as galaxies go out. The location of LINERS in
the color-mass diagram suggests that they may also be
recently quenched RS galaxies.
- This project would build on three previous
First-Year Projects by UCSC students. The
work of J Cheng, E Lopez, and J Graves produced
a large database on Sloan RS galaxies, including
structural properties, bulge-disk ratios (i.e.,
E vs S0 classifications), velocity dispersions, radii,
stellar population ages and metallicities, and
halo mass. These stuents found many results showing
how the structural properties of RS galaxies vary
with galaxy mass, sigma, radii, and environment. However,
for simplicity the analysis to date has focussed
on non-LINER, purely quiescent galaxies without either
AGN or SFR activity. This
project would add LINERS to the data base to see
if they exhibit different properties compared to

the many relationships already discovered for
the normals. Differences could reveal something
about the life-histories of LINERS vs. quiescents,
and also whether the existing relationships for
quiescents need substantial reworking for LINERS.
- Skills needed: using the Sloan data base. Learning
to use IDL to analyze data and make plots.
General familiarity with early-type
galaxy stellar populations AND AGN activity.
Potentially, advanced statistical techniques needed
to compare LINERS to non-LINERS