The Halo Occupation Distribution of H-alpha emitters Carlton Baugh - PowerPoint PPT Presentation

The Halo Occupation Distribution of H-alpha emitters Carlton Baugh Institute for Computational Cosmology Durham University

Predicting H- a flux • Compute number of Lyman continuum photons • Depends on metallicity stars are produced with • x1.5 variation over range close to solar • Canonical conversion: Kennicutt 1983

Predicting H- a flux • Compute number of Lyman continuum photons • Depends on metallicity stars are produced with • x1.5 variation over range close to solar • Canonical conversion: Kennicutt 1983

Predicting H- a flux Variations due to metallicity with which stars are formed and SF history

Direct estimate now includes Dust extinction (as per continuum) Typically, 1 magnitude of extinction is assumed in observational work.

Direct estimate now includes Dust extinction (as per continuum) Typically, 1 magnitude of extinction is assumed in observational work.

Evolution of the LF Observed LF: HiZELS Sobral et al. 2012

HOD of H- a emitters at z=2.23 370 emitters, ~2sq deg z=2.23 Geach et al. 2012 arXiv:1206.4052

HOD z=0.40 Euclid flux limit • Black: total • Blue: central • Red: satellite

HOD z=0.84 Euclid flux limit

HOD z=1.4 Euclid flux limit

HOD z=2.23 Euclid flux limit

Summary • H-alpha luminosity depends on Lyman continuum photons • Number of Lyman continuum photons depends on metallicity & SF history • Using solar conversion factor can lead to large errors • Also need to include dust extinction • HOD for Euclid flux limits: N<<1