Science Overview and the Key Design Space for MSE

Science Overview and the Key Design Space for MSE Alan McConnachie MSE Project Scientist First Annual MSE Science Team Meeting http://mse.cfht.hawaii.edu

Original Concept MSE will: obtain efficiently very large numbers (>10 6 ) of low- (R ~ 2 000), moderate- (R ~ 6 500) and high-resolution (R > 20 000) spectra for faint (20 < g < 24) science targets over large areas of the sky (10 3 10 4 sq.deg ) spanning blue/optical to near-ir wavelengths, 0.37 > NIR (J or H band) At the highest resolutions, it should have a velocity accuracy of <<1 km/s At low resolution, complete wavelength coverage should be possible in a single observation

Gaia: stellar astrophysics, stellar populations, Milky Way Euclid, WFIRST : extragalactic astrophysics and cosmology TMT (and the other ELTS): General purpose, forefront science facilities, efficient target selection important for best use of facilities erosita: High energy astrophysics, clusters of galaxies LSST: Wide field imaging for transients, MW and Cosmology SKA: Spectral stacking; serious number of new objects with no OIR spectral data

Gaia: stellar astrophysics, stellar populations, Milky Way Euclid, WFIRST : extragalactic astrophysics and cosmology Within this context, consider the impact of a 10-m class version of SDSS at the best site on the planet. TMT (and the other ELTS): General purpose, forefront science facilities, efficient target selection important for best use of facilities erosita: High energy astrophysics, clusters of galaxies And consider the popularity of those that have a major voice in deciding how it is deployed. LSST: Wide field imaging for transients, MW and Cosmology SKA: Spectral stacking; serious number of new objects with no OIR spectral data

Competition is good for the soul

Competition is good for the soul Guo Shoujing/LAMOST 4m class, optical 19.6sq.deg FoV 4000 objects R=1000-10000 Mayall/DESI 4m class, optical 7.1 sq.deg 5000 objects R4000 VISTA/4MOST 4m class, optical 2.5 sq.deg 2400 objects R5000, 18000 WHT/WEAVE 4m class, optical 3.14 sq.deg 1000 objects R5000, 20000 VLT/MOONS 8m class, NIR (~0.8-1.8um) 0.14 sq.deg 1000 objects R4000/20000 AAT/HERMES 4m class, optical 3.14 sq.deg 392 objects R28000 (+ ~R50K) Subaru/PFS 8m class, opt+nir (0.38-1.3um) 1.25 sq.deg 2400 objects R2000/5000 MSE is the only proposed, dedicated, large-aperture spectroscopic facility. Nevertheless, MSE must be positioned to be able to perform transformative, unique and high impact science

MSE Science Team & First Tasks

MSE Science Team & First Tasks International Science Team with 84 members Australia - 12; Canada - 10; China - 8; France - 22; India - 10; USA - 7; Other - 15 ~30-40 present at this meeting Immediate (i.e., 2015) focus on completing drafts of key science foundational documentation. Revisit science baseline to ensure subsequent work is correctly focused: Detailed Science Case (DSC) Science Requirements Document (SRD) Process for DSC and SRD development: Science team charged with developing Science Reference Observations, that describe science programs that are high profile, transformative in their field, and which are UNIQUELY POSSIBLE with MSE Constitutes a Design Reference Mission for MSE. Includes details on (e.g.) target selection, data requirements, calibration requirements, etc Science requirements are then the range of capabilities that MSE must have in order to be able to conduct the SROs Science team split into three groups: Stars, Low-z and High-z, coordinated by Babusiaux, Balogh and Driver, respectively White papers submitted by science team members highlighting key science topics in October 2014 Submitted first draft of candidate SROs in January 2015. Typically ~6-8 per group

Driving science SROs reviewed by Science Executive and Project Office. 12 SROs selected for continued development These 12 SROs spawn the range of issues addressed by the science requirements described in the Science Requirements Document The composition and dynamics of the faint Universe Science Reference Observations include: SRO-1 Exoplanets and stellar velocity variability SRO-2 Revealing the physics of rare stellar types SRO-3 The formation and chemical evolution of the Galaxy SRO-4 Unveiling cold dark matter substructure with precision stellar kinematics SRO-5 The chemodynamical deconstruction of Local Group galaxies SRO-6: The baryonic content and dark matter distribution of the nearest massive clusters SRO-7: Galaxies and their environments in the nearby Universe SRO-8: Multi-scale clustering and the halo occupation function SRO-9: The chemical evolution of galaxies and AGN SRO-10: Mapping the inner parsec of quasars through reverberation mapping SRO-11: Linking galaxy evolution with the IGM through tomographic mapping SRO-12: A peculiar velocity survey out to 1Gpc and the nature of the CMB dipole

SRO-4: Unveiling CMD substructure with precision kinematics (Ibata)

SRO-4: Unveiling CMD substructure with precision kinematics (Ibata) +

SRO-8: Multi-scale clustering and the halo occupation function (Robotham) 8 photo-z selected survey cubes (300Mpc/h on a side) to probe the build-up of large scale structure, stellar mass, halo occupation and star formation out to a redshift of z=4 ~100% completeness per cube (1 dex below M* for first 4 cubes, beyond this limited by LSST photo-z accuracies) Sensitivity to ~1.8um preferred. ~5-7 year observing program only possible on a dedicated facility

SRO-10: Mapping the inner parsec of quasars (Gallagher) ~60 observations of ~5000 quasars spread over ~years to map the structure and kinematics of the inner parsec around a large sample of supermassive black holes actively accreting during the peak quasar era (Compare with ~50 local, lowluminosity AGN that currently have high quality RM measurements; evolution as a function of z essentially unknown) Calibration is key: Stable environment and well understood spectroscopic system essential.

SRO-10: Mapping the inner parsec of quasars (Gallagher) ~60 observations of ~5000 quasars spread over ~years to map the structure and kinematics of the inner parsec around a large sample of supermassive black holes actively accreting during the peak quasar era (Compare with ~50 local, lowluminosity AGN that currently have high quality RM measurements; evolution as a function of z essentially unknown) So what are the requirements that flow from all these SROs??? Calibration is key: Stable environment and well understood spectroscopic system essential.

Science Requirements I: A spectroscopic telescope

Science Requirements I: A spectroscopic telescope Etendue All SROs want to observe faint targets over fields of view from several to thousands of square degrees [e.g., Nearby Galaxies and their environments, 3200 + 100 sq. deg] Requirement is equivalent to a 10m effective aperture and a 1.5 sq. degree FoV 10m class essential to push to the faintest targets not accessible with smaller facilities Driver of all the SROs See upcoming Sensitivity requirement KEI S PRESENTATION: MSE will is a 11.25m segmented Prime Focus Telescope with a 1.5 sq. degree FoV

Science Requirements I: A spectroscopic telescope

Science Requirements I: A spectroscopic telescope Multi-object Spectra At first light, MSE will be be a MOS facility Spatially resolved spectra MSE will be able to host a suite of IFUs during its lifetime (i.e. not a first light capability) Many compelling science programs need IFUs (e.g., Dynamics of the dark and luminous cosmic-web during the last 3 billion years ) For programmatic/cost/schedule reasons, it is expected that IFUs will be a secondlight capability (likely feeding the same spectrographs as the MOS mode) Informal MSE working group: Alessandro Boselli, Kevin Bundy (+MANGA team), Scott Croom, Laura Ferrarese, Andrew Hopkins, Mike Hudson, Your-name-here? Want to provide some initial science concepts by mid-fall (e.g., number of IFUs, sizes, spaxel size etc)

Science Requirements II: Operation at a range of spectral resolutions

Science Requirements II: Operation at a range of spectral resolutions Low Res: R~3000 (e.g., Evolution of galaxies, halos and structure over 12Gyrs; Mapping the Inner Parsec of Quasars with MSE ) Moderate Res: R~6500 (e.g., A chemodynamical deconstruction of the Local Group ; Nearby Galaxies and their environments ; Connecting high redshift galaxies to the IGM High Res: R~XX000 (40K?) Galactic Archaeology High Resolution: Original requirement was R20K. Strong push by science team to change to R40000 (e.g., AAT/HERMES, ESO Gaia survey, UVES vs FLAMES). Very significant design specifications still need to be set (see later)

Science Requirements III: Extremely multiplexed spectroscopy

Science Requirements III: Extremely multiplexed spectroscopy Low & Moderate Res Multiplexing: both >3200 spectra/field or equivalent space density (0.59/ sq.arcmin) if field is larger than 1.5 sq. deg Original multiplexing spec inherited from WFMOS Justifiable, e.g. space density of z<0.2 galaxies brighter than i~23 is ~2000/sq.deg But without preselection of specific targets, the space density of (extragalactic) targets brighter than i~24 (see later) is high (closer to ~1 per sq. arc min) Higher multiplexing = better

Science Requirements III: Extremely multiplexed spectroscopy High Res Multiplexing: >1000 spectra/field or equivalent space density (0.18/ sq.arcmin) if field is larger than 1.5 sq. deg Galactic Archaeology Original multiplexing spec was N~800, inherited from WFMOS Lots of 4-m class surveys can target the disk Multiplexing req. based on space density of thick disk and halo stars with 16 < g < 21.5

Science Requirements IV: Broad wavelength range

Science Requirements IV: Broad wavelength range Low Res Wavelength Coverage: 0.36 > at least 1.3um and with a very serious effort to get to 1.8um optimised for longward of 0.37um Evolution of galaxies, halos and structures over 12Gyrs, Mapping the inner parsec of quasars with MSE Red-end cut-off set by technical and financial limitations, not by science H band imposes very significant design challenges in terms of cost and complexity

Science Requirements IV: Broad wavelength range Moderate Res Wavelength Coverage: TBD The dark substructure of the Milky Way; A chemodynamical deconstruction of the Local Group; Nearby galaxies and their environment; Connecting high redshift galaxies to their local IGM The total wavelength coverage in this range is anticipated to be approximately half that available at R3000. Use R6500 as a follow up to R3000 mode? CaT region crucial (CaII Triplet region [8498, 8542, 8662A]). Also MgI 8806 (gravity-sensitive for dwarf-giant discrimination) Any other red features, including NIR, for which moderate resolution is critically important? Strong possibility that NIR will operate only at R~5000 (sky line considerations) Blue wavelengths: Target the bluest wavelength range of MSE (360-430nm; Blamner series, CaII HK, CN band [3883], CH band [4320], SrII[4077, 4215], CaI [4227]? Any other features critically important? e.g. HBeta[4863] - NII[6583]?

Science Requirements IV: Broad wavelength range High Res Wavelength Coverage: TBD Galactic Archaeology The major outstanding issue for the science requirements The Problem Not possible to get full wavelength coverage for 1000 objects at R~20-40K As resolution goes up, accuracy of chemical abundances improves = good As resolution goes up, number of species for which you can derive chemical abudances goes down (not to be found on your detector) = bad Range,'nm' 70" 60" 50" 40" 30" 20" 10" No slicing, 1.2 arcsec fibers F/1.8 camera Two CCDs wide per arm Wavelength'Range'for'1.2"'fibre' 0" 400" 450" 500" 550" 600" 650" 700" 750" 800" Central'Wavelength,'nm' R20K R30K R40K

Science Requirements IV: Broad wavelength range Right: spectral features visible in synthetic metal poor RGB star at R20K. Grey is proposed wavelength coverage from Feasibility Study (426-491nm; 585-675nm) ~17 chemical species Consider R40K (~0.5 x previous wavelength coverage) 449.5-482nm and 628-673nm Elisabetta Caffau kindly ran a spectral synthesis code using a real spectrum of HD122563 (metal-poor giant, stellar parameters in Cayrel et al. 2004) from UVES R40000, analyzing just the interval above Obtain metallicity and log(g) in agreement with Cayrel et al. 2004 Teff low by >200K (a well known problem due to the available FeI lines in metal poor stars) Abundances obtained for the following species (9 in total, typical uncertainties of order 0.1-0.2 dex): Fixed Vturb=2.0km/s Derived Teff=4393.7 Logg=1.02 ############################# [X/H] Sigma [X/Fe] Sigma Ca -2.68 0.0571 0.35 0.0946 Sc -3.08 NaN -0.05 NaN Ti -2.78 0.0383 0.25 0.0846 Ti -2.79 0.1031 0.24 0.1833 Cr -3.15 0.0333-0.13 0.0824 Cr -2.94 0.1600 0.08 0.2204 Mn -3.20 0.0114-0.17 0.0763 Fe -3.02 0.0754 0.00 0.1066 Fe -3.03 0.1515 0.00 0.2142 Ni -2.94 0.0422 0.09 0.0864 Zn -2.88 0.0098 0.14 0.0760 Y -3.21 NaN -0.18 NaN ###############################

Science Requirements IV: Broad wavelength range Right: spectral features visible in synthetic metal poor RGB star at R20K. Grey is proposed wavelength coverage from Feasibility Study (426-491nm; 585-675nm) ~17 chemical species Consider R40K (~0.5 x previous wavelength coverage) 449.5-482nm and 628-673nm Elisabetta Caffau kindly ran a spectral synthesis code using a real spectrum of HD122563 (metal-poor giant, stellar parameters in Cayrel et al. 2004) from UVES R40000, analyzing just the interval above Obtain metallicity and log(g) in agreement with Cayrel et al. 2004 Teff low by >200K (a well known problem due to the available FeI lines in metal poor stars) Abundances obtained for the following species (9 in total, typical uncertainties of order 0.1-0.2 dex): What is the fundamental (or, more likely, optimal) requirement on the high resolution mode in terms of specific chemical species to be observed and/or total number of species to be observed? Fixed Vturb=2.0km/s Derived Teff=4393.7 Logg=1.02 ############################# [X/H] Sigma [X/Fe] Sigma Ca -2.68 0.0571 0.35 0.0946 Sc -3.08 NaN -0.05 NaN Ti -2.78 0.0383 0.25 0.0846 Ti -2.79 0.1031 0.24 0.1833 Cr -3.15 0.0333-0.13 0.0824 Cr -2.94 0.1600 0.08 0.2204 Mn -3.20 0.0114-0.17 0.0763 Fe -3.02 0.0754 0.00 0.1066 Fe -3.03 0.1515 0.00 0.2142 Ni -2.94 0.0422 0.09 0.0864 Zn -2.88 0.0098 0.14 0.0760 Y -3.21 NaN -0.18 NaN ############################### e.g. c.f. AAT/HERMES, 4MOST, Gyes

Science Requirements V: Targeting the faint Universe

Science Requirements V: Targeting the faint Universe Low res sensitivity: SNR=2 for m=24 in 1 hour (SNR=1 at <400nm) e.g.,evolution of galaxies, halos and structure over 12Gyrs Moderate res sensitivity: SNR=2 for m=23.5 in 1 hour (SNR=1 at <400nm) e.g.,nearby galaxies and their environment; The chemodynamical deconstruction of the Local Group High res sensitivity*: SNR=10 for m=20 in 1 hour (SNR=5 at <400nm) e.g.,galactic Archaeology *pending hi-res decisions

Science Requirements VI: Stable & calibrate-able

Science Requirements VI: Stable & calibrate-able Velocities at R3000: 20km/s at SNR=5 Velocities at R6500: 9km/s at SNR=5 (standard velocity accuracy in both modes, no wavelength dependence) Velocities at RXX000*: 0.1km/s at SNR=30 Velocity accuracy better than nominal Exoplanets and stellar velocity variability; Revealing the physics of rare stellar types ; The dark substructure of the Milky Way *pending hi-res decisions

Science Requirements VI: Stable & calibrate-able

Science Requirements VI: Stable & calibrate-able Relative Spectrophotometry 3% at SNR=30 Mapping the inner parsec of quasars Also required for stellar population analysis of extragalactic targets Accurate relative spectrophotometry is extremely hard Requires precise knowledge of the relative transmission of all your system as a function of wavelength to a very high level at all times Requires precise knowledge of the amount of flux entering your system as a function of wavelength ie where your source is relative to your fibers The dedicated and stable nature of MSE is essential for spectrophotometry Note that, ideally, you would like to have big fat fibres [ Discussion on Friday ]

Science Requirements VI: Stable & calibrate-able

Science Requirements VI: Stable & calibrate-able Sky subtraction 0.5% accuracy away from sky lines (or limited by expected photon statistics) Residual noise consistent with variance from sky in regions of sky lines e.g. m=24 (SNR=2 limit in 1hr) is 3.3 mags fainter than median sky brightness in dark time (V=20.7mags/sq.arcsec) so sky is ~20 times brighter than the object 1% sky subtraction means 20% of flux in sky subtracted object spectrum is sky Very good sky subtraction is hard; this requirement is pushing the limits of what can be achieved with fiber fed systems But good results achieved using advanced analysis procedures e.g., Principle Component Analysis (see Sharp & Parkinson 2010); no plans for (e.g.) N&S A lot of collective experience in the MSE science team to draw upon

The bottom line MSE is the world s only large aperture (>8m) observatory to be dedicated to spectroscopy at OIR wavelengths. Its first light capabilities will enable transformative science, and over its lifetime it will act as a premier platform for exploration of the faint Universe * from Sugai et al. 2014 (SPIE); area based on effective diameter of circle with area equal to patrol region of fibers"

Outstanding Requirement Issues

Outstanding Requirement Issues High spectral resolution mode Thursday science discussion topic? Can we define a path forward at this meeting to resolve these questions? Data requirements [ Friday data discussion ] What data products does MSE need to provide as standard? Calibration requirements [ Friday calibration discussion ] Detailed calibration plans are next major focus for science Do the requirements reflect your science needs? Primary focus of the science sessions today and tomorrow should be in identifying key capabilities and ensuring these are accurately reflected by the science requirements Science Requirement Document will soon be put under configuration control (~September) and cross referenced to Detailed Science Case. Finalisation of these documents marks the end of the first set of tasks for the science team

As one door closes

As one door closes Next priorities for science team: Integral field units concept and implementation strategy Operations Concept how do we implement the science programs? See discussion on Friday Calibration plan See discussion on Friday Set-up a calibration working group to advise the Project Office Data pipelines and concepts Science simulations MSE observing simulator lots to do :-)

Fin

Fin Thank you Questions?