Malcolm Smith
CTIO Scientific Staff
Areas of Interest
Quasars, Active Galactic Nuclei, Faint Red Objects at High Galactic
Latitude
Recent Research Results
Smith has begun a number of complementary, collaborative surveys aimed
at discovery of quasars at z>5 and characterization of the quasar
luminosity function at such redshifts. This research has the goal of
clarifying the controversial question of the evolution of the
luminosity function of quasars at early epochs in the universe; an
estimate of the time which elapsed between the big bang and the time
when quasars switched on should prove relevant to an understanding of
the early formation of galaxies. This is a long- term project
involving extensive calibration work, surveys, and data reduction.
Smith is working on this problem with groups from Ohio State
University, Pomona College, Maria Mitchell College, and the University
of Michigan. The surveys with the Blanco 4-m and Schmidt telescopes
are based on selecting such high-redshift quasars by means of their
very red (Gunn-Thuan) g-i colors and blue i-z colors. This project is
now proceeding well as a result of the program of improvements to the
image quality at the 4-m. Smith has been working with Athey (Pomona
College) and Friel (Maria Mitchell)--participant and organizer of the
NSF REU program at Cerro Tololo--to set up calibrations of the
Gunn-Thuan filter system in the south and apply it to deep observations
of a single 1/16 degree field near NGC300. No quasars have been found
at this early stage of that deep survey.
Future Research Plans
Smith, Kennefick (OSU), Osmer (OSU), Friel (Maria Mitchell), and Athey
(Pomona College) are using the CCD camera at the Curtis Schmidt
telescope on Tololo in conjunction with a digitized version of the
second Palomar Observatory Sky Survey (POSS II). Data obtained in r,
g, and i from POSS II by Kennefick are being augmented by 1 sq. deg.
Curtis Schmidt CCD frames obtained through a z filter. In this way, it
will be possible to cover several hundred degrees of sky, and the
probability will be high of discovering at least one or two quasars
even if the co-moving space density turns down sharply beyond z>3 as
some researchers believe. If no quasars are discovered, the resulting
limits will rule out some current models that postulate that at least
the most luminous quasars continue to exist at essentially constant co-
moving space density out to redshifts 4 or 5.
Service
Smith has, of course, multiple service duties as director of CTIO. He
has been initiating the renewal of CTIO into an international
observatory centered around support of the 8-m Gemini South telescope
and two complementary 4-m telescopes--the Blanco and SOAR telescopes;
this program is described in more detail in NOAO's renewal proposal. In
addition he has initiated and participated in an extensive program to
combat light pollution in Chile; he is also introducing a greater
degree of privatization in the operation of the smaller telescopes at
CTIO. He has worked closely with NOAO Tucson in encouraging
collaboration in the production of large instruments for Gemini and the
NOAO telescopes. The most recent detailed external review of these
activities at CTIO is given in the 1995 report by the Observatories'
Visiting Committee.
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Posted: 06Dec1996