Polarization Measurements at the Daniel K. Inouye Solar Telescope (formerly ATST) Valentin Martinez Pillet David Elmore

Summary Inouye Solar Telescope will observationally test models with spatial resolution 2.5X any existing solar telescope Science cases in the Critical Science Plan require spectropolarimetry Suite of spectro-polarimeters with wavelengths spanning 0.38-1.1μm 0.5-1.8μm 0.52-0.76μm 1.0-5.0μm Multiple S-Ps operate simultaneously each sensing multiple pass bands permitting multi-line diagnostics B vector vs. height, separate temperature from velocity, fill factor,

Overview of Observatory 10/26/2014 3

SPIE Montreal 4

East-West Section Through Site (work completed @ Oct 2014 shown in color) Pre-Cast Siding Platform Lift Assy Also completed but not shown: 1) site infrastructure & electrical transformers; 2) backfeed electrical, comm., and fiber to IfA facilities; 3) retaining wall & roadwork 10/26/2014 5

Enclosure 10/26/2014 6

Telescope Mount Assembly Alt-Az Mount 10/26/2014 Coudé Rotator 7

DKIST Technical Specifications: 4 m aperture, off-axis Gregorian Integrated adaptive optics. Hybrid enclosure with thermal control and dust mitigation. Field of view: 5 arcminutes. Angular resolution < 0.03 arcsecond @ 0.6μ Polarization accuracy 0.05%. Wavelength range 0.3-28 microns, 0.38-5 microns at commissioning. Coronagraphic capabilities in IR Facility instruments: VBI: 390 860 nm VISP: 380 1100 nm VTF: 520 870 nm Cryo-NIRSP: 1000 5000 nm DL-NIRSP: 500 2500 nm 11

DKIST CRITICAL SCIENCE PLAN (CSP) DKIST CSP outlines the specific science topics that the telescope will address in the first 1-2 years of commissioning/operations. Goal is to develop detailed observing proposals (next slide) to address specific science questions. This will help to - facilitate early science - clarify operations and pipeline data processing needs - instrument validation DKIST CSP: Community driven with discussion led by the DKIST Science Working Group Chair (Mark Rast) Described in a living document that will be updated as needed. Specro-polarimetry is critical to nearly CSP science topics

Magnetoconvection physics Formation of kilogauss fields in the photosphere (Knölker) Structure & dynamics of small-scale magnetic elements (Criscuoli,Cauzzi) Magnetic field transport: surface dynamo phenomena (Rast) Sunspot umbral structure (Balasubramaniam) Sunspot penumbral formation and structure (Tritschler, TBD) Wave generation and propagation local helioseismology (TBD)

Dynamo processes and magnetohydrodynamics: Small-scale photospheric magnetic fields: formation, structure, dynamics (Brown) Turbulent dynamo: Hanle effect imaging of the quiet-sun (Bellot) Wave generation and propagation (Rast) Magnetoconvective modulation of solar luminosity (Criscuoli) Sunspots: umbral and penumbral structure and dynamics (Tritschler) Flux emergence and active region formation (Katsukawa) Magnetic connectivity and energy flows in the outer atmosphere: The chromosphere/corona connection (Cao) Spicule physics (McIntosh) Formation, evolution, and eruption of non-potential configurations (Parnell) Multilayer magnetometry and atmospheric heating (Socas-Navarro) Coronal waves and energy fluxes (Cranmer) Energy and magnetic helicity in coronal structures (Judge) Prominence morphology, connectivity, and life cycles (Scullion) Infra-red survey of the solar atmosphere (Penn) Flares and eruptive activity: Flare precursors in the lower atmosphere Magnetic field connectivity and changes in flares (Qiu) Flare electron diagnostics in visible light (Cauzzi) Flare foot points at their fundamental scales (Fletcher) CMEs Miscellaneous topics: Sun-grazing comets (Liu) Under revision!!

Magnetic connectivity and energy flows in the outer atmosphere The chromosphere/corona connection (Judge) Spicule physics (Cao, Carlsson) Coronal imaging (Woger, TBD) Coronal magnetometry (Judge) Quiet-Sun magnetic activity (DeForest, Deng)

Flares and eruptive activity Formation and evolution of prominences and coronal cavity systems (Berger, Gibson) Flare precursors in the lower atmosphere (TBD) Flare footpoint dynamics (Fletcher, Qiu) Flare electron diagnostics in visible light (Fletcher, Cauzzi)

Miscellaneous topics Sun-grazing comets (Liu, Wooden, Berger) Infra-Red survey of the solar atmosphere (Penn, Judge, Ayres) High-resolution Hanle Effect survey (Martinez-Pillet, Judge)

. Making an unambiguous connection between model results and observations requires the forward modeling of spectral lines and detailed comparison with observations,... (Rempel & Schlichenmaier LRSP) Courtesy M. Rempel Courtesy F. Wöger D=0.75m D=1.5m D=4m Model Putting models to the test: Resolution, resolution, resolution

Photospheric field: FeI 525nm, FeI 630.2nm, FeI 1.56μm lines Chromospheric field: CaII 854.2nm, HeI 1083.0nm Coronal field: FeXIII 1.0747μm, SiIX 3.9μm 3D structure of magnetic field diagnostic tools: UV far IR coverage Credit: B. DePontieu Credit: NASA/ESA/LMSAL. Field extrapolation

The coronal magnetic field controls the plasma dynamics. The magnetic field: Can be modeled using extrapolations Has been estimated with proxies Measurements are mostly lacking!

Courtesy J. Kuhn

Bak-Steslicka et al (2013) measure the magnetic morphology of prominence cavities using HAO COMP data The technique uses linear polarization of Fe XIII 1075nm and forward modeling.

Spectrograph Inversion-driven physics requiring instantaneous realization of the Stokes profiles. Multiple line diagnostics within spectral band Wavelength Y Tunable Filtergraph Spatial correlation of widely-separated features is required. Image reconstruction techniques over a wide field. Imaging Spectrograph Strict simultaneity of both spectral and spatial samples is required. 26

Cryogenic Near Infrared Spectro- Polarimeter (Cryo-NIRSP)

Cryogenic Near Infrared Spectro- Polarimeter (Cryo-NIRSP) Jeff Kuhn IfA University of Hawaii Cryogenic spectrograph and imager with pass bands between 1.0μm and 5.0μm Full Stokes spectro-polarimetry 180x240 arcsecond 2 scanned field of view Coronal lines 1.075μm, 1.080μm, 3.95μm. CO at 4.66μm

Visible Spectro-Polarimeter (ViSP)

Visible Spectro-Polarimeter (ViSP) Roberto Casini High Altitude Observatory From 30 lines of interest between 380nm and 1100nm: probability of observing 1 line = 100% 2 lines = 98% 3 lines = 85% Broad spectral bands for even more lines that can be simultaneously observed

Visible Tunable Filter (VTF)

Visible Tunable Filter (VTF) Wolfgang Schmidt KIS Freiburg Scanning Fabry-Perot spectro-polarimeter Selected lines between 520nm and 870nm Image reconstruction over 1 arcmin 2 field of view.

Diffraction Limited Near Infrared Spectro-polarimeter (DL-NIRSP)

Diffraction Limited Near Infrared Spectro-polarimeter (DL-NIRSP) Haosheng Lin IfA University of Hawaii Imaging spectro-polarimeter Three channels. DWDM filters within 500nm 900nm 900nm 1350nm 1350nm 1800nm+ Spatial sample sizes of 0.03, 0.08, and 0.42 arc seconds 2 Fields of view of 1.8x2.4, 3.6x4.8, and 20x30 arc seconds 2