asteroseismology for galactic archaeology: bridging two fields...asteroseismology for galactic...
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Asteroseismology for Galactic Archaeology:
bridging two fields
Luca Casagrande Victor Silva Aguirre
Dennis Stello, Aldo Serenelli Daniel Huber, Katie Schlesinger, Ralph Schönrich, Sofia Feltzing
Asteroseismology for Galactic Archaeology:
bridging two fieldswww.mso.anu.edu.au/saga
Casagrande, Silva Aguirre, Stello et al. 2014, ApJ, 787, 110Casagrande, Silva Aguirre, Schlesinger et al. 2015, MNRAS, submitted
Luca Casagrande Victor Silva Aguirre
Dennis Stello, Aldo Serenelli Daniel Huber, Katie Schlesinger, Ralph Schönrich, Sofia Feltzing
WFC @ INT: •2.5 m •34’ x 34’ FOV •Strömgren uvby • ~30 nights (2012-2014) • ~40 nights (2015)
Isaac Newton Telescope Kepler field
Kepler is dead, long live to Kepler!
WFC @ INT: •2.5 m •34’ x 34’ FOV •Strömgren uvby • ~30 nights (2012-2014) • ~40 nights (2015)
Isaac Newton Telescope Kepler field
Kepler is dead, long live to Kepler!
WFC @ INT: •2.5 m •34’ x 34’ FOV •Strömgren uvby • ~30 nights (2012-2014) • ~40 nights (2015)
Isaac Newton Telescope Kepler field
Kepler is dead, long live to Kepler!
WFC @ INT: •2.5 m •34’ x 34’ FOV •Strömgren uvby • ~30 nights (2012-2014) • ~40 nights (2015)
Isaac Newton Telescope Kepler field
Kepler is dead, long live to Kepler!
~ 1000 red giants
Image credit: NASA/JPL-Caltech
Image credit: NASA/JPL-Caltech
⦿
Galactic Evolution (=baryons!)e.g. Lynden-Bell 1975, Tinsley 1980, Matteucci & Francois 1989, Chiappini et al. 1997, Schönrich & Binney (2009)
⦿
⦿
Galactic Evolution (=baryons!)e.g. Lynden-Bell 1975, Tinsley 1980, Matteucci & Francois 1989, Chiappini et al. 1997, Schönrich & Binney (2009)
⦿
⦿
Galactic Evolution (=baryons!)
AMR
e.g. Lynden-Bell 1975, Tinsley 1980, Matteucci & Francois 1989, Chiappini et al. 1997, Schönrich & Binney (2009)
[Fe/
H]
⦿Schönrich & Binney (2009)
age
Galactic Evolution (=baryons!)e.g. Lynden-Bell 1975, Tinsley 1980, Matteucci & Francois 1989, Chiappini et al. 1997, Schönrich & Binney (2009)
AMR
[Fe/
H]
⦿
age
Galactic Evolution (=baryons!)e.g. Lynden-Bell 1975, Tinsley 1980, Matteucci & Francois 1989, Chiappini et al. 1997, Schönrich & Binney (2009)
AMR
[Fe/
H]
⦿
age
Galactic Evolution (=baryons!)e.g. Lynden-Bell 1975, Tinsley 1980, Matteucci & Francois 1989, Chiappini et al. 1997, Schönrich & Binney (2009)
AMR
[Fe/
H]
⦿
AVR
age e.g. Holmberg et al. (2007), Casagrande et al. (2011)
age
Schönrich & Binney (2009)
Strömgren (uvby)→ [Fe/H]
Broad-band photometry→ Teff ← Asteroseismology
(evol. phase, Δν
, νMAX )
Radii, Masses,
distances, ages,
metallicities
✓ Kepler selection function: how well the red giants observed by Kepler are representative of the underlying population of giants in the field. (benchmarking against an unbiased sample).
✓ Target selection effects: once the selection function is known, how this bias the observations. (population synthesis).
✓ Kepler selection function: how well the red giants observed by Kepler are representative of the underlying population of giants in the field. (benchmarking against an unbiased sample).
✓ Target selection effects: once the selection function is known, how this bias the observations. (population synthesis).
all stars
Kepler selection function
V < 14
Kepler selection function
V < 14
GCS dwarfs
-2.0 giants
Kepler selection function
V < 14
seismic
GCS dwarfs
-2.0 giants
Kepler selection function
V < 14
seismic
GCS dwarfs
-2.0 giants
Kepler selection function
unbiased sample
Kepler sample
~400 red giants
V < 14
seismic
GCS dwarfs
-2.0 giants
Kepler selection function
unbiased sample
Kepler sample
~400 red giants
Target selection effects
Stellar Mass gradient
height above the Galactic plane (kpc)
Stellar Mass gradient
height above the Galactic plane (kpc)
Age gradient
height above the Galactic plane (kpc)
Age gradient
height above the Galactic plane (kpc)
Age gradient
height above the Galactic plane (kpc)
4 ± 2 Gyr / kpc
NOW Lookback time
Age-metallicity relation
NOW Lookback time
Age-metallicity relation
NOW Lookback time
Age-metallicity relation
ConclusionsADVANCES IN GALACTIC ASTRONOMY FROM
ASTEROSEISMOLOGY
Vertical structure of the disk:
vertical age gradientage-metallicity
suggest quiescent evolution for Milky Way disc over the last 10 Gyr, thus highlighting the importance of
secular processes in disc evolution