Οπτικές παρατηρήσεις στο μικρό νέφος του μαγγελάνου με το τηλεσκόπιο 6.5 m Magellan

Postgraduate Thesis uoadl:1319283 357 Read counter

Unit:
Τομέας Αστροφυσικής, Αστρονομίας και Μηχανικής
Library of the School of Science
Deposit date:
2013-02-15
Year:
2013
Author:
Στράντζαλης Αχιλλέας
Supervisors info:
Χατζηδημητρίου Δέσποινα Αναπλ. Καθηγ.(Επιβλέπουσα), Κοντιζά Μαίρη Επικ. Καθηγ., Αντωνοπούλου Ευγενία Επικ. Καθηγ.
Original Title:
Οπτικές παρατηρήσεις στο μικρό νέφος του μαγγελάνου με το τηλεσκόπιο 6.5 m Magellan
Languages:
Greek
Summary:
The aim of this Master’s is the photometric study of field with diameter 0.44o
(the centre is RA 00 53 28.2, DEC -72 26 34.51 (2000)) in the central region of
the Small Magellanic Cloud (SMC). The observations were performed in 2004 at
the Magellan Telescope in Chile by Antoniou Valia (Iowa State University),
Zezas Andreas (University of Crete), and Chatzidimitriou Despoina (University
of Athens).
In this thesis, astrometric and photometric studies for 602.388 stars
of the field (with IRAF package of the image) were performed. The photometric
magnitudes were converted, with the method of secondary standards in
photometric system Johnson, using common bright stars from the catalogue of
Harris and Zaritsky 2004. Afterwards, star clusters of this field were studied,
that are referred from the catalogues of star clusters of Bonnato & Bica (2010)
and Glatt et al. (2010). The studied star clusters are Β79, NGC330, H86-135,
H86-129, H86-127, H86-138, NGC306, H86-146, SOGLE220, B69 ή SOGLE89, H86-136,
H86-145, BS259, H86-149, H86-142, H86-119, BS257, B73 ή SOGLE96.
For all the clusters the radial density's distribution was evaluated,
Colour Magnitude Diagram (CMD) were constructed and their ages were estimated
using isochrones curves of model Bressan et al. (2012). Also the interstellar
reddening of each cluster was estimated. From the 18 objects under study that
are also in the above catagues, only 12 were confirmed as clusters.
This large percentage of objects that had falsely been characterised as
clusters is due to the relatively small spatial resolution of the past
observations. Only one of the 18 star clusters that were studied has been
observed with the Hubble Space Telescope – and thus with high resolution.
The studied CMD of a region of field, led to the discovery of a
discrete episode of intense star formation about 1.5 Gyr ago. These results are
in accordance with the statistical analysis of field diagrams CMD from Harris &
Zaritsky (2004), while equivalent amplification of the star formation is shown
from the age distribution of star clusters (Harris & Zaritsky 2004). However,
it is the first time that these results are confirmed with the discovery of a
discrete turnoff in the CMD diagrams of a field in SMC
Keywords:
Small Magellanic Cloud, Photometry, Colour Magnitude Diagram, Magellan Telescope, Star Clusters
Index:
No
Number of index pages:
0
Contains images:
Yes
Number of references:
36
Number of pages:
115
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