What is EVLA? Build on existing infrastructure, replace all electronics (correlator, Rx, IF, M/C) => multiply ten-fold the VLA s observational capabilities 80x Bandwidth (8 GHz, full stokes), with 4000 channels Full frequency coverage (1 to 50 GHz) 10x continuum sensitivity (<1uJy) 30% FBW at 20GHz => Large volume high z line surveys (eg. z =3.2 to 5.0 in CO 1-0 in K) EVLA + ALMA represent > 10x improvement in observational capabilities from 1GHz to 1 THz
EVLA Status Digital retrofits 100% complete Receivers 100% complete at ν 18GHz w. 2GHz BW Full receiver complement completed 2013 + 8GHz BW Early science started March 2010 using new correlator Today w. 2GHz BW
EVLA (and GBT!) and galaxy formation 100 M o yr -1 at z=5 cm telescopes: low order molecular transitions = total gas mass, dense gas tracers Synchrotron + Free-free continuum = SFR (sub)mm: high order molecular lines. fine structure lines, dust continuum
1.4 GHz Source Counts: ujy sky will light up with SF galaxies AGN steep flat starbursts Star forming galaxies spirals 1st/NVSS 3C EVLA ujy ~ 10 4 galaxies per pointing in 12hr
Radio stacking of 30,000 sbzk galaxies in COSMOS: Large disk galaxy formation at z ~ 2 M * = 10 10 M o Stacking in bins of 3000 3x10 11 M o 0.9 +/- 0.2uJy => SFR ~ 20 M o /yr 20uJy SFR independent B AB Extinction increases SFR increases w. with SFR stellar mass Pannella ea.
Dawn of Downsizing: SFR/M * vs. M * 1.4GHz SSFR 5x UV SSFR z=2.1 z=1.5 t -1 H (z=1.8) z=0.3 SSFR constant with M *, unlike z<1 z>1.5 sbzk well above the red and dead line (t h -1 ) => even large galaxies actively star forming UV dust correction = f(sfr, M * ) EVLA will sbzk individually over wide fields
EVLA early science: molecular gas across cosmic time I. Quasar host galaxies at z ~ 6 SDSS 0927+2001 z = 5.8 CO 2-1 11kpc 500 km/s Wang, Wagg ea Very highly excited M BH ~ 10 9 M o H 2 mass ~ few x 10 10 (α/0.8) M o SFR ~ 10 3 M o /yr => very early formation of SMBH + massive galaxies at t univ < 1Gyr
II. GN20 molecule-rich proto-cluster at z=4 (Daddi ea) CO 2-1 in 3 submm galaxies, all in 256 MHz band 0.3mJy z=4.055 4.051 4.056 0.7mJy CO2-1 46GHz SFR ~ 10 3 M o /year 0.4mJy M gas ~ 10 11 (α/0.8) M o Early, clustered massive galaxy formation 1000 km/s
Spectroscopic imaging GN20 z=4.0 EVLA: well sampled velocity field +250 km/s -250 km/s CO 1-0 region ~ 15 kpc Rotating disk + possible tidal tail Dynamical mass = 3e11 M o Gas mass = 1.3e11 M o Stellar mass = 2.3e11 M o => Baryon dominated
EVLA: well sampled velocity field GN20 CO 2-1 0.4 0.18 High and low excitation components Clumpy, rotating CO disk ~ 10kpc clumps resolved, sizes >~ 1 kpc clumps H 2 masses ~ 10 9 to 10 10 M o => Dekel Disk : Cold Mode Accretion scales up to SMGs at t univ < 2Gyr?
III. CO observations of sbzk with EVLA/Bure: Massive gas reservoirs without extreme starbursts (Daddi, Aravena, Dannerbauer) CO 1-0 EVLA z ~ 1.5 6 of 6 sbzk detected in CO with Bure and/or EVLA, sizes > 10kpc Gas masses ~ 10 11 M o ~ gas mass in SMG, but SFR < 10% SMG Gas masses stellar masses => pushed back to epoch when galaxies are gas dominated!
SMG/QSO 1.5 1 Lower CO excitation ~ MW [low J observations are key!] FIR/L CO: Gas consumption timescales ~ few x10 8 yrs ~ MW secular formation of large disk galaxies during epoch of galaxy assembly (Genzel, Tacconi, Daddi ) high z Universe is rich in molecular gas!
Higher Density Tracers: Realm of cm telescopes! z=2.6 HCN 1-0 200uJy n cr > 10 5 cm -3 (vs. n cr (CO) ~ 10 3 cm -3 ) => high order transitions hard to excite Linear correlation with SFR => [SFR/dense gas] ~ constant ( counting SF clouds ) HCO+ 1-0 Index = 1 Gao +, Wu +
Dense gas history of the Universe Tracing the fuel for galaxy formation over cosmic time sbzk BX/BM SFR SF Law Millennium Simulations Obreschkow & Rawlings See also Bauermeister et al. M gas DGHU is primary goal for studies of galaxy formation this decade!
z ~ 3 Lensed LBG Riechers ea Next proposal deadline is February 1, 2011
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EVLA/ALMA Deep fields: the missing half of galaxy formation 1000 hrs, 50 arcmin 2 Volume (EVLA Ka, CO 1-0 at z=2 to 2.8) = 1.4e5 cmpc 3 1000 galaxies z=0.2 to 6.7 in CO with M(H 2 ) > 10 10 M o 100 in [CII] z ~ 6.5 5000 in dust continuum Millennium Simulations Obreschkow & Rawlings
GN20 CO 2-1 0.4 EVLA: well 0.18 sampled velocity field Regions of active star formation are totally obscured in HST ACS image Clumpy, rotating CO disk ~ 10kpc clumps resolved, sizes >~ 1 kpc clumps H 2 masses ~ 10 9 to 10 10 M o => Dekel Disk : Cold Mode Accretion scales up to SMGs at t univ < 2Gyr?
Spectroscopic imaging GN20 z=4.0 EVLA: well sampled velocity field CO 1-0 region ~ 15 kpc Rotating disk + possible tidal tail Dynamical mass = 3e11 M o Gas mass = 1.3e11 M o Stellar mass = 2.3e11 M o => Baryon dominated