Remember [SEMINARI] Stellar tidal streams in nearby galaxies: mapping the minor merger rate in the local Universe with small telescopes

[Enric Marco]

Title:Stellar tidal streams in nearby galaxies: mapping the minor
merger rate in the local Universe with small telescopes
 
By:Dr David Martinez-Delgado
From: Max-Planck Institut fur Astronomy, Heidelberg, Germany
 
Fecha: viernes 27 Abril 2012
Hora: 13:30
Lugar: SALÓN DE GRADOS DE MATEMÁTICAS

http://celeste.uv.es/daa/seminari.php.UTF8?id=1053
  
Abstract
 
Within the hierarchical framework for galaxy formation, minor merging
and tidal interactions are expected to shape large galaxies to this
day. As part of a pilot survey, we have carried out ultra-deep,
wide-field imaging of some isolated spiral galaxies similar to the
Milky Way in the local universe with data taken at small (0.1 to
0.5-meter diameter), robotic telescopes that provide exquisite surface
brightness sensitivity. Our observational effort has led to the
discovery of previously undetected giant stellar structures in the
halos of these galaxies, likely associated with debris from tidally
disrupted satellites. Our collection of galaxies presents an
assortment of tidal phenomena exhibiting strikingly diverse
morphological characteristics. The comparison with available stellar
halo simulations set in a Lambda-Cold Dark Matter cosmology suggests
that this extraordinary variety of morphological specimens detected in
our survey could represent one of the first comprehensive pieces
of evidence to support that the hierarchical formation scenarios
predicted for the formation of galaxies similar to our Galaxy.

I also present the discovery of a tidal stream around a nearby dwarf
irregular galaxy with our small telescopes. Follow-up observations
with Subaru telescope show this stream completely resolved into stars,
providing observational evidence of a minuscule merger in a LMC-type
system in the local universe. This result suggests that dwarf
accretion could play an important role in the star formation history
and evolution of nearby dwarf galaxies.

Links:
 
http://www.cosmotography.com/image/stellar_stream_survey_overview.html
http://www.cosmotography.com/images/dwarf_galaxy_dark_matter.html
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Dr. Enric Marco
Departament d'Astronomia i Astrofísica
Facultat de Física
Universitat de València
C/  Dr. Moliner, 50
46100 Burjassot, Spain
Phone: (34)-96-354-3069
Fax:(34)-96-354-3084
enric.marco en uv.es
www.uv.es/marco
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