FRENEL Meeting, Nice, September 2009 FRESNEL Imager: Extragalactic Science in the UV-Optical domains Roser Pelló Laboratoire d’Astrophysique de Toulouse-Tarbes

FI and extragalactic studies Spatial resolution Wavelength coverage (100nm to 10 microns) High dynamic range FI... starts operations after JWST, ALMA and possibly SKA,... it is intended to be a follow up rather than a survey facility could be efficiently used to target galaxies selected from utra- deep photometric and spectroscopic surveys  Mapping the Star Formation of galaxies, from the local universe to ~75% look back time (UV, z~0 to 2)  Constraining the physical properties of the first galaxies (IR)

Extragalactic studies in the UV Galaxy Evolution Explorer (GALEX, 2003-) GALEX FUV GALEX NUV

Ex.: composite spectra of high-z galaxies observed in the optical domain (VVDS Survey Le Fevre et al. 06, Paltani et al. 07) Paltani et al. 07)

Composite spectra of z~3 LBGs, for different Ly a equivalent widths, observed in the optical (lambda~ A) (Shapley et al. 2003)

Line diagnostics and redshift near-IR visible Ly a HeII 1640 [OII]3727 Hb + [OIII]5007 Ha + [NII]

Line diagnostics and redshift Line diagnostics shift towards the near-IR (lambda>1 micron)

Ha/[NII] [S II] AGN Starbursts Empirical discrimination between AGN/starbursts From Erb et al combined spectra of galaxies at z~2 (~14-15 specta/ mass bin)

Star-formation rate determinations Different calibrations available :  UV continuum flux  FIR emission  H alpha  [OII]3727  (Ly alpha) Based on the properties of the integrated population Groves 2005 (Kennicutt 1998, Schaerer 1999,...)

Star-formation rate determinations (from Schaerer 1999) IMF UV continuum flux density L(Ha) luminosity

Cosmic SFR density Inhomogneous SFR indicators at different redshifts Inhomogneous SFR indicators at different redshifts Old paper by Steidel et al Lilly et al. 96 Connolly et al. 97 Madau et al. 96 Steidel et al. 99 H alpha z< 0.5 H alpha z< 0.5 [OII] <z<1.5 [OII] <z<1.5 continuum UV z > 1.5 continuum UV z > 1.5

Cosmic SFR density Inhomogneous SFR indicators at different redshifts Inhomogneous SFR indicators at different redshifts Lilly et al. 96 Connolly et al. 97 Madau et al. 96 Steidel et al. 99 H alpha z< 0.5 H alpha z< 0.5 [OII] <z<1.5 [OII] <z<1.5 continuum UV z > 1.5 continuum UV z > 1.5 Bouwens et al. 2008

GALEX HDF Dust extinction correction is an issue... D'apres Schiminovich et al. 05

Extragalactic studies in the UV with FI UV (restframe) observations ==> Star Formation activity UV-calibrated Star Formation Rate measurements Lyman alpha properties Metal abundances Extinction UV (SF) – morphology Recent (age<~ 100 Myr) SF history A complete view of star-formation at 0<z<2 (75% of light travel time... ) Calibration in the local universe

Ly alpha emission IZw18 A complex Ly a emission in a Local sturburst (Atek et al. 09) 4'' HST/STIS

Ly alpha emission A complex Ly a emission in a Local sturburst (Atek et al. 09) - Empirical estimate of Ly a escape fraction in a statistically significant sample of z~0-0.3 Lya emitters detected by GALEX (24 galaxies) Atek et al. 2009

The size of local starburst galaxies From Ostlin et al. 08 5''x5'' 7.5''x7.5'' 15''x15'' - Emission-line images of local starbursts (Ha, [OIII] and Hb). - Comparison between Lya, Ha and UV continuum emission Ly a emission

Ly alpha/UV emission in distant galaxies Lemoine-Busserolle et al Pello et al Lensed galaxies : Z =

Le Borgne et al. AC114-S2 Local starbursts SED fitting to constrain SFR history, age of stellar population, E(B-V), metallicity

Ly alpha/UV emission in distant galaxies Le Borgne et al. SED fitting to constrain SFR history, age of stellar population, E(B-V), metallicity Metallicity constraints from UV slope β extinction corrected SED U B V R I J K z~1.7 lensed galaxy

Ex.: Schaerer & Verhamme 08, modeling Lyman alpha line in Ms1512 – cB58 (lensed LBG, z~2.7) Ly alpha emission in distant galaxies

The size of high-z star-forming galaxies From Bouwens & Illingworth 09 ~L* galaxies

The size of high-z star-forming galaxies From Bouwens & Illingworth 09 3 arcsec Z~6 dropouts in the HUDF

The size of high-z star-forming galaxies From Rauch et al. 08 Z~ Ly a emitters 2D spectra Lambda ~5000 A 15 arcsec 40 A

1 arcsec 0.1 arcsec 0.01 arcsec arcsec galaxies

1 arcsec 0.1 arcsec 0.01 arcsec arcsec galaxies bulges Spiral arms Globularclusters HII regions Paladini et al. 04

Urry & Padovani, (1995) Jets BH Obscuring torus ( K, ~1-300 pc) NB region (T eff ~ 60K) BL region (T eff ~ 2000 K, ~ pc) Accretion disk (T eff ~ 10 5 K, ~0.01 pc) θ

1 arcsec 0.1 arcsec 0.01 arcsec arcsec AGN obscuring torus galaxies bulges Spiral arms Globularclusters AGN accretion disk (~0.01 pc) HII regions

Conclusions (I) FI should be able to yield a HR UV (restframe) picture of the local universe. Study of photoionization regions: structure (high dynamics), physics (line diagnostics -stellar, ISM-, stellar populations,...).  UV-calibrated Star Formation Rate measurements  UV-calibrated indicators for extragalactic physics in the distant universe (metallicity, age of underlying stellar populations, IMF?,...)  Lyman alpha properties in local starbursts. Scape fraction as a function of relevant parameters ==> High-z universe  Unprecedented capability in understanding star-formation processes at HII-region's scale.  Understanding co-evolution AGN host galaxy. Nuclear regions of galaxies: looking for AGN signatures in the core region, constraining AGN feedback...

Conclusions (II) Depending on sensitivity, FI could provide the UV budget of star formation in galaxies from z~0 to z~2 (universe aged of Gyr).  Understanding the downsizing mechanism at the spatial scale corresponding to a typical HII region up to z~2, and a well suited FOV(ex. FOV(z~1-2)~ is ~70 kpc; FOV(z~0.5)~50 kpc, and ~32 kpc at z~0.3).  Lyman alpha emission in details: mechanism and geometry of SF activity  Metallicity evolution for different galaxy environments. Other interesting cases requiring high dynamic range: multiple- imaged QSOs (FVO~1-3''); clusters of galaxies (cluster core, AGN feedback, FVO~1-10''). Tentative topic: looking at new-born galaxies at all z. This means looking for PopIII signatures (e.g. HeII1640 line) in (compact/ small/ BCGs) galaxies.

Open questions: The band-pass is relatively narrow (e.g. ~70A in the UV and ~450A in the near-IR at ~8000A in the imaging mode): ==> Sensitivity issue in the continuum detection (usual BB filters are ~5-10 larger in the UV) ==> For a given configuration, and for a given spectral feature, only a small redshift domain is accessible : dz~0.05(1+z) Ex. In the local universe, for the first UV band, we can reach ~2d(Coma) for a given spectral feature (e.g. Ly a). The spatial resolution decreases with lambda, i.e. as (1+z) for a given spectral feature ==> In practise, most studies with strong requirements in spatial resolution will be limited to the « nearby » universe (z<1).

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