clash photometric redshifts for galaxies in cluster field n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
CLASH Photometric redshifts for galaxies in cluster field PowerPoint Presentation
Download Presentation
CLASH Photometric redshifts for galaxies in cluster field

Loading in 2 Seconds...

play fullscreen
1 / 18

CLASH Photometric redshifts for galaxies in cluster field - PowerPoint PPT Presentation


  • 140 Views
  • Uploaded on

CLASH Photometric redshifts for galaxies in cluster field. Stephanie Jouvel & CLASH photo- z team. Jouvel et al 2013 submitted. CLASH/HST Photo- z goals. Accurate photo- z for the SL arcs Clean cluster/background galaxy selection. 690 galaxies with spec- z covered by HST:

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'CLASH Photometric redshifts for galaxies in cluster field' - bruce-sosa


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
clash photometric redshifts for galaxies in cluster field

CLASH Photometric redshifts for galaxies in cluster field

Stephanie Jouvel & CLASH photo-z team

Jouvel et al 2013 submitted

Stephanie Jouvel

clash hst photo z goals
CLASH/HST Photo-z goals
  • Accurate photo-z for the SL arcs
  • Clean cluster/background galaxy selection

690 galaxies with spec-z covered by HST:

584 cluster+foreground

106 lensed background

We use BPZ & Le Phare

Not enough galaxies to train NN and other training methods

Stephanie Jouvel

cosmos templates library for le phare
COSMOS templates library for Le Phare

Lines are templates colors, dots are CLASH observations for the full specz sample

Good agreement between model & the CLASH observations

Stephanie Jouvel

lensed background galaxies z z cluster 0 2
Lensed background galaxies z>zcluster+0.2

Very good accuracy of NMAD~3%

Stephanie Jouvel

clash photoz accuracy with simulations
CLASH photoz accuracy with simulations

Simulation of the CLASH photometry in the 16 HST filters

We reach a limit in the photo-z scatter due to the filter resolution

=> It’ll be hard to beat the 2-3% NMAD using broadband photometry

Stephanie Jouvel

macs1206 strong lensing arcs
MACS1206 strong-lensing arcs

4 systems with spec-z:

Sys 1: zs=1.03

Sys 2: zs=3.03

Sys 3: zs=3.03

Sys 4: zs=2.54

Stephanie Jouvel

macs1206 system 1
MACS1206 System 1

Balmer break

Lyman break

Zs=1.03: Balmer & Lyman break

=> Good photoz

Stephanie Jouvel

macs1206 system 2
MACS1206 System 2

Lyman break

Zs=3.03: Balmer break outside the CLASH filters

Stephanie Jouvel

macs1206 system 3
MACS1206 System 3

Lyman break

Zs=3.03: Balmer break outside the CLASH filters

Stephanie Jouvel

macs1206 system 4
MACS1206 System 4

Balmer break

Lyman break

Cluster light contamination

Zs=2.54: Balmer & Lyman break

=> Good photoz

Stephanie Jouvel

uv filters in the photoz estimation of background lensed galaxies
UV filters in the photoz estimation of background lensed galaxies
  • UVIS filters are useful to follow the Lyman break for galaxies 0.7<z<2.5
    • At z>2.5 the Lyman break is in F435W and the UVIS filters stop being useful.
    • At z<0.7 the Lyman break did not reach F225W
  • UVIS filters useful for the photo-z of background galaxies

Stephanie Jouvel

photoz scatter lss in lensing
Photoz scatter & LSS in lensing

Translating a 4% photoz error into a SL arcs positional error when deriving gravitational potential on A1689 (cause it has more than 106 arcs).

A 4% photoz error is bigger than LSS positional error for 6/106 arcs.

=> 3% photoz error is ok for SL

Stephanie Jouvel

bpz and le phare
BPZ and Le Phare

Some work needed to understand

the discrepancy at low z between BPZ and Le Phare

Stephanie Jouvel

bpz and le phare1
BPZ and Le Phare

Some work needed to understand

the discrepancy at low z between BPZ and Le Phare:

Low odds are lowz for Le Phare and highz for BPZ

Stephanie Jouvel

some ideas
Some ideas

Stephanie Jouvel

conclusion
Conclusion
  • Good photoz accuracy for the SL arcs from both BPZ and Le Phare of NMAD~3%
  • Progress needed for the background/foreground galaxy selection. BPZ and Le Phare have different estimates for 7% of galaxies in MACS1206 field
  • Use the full P(z) to improve the photoz estimates

Stephanie Jouvel