FIR Surveyor early U Talking points 14 June 2016 Matt Bradford 2-page science case papers due mid- late July Will be ‘anonymized’ and distributed to the entire STDT To be ranked with top few guiding architecture selection to inform the rest of the study. Some overlap with Galaxy evolution group

Our Themes Primordial cooling via H2 (definitely a case paper) Appleton lead with help from group First dust and heavy elements (definitely a case paper) Redshifted aromatics features – relatively easy to detect but what can we learn? Dust mass? Metallicity? Constraints on dust production? JD Smith agreeing to lead, but hoping for help from group. Properties of the Reionization Epoch galaxies Total star formation rate, UV field strength and hardness, relation to dark matter halos Via intensity mapping, possibly stacking. (some skepticism regarding this technique among the astronomers). A technique rather than a science case paper. Early black hole collapse What is observable? Distortions in background spectrum Followup of LISA source Not clear what signal would be in mid-IR

Galevol case paper per Alex / Lee last week: 1.Rise of metals (we will help with this one) Ferkinhoff, Stacey + Shull? 2.Environment and Large-scale structure Viero, Farrah, Marrone 3.AGN / StarFormation co-evolution Malkan + ? 4.Physics of star formation Murphy, Narayanan Halo gas properties via SZ cluster measurements

Phil Appleton The pre shock proton density is nH=1e4 cm- 3 and the pre-shock magnetic field is 100 micro Gauss (sort of related to the density). The pre shock gas is molecular and at 20 K Although this high molecular fraction does not follow the conditions at z = 10, it is a start towards exploring the effects of MHD shocks in low metallicity gas. We are exploring even lower metallicities and can probably modify the molecular fractions. I can also scale from the M_dot ratios of gas being processed through local shocks to the case of gas in a DM halo. Lot of work to do but encouraging!!

Signatures of first dust PAH emission features in the rest-frame mid-IR are bright and thus easily detectable e.g. 7.7 micron complex is ~4% of TIR bolometric! Built-in redshift encoding. Potentially the first signature of dust in galaxies. (but UV slope?) Can we extract mass, metallicity? Or is luminosity more dependent on heating? 10 meter telescope with CALISTO-like spectrograph should be able to 3e10 Lsun source if similar to the nearby galaxies. Lensing and intensity mapping experiments enables extraction of aggregate signal (see below) JD Smith et al. nearby galaxies with Spitzer IRS Science Case #2

Measuring individual objects Wm -2 is ~ULIRG at z=6 with line fraction. For LIRG, would like 1e-21 Wm meter gets close. PAH fluxes refer to R=500 here, so would be an effective boost in SNR when binned e.g. to R=10 (7x) if the spectrometer is well behaved. 10 meter telescope detects 3e10 Lsun galaxy in PAH (1 hour) ….Problem is EoR galaxies are likely to be sub-LIRG. Flux [Wm -2 ] 5-meter telescope

1-halo clustering 2-halo clustering Using the linear clustering signal Viero et al. 2013, ApJ 722, 77

Example [CII] power spectra from the ground (this for 0.1 Msun/yr / Mpc^3, constant CII fraction) Example power spectra calculations for 300 hours at goal sensitivity assuming 84-element spectrometer. (Y. Gong / A. UC Irvine) Halo-halo clustering term encodes mean intensity (with galaxy bias). Large scale structure and galaxy-galaxy clustering Poisson (shot) noise due to discrete galaxies 8

Can detect z of 7 to 9 signal in CII from the ground with 300 hours x 100 spectrometers SNR in clustering signal scales as f i is fractional luminosity in line NEP is system NEP -> 100 x lower in space λ accounts for AΩ. Can do this for the most important Far-IR lines and the PAHs. Requires careful study Survey geometry, understanding biases will be important. Intensity mapping sensitivity with the Surveyor f_iλNEPSNR CII (ground)1.00E E-1815 OI /OII1.00E E SiII1.00E E Ne II, Ne III5.00E E S III, Si IV2.50E E-2084 PAH2.00E E Preliminary Scaled sensitivities