SOTSP: Center to limb variation of magnetic elements
2007-09-08T11:22:01 to 2007-09-08T15:29:35
Science Goal: Hinode-ITP campaign
Program: very deep mode 164x164"
Target: Quiet Sun
xcen=-782 ycen=76
Instrument: SOTSP
HOP/JOP: 25
Description:
Daily Note and User Entry: Center to limb variation of magnetic elements
Request to SOT: We would propose to use the SP instrument in SOT to measure the photospheric magnetic field with the line pair at 630.2 nm. Additional Filtergram observations with SOT would be necessary for doing the alignment with the ground- based data. We propose to perform a time series of rather short scans with a high repetition cadence of about 2 minutes at disk center. With an exposure time of 4.8 seconds and a step size of 0.16'' the scan would amount to some 4''. That means that alignment is an issue. But since the slit of SP is 160'', there should be enough room for overlapping field of views.
Scientific Objectives: The goal of our campaign is an understanding of the dynamic quiet sun magnetic and of its coupling from the photosphere to the chromosphere. We will acquire spectro-polarimetric
data from the SST, the VTT, and THEMIS. At the VTT
will use the spectropolarimeter TIP and POLIS to measure the deep photosphere (Fe I 1564.8 nm), the middle photosphere (Fe I 6302 nm), and the chromosphere (intensity profiles of Ca II H 397 nm). At THEMIS we will concentrate on the infrared Ca lines (849.8 nm, 854.2 nm) to study the chromospheric response on photospheric magnetic field. For alignment we will also record a photospheric line like Fe I 525.0 nm at THEMIS. At the SST we will take advantage of the tunable filter imaging system to obtain context information (images and magnetograms) at highest possible resolution.
This multi-wavelength approach will be complemented with speckle- reconstructed Halpha images from DOT. For this campaign it would be of great advantage to complement the data set with spectro-polarimetric data at 0.3'' spatial resolution (at the VTT we may achieve a spatial resolution of only 0.5'' at best with the help of the adaptive optics system).
Other Instruments: STT, VTT, THEMIS, DOT
