RG lunch Talk
18 July 2008 
M340, 12:30pm

Dr. Juan Uson
(NRAO)

HI observations of Superthin Galaxies


Superthin galaxies are bulgeless, late-type spiral galaxies seen
edge-on.  HI synthesis observations probe the kinematic structure of
their interstellar medium. I shall present the results of
high-sensitivity VLA observations of UGC7321, IC2233, UGC3697 and
UGC10043 done in collaboration with Lynn Matthews (CfA).  Two of these
galaxies are rather isolated while the other two are the dominant
members of small groups.

We have detected a pattern of "corrugations" in IC 2233, the first such
detection in neutral Hydrogen in an external galaxy.  UGC 3697, the
"Integral Sign" galaxy shows a spectacular S-shaped bend that has been
triggered by the passage of an intruder through its disk.  UGC 10043,
not quite a superthin galaxy, has presented us with an unexpected, rich
interaction with a previously unknown companion which is reminiscent of
the M51 system (the Whirlpool galaxy) "seen from the side."

These results have required the development (in collaboration with Bill
Cotton) of an algorithm to correct the VLA beam-squint.  This in turn
has presented us with the pieces of a VLA pipeline.  I'll discuss this
development briefly and (time-permitting) I shall include a "live"
demonstration of the squint-correcting algorithm.