1 / 14

Properties of Galaxies at High- redshift in the UDS : Environmental Dependence

Properties of Galaxies at High- redshift in the UDS : Environmental Dependence. Seong -Kook Lee, M. IM & J.-W. Kim CEOU@SNU / Feb. 15, 2013. Motivation. Correlation among color (SF), environment and mass. at z~0, density => color : Blanton+05 mass => color : van der Wel08

leone
Download Presentation

Properties of Galaxies at High- redshift in the UDS : Environmental Dependence

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Properties of Galaxies at High-redshift in the UDS : Environmental Dependence Seong-Kook Lee, M. IM & J.-W. Kim CEOU@SNU / Feb. 15, 2013

  2. Motivation • Correlation among color (SF), environment and mass • at z~0, • density => color : Blanton+05 • mass => color : van der Wel08 • at high-z (z~1), • density => color : Cooper+07,Patel+09 • mass => color : Cucciati+10,Grutzbauch+11 Nature vs. ? nurture Aim : investigate dependence among galaxies’ stellar mass, environment, and stellar population properties (incl. color, SF, SFH) and its evolution up to z<2 SSG Workshop

  3. Motivation • Correlation among color (SF), environment and mass Aim : investigate dependence among galaxies’ stellar mass, environment, and stellar population properties (incl. color, SF, SFH) and its evolution up to z>1 We need, (1) deep imaging data, esp. at rest-frame optical (aka. NIR), to reach z < 2 (2) panchromatic coverage from optical to MIR, for robust estimation of stellar population properties • UKIDSS (UKIRT Infrared Deep Sky Survey) / Ultra-Deep Survey (UDS) • deep NIR data from the UKIRT (J, H, & K) • wide coverage of multi-wavelength data • : Optical from SUBARU (B, V, R, I’, and z’) • MIR from Spitzer/IRAC • - ~0.8 sq. degrees, centered at • the Subaru SXDS field (J0218-05) SSG Workshop

  4. DATA • Multi-wavelength Data (12 bands) - optical from Subaru/Suprimecam : B (28.4), V (27.8), R (27.7), i’ (27.7) and z’ (26.7, 3-sigma,AB) - NIR from UKIRT/WFCAM : J(24.9), H(24.2), K(24.6, 5-sigma,AB) - MIR from Spitzer/IRAC : (Ch1 – Ch4,~24,5-sigma,AB) - ~ 50,000 Objects (K-selected, z<2.2) • Photometric Redshift - scatter Δz/(1+z)~ 0.032 SSG Workshop

  5. Stellar Population Analysis • SED-fitting - BC03, Chabrier IMF - delayed SFHs (τ = 0.1 ~ 7.0 Gyr, t = 0.1 Gyr ~ tage) - 0<E(B-V)< 1.5 - Z = 0.2, 0.4, 1.0, & 2.5 Z => find best-fit among more than 200,000 templates SSG Workshop

  6. Environmental Dependence Stellar Population Properties of high-z galaxies depending on the Galaxy Environment (measured by number density) Candidates of high-z (proto-)Clusters and Properties of Cluster Galaxies • Stellar Population Properties of high-z galaxies depending on the Galaxy Environment (measured by number density) • Candidates of high-z (proto-)Clusters and Properties of Cluster Galaxies SSG Workshop

  7. 1. Galaxy Properties @ different Environment • Method 1. Count galaxies within distance < 500/h kpc, and at Δz < 0.032*(1+z) => N_gal 2. To estimate background, calculate N_gal for all galaxies within redshift bin => find mean (N_0) and SD (sigma_N) 3. Define over-(under-)density measure as (N_gal – N_0)/(sigma_N) SSG Workshop

  8. 1. Galaxy Properties @ different Environment • Results : Colour - Density SSG Workshop

  9. 1. Galaxy Properties @ different Environment • Results : Colour – Stellar Mass SSG Workshop

  10. 2. (proto-) Cluster Candidates @ High Redshifts • Method 1. Galaxy counts at each grid point in RA-Dec space (Δ = 12”) within r < 500/h kpc, at each redshift bin (Δz = 0.02) 2. Find large structures of connected bins (> 10 bins) with galaxy counts > 4-sigma SSG Workshop

  11. 2. (proto-) Cluster Candidates @ High Redshifts • Method : continued 3. Connect the structure found in successive redshift bins (> 3-bins) and find central position and redshift for each (proto-) cluster candidates 4. Find galaxies belonging to each (proto-)cluster (within r < 700/h kpc, Δz/(1+z) < 0.032) SSG Workshop

  12. 2. (proto-) Cluster Candidates @ High Redshifts • Results - found 38 candidates within 0.5 < z < 2.0 - recovers 14 (proto-)clusters published (van Breukelen+06,Finoguenov+10,Papovich+10) SSG Workshop

  13. 2. (proto-) Cluster Candidates @ High Redshifts • Results: sSFR dist. (cluster vs. field) SSG Workshop

  14. Summary • Using Deep NIR imaging data from the UKIRT & panchromatic photometric data, • We are investigating stellar population properties of high-redshift galaxies depending on the environment • And, searching galaxy (proto-)cluster candidates at high redshifts, and studying their evolutionary properties. Please stay tuned !! SSG Workshop

More Related