FRENEL Meeting, Nice, 23-25 September 2009

FRESNEL Imager: FRESNEL Imager: Extragalactic Science in Extragalactic Science in the UV-Optical domainsthe UV-Optical domains

Roser Pelló Roser Pelló Laboratoire d’Astrophysique de Toulouse-TarbesLaboratoire d’Astrophysique de Toulouse-Tarbes

FI and extragalactic studiesFI and extragalactic studies Spatial resolution

Wavelength coverage (100nm to 10 microns)

High dynamic range

FI ...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 UVExtragalactic studies in the UV

Galaxy Evolution Explorer (GALEX, 2003-)

GALEX FUV

GALEX NUV

Ex.: composite Ex.: composite spectra of high-z spectra of high-z galaxies observed galaxies observed in the optical in the optical domaindomain(VVDS Survey(VVDS SurveyLe Fevre et al. 06,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~4500-7000 A)

(Shapley et al. 2003)

Line diagnostics and redshiftLine diagnostics and redshift

near-IR

visible

Ly a

HeII 1640

[OII]3727Hb + [OIII]5007Hb + [OIII]5007Ha + [NII]

Line diagnostics and redshiftLine diagnostics and redshift

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

Ha/[NII][S II]

AGN

Starbursts

Empirical Empirical discrimination discrimination between between AGN/starburstsAGN/starbursts

From Erb et al. 06

87 combined spectra of galaxies at z~2 (~14-15 specta/ mass bin)

Star-formation rate determinationsStar-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 2005Groves 2005

(Kennicutt 1998, Schaerer 1999, ...)

Star-formation rate determinationsStar-formation rate determinations(from Schaerer 1999)

IMFIMF

UV continuum flux density

L(Ha) luminosity

Cosmic SFR densityCosmic SFR density Inhomogneous SFR Inhomogneous SFR

indicators at different indicators at different redshiftsredshifts

Old paper by Steidel et al. 1999... Old paper by Steidel et al. 1999...

Lilly et al. 96Lilly et al. 96

Connolly et al. 97Connolly et al. 97

Madau et al. 96Madau et al. 96

Steidel et al. 99Steidel et al. 99

• H alpha z< 0.5H alpha z< 0.5• [OII]3727 0.5<z<1.5[OII]3727 0.5<z<1.5• continuum UV z > 1.5continuum UV z > 1.5

Cosmic SFR densityCosmic SFR density

Inhomogneous SFR Inhomogneous SFR indicators at different indicators at different redshiftsredshifts

Lilly et al. 96Lilly et al. 96

Connolly et al. 97Connolly et al. 97

Madau et al. 96Madau et al. 96

Steidel et al. 99Steidel et al. 99

• H alpha z< 0.5H alpha z< 0.5• [OII]3727 0.5<z<1.5[OII]3727 0.5<z<1.5• continuum UV z > 1.5continuum UV z > 1.5

Bouwens et al. 2008Bouwens et al. 2008

GALEXGALEX

HDF

Dust extinction correction is an Dust extinction correction is an issue... issue...

D'apres Schiminovich et al. 05

Extragalactic studies in the UV with FIExtragalactic 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... )

Calib

ration in

the local u

niverse

Ly alpha emissionLy alpha emission

IZw18

A complex Ly a emission in aLocal sturburst (Atek et al. 09)

4''

HST/STIS

Ly alpha emissionLy alpha emission

A complex Ly a emission in aLocal 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 galaxiesThe size of local starburst galaxies

From Ostlin et al. 08

5''x5''

7.5''x7.5''

15''x15''15''x15''

15''x15''

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 galaxiesLy alpha/UV emission in distant galaxies

Lemoine-Busserolle et al. 2003Pello et al. 2003

Lensed galaxies :

Z = 2.5 1.7 2.7

Le Borgne et al.

AC114-S2

AC114-S2

AC114-S2

Local starbursts SED fitting to constrain SFR history, age of stellar population, E(B-V), metallicity

Ly alpha/UV emission in distant galaxiesLy 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

UB

V

R

IJ

Kz~1.7 lensed galaxy

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

Ly alpha emission in distant galaxiesLy alpha emission in distant galaxies

The size of high-z star-forming galaxiesThe size of high-z star-forming galaxies

From Bouwens & Illingworth 09

~L* galaxies

The size of high-z star-forming galaxiesThe 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 galaxiesThe size of high-z star-forming galaxies

From Rauch et al. 08

Z~2.7-3.7 Ly a emitters

2D spectra

Lambda~5000 A

15 arcsec

40 A

1 arcsec1 arcsec

0.1 arcsec0.1 arcsec

0.01 arcsec0.01 arcsec

0.001 arcsec0.001 arcsec

galaxiesgalaxies

1 arcsec1 arcsec

0.1 arcsec0.1 arcsec

0.01 arcsec0.01 arcsec

0.001 arcsec0.001 arcsec

galaxiesgalaxies

bulgesbulgesSpiral armsSpiral arms

GlobularGlobularclustersclusters

HII regionsHII regions

Paladini et al. 04

Urry & Padovani, (1995)

Jets

BH

Obscuring torus(200-800K, ~1-300 pc)

NB region(T

eff ~ 60K)

BL region(T

eff~ 2000 K, ~0.1-0.01 pc)

Accretion disk(T

eff ~ 105 K, ~0.01 pc)

θ

1 arcsec1 arcsec

0.1 arcsec0.1 arcsec

0.01 arcsec0.01 arcsec

0.001 arcsec0.001 arcsecAGNAGNobscuring torusobscuring torus

galaxiesgalaxies

bulgesbulgesSpiral armsSpiral arms

GlobularGlobularclustersclusters

AGNAGNaccretion disk (~0.01 pc)accretion disk (~0.01 pc)

HII regionsHII regions

Conclusions (I)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)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 3.342 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: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).

The endThe end