Transcript Metallicity maps

Metal Enrichment Processes
Sabine Schindler
University of Innsbruck
With XMM observations it is now possible to
determine not only the metallicity (Fe abundance)
of a cluster or the metallicity profile, but a
2D metallicity map
red – high metallicity
blue - low metallicity
Centaurus
Metallicity maps
Sersic 159-03
Lovisari et al., subm.
A496
A2029
Hydra A
A2319
red – high metallicity
blue - low metallicity
Centaurus
Metallicity maps
A496
Lovisari et al., subm.
A2029
Even for relaxed clusters the metal distribution
is non-spherical
very inhomogeneous
Sersic 159-03
Hydra A
A2319
red – high metallicity
blue - low metallicity
Centaurus
Metallicity maps
A496
Lovisari et al., subm.
A2029
Metal mass:
determined with the 2D metal maps the metal mass is up to a factor 2
higher than determined by a single metallicity value
so far metal masses have been
underestimated
Hydra
A
(see predictions by simulations, Kapferer et al. 2007)
Sersic 159-03
A2319
Radial profiles of different elements
• Contribution SNII / SNIa decreases towards centre
• Fraction SNII/ SNIa ~ 65-80%
Lovisari et al., subm.
O/Fe
Si/Fe
Where do the metals come from?
What processes are responsible?
Complex mixture of processes
Simulations required
Stefanie
Unterguggenberger
Markus
Heider
Wolfgang
Kapferer
Sabine
Schindler
Thomas
Kronberger
Eelco
van
Kampen
Lorenzo
Lovisari
Thomas
Kronberger
Magda
Mair
Chiara
Ferrari
Emanuela
Orrú
Martin
Pančišin
Julia
Weratschnig
Sabine
Schindler
Magda
Mair
Josef
Stoeckl
Wolfgang
Kapferer
Julia
Weratschnig
http://astro.uibk.ac.at/astroneu/hydroskiteam/index.htm
Simulation
Metal enrichment
Many different scales involved
Simulations
 on galaxy scales
 on cluster scales
Galaxy scales…
Ram-pressure stripping is an important
process in clusters
• More and more observational
evidence for ram-pressure
stripping….
Crowl et al. 2006
Film1
Kronberger et al. 2008
Results
 star formation is increased significantly by
ram-pressure stripping (up to a factor of 10)
 stars form in the central compressed region and in the
stripped gas behind the galaxy  intra-cluster
stellar population
 stars fall back onto and through disc  different morphology
Kronberger et al. 2008
Kapferer et al. 2008
Evidence for star formation in stripped gas
Blue knots behind a galaxy
in the Coma cluster
Star formation in the wake
of ESO137-001 in A3627
Yoshida et al. 2008
red: CHANDRA contours
blue & cyan: star forming
regions
Sun et al. 2007
A3627: ESO137-001
Hester et al. 2010
Tail of star formation
trailing IC3418
in Virgo
Ram pressure stripping is also important
in collisions within clusters….
Film2
Kapferer et al. 2008
Systematic study of ram-pressure stripping varying
 surrounding gas density
 relative velocity
gas
density
stellar surface
brightness
log
scale
v = 500 km/s
ρ = 5 10-27 g/cm3
t = 500 Myrs
Kapferer et al. 2009
Results
 even ram-pressure in the outskirts of clusters is sufficient
to strip gas and form new stars
 up to 95% of newly formed stars can be in the wake
Kapferer et al. 2009
simulated
observations
Kapferer et al. 2009
Simulations on cluster scales…
Density and temperature
Density and metalliticy
Ram-pressure stripping – galactic winds
Ram-pressure stripping – galactic winds (X-ray)
Results:
simulation
 inhomogeneous metal
distribution
 enriched gas is not mixed
immediately with the ICM
observed metallicity map
Lovisari et al. 2009
Comparison of ram-pressure stripping
and galactic winds Kapferer et al. 2007
Movie1
mass loss
redshift
Movie2
profile
Comparison Winds – Ram-Pressure Stripping
 Distribution of Metals
Galactic winds
extended distribution
Ram-pressure stripping
centrally concentrated distribution
 Efficiency
Galactic winds are more efficient in earlier epochs
Ram-pressure stripping is more efficient after z=1-2
 Amount of Metals
Ram-pressure stripping can produce considerably more metals
than galactic winds (depending on cluster mass and other cluster
properties)
Schindler et al. 2005, Kapferer et al. 2007, 2009
Summary
 different processes contribute to the metallicity (not just a single process,
but ram-pressure stripping is very important),
they yield different metal distributions and have different time scales
 ram-pressure in the outskirts of clusters is sufficient to strip gas and form
new stars
 inhomogeneous metallicity distribution,
enriched material is not mixed immediately with ICM
 metal mass from X-ray observations is considerably underestimated
due to inhomogeneous metal distribution
 ram-pressure stripping leads to enhanced star formation,
star formation also behind the galaxy  intra-cluster stars
Schindler et al. 2005, Kapferer et al. 2005, Kapferer et al. 2006, Domainko et al. 2006, Kapferer et al. 2007a,b,
Kronberger et al.2008, Kapferer et al. 2008, 2009, 2010, Lovisari et al. 2009, Lovisari et al., subm.