My research centers around issues of low surface brightness (and possibly "no
surface brightness") objects. I am interested in dynamical estimates and
observational determinations of the amount of mass present in a wide variety of
objects--clusters of galaxies, groups of galaxies, individual galaxies, and even
planetary nebulae. My slant on this research is to investigate whether our natural human
bias toward visible wavelengths of light has biased us against detecting certain classes
of objects. 

The class of low surface brightness galaxies appaears to be large but it is poorly
studied. These galaxies' visual surface brightnesses barely exceed the sky
background and have therefore been overlooked in most optical surveys. However, dynamical
studies we have made of these galaxies' rotation speeds indicate that they are
comparable in mass to the largest "normal" spiral galaxies. The mystery is why
they show such weak star formation despite their mass. This may be due to a lack of
interactions with other galaxies, 

A more fundamental question is how many of these objects populate the universe?
Unfortunately, objects with little star formation are difficult to detect at almost any
wavelength, since stars are the ultimate source that powers almost all of the emission
from galaxies. One of the only alternatives is to study the emission of neutral hydrogen
at 21 cm, which is a primordial material and does not require starlight to excite the
transition. 

Our blind surveys are detecting many previously uncataloged objects which have a wide
range of properties. They include nearby faint dwarf galaxies, peculiar objects which
defy simple classification schemes. and the low surface brightness giants described
above. This research is perhaps an indication that much of our understanding of
extragalactic space is still in its infancy. I have undertaken a wide array of
observations here at the Five College Radio Astronomy Observatory, and at observatories
around the country: the Arecibo Observatory in Puerto Rico, the VLA in New Mexico, the
GBT in West Virginia, Nancay in France, and Kitt Peak in Arizona.

No subject area

PDF

Serendipitous 2MASS Discoveries Near the Galactic Plane: A Spiral Galaxy and Two Globular Clusters (with Robert L. Hurt, Tom H. Jarrett, J. Davy Kirkpatrick, Roc M. Cutri, Mike Skrutskie, and Willem van Driel), Astronomy Department Faculty Publication Series (2000)

We present the basic properties of three objects near the Galactic Plane—a large galaxy and...