Lecture #5 Observational facts Olivier Le Fèvre – LAM Cosmology Summer School 2014

Lecture plan 1. Finding galaxies at z>>4 2. Luminosity Function and SFRD 3. The future

Finding needles in a haystack !  Use the Ly  emission  Emission line brighter than continuum  Seems that Ly  drops at z>6  Use “dropout” technique  Based on continuum properties  The “Lyman-break” generalized

Lyman-break / dropout technique movie

Using Lyman- emission But seems that Ly  drops at z>6 Fraction Ly 

UDFj The most distant galaxy confirmed (today !)  Detected in H-band only !  confirmed  Dropout at 1.4 microns  zspec = , but controversial

A tricky business…

Looking for faint very red smudges Lyman-break search

Mostly HST business  ACS and WFC3 cameras cover B band to H band  Various deep fields  HDF  HUDF  XDF  … LF Z~4 Z~5 Z~6 Bouwens+ 2007

HUDF

Bouwens+ 2011

When, how long, and how works the reionisation: bets are open ! Neutral !

The exploration with galaxy surveys will continue  All wavelength  Extreme sensitivities mag_AB>30  All sky ultra-deep  Large samples  ALMA (sub-mm)  JWST (IR)  EELT (visible+NIR)  Ultra-Deep  EUCLID (visible+NIR)  All-sky

Space telescope Space telescope Diameter: 6.5m Diameter: 6.5m microns microns Observe first light Observe first light Launch 2018 Launch 2018 JWST

JWST instruments  NIRCAM: microns  2.2’x4.4’  NIRSPEC: 1-5 microns  3’x3’  Multi-slit  MIRI: 5 to 27 microns  Imaging and spectroscopy  1.3’x1.7’ 15

The ESA-Euclid space mission  The major space cosmology mission for the next decade  Selected by ESA in Oct.2011  Launch 2020  Goals: understand the nature of dark matter and dark energy 16

EELT: European Extremely Large Telescope Construction to be decided in 2013 ? One of the main goals: find and study the most distant galaxies at reionisation

A bright and busy future for deep surveys !