Magpop Midterm ReviewNode OAMP-LAM, Marseille
Coordinator: V. Buat
E.R.: Jakob Walcher
S. Arnouts1, S. Boissier, A. Boselli, D. Burgarella, J. Iglesias-Paramo2
& L. Tresse1: also at CFHT
2: also at IAA, Granada, Spain
Summary of the activities
• Main input from OAMP/LAM: GALEX & VVDS data, interpretation.
• Topic 1: Nearby Galaxies, physics of star forming galaxies
• Topic 2: Distant Galaxies, star formation characteristics
The GALEX missionP.I: C. Martin, Caltech, participation of CNES/ LAM
1.2 deg
ELAIS-S1, 12 000 secM31, mosaics
GALEX: A UV surveyor with a large field of view
The GALEX missionP.I: C. Martin, Caltech, participation of CNES/ LAM
GALEX satellite, launch: Avril 2003, still observing Imaging mode at 1530 Å (FUV) and 2315 Å (NUV),
spatial resolution ~5 arcsec
• All Sky Imaging Survey @ 20-21ABmag/14000 fields• Medium Imaging Survey @ 23 ABmag/1200 fields• Deep Imaging Surveys @ 25.5 ABmag/150 fields • Nearby Galaxies Survey: ~1000 galaxies
X-correlations with surveys at other wavelengths
GALEX sky coverage 10/02/2006
The VIMOS VLT Deep Survey
More than 220 galaxies observed simultaneously (march 2002)
VIMOS mounted at Nasmyth B focus of VLT Melipal
The VIMOS VLT Deep SurveyP.I.: O. Le Fèvre & G. Vettolani
• 16 deg2 in four separate fields• Imaging survey (CFHT, ESO) UBVRI-K• Spectroscopic survey: few thousands of
spectra @ R=250, redshift measurements
I band selection: shallow survey IAB= 22.5 mag and deep survey IAB=24 mag (2 deg2/1 field)
--> galaxies from z ~0 to z ~5 <z>=0.8
Multi-wavelengths analyses
Combining several wavelengths from ultraviolet to far infrared enables us to study:
• Current Star formation in an unbiased way• Dust obscuration• Star formation history • Environmental effects
In the nearby and more distant universe
Nearby Galaxies: star formation laws
Based on the Nearby Galaxies Survey of GALEX: UCM Madrid/OAMP-LAM Marseille
Boissier et al. 06
The star formation as seen in UV extends to significantly lower gas densities than in H: for low levels of SF the H radiation becomes stochastic (very low number of ionizing stars) whereas the UV radiation due to older stars in larger number shows no break
Nearby Galaxies: The effect of the environment on the evolution of galaxies
LAM/UCM Boselli et al. 06NGC 4569: a typical HI deficient, anemic Virgo galaxy Models for ram pressure stripping consistent with the observed profiles (from NIR to FUV). A method to age-date the interaction.
Nearby galaxies: other on-going projects
•The dwarf galaxy survey: P.I. R. Peletier Groningen/LAM/UCM/Nottingam/Padova Obs.
Observation of a UV selected sample of ~ 100 dwarf irregular and quiescent galaxies in the Virgo cluster and in the field in imaging mode : near-IR, H imaging, low- res. and 2D spectroscopy
Status: 48 night (5% of the whole telescope time) allocated in two semesters 2006 at WHT, TNG, INT, NOT; 12 nights allocated in the first
semester 2007. 2006 data under reduction
•SFH in normal late type galaxies: LAM/Padova ObsConstraining the star formation history of normal, late-type galaxies by comparing the UV to radio centimetric SED to the GRASIL model Status: work just started
Nearby universe: Understanding star formation and dust obscuration
GALEX/IRAS samples in the nearby universe: several hundreds of galaxies carefully selected
Several studies:
•Statistical analyses, IR/UV luminosity functions Buat et al. 06
•Star formation history and dust attenuation through SED fitting Burgarella et al. 05
•Dust attenuation analysis: Buat et al. 05, Panuzzo et al. 06, Inoue et al. 05
•Star formation estimations: Iglesias-Paramo et al. 05
Understanding dust obscuration in nearby galaxies: Panuzzo et al 06
•A MW extinction curve is consistent with the FTIR/FFUV vs FUV-NUV color: the age-dependent extinction reduces the presence of the 2175 A bump
•The wavelength dependence of the scattering albedo has also a strong impact on the FUV-NUV color (Inoue et al. 2005)
FTIR/FFUV measures the amount of dust attenuation
FUV-NUV color is sensitive to the wavelength dependance of
dust attenuation
Starbursts locus
Based on GRASIL models: Padova obs. /OAMP-LAM
Analyses of Spectral Energy Distributions of galaxies at z>0
1. GALEX/SPITZER-SWIRE: SED fitting of UV selected galaxies with GRASIL models
2. GALEX/SPITZER-MIPS: SED fitting of Lyman Break Galaxies at z~1
3. GALEX/VVDS/SWIRE: SED fitting of optically selected galaxies from z=0 to
z~5 --> Jakob Walcher talk
UV (rest-frame) selected galaxies from z~0 to z~1 with GALEX/SWIRE
Iglesias-Paramo et al. 07
• Templates:GRASIL models• Data: GALEX/ELAIS/SWIRE data UV vis NIR+MIR+FIR
UV (rest-frame) selected galaxies from z~0 to z~1 with GALEX/SWIRE
Total galaxy luminosityMstar
L du
st/L
UV
SF
R/M
sta
r
A diminution of dust attenuation in UV selected galaxies as z increases
The so-called downsizing also seen in a pure UV selection
Lyman Break Galaxies @ z~1 with GALEX/MIPS Burgarella et al. 06
FUV dropouts, z=0.9-1.3.
CDFS: photometric redshifts, optical photometry, IRAC and MIPS dataObserved wavelength A
Thank you for your attention and please listen to Jakob for the continuation of the
story….