High Resolution Science with solar Adaptive Optics NSO

High Resolution Science with solar Adaptive Optics NSO AO Heritage T. Rimmele 1

Ground-based Advantage • larger apertures • and therefore w/adaptive optics higher resolution (at given λ) • Well/best suited for high resolution IR (large r 0) observations – magnetic sensitivity • higher photon flux – sensitivity & cadence • coronal magnetometry require large apertures. • more sophisticated, more powerful & up-to-date instrumentation is available at ground based telescopes. • flexibility and complexity to bring many different diagnostic tools to bear on a problem • high data rates/volumes • pathfinder for space based experiments • COST $$$$$ - if it can be done from the ground it should be done from the ground!! June 10 -12, 2007 2

. 10 -31 -2006 3

Stable, high-Strehl resolution for long-periods of time at high magnetic sensitivity NIR wavelengths F. Woeger, 430 nm e. g: 4 m ATST/1300 dof AO on Haleakala S>0. 6, i. e. , space quality imaging, for 90% of the clear time!! June 10 -12, 2007 4

Wavefront Control is Essential • Quasi-static alignment (QSA): – for keeping the entire optical path- most importantly M 1 and M 2 - aligned in closed-loop. • The active optics (a. O) system: – keep the figure of M 1 within spec compensating for deformation due to gravitational and thermal distortions. • Tip/tilt devices for image stabilization. • High order adaptive optics (HOAO): – for correcting atmospheric and internal seeing and residual optical aberrations. 10 -31 -2006 5

The Prototype: Dunn Solar Telescope AO works great and produces good science • Two 97 actuator systems operational since 2000 • Used routinely for observing runs - > 90% of actual observing time • Operated by observing staff (2 people) – Optical setup and alignment (after optics cleaning or re-coating) – Calibration procedures – Operate AO and Science Instruments • Impressive Science Output – Over-subscribed DST – Many publications based on AO data – Recognition of (old) DST as one of the most productive high res solar telescopes – DST competes well with new Swedish Telescope –Scharmer 2006: “You have a better AO system” 10 -31 -2006 6

DM WFS FIBER IF DLSP 10 -31 -2006 UBF 7

Experimental Bench 10 -31 -2006 8

3 sec exposure Tip/tilt on 10 -31 -2006 9

AO loop on 500 nm 10 -31 -2006 10

Solar Adaptive Optics Performs as Advertised Vw=10 m/s; fs=300 Hz=-3 d. B BW Pupil Misalignment? WFS noise anisoplanatism? Model includes: • Fitting error • Aliasing • Bandwidth • WFS noise 10 -31 -2006 11

LE PSF estimation from AO loop data Dopplergram - well, not really June 10 -12, 2007 This is more like it!! J. Marino 12

A. Tritschler June 10 -12, 2007 13 NSO/HAO/KIS Diffraction-Limited Spectro Polarimeter

Solar MCAO is becoming a reality! MCAO DM 2 @ 6 km, target: granulation 10 -31 -2006 Conventional AO 14

Examples of Science Results with a personal bias, of course! • • Dynamics of g-band bright points (BP) Spectroscopy of g-band BP Flare observations at the diffraction limit Chromospheric dynamics – Wave propagation – Acoustic Shocks • Sunspot dynamics – Penumbra and Evershed effect (keep those theoreticians honest!) – Umbral sub-structure (keep those …. ) 10 -31 -2006 15

DLSP Speckle Imager 2 kw 2 k, 25 fps Frame selection Speckle bursts Virtual camera Prototype 10 -31 -2006 16

AO + Speckle Oct. 2003 Region which produced Halloween events 10 -31 -2006 17

Diffraction limit achieved - We are beginning to detect substructure in umbral dots gband 10 -31 -2006 18

…. and we can perform quantitative physical measurements Only possible with AO (14 sec exposure)! 10 -31 -2006 Integrated Fe. I 5434 line absorption 19

… which will allow us to test models/simulations Umbral Dots 10 -31 -2006 Simulations by Schuessler&Voegler 2006 20

Sample High-Resolution Spectra • Fe. I 1564. 8/1565. 3 nm, g = 3/1. 5 line pair is the most sensitive line pair for magnetic field measurements • NIR-polarimetry is essential tools for weak fields • Currently about 0. ” 4 resolution (diffraction limit) 10 -31 -2006 Lin @ DST 21

Quiet Sun Observations • Most challenging for AO – Lock on low-contrast granulation – Keep lock for hours – Can be done routinely at DST in seeing of <1”. 5 • Comments concerning this data set: – Service Observing • important operational mode for ATST – Several groups are working on these data – open data • US, Italy, India • Requested by M. Carlsson, Norway –”it’s a unique data set at this point” • New insights into Chromospheric Dynamics 10 -31 -2006 22

Velocity power maps High frequency power – only w/AO 2. 4 -- 4. 0 m. Hz 10 -31 -2006 5. 5 -- 8. 0 m. Hz 23

Spectral profiles vs. time (quiet, high vel. power at > 5. 5 m. Hz) 10 -31 -2006 Courtesy of A. Pietarila 24

‘ 3 -min Shock’ maps Cumulative shocks 10 -31 -2006 5. 5 -- 8. 0 m. Hz vel. power 25

Fe. I 7090 - Ca. II 8542 phase diff. Red > waves propagating upwards 2. 4 -- 4. 0 m. Hz 10 -31 -2006 5. 5 -- 8. 0 m. Hz 26

Testing Penumbral Models 10 -31 -2006 27

Summary • High resolution observations are essential for solving many of the mysteries the Sun still holds – Detailed physical understanding results from comparison of observations and models • Wavefront control is essential to achieve diffraction limit – Solar AO is proven technology and is having a huge scientific impact • Coronal Magnetometry is essential tool to understand coronal structure&dynamics: CMEs, coronal heating • Feasibility of Coronal Marnetometry has been demonstrated with Solar-C&COMP – Need the 4 m aperture for sufficient S/N 10 -31 -2006 28