Survey spectroscopy in the next decade & the case for SIDE

1. Surveyspectroscopy in the next decade& the case for SIDE ChristianWolf

2. Outline • New instrumentation and proposals • Focus in extragalactic research and cosmology • Technical issues in spectroscopic z surveys • Case for SIDE & cornerstone surveys • Conclusion

3. Newinstrumentation and proposals • Multi-object spectroscopy • Integral observations • Integral-field units (IFU) • Resolving internal structure • Covering cluster fields • Deep imaging surveys • Photometric redshifts

4. Multi-Object Spectroscopy • VIMOS @ VLT • Optical, lo-res, 400 to 1001 slits • Low-S/N redshift surveys, LSS • BOSS @ Sloan (2008) • Optical, mid-res, 1000 fibers • 1 M galaxy BAO survey z < 0.7 • FMOS @ Subaru (2008) • 0.9-1.8, OH suppr., 400 fibers • 300 k galaxy BAO survey z ~ 1 • Stellar populations at z = 1.5..3 • WFMOS (2014) • Optical, 5000 fibers • 2.5 M galaxy BAO survey

5. Integral-Field Units • VIMOS @ VLT • Optical, 1’1’ • Cluster populations, strong lensing • SWIFT @ Palomar (2008) • 0.7-1.0, 20”10”, pixel 0.08”, AO • Stellar population, dynamics, z ~ 1 • KMOS @ VLT (2011) • 1.0-2.5, 24  2.8”  2.8”, AO • High-z galaxies & clusters • MUSE @ VLT (2012) • Optical, 1’1’, pixel 0.025”, AO • High-z galaxies & clusters, deep surveys SWIFT image slicer

6. Approaches Optical-to-NIR, add multi- Range of depth vs. area Photo-z precision 0.01..0.05 Purposes Galaxy population evolving as (z, mass, SFR) Lensing, BAO, LSS growth Dark matter & dark energy Moving bodies Variables & transients Surveys & facilities At present: COSMOS-21, CFHT-LS, UKIDSS … Start 2009: DES, VST, VISTA, PanSTARRS-1 HyperSuprimeCam at Subaru (2012) 1.6 , medium-bands Galaxies & high-z surveys LSST (2014): Solar system, Milky Way, transients, dark energy Deep Imaging Surveys And then there will be NGST…

7. Focus in extragalactic research and cosmology • Baryonic Oscillations • Stellar mass build-up at z = 1..10 • Photo-z training (for billion-galaxy surveys) • Cosmic chemistry • Galaxies’ internal structure

8. Percival+ 2007 Baryonic Oscillations: Vast Volume • Measure expansion history • Volume  BAO scale3 • Issues: nonlinear growth, redshift space distortions, selection function • BOSS (Schlegel+ 2008-13): • SDSS system upgrades • 1.5 million LRG, z<0.8 • Aim for 1% error on D(z) • WFMOS (2014): • 2 million gal’s at z=[0,1.3] + 0.5 million LBG z=[2.5,3.5] Percival+ 2007

9. Panter+ 06 Hopkins+ 06 Panter+ 03 Stellar Mass Build-Up at z = 1..10 • In-situ SFR measurements • From UV cont, HII lines, FIR, showing IMF high-mass end • Delicate extinction correction • Age decomposition of stellar mass (= fossil record) • From highest-S/N spectra, showing rest of IMF • Solves for extinction, metals • Towards full spectral fitting • Binaries, TP-AGB’s, EL’s… • At z  0.3 only in-situ SFR

10. Hildebrandt+ 08 Abdalla+ 07 Photo-z Training • Weak lensing & BAO probe gravity & expansion history • LSS in photo-z slices • Pan-STARRS, LSST, DUNE • Critical: zphot bias at all z • Data in despair… • Required: Deep & complete multi-object random sample of 30-100,000 zspec • VVDS ultra-deep: ~1,000, ~20% selectively incomplete • Towards a perfect algorithm • PHAT initiative

11. Podsiadlowski, Mazzali, Lesaffre, Wolf & Förster 2008 Interlude:Supernova Type Ia Calibration and Cosmic Chemistry • Dark energy surveys • Require 1% precision LSN • State of the Art: ~10% • Second parameter? • 58Ni/56Ni plausible: /L(Mazzali & Podsiadlowski 2006) • 58Ni/56Ni = f(initial O/H)(Timmes, Brown & Truran 2003) • O dependent calibration(Lesaffre+ in prep) • Evolving O/H(z) in SF gas? • Calibration debate • Evolving mix? Calib = f(tdelay)

12. Savaglio+ 2005 z~0.7 Cosmic Chemistry • Relevant for • Stellar evolution, mass loss, binary evolution, SNe/GRBs • SF timescales, galaxy SEDs • M-Z relation • Debated: emission line R23 • Weak emission lines and stellar absorption lines • Near future • FMOS surveys at z~2-2.5 • IFUs on individual galaxies • M-Z survey at z~1 + above Erb+ 06 z~2.3 stacked

13. Basic paradigm? Origin of Galaxy sizes Disk/spheroid dichotomy Age & metallicity gradients Role of bars? Disk settling, merger history Interaction with environment How do these fit in? globular clusters tidal dwarfs + intermediates halo populations Maps of Age, velocity, metallicity Growth moded/dt M* = SF + reordering by mergers… Several groups & instruments SAURON z~0 SWIFT z<1.4 IR no z limit … Growing Star-forming Sarzi+ 06 Galaxies’ Internal Structure

14. Technical Issuesin spectroscopic redshift surveys • Completeness & reliability • VVDS wide IAB<22.5 and ultra-deep IAB24.7 each: ~20% selectively incomplete • Origin of problems •  coverage,  resolution • Night-sky, flux calibration • Want optical+NIR coverage, high resolution, high signal • Background subtraction • Redshift auto-determination • Complete line detection

15. The Case for SIDE • BAO probably taken care of, but • More IFU capacity! • Multi-object spectrograph in new performance regime • Full  coverage • Resolution between night-sky lines • Many objects, large telescope

16. Cornerstone Surveys • SIDE-1 legacy survey • Better than Sloan quality - at z~1 • The Deep Complete • 50,000 galaxies to I=25 complete • The 1Gyr Slice Cube • A 3-D map of the young Universe • Internal structure projects

17. In 75 nights: What? 30,000 galaxy spectra over 0.62-1.37 at R~4000 Complete at I < 23.5 across 2.5  and z = 1 0.07 * Complete for red / blue gals to log M* = 10.6 / 9.8 Rest-frame 320-670 nm with S/N > 7/Å at 400 nm, incl. 4000 galaxies > 20/Å Best signal at 350-550 nm, just where needed for line indices and 4000-Å-break Science COSMOS field HST/Multi- Chemistry, masses and morphology, velocity disp. Full spectral fitting & stellar population decomposition Add 75 nights deep! >10,000 galaxies complete to log M* = 10.8 / 10.0 with S/N > 20/Å on 0.7  Fossil record 8-13 Gyr ago on galaxies with > 1010 M SIDE-1 Legacy Survey Better than Sloan quality - at z~1 *or 75,000 spectra at I < 23, z = 0.94  0.14

18. Abdalla+ 07 The Deep Complete • In 50 nights: What? • 50,000 galaxy spectra over 0.53-1.7 at R~1500 • Complete at IAB= 25 across 0.5  0.5  and z = 0..10 • Subarea of COSMOS field? • Science • Classical deep field benefits • Redshift distribution, extreme high-z objects • Full-depth photo-z training for BAO/lensing surveys!

19. z=6.5 z=6.1 z=5.7 z=5.2 z=4.7 500 Mpc 500 Mpc The 1Gyr Slice Cube • 50 nights of spectroscopy • 30,000 Lyman- emitters (and LBGs) at z = [4.7,6.5] • 3-D map of young Universe(1 Gyr after Big Bang) • Large-scale structure, Ly--density relation,Ly- line properties • Volume (500 Mpc)3 • Collaboration required • Deep medium-band imaging with HyperSuprimeCam e.g.

20. Internal Structure Projects • Starburst and AGN hosts • Triggers of SF/AGN, relation to interaction, evolutionary path • Complete dissection of low-redshift galaxies • Age, chemistry and kinematics of structural components • Landmark nearby spiral at useful inclination: M33 • Star formation modes and workings • Giant HII regions in irregulars: gas kinematics & relation to stars • Starburst galaxies: super star clusters, triggers & feedback • The Milky Way, its dwarf satellites and tidal streams • Gravitational potential, formation and interaction history • …

21. Conclusions • Baryonic Oscillations, LSS • Stellar mass build-up at z = 1..10 • Photo-z training (for billion-galaxy surveys) • Cosmic chemistry • Galaxies’ internal structure SIDE would… contribute some to LSS (A) + quite someto internal structure (E) be an excellent instrumentto do (B), (C) & (D) + leave a large legacy value to the astronomy world!