CCAT survey of the GEMS Legacy field in ECDF-S Shardha Jogee (UT Austin)

30’ CCAT survey the legacy GEMS/Extended CDF-S field GEMS ( Galaxy Evolution from Morphology and SEDs) is the largest area 2-filter survey completed to date with HST (Rix et al. 2004)  Area : 30’x30’ = 120 x HDF = 78 x HUDF= 5 x GOODS-S  Filters : F606W (V), F850LP (z) (26.8, 25.7 AB mag); 0.07”  Has accurate redshifts for ~9000 galaxies out to z=1.2 (T back = 8 Gyr) from Combo-17 (Wolf et al 2004) dz/(1+z) ] ~ 0.02 for R Vega <24

GEMS field  Has HST, Spitzer (3.6 to 24 mu), and Chandra data providing optical-to-IR SEDs morphology, SFRs, AGN for 9,000 galaxies over z= ( T back ~ 2-8 Gyr)  Is missing a census of gas, dust, IR-to-summ SEDs which CCAT can provide  Has dec= -28 and is ideal for CCAT surveys and target follow-ups by ALMA

GEMS

Spitzer 3.6m IRAC 1’ Courtesy P Gonzalez/ Spitzer GTO team

CCAT survey of GEMS galaxies out to z~1: Science Goals a) Decline in cold gas content of galaxies ? (CCAT) b) Decline in rate of minor mergers ? c) Change in internal structure (e.g., bars) and gas concentration ? (HST/CCAT) d) Decline in rate of major mergers ? ( ruled out from HST/Spitzer ; Bell et al 2005; Wolf et al 2004) e) Decline in gas accretion rate from cosmological filaments ? 1. What causes the SFR density to decline by a factor of ~10 from z=1 to 0 ?

2. Constrain gas and mass assembly in interacting galaxies at different lookback times z ~ 0.2 T ~12 Gyr z=0.5 or T~8 Gyr z=0.7 or T~7 Gyr

3. Constrain content and concentration of gas/dust in young barred galaxies (Jogee et al. 2004) vs unbarred ones at z = (T back =4.5 to 8 Gyr).

CCAT survey of GEMS galaxies out to z~1 1) Continuum mapping at micron - Assuming a mapping speed = 0.5 sqarcmn/sec - Assuming sensitivity of 1 sigma (10-15 mJy) in 1 sec, - Can cover GEMS (900 sq arcmin) field in 4 hrs down to confusion limit of 3 mJy 2) Spectral estimates? In 10,000 seconds of integration time: - The [CII] 158  m line is detectable from galaxies with L far-IR ~ 2  L  at z ~ 0.2 in the 200  m window and at 8  L  at z ~ 1.2 in the 350  m window. - The [NII] 205  m line is detectable from galaxies with L far-IR ~ 2  10 10, at z = 0.1, and 1.6  L  at z ~ 0.7 in the 350  m window - The [NII] 122  m line is detectable from galaxies with L far-IR ~ 1.2  L  at z = 0.64 in the 200  m window. -The CO(7-6) line is detectable from galaxies with L far ~ 1.2  L  at z ~ 0.22 in the 450  m window -We could therefore pursue spectroscopic follow-up of many galaxies detected in the survey 3) Operate down to  <= 200 mu ? A galaxy with a diameter of 20 kpc has an angular size of 2.4 to 4.6” at z= The high angular resolution (< 2”) and low confusion limit (0.04 mJy assuming 10 beams/src at  <= 200 mu) will help to identify individual galaxies and reduce overblending