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CFHT Legacy Survey: Evolution of disk galaxies 0< z < 1. David Schade Canadian Astronomy Data Centre Herzberg Institute of Astrophysics National Research Council Canada Collaborators: Anudeep Kanwar (poster at this meeting) Amelie Saintonge Luc Simard Stephen Gwyn Felipe Barrientos
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CFHT Legacy Survey: Evolution of disk galaxies 0< z < 1 David Schade Canadian Astronomy Data Centre Herzberg Institute of Astrophysics National Research Council Canada Collaborators: • Anudeep Kanwar (poster at this meeting) • Amelie Saintonge • Luc Simard • Stephen Gwyn • Felipe Barrientos • Howard Yee • Erica Ellingson • Ray Carlberg
Evolution of disk galaxies First detection of evolution of properties of disk galaxies: 1995, 1996 It is curious that the past decade of work has left us without a clear consensus Surface brightness evolution of disks on 0< z < 1? • Schade et al. (1996):B~1.6 mag relative to Freeman value (small disks HST & CFHT) • Lilly et al. (1999): B~0.8 +- 0.3 mag large disks HST • Simard et al. (1998): B~0 HST • Roche et al. (1998): B~0.95+- 0.22 mag HST • Bouwens & Silk (2002) B~1.5 mag • Ravindranath et al 2004: B< 0.4 MV < -19.5 HST, Sersic n < 2 • Barden et al. (2005): v ~ 1.0 mag HST & GEMS & Sersic MV < -20 • Kanwar et al. 2006: B=1.5 +- 0.2 MB < -18.75 HST
Disks in the Canada-France Redshift Survey Redshift < 0.5 Redshift > 0.5 Schade et al. 1995,1996
Disks in the Canada-France Redshift Survey Mean surface brightness 1.6 mag brighter than Freeman value Redshift < 0.5 Redshift > 0.5 Schade et al. 1996
Disks in the Canada-France Redshift Survey The size-function of disks Luminous disks: (MB < -20) At z > 0.5 there is a large excess of small (h~2-3 kpc) disks compared to low redshift
Disks in the Canada-France Redshift Survey The size-function of disks Luminous disks: (MB < -20) If you reach 1.5 magnitudes fainter into the disk popuation at z < 0.5 then you find the appropriate volume density of small disks That is: Luminosity evolution (of ~1.5 magnitudes) reconciles the low and high-redshift disk populations
Evolution of disk galaxies First detection of evolution of properties of disk galaxies: 1995, 1996 It is curious that the past decade of work has left us without a clear consensus Surface brightness evolution of disks on 0< z < 1? • Schade et al. (1996):B~1.6 mag relative to Freeman value (small disks HST & CFHT) • Lilly et al. (1999): B~0.8 +- 0.3 mag large disks HST • Simard et al. (1998): B~0 HST • Roche et al. (1998): B~0.95+- 0.22 mag HST • Bouwens & Silk (2002) B~1.5 mag • Ravindranath et al 2004: B< 0.4 MV < -19.5 HST, Sersic n < 2 • Barden et al. (2005): v ~ 1.0 mag HST & GEMS & Sersic MV < -20 • Kanwar et al. 2006: B=1.5 +- 0.2 MB < -18.75 HST
Clusters: HST Imaging of 4 clusters 0.3 - 0.83 Saintonge, Schade, Yee, Ellingson, Carlberg 2005 Disk detection and measurement completeness corrections • Add simulated galaxies to real frames • Recover using sExtractor • Measure using fitting routine
Clusters: Saintonge, Schade, Yee, etc Issues: Completeness Field galaxy contamination Mass normalization In these clusters there is an excess of small high-surface brightness disks at high redshift that persists after completeness and field contamination corrections are applied
Clusters: Saintonge, Schade, Yee, etc Issues: Completeness Field galaxy contamination Mass normalization In these clusters there is an excess of small high-surface brightness disks at high redshift that persists after completeness and field contamination corrections are applied
Clusters: Mass Normalization • Cluster size • Cluster mass • Observational sampling • Integrate mass model over the lines of sight In these clusters there is an excess of small high-surface brightness disks at high redshift that persists after completeness and field contamination corrections are applied
Clusters: Saintonge, Schade, Yee, etc Issues: Completeness Field galaxy contamination Mass normalization In these clusters there is an excess of small high-surface brightness disks at high redshift that persists after completeness and field contamination corrections are applied
Canada-France-Hawaii Telescope Legacy Survey CFHT Megacam 36 CCD’s 1 square degree field Deep Fields D1 and D3 (Kanwar et al 2006) Morphology, Photometric redshifts (Gwyn) for ~500,000 galaxies to i ~ 26
Kanwar et al 2006 Completeness at z =0.9 Disk Galaxies > 23,000 galaxies I(AB) < 24.5 B/T < 0.2 MB <-18.75 Region of high completeness at z=0.9 plotted on all redshift plots
Galaxies in the Canada-France-Hawaii Telescope Legacy Survey Completeness at z =0.9 Disk Galaxies 23,000 disk galaxies I(AB) < 24.5 B/T < 0.2 MB <-18.75 Emerging population of small disk galaxies
Size Function Disk Galaxies 23,000 disk galaxies I(AB) < 24.5 B/T < 0.2 MB <-18.75 This rules out the no evolution model at high confidence level Factor 2-4x fewer disks at low redshift to a fixed luminosity limit
Evolved size function Evolved Disk Galaxies 23,000 disk galaxies I(AB) < 24.5 B/T < 0.2 MB <-18.75 Evolution of 1.5 mag in luminosity (surface brightness) from z=0.9 to z=0.3
Galaxies in the Canada-France-Hawaii Telescope Legacy Survey Disk Galaxies 23,000 disk galaxies I(AB) < 24.5 B/T < 0.2 MB <-18.75 Luminosity evolution of 1.5 mag is sufficient to bring the size functions into agreement
Galaxies in the Canada-France-Hawaii Telescope Legacy Survey Disk Galaxies 23,000 galaxies I(AB) < 24.5 B/T < 0.2 MB <-18.75
Galaxies in the Canada-France-Hawaii Telescope Legacy Survey • What is the reason for the lack of consensus? • Sersic versus bulge-plus-disk models? • Different selections of the population? • Different luminosity ranges? • Different galaxy size ranges? • Are the observations fundamentally in conflict with one another? • We are dealing with a censored distribution of surface brightness. • Interpretations are different.
Evolution of disk galaxies • Conclusions from CFHT Legacy Survey data: • The no-evolution model for the disk size function is rejected • A simple model with uniform evolution of surface brightness with redshift is sufficient to represent the observations
Massive galaxies in the CFHT Legacy Survey Barrientos, Schade, Kanwar: Examine the variance in the properties of the most massive galaxies in order to estimate the variance in their formation histories relative to less massive galaxies
Galaxies in the Canada-France-Hawaii Legacy Survey Most luminous (MB) galaxies
Galaxies in the Canada-France-Hawaii Legacy Survey The most luminous galaxies at z=0.9 have a distribution of types where late-type galaxies are over-represented relative to the population at the same volume density at z=0.3. There is evolution that is differential with respect to morphology even in the most luminous (massive?) galaxies.
CFHT Legacy Survey: Evolution of disk galaxies 0< z < 1 David Schade Canadian Astronomy Data Centre Herzberg Institute of Astrophysics National Research Council Canada Collaborators: • Anudeep Kanwar • Amelie Saintonge • Luc Simard • Stephen Gwyn • Felipe Barrientos • Howard Yee • Erica Ellingson • Ray Carlberg