Professor of Astronomy
UMass Department of Astronomy
517K Lederle Graduate Research Tower
Amherst, MA 01003
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,
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
and have therefore been overlooked in most optical surveys.
However, dynamical studies we have made of these galaxies' rotation
indicate that they are comparable in mass to the largest "normal"
The mystery is why they show such weak star formation despite
their mass. This may be due to a lack of interactions with other
A more fundamental question is how many of these objects populate
universe? Unfortunately, objects with little star formation are
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.
Optical images of HI-detected galaxies are
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
at the Five College Radio
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
Astronomy Course Pages
Astronomy 100 Exploration of the Universe
- Pathways to Astronomy, S. E. Schneider and T. T. Arny, 2006 (McGraw-Hill)
college-level introduction to astronomy.
- "The Contribution of HI-rich
Galaxies to the Damped Ly-alpha Absorber Population at z = 0," J. L.
Rosenberg and S. E. Schneider, 2003, Astrophysical Journal 585, 256-267
characteristics of the galaxies discovered in HI surveys appear similar
to sources identified in absorption studies of quasars.
- "The Arecibo Dual-Beam Survey: The HI
Mass Function of Galaxies," J. L. Rosenberg and S. E. Schneider, 2002,
Journal 567, 247-257 -- results of the largest "blind" HI survey at Arecibo
before the building of the ALFA receiver system.
- "A Warped Disk Model for M33 and the 21-cm Line Width in Spiral Galaxies," E.
Corbelli and S. E. Schneider 1997, Astrophys. J, in press. --our nearby
companion galaxy has a peculiar structure which suggests some possible problems
in estimating galaxy distances
- "The HI Luminosity Function from `Blind' Surveys," S. E. Schneider 1997,
Pub. Astron. Soc. Australia 14, 99-105 --past, present, and future
determinations of the mass distribution of neutral hydrogen among galaxies.
- "Neutral hydrogen around early-type galaxies," K. DuPrie and S. E. Schneider
1996, Astron. J., 112, 937. -- a student's senior project to study
the gaseous environment around gas-poor galaxies.
- "HI Selection Effects and the Galaxy Mass Function," S.
E. Schneider 1996, in Minnesota Lectures on Extragalactic HI, ed. E.
Skillman, ASP Lecture Series,
pp. 323-356. -- a graduate level description of how optical and
radio observations of galaxies are used to determine the total mass
of these populations
- "Neutral Hydrogen in the M96 Group: The Galaxies and the Intergalactic Ring," S.
E. Schneider, 1989, Astrophys. J., 343, 94-106. --evidence of dynamical
interactions between an unusual intergalactic cloud in a group of galaxies,
and its implications for the presence of dark matter
- "Between the Galaxies," S.E.
Schneider and Y. Terzian, 1984, American
Scientist, vol. 72, pp. 574-581. --a popular introduction to the topic of dark matter
- 2001 Hewlett Teaching Fellowship
- 2000 College Outstanding Teacher Award
- 1997-98 President, UMass Chapter of Sigma Xi
- 1991 Presidential Young Investigator Award
- 1987 Trumpler Award of
the Astronomical Society of the Pacific for outstanding thesis in North
- 1979-83 National Science Foundation Fellowship
- 1979-80 Cornell
- Ph.D. in Astronomy, Cornell, 1986 -- Thesis: Galaxy Groups:
Neutral Hydrogen and Dynamics
- M.S. in Astronomy, Cornell, 1982
- B.A. Magna Cum Laude in Astronomy and Astrophysics, Harvard
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Last Update: 1/31/2006