|
Biography
|
Giuseppe Galletta born in
Messina, Italy, in 1954. He started his interest to
Astronomy very young. He obtained
the
degree in Astronomy at the Padua University in 1975.
He has married Daniela
Bettoni,
astronomer, in 1979 and has two daughters,
Eva and Anna.
Other
interests: Art, Motorcycles, Photography
Sports: Judo
(Budokai Judo Clud, Pisa and Padova 1972-1982), Swimming
(Società
Nuotatori Padovani 1991-1995), Apnea
diving
(Free Sport
Club, Padova 1996-1997).
Languages
spoken (in decreasing
order):
Italian, English, French, Spanish.
Didactic
and Academic
activity
Giuseppe Galletta, doctor in Astronomy at
Padua University (1975), Teacher of Exercises of Structure of the
Matter (1976-78), Granted researcher of CNR (1977-79), Astronomer at
the Padova Observatory (1979-86), Professor at Padua University since
1986.
Giuseppe
Galletta born in
Messina, Italy, in 1954. He started his interest to
Astronomy very young. He obtained
the
degree in Astronomy at the Padua University in 1975.
He has married Daniela
Bettoni,
astronomer, in 1979 and has two daughters,
Eva and Anna.
Other
interests: Art, Motorcycles, Photography
Sports: Judo
(Budokai Judo Clud, Pisa and Padova 1972-1982), Swimming
(Società
Nuotatori Padovani 1991-1995), Apnea
diving
(Free Sport
Club, Padova 1996-1997).
Languages
spoken (in decreasing
order):
Italian, English, French, Spanish.
He was
teacher of several courses in a number of degree and diplomas.
At present is teaching in the courses of : Elements of Astronomy and
Complements of Astronoy (Sc. and Tecn. for the Nature), Astrobiology
(Spec. degree Nat. Sciences and Astronomy).
Student's
judgements
from the
anonymous forms analysed by the University (based on 4 courses of
lectures):
Clarity
in exposing
Abilty
to stimulate the
interest
Availability
for the student's problems
General
satisfaction about the lectures
He was
supervisor of dozen of theses for students of Astronomy, Natural
Sciences and didactic diplomas.
Main
memberships: Italian Physical Society, International Astronomical
Union, Founding Member of the European Astronomical Society, European
Exo-AstroBiology Network Association (EANA), International Society for
the Studies on Origin of Life (ISSOL- International Astrobiology
Society).
Since 1980 he
was coordinator or responsible of more than twenty
commissions at the padua Observatory, Padua University and Roma CNR.
Main
scientific
results
1. The existence of
'prolate' galaxies (Ap.J. 226, L115, 1978).
Around the end of
the '70s, some astronomers, such
as J. Binney, were suggesting that the structure of the elliptical
galaxies could be not oblate, but triaxial. Most part of efforts of
those years were devoted to statistical tests of this idea, while no
direct proofs of non-oblate galaxies were existing. In 1978, Bertola
and Galletta's discovery of a class of ellipticals with minor-axis dust
lanes suggested that these galaxies would be good candidates for being
prolate1.
They suggest a new
class of galaxies: prolate stellar structures cut equatorially by
gaseous planes 2.
This was
one of the first papers attempting to use the existing
observations
to distinguish between oblate and prolate potentials.
The discovery of inclined and warped gas disks in ellipticals has
opened up the possibility to learn about the shape of the potential,
i.e., whether it is generally oblate, prolate or triaxial. As a result,
many theoretical and observational papers have been devoted to this
subjects in the past years1.
In the paper, Bertola and Galletta indicates a
few objects called
possibly related with minor-axis, dust-lane ellipticals, such as NGC
2685 (the spindle galaxy) and NGC 4650A. These galaxies were later
discovered to be another class of peculiar objects, the Polar
ring
galaxies3.
2. Triaxial models of
Elliptical galaxies (MNRAS, 193, 885, 1980).
The statistical
approach to demostrate the
triaxiality of Elliptical galaxies was an hot subject in the begin of
the '80s. In this year, appears a paper where Benacchio and
Galletta
have made an interesting first attempt to study the distribution of
intrinsic shapes [...] The best fit is obtained for models that are
mildly triaxial. [...] The machinery developed in this paper is useful,
and should yeld stricter limits on galaxies shapes when applied to more
accurate measurements of a larger sample of galaxies4.
3. The relation between
twisting and flattening in Ellipticals (A&A, 81, 179, 1980).
Another way to
demonstrate the triaxiality of some
elliptical galaxies is to study the presence of twisting of the
isophotes, a typical consequence of the triaxiality. Differently from
intrinsic distorptions, such as the warping of the equatorial plane,
triaxiality has its own rules. In 1980 appears the first paper showing
that the total twist angle Df correlates with apparent
ellipticity.
Galaxies which are very flattened (e > 0.25) show only small
twists
(Df < 20°). This relation for galaxies with luminosity
profile
following the r1/4 law has been confirmed by
various authors.
4. The existence of S0s with
counterrotation (ApJ 318, 531, 1987).
In 1986, during a
systematic study of barred S0s,
find at ESO the first S0 galaxy (NGC 4546) in which the gas disk
rotates
in the opposite direction with respect to the gas (counterrotation).
Parallel to the discovery of the counterrotation in Ellipticals5,6
this was an
extraordinary clear
example for a `` second event'' in the history of a galaxy 7.
5. The existence of Spirals
with counterrotation (Nature, 375, 661, 1995).
Following the
problems of interactions between
galaxies, Galletta try to link in a general frame various type of
galaxies (dust-lane Ellipticals, polar-ring S0s, Ellipticals and S0
galaxies with counterrotation) supposing they are different results of
the phenomenon of gas accretion. Then, since 1983
try to observe
a number of spiral galaxies having anomalous dust arcs. Finally, with
Ciri and Bettoni found the first spiral galaxy where the whole disk of
gas is in counterrotation.
(in
italic
are the citations from review by other authors)
- from:
F.Schweizer,
1983, I.A.U. Symp. n.127, ed. T.de
Zeeuw, p114.
- from: Voigt,
Huchtmeier, 1982, Landolt-Bornstein, Handbuch
der Physic, Vol.2c, p.256 Springer-Verlag
- F.
Schweizer, B.C.
Whitmore, V.C. Rubin, 1983, AJ 88, 909.
- from:
J.Kormendy,
1982, Morphology and Dynamics of Galaxies,
XX Adv. Couse SAAS-FEE, ed. L.Martinet and M.Mayor, p.150.
- D.Bettoni,
1984, Messenger
37, 17.
- N. Caldwell,
R.P.
Kirshner, D.O. Richstone, 1986, ApJ
305, 136.
- from
a letter of
Prof. M. Schwarzschild, Princeton, 2 march
1987.
|
|