The GALEX Ultraviolet Virgo Cluster Survey (GUViCS): A Unified Picture of Galaxy EvoluCon A. Boselli, E. Voyer, S. Boissier, O. Cuccia5, G. Consolandi, L. Cortese, G. Gavazzi, S. Heinis, Y. Roehlly, E. Toloba
The GALEX Ultraviolet Virgo Cluster Survey (GUViCS) Mapping ~ 300 sq.deg. of the Virgo cluster with GALEX All Imaging Survey (~200 sec) ~ 94% complete Medium Imaging Survcey (~ 1500 sec) ~ 65% complete (NUV band) ~ 1,200,000 detec5ons in the NUV (Voyer et al. 2014, submized to A&A)
The Sample All galaxies detected in the NUV band (2316 A) with: 12<RA<13h; 0<dec<20deg NUV(AB) < 22 mag vel<3500 km/s 854 galaxies
The Data FUV (1539 A) GALEX (62%) SDSS photometry (ugriz) (100%) & spectroscopy (nuclear Hα emission and Hδ absorp5on lines; 68%) WISE 22 μm (75%) Herschel 250 μm (64%) HI 21cm (ALFALFA + GOLDMine) (85%) Kinema5cs (ATLAS- 3D + de of Toloba et al.) (13%) 854 galaxies
GALEX AIS GALEX MIS X- rays VCC NGVS HeViCS
Galaxies in the velocity space
Galaxy density Voronoi tassella5on method to iden5fy the cluster substructures and calculate galaxy density Δρ = ρ/ρfield - 1
Colour- stellar mass relacon NUV- i vs Mstar rela5on to iden5fy galaxies in the red sequence, green valley and blue cloud NUV and i data corrected for dust azenua5on using WISE 22 μm data Filled dots: HI- def<0.4
Morphology (colour) segregacon
Massive galaxies Filled dots: slow rotators (major merging) Crosses: fast rotators
Massive galaxies Filled dots: slow rotators (major merging) Crosses: fast rotators
Massive galaxies Filled dots: slow rotators (major merging) mainly located within the caus5c and virial radius è cluster members since early epochs Crosses: fast rotators also outside the caus5c and the virial radius è more recently accreted
The role of environment on galaxy evolucon Filled dots: HI- def<0.4
The role of environment on galaxy evolucon Comparison with models (Boselli et al 2006; 2008) Starva5on Ram pressure stripping - Low efficiency - High efficiency (NGC 4569)
The role of environment on galaxy evolucon UV upturn: very old stellar popula5ons è old merging event? Starva5on Ram pressure stripping - Low efficiency - High efficiency (NGC 4569)
Dwarf galaxies Mstar < 108.5 Mo
Dwarf galaxies The colour segrega5on effect is much stronger in dwarfs than in massive galaxies
Dwarf galaxies: ISM Filled dots: dwarf galaxies (Mstar<109.5 Mo) detected by Herschel at 250 μm è dust rich systems (ISM not fully removed)
Dwarf galaxies: nuclear SFR Filled dots: dwarf galaxies (Mstar<109.5 Mo) with HαEW> 3 A è nuclear star forma5on from residual gas kept in the core of the galaxy
A unified picture of galaxy evolucon: Massive early- type galaxies Massive ellip5cal galaxies are too massive to be formed by a simple quenching of the SFA of spirals They are all slow rotators They are all the most massive galaxies of each cluster substructure generally associated with the diffuse X- ray emission of the IGM In cluster A they are virialised within the poten5al well of the cluster They are characterised by a very old stellar popula5on (UV upturn) ê Formed by major merging events within the different subgroups at early epochs (pre- processing)
A unified picture of galaxy evolucon: Dwarf early- type galaxies Star forming dwarfs are totally lacking within cluster A They can be easily stripped of their gas in a ram pressure stripping event de are stripped of their ISM in cluster A The few slow rotators are located within the inner regions of cluster A associated with the and X- ray emission of the IGM. They are also virialised within the cluster Fast rotators are located mainly at the periphery of the cluster and are not virialised within the cluster ê The majority of de are formed aver a ram pressure stripping event; Those which entered the cluster at early epochs have been perturbed by gravitaconal interaccons (harassment)
The GALEX Ultraviolet Virgo Cluster Survey (GUViCS): A Unified Picture of Galaxy EvoluCon A. Boselli, E. Voyer, S. Boissier, O. Cuccia5, G. Consolandi, L. Cortese, G. Gavai, S. Heinis, Y. Roehlly, E. Toloba