XRT: HOP15 AR
2007-12-06T09:38:51 to 2007-12-06T23:58:23
Science Goal: DST/IBIS, Hinode/EIS+SOT+XRT, SOHO/MDI and TRACE -Magnetic helicity in active filaments
Program: HOP15_tracking_AR
Target: AR
xcen=-891 ycen=-127
Instrument: XRT
HOP/JOP: 0
Description:
Daily Note: First pass is extremely early!! (2:51 JST!) No SOT table upload today. SOT: - HOP 35 - HOP 15 XRT: - HOP 35 - support EIS coronal hole studies. - XRT to support EIS numbers 4 and 5 (in particular) this week. EIS: (Aim to be done this week.) 1a. Study of spicule signature in TR lines. On the disk QS or, if available AR plage, covering the boundary of a CH would also be of interest. EIS fast (5 minute) rasters or 30 s cadence sit'n'stare with 200 arcsec wide rasters before and after for co-alignment. Duration of order 45 minutes (plus time for large rasters) co-ordinated with SOT. 1b. The limb target(s) would ideally cover QS and CH. EIS sit'n'stare in cool lines at E/W limb, small (10 arcsec, 5 positions) raster in cool lines at S/N limb. Co-ordinated with SOT. 2. Attempt to capture flux emergence in both SOT and EIS to compare with numberical flux emergence models. EIS slots or slot rasters at high (30 s) cadence. Run of order an hour or two on QS. SOT co-ordination required. 3. HOP 35, Romano et al, Magnentic Helicity in Active Filaments. Co-ordination with Sac Peak 16:00 - 20:00 UT. 4. Limb observations for line broadening and diagnostic line ratios above limb. XRT support to provide context FoV images. Of order 2 x 3.5 hours, once for large raster, once for sit'n'stare at three locations above limb (10, 20, 30 arcsec). 5. Quiet limb observations from just inside to well outside limb. Both E and W line required, not necessarily on same day. Minumum duration 4.5 hours hours at each limb. XRT support to study X-Ray luminosity relationship to solar wind at 1 AU. 6. Observations of disk coronal hole. Raster to be run five times to cover CH and surroundings, and on consequtive days. Duration 5.5 hours. XRT support
observe CH at E/W limb
disk/pole jet comparison. 7. On-disc coronal hole at limb to observe jets at multiple wavelengths. EIS runs narrow slot. Duration of order 1 hour, CH at limb.
Request to XRT HOP Number 0035:
Other Instruments: DST/IBIS SoHO/MDI TRACE
Scientific Objectives: We want to investigate whether the conditions for filament eruption occurrence depends on the shear / twist of the filament magnetic field or on the interaction between the highly sheared core field of the filament and the overlying flux rope. In this context, two main theoretical models have been proposed. The former suggests that the magnetic eruption and the impulsive energy release begins deep in the highly sheared core field of the filament and the overlying flux rope then erupts into interplanetary space (Moore et al., 2001). The latter assumes that a sheared core field pushes through an overlaying restraining filed and that a slow reconnection begins at a neutral point high in corona. After the restraining force of the overlaying field significantly weakens because of the reconnection, the sheared core field explosively erupts into interplanetary space (Antiochos, 1998). We think that the measure of the magnetic helicity or of its flux from the photosphere into the filament axis and the study of the magnetic topology of the active region where the filament eruption occurs, will give us the opportunity to discriminate between these two theoretical models.
