David Schade Canadian Astronomy Data Centre Herzberg Institute of Astrophysics

Structures in the Universe, Venice March 28, 2006

David SchadeCanadian Astronomy Data CentreHerzberg 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

CFHT Legacy Survey: Evolution of disk galaxies 0< z < 1CFHT Legacy Survey: Evolution of disk galaxies 0< z < 1CFHT Legacy Survey: Evolution of disk galaxies 0< z < 1CFHT Legacy Survey: Evolution of disk galaxies 0< z < 1


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

Evolution of disk galaxiesEvolution of disk galaxiesEvolution of disk galaxiesEvolution of disk galaxies


Disks in the Canada-France Redshift SurveyDisks in the Canada-France Redshift SurveyDisks in the Canada-France Redshift SurveyDisks in the Canada-France Redshift Survey

Redshift > 0.5

Redshift < 0.5

Schade et al. 1995,1996



Redshift > 0.5

Mean surface brightness

1.6 mag brighter than Freeman

value

Redshift < 0.5

Schade et al. 1996


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



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



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



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: HST Imaging of 4 clusters 0.3 - 0.83Clusters: HST Imaging of 4 clusters 0.3 - 0.83Clusters: HST Imaging of 4 clusters 0.3 - 0.83Clusters: HST Imaging of 4 clusters 0.3 - 0.83


Saintonge, Schade,

Yee, etc

Issues:

Completeness

Field galaxy contamination

Mass normalization

Clusters:Clusters:Clusters:Clusters:

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


Saintonge, Schade,

Yee, etc

Issues:

Completeness


Mass normalization




Mass Normalization

• Cluster size

• Cluster mass

• Observational sampling

• Integrate mass model over

the lines of sight




Saintonge, Schade,

Yee, etc

Issues:

Completeness


Mass normalization




MS1054 at z=0.82 compared to evolved local sampleMS1054 at z=0.82 compared to evolved local sampleMS1054 at z=0.82 compared to evolved local sampleMS1054 at z=0.82 compared to evolved local sample


Canada-France-Hawaii Telescope Legacy SurveyCanada-France-Hawaii Telescope Legacy SurveyCanada-France-Hawaii Telescope Legacy SurveyCanada-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


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

Kanwar et alKanwar et al20062006Kanwar et alKanwar et al20062006

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

Galaxies in the Canada-France-Hawaii Telescope Legacy Galaxies in the Canada-France-Hawaii Telescope Legacy SurveySurveyGalaxies in the Canada-France-Hawaii Telescope Legacy Galaxies in the Canada-France-Hawaii Telescope Legacy SurveySurvey

Completeness at z =0.9


Size FunctionSize FunctionSize FunctionSize Function

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 sizeEvolved sizefunctionfunctionEvolved sizeEvolved sizefunctionfunction

Evolved

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



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



Disk Galaxies

23,000 galaxies

I(AB) < 24.5

B/T < 0.2

MB <-18.75



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.



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 SurveyMassive galaxies in the CFHT Legacy SurveyMassive galaxies in the CFHT Legacy SurveyMassive 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 SurveyGalaxies in the Canada-France-Hawaii Legacy SurveyGalaxies in the Canada-France-Hawaii Legacy SurveyGalaxies in the Canada-France-Hawaii Legacy Survey


Galaxies in the Canada-France-Hawaii Legacy SurveyGalaxies in the Canada-France-Hawaii Legacy SurveyGalaxies in the Canada-France-Hawaii Legacy SurveyGalaxies 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.


David SchadeCanadian Astronomy Data CentreHerzberg Institute of Astrophysics

National Research Council Canada

Collaborators:

– Anudeep Kanwar– Amelie Saintonge– Luc Simard– Stephen Gwyn– Felipe Barrientos– Howard Yee– Erica Ellingson– Ray Carlberg

CFHT Legacy Survey: Evolution of disk galaxies 0< z < 1CFHT Legacy Survey: Evolution of disk galaxies 0< z < 1CFHT Legacy Survey: Evolution of disk galaxies 0< z < 1CFHT Legacy Survey: Evolution of disk galaxies 0< z < 1

Documents

David Schade Canadian Astronomy Data Centre Herzberg Institute of Astrophysics