Bibcode
Galera Rosillo, R.; Corradi, R. L. M.; Mampaso, A.
Bibliographical reference
IAU General Assembly, Meeting #29, #2248296
Advertised on:
8
2015
Citations
0
Refereed citations
0
Description
The nearby disc galaxy M33 is one of the best laboratories for testing
chemical evolution models in galaxies and for understanding disc
formation mechanisms. In this galaxy, planetary nebulae (PNe) were
previously extensively studied only within a galactocentric radius of 8
kpc.In the framework of a broad study of the population of PNe in Local
Group disc galaxies, we present the results of a deep narrow-band
imaging of the outer regions of M33, performed using the Wide Field
Camera at the 2.5 m Isaac Newton Telescope (INT).The INT images were
obtained in the narrow-band filters selecting the [OIII] 5007 Å
and Hα 6563 Å lines, plus broad-band filters SDSS g and i. A
photometric catalog of around 150000 sources covering a total area of 5
square degrees, and extending out to 2 deg (30 kpc at the adopted
distance of 840 kpc) from the centre of the galaxy is presented.PNe
candidates are selected in the [OIII]-g vs Hα-r colour-colour
diagram as bright emitters in the narrowband filters. A number of
candidates with similar colours to those of known PNe, and with an
apparent [OIII] magnitude > 21 have been selected for future
follow-up. Three of these have been already spectroscopically confirmed
at the William Herschel Telescope (WHT).Our survey will improve the
knowledge of the PNe population in the outskirts of M33, constraining
the properties of its metal-poor halo and of the extended disc
substructures that have been proposed to be related to a relatively
recent interaction with M31.