Observational signatures for shocks in the solar photosphere

Observational signatures for shocks in the solar photosphere – possible HINODE/SOT observations Jan Rybak and A. Kucera, A. Hanslmeier, H. Woehl Astronomical Institute, Slovak Academy of Sciences Tatranská Lomnica, Slovakia and IGAM/Institute for physics, KF University, Graz (Austria) KIS, Freiburg (Germany) Hinode workshop, Orsay, France, 13 -15/11/2007

NUMERICAL SIMULATIONS (1) Numerical simulations (SIMs) of the solar convection: supersonic flow near edges of granules (~10 km/s) and shocks on the G/IG interface (Cattaneo et al. , 1989, 1990, Steffen & Freytag, 1991, Solanki et al. , 1996, Stein & Nordlund, 1998, Steiner et al. , 1998, Gadun, 2000) – at some locations only Nesis et al. , Ap. J, 1993, 399, L 99 Stein & Nordlund, 1998, Ap. J 499, 914

NUMERICAL SIMULATIONS (2) numerical simulations of the solar atmosphere dynamics (PH+CH): hot + cold components at the same time spatial fragmentation, dynamical nature of processes Wedemeyer et al. , 2004, A&A 414, 1121

OPEN QUESTIONS Question stated: Is amount of the dynamic events well estimated? It is much more significant we are used to think. . . Is this question worth to study? Numerical simulations are affected by: Limited spatial resolution Physical simplifications Numerical simplifications Possible cumulative effects Effects of the magnetic field Wedemeyer et al. , 2004, A&A 414, 1121

OBSERVATIONS (1) Comparison of the results of numerical simulations of the photospheric dynamics (SIMs) to observational evidence for dynamical events in the upper photosphere (OBSs) Signature – line broadening near the limb: Case studies of the individual events Statistical analysis What has been already done/published? “SIMs ~ OBSs comparison” papers : 1/ Solanki et al. , 1996 : 1 D spectra near limb, combination of the spectral line parameters FWHM, V_doppler, I_cont, I_res in agreement with the 2 D HD simulations - Solanki, Ruedi, Bianda, Steffen, 1996, A&A 308, 623 2/ Rybak et al. , 2004 : 1 D spectra near limb, combination of the spectral line parameters FWHM, V_doppler, I_cont, I_res in agreement with the 2 D/3 D HD simulations, temporal evolution of the event, relation to the magnetic flux concentration + statistical estimates - Rybak, Wohl, Kucera, Hanslmeier, Steiner, 2004, A&A 420, 1121

OBSERVATIONS (2) An identified shock signature: behaviour of the spectral characteristics – VTT/Tenerife: Fe II 645. 6 nm Rybak, Wohl, Kucera, Hanslmeier, Steiner, 2004, A&A 420, 1121

OBSERVATIONS (3) Shock signature: statistics of the FWHM - VTT/Tenerife: Fe II 645. 6 nm line Rybak, Wohl, Kucera, Hanslmeier, Steiner, 2004, A&A 420, 1121

OBSs ~ SIMs SIMSs : Wedemeyer-Bohm (ITA, Oslo), O. Steiner (KIS, Freiburg) CO 5 BOLD & LINFOR 3 D codes: 3 D snapshot cubes inclination, synthetic spectra integration for the Fe II 645. 6 nm line, degradation of SIMs (30 km) to resolution of OBSs (~300 km) Rybák, J. , Kucera, A. , Wohl, H. , Wedemeyer-Bohm, S. , Steiner, O. , 2006, ASP Conf. Proc. Series, 354, 80 -85

AIM OBSs: 2 D time series of the spectral line profiles at different CLV positions using the best spatial resolution with the adaptive optics Search for observational evidences of the dynamic events in the photosphere (CVL) Possibilities: VTT/Tenerife : VTT + TESOS (KIS, Freiburg), VTT + Goettingen FPI (SWG, Goettingen) DST/Sac. Peak: DST + IBIS (INAF, Arcetri) THEMIS/Tenerife: THEMIS + IPM (INAF, Roma) HINODE: SOT

OBSERVATIONS (4) OBSs: VTT, Observatorio del Teide, (Tenerife): Echelle spectrograph + TESOS, 16 -28/10/2006 DATA taken mostly only with Tip/Tilt ON, AO mostly for the disk centre 1 CLV TESOS SET: TESOS : 543. 4 nm: 0, 45, 60 degrees positions 24 scans per run each scan: 101 steps per 1. 2 m. A, 25 s, +/- 0. 609 A, delta = 0. 0012 A, t_exp = 50 ms 0 degrees: with AO (2 interruptions) 45 degrees: with TT (4 interruptions) 60 degrees: without TT/AO (TT problems) DAY : 26/10/2006

OBSERVATIONS (5) Example of a shock signature: 60 degrees – scan 16, position [22, 20] arc sec WL: typical, the best images NB: I_cont, I_res, V_dopp, FWHM@0. 5, v_bis@0. 5, EQVW

OBSERVATIONS (6) Example of a shock signature: 60 degrees – scan 16, position [22, 20] arc sec

OBSERVATIONS (7) Statistics of the SPCHs: 0 (two), 45, and 60 degrees, better scans only, > 1 million samples

FUTURE OUTLOOK OBSs ~ SIMs: aim to publish not only observational evidences. . . SIMs: data available – S. Wedemeyer-Bohm (ITA, Oslo), O. Steiner (KIS, Freiburg) 3 D snapshot cubes, inclination, synthetic spectra integration for the Fe I 543. 4 nm line CO 5 BOLD + LINFOR 3 D codes Degradation of SIMs (30 km) to resolution of OBSs (~300 km): method invented and already presented here for comparison of the echelle high-resolution spectra with results of such simulations -> new one based on suggestions published by Keller (2006) Targets: statistical distributions -> is the photosphere so dynamic ? Close-look into 3 D cubes of the physical parameters where/when degraded synthetic spectra are similar to the observed ones -> is the shock really what have in mind? Other ones: e. g. acoustic flux generation in the photosphere (disk centre) Future: to add chromospheric signatures

HINODE/SOT ? OBSs: large volume of spectral profiles with different CL positions (~20 x 100 arcsecs, ~1 hour) SOT/NFI : filtergrams - ~90 m. A spectral resolution : Fe I 557. 6 nm Scanning the profile available but a 30 s cadence seems to be too low… SOT/SP : spectral profiles of the Fe I 630. 1 and Fe I 630. 2 nm lines Can the magnetic and the Doppler signal be devided using inversions of these profiles ? SOT/BFI : context images – Ca II H, G-band channels Avoiding the seeing problems of the ground-based observations would be so helpful. . .