Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-00119) (for September 2001) OVERVIEW The YOHKOH Mission is a program of the Japanese Institute of Space and Astronautical Science (ISAS) with collaboration by the U. S. National Aeronautics and Space Administration and the U. K. Science and Engineering Research Council. The YOHKOH satellite was launched on 30 August 1991 from Kagoshima Space Center (KSC) in Japan. The purpose of this mission is to study high energy phenomena in solar flares and the Sun's corona. Under an international cooperative agreement, Lockheed Martin, under NASA contract, is providing a scientific investigation using the Soft X-ray Telescope (SXT), one of the primary experiments of the mission. The SXT was developed at the Lockheed Martin Solar and Astrophysics Laboratory in cooperation with the National Astronomical Observatory of Japan, and the Institute for Astronomy of the University of Tokyo. MAJOR PROGRAMMATIC ACTIVITIES IN THE MONTH SXT activities were heavily dominated by developing a viable program plan for future years based on the directions that culminated from the senior review. SOLAR ACTIVITY In early September, solar activity was high but in an odd way - 30 M-class flares and no X-class flares, not counting the M9.5 of 9-Sep. However the active regions were quite bright and the background GOES level remained above the C level for most of this period. The largest active region, NOAA 9808 (S26), grew rapidly in complexity (but wasn't huge in area, attaining an area of 940 millionths on 9-Sep). People who predict big flares got this one right (M9.5). As September continued, solar activity was high, but again short of X-flares. There were 10 M-class flares and many C-class flares during mid-month. The background GOES flux stayed around C2 during this time. The baseline flux was elevated by a large and complex group of active regions (9607, 9608, 9610, 9618) which were also remarkably far south. The largest flare was M4.5. The trend of solar activity noted in early September continued to the end of the month: many M flares but no X flares. In fact, about 50 M-class flares have happened since the memorable August 25, 2001 event, the subject of our science nugget that week because of its exquisite white-light and mm-wave observations. We sense something scientifically interesting here, perhaps related to the large number (15 on 21-Sep) of active regions vying for access to the stored coronal energy. The multiple magnetic connections between these regions may make it impossible for significant energy to build up around any one region. The 15 sunspot groups on the solar disk included three regions of high radio intensity, pushing the 10.7 cm radio flux to the highest level of the cycle. At the very end of September, we finally got an X-flare with an X2.6 event on Sep. 24 from NOAA AR 9632. Unfortunately, Yohkoh was in the S/C night at the peak time of the X-class flare. The GOES X-ray background level continued to be around C2 through the end of the month. Transequatorial interconnecting loops were also seen, and at the end of the month two slow LDEs from 9628, 9632 led to beautiful spiny arcades. CAMPAIGNS SXT declared a sigmoid alert on 4-Sep, based on alert pattern recognition at KSC, and then withdrew it on 6-Sep when the region neared the limb. We supported JOP 146, which aims to determine "once and for all" the temperature structure in simple bipolar loops, using TRACE, CDS and SXT data. It took us a day or two to work out the optimum program, but settled on alternating cycles of 3 PFIs, one cycle exposed for the fainter loops and the other for the AR core. Although we had a hard time devoting time to this because of the plethora of bright regions, which worries us regarding SXT saturation if the target is faint, nevertheless the main organizers (J. Cirtain and C. Kankelborg of MSU) have pronounced themselves happy already with good data. There were also, as a byproduct, complicated developments in trans-equatorial loops on the E limb. SCIENCE Yohkoh has seen multiple spiny arcades this month. "Arcade" refers to the nearly cylindrical array of coronal magnetic loops that long-duration flares often produce. During the early phase of a flare, these arcades often seem quite well-rounded and semicircular in cross-section. However, some of them tend strongly to become spiny later on. A pointy coronal streamer is a often called a "helmet streamer", but following this analogy a spiny arcade would be more like a whole platoon of Prussian soldiers wearing helmets with spikes. There is not much literature on these spiny arcades, and little knowledge of their properties. The as-yet-unexplained properties include the existence of a spine, its multiple occurrence, its timing relative to the flare, and its magnetic topology during its SAD phase. Our new observations don't have complete explanations on the theoretical side. Although we don't know what causes the spininess (even though we can make cartoons of "patchy reconnection"), one simple and possibly OK idea for the spatial scale of the spines (ie, their number) is just that it results from the photospheric field structure, with regard for the simplification of this pattern expected from the height in the corona (argument of famed theorist E. Priest and others). However, the recent data show that the number of spines increases as the event ages and becomes larger. LMSAL completed a new Yohkoh poster entitled "A Decade of Discovery". The poster details the prominent discoveries made by Yohkoh over its 10 years in orbit and shows the solar cycle as seen by SXT. Nitta restarted work on the relation between the intensity of TRACE UV 1600 A and that of hard X-rays, in a flare not included in the recent paper by Warren et al. In that flare, the flare consists of three hard X-ray sources as imaged by HXT, and one can immediately conclude that the third source is located at the loop top, given that there is no UV emission there, even though this is not a limb flare. The UV intensity at the two foot-points is reasonably well correlated with hard X-ray light curves, even during the second and later peaks. To see if the hard X-ray sources have different temporal behaviors, he compared the spatially resolved light curves. They look quite similar, probably reflecting the limited imaging capability of HXT. The UV brightening is not limited to the hard X-ray foot-point sources, and the outer UV ribbons seem to be associated with filament eruption/CME, as were the case in the Bastille Day 2000 event. PUBLICATIONS Submitted: Schrijver,C.J., Aschwanden,M.J., and Title,A. 2002 Solar Phys., "Transverse Oscillations in Coronal Loops Observed with TRACE: I. Movies, an Overview of Events, and the Identification of Required Conditions " Aschwanden,M.J., DePontieu,B., Schrijver,C.J., and Title,A. 2002 Solar Phys., "Transverse Oscillations in Coronal Loops Observed with TRACE: II. Measurements of Geometric and Physical Parameters" Kahler, S. W., and Hudson, H. S., "Boundary structures and changes in long-lived coronal holes," ApJ Accepted: Schrijver,C.J. and Aschwanden,M.J. 2002 ApJ, "Constraining the properties of non-radiative heating of the coronae of cool stars and the Sun" Hudson, H. S., Kosugi, T., Nitta, N. V., and Shimojo, M., "Hard X-radiation from a fast coronal ejection," ApJL Sattarov, I, Pevtsov, A. A., Hojaev, A. S., Sherdonov, Ch. T.:2002, "X-ray Bright Points and Photospheric Bipoles During Cycle 22 and 23", Astrophys. Journal, 564 Persistent Coronal Streamers and the Identification of Sunspot Clusters by Jing Li, Barry LaBonte, Loren Acton, and Greg Slater Astrophys. J. Published: Aschwanden,M.J.2001 ApJ 559, L171-L174, "Revisiting the Determination of the Coronal Heating Function from Yohkoh Data " Watanabe, T., Sterling, A. C., Hudson, H. S., and Harra, L. K., "Energetics of an active region observed from helium-like sulphur lines," Solar Phys. 201, 71-91 (2001). McKenzie, D. E., and Hudson, H. S., "Downflows and structure above LDE arcades: Possible signatures of reconnection?" Earth Planets Space 52, 577-580 (2000). Hudson, H. S., and McKenzie, D. E., "Hard X-rays from slow flares," Earth Planets Space 52, 581-584 (2000). "Origin and Evolution of Filament-Prominence Systems", P.C.H. Martens and C. Zwaan 2001, Astrophys. J., 558, 872-887 "Chromospheric Damping of Alfven Waves", B. De Pontieu, P.C.H. Martens, and H.S. Hudson 2001, Astrophys. J., 558, 859-871. "Observation of the coronal hard X-ray sources of the 1998 April 23 Flare", J. Sato, ApJL, 558, 137-140 (2001) Watanabe, T., Sterling, A. C., Hudson, H. S., and Harra, L. K., "Energetics of an Active Region Observed from Helium-Like Sulphur Lines": Solar Phys. 201, 71-91 (2001). PUBLIC USE OF SXT IMAGES We are continuing to make Yohkoh/SXT images available for a variety of uses. Efforts continue to make selected images available on the LMSAL SXT WWW homepage (http://www.lmsal.com/SXT/). We receive requests for the Yohkoh posters (#2 and #3) by way of the form on the SXT homepage. Currently we receive requests via our homepage at the rate of 2 or 3 per day. The WEB access statistics in September were 1509115 accesses and 9,572 Mbytes transferred for the SXT website and 157620 accesses and 4,136 Mbytes transferred for the YPOP website. YOHKOH OPERATIONS AND HEALTH Yohkoh and the SXT continue to function very well. SXT experienced a normal level of Single Event Upset (SEU) events during the month: SXT Bit Map Error 04-Sep-01 Pass 3: 010904-0722 Recovered in the same pass. SXT Bit Map Error 08-Sep-01 Pass 5: 010908-0825 Recovered in the same pass. Page 4 DATA FLOW Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Thru Jul-99 633444 231128 2549385 652995 3202380 1130899 25.96 Aug-99 6827 2503 21725 23361 45086 11844 20.80 Sep-99 5768 2011 21890 3434 25324 10846 29.99 Oct-99 5768 2308 22994 10487 33481 11517 25.59 Nov-99 7552 3425 20754 18772 39526 11974 23.25 Dec-99 7488 2791 22047 5354 27401 10663 28.01 Jan-00 5426 1736 19802 4040 23842 8958 27.31 Feb-00 6533 2052 21801 7017 28818 8982 23.76 Mar-00 6447 2007 22692 21914 44606 11192 20.06 Apr-00 6412 2100 31195 7214 38409 13438 25.92 May-00 6995 1556 28175 14961 43136 8967 17.21 Jun-00 7043 1722 24413 16369 40782 8690 17.57 Jul-00 6674 1920 23505 31739 55244 10235 15.63 Aug-00 9623 1996 20925 1197 22122 6577 22.92 Sep-00 8835 2240 22233 5764 27997 8307 22.88 Oct-00 6348 1524 23309 6629 29938 7916 20.91 Nov-00 6525 1639 20087 10318 30405 6972 18.65 Dec-00 6585 1918 20718 5422 26140 8071 23.59 Jan-01 5610 1231 20469 3161 23630 7317 23.64 Feb-01 6917 1497 25366 1144 26510 7871 22.89 Mar-01 6851 1272 26315 17139 43454 9470 17.89 Apr-01 5531 1804 15991 20001 35992 9216 20.39 May-01 7410 1758 21042 1767 22809 7152 23.87 Jun-01 7037 1024 24643 5760 30403 5075 14.30 Jul-01 7184 1805 19361 1340 20701 6358 23.50 Aug-01 6741 1443 25710 17252 42962 9100 17.48 Sep-01 1687 530 6325 8357 14682 3084 17.36 Total 805261 278940 3122872 922908 4045780 1360691 25.17 Number of Full Frame Images Received: 805261 Number of Observing Region Images Received: 4045780 Total: 4851041 Approximate Number of Shutter Moves/CCD Readouts: 8274598 NOTES: * The loss of images is mainly due to BDR overwrites, but there are also occasional DSN dumps which are lost. * It is common to have observing regions which contain more than 64 lines, which requires multiple exposures to make a single observing region image. This is why the number of shutter moves is larger than the number of images received plus those lost. Page 5 ENGINEERING SUMMARY TABLE Month Avg Dark Level # of Dark Spikes CCD Warmings Front Optical (DN) (e/sec) Over 48 Over 64 High / # Support Trans Temp /Days Temp (%) Aug-99 59.39 1083.0 229319 43067 21.7 N/A Sep-99 60.04 1107.3 231585 49084 21.8 N/A Oct-99 59.66 1092.9 229735 45263 22.8 N/A Nov-99 59.90 1102.0 231288 47102 23.0 N/A Dec-99 60.55 1126.3 233523 53920 22.5 / 2 25.3 N/A Jan-00 60.27 1115.9 233820 50214 23.4 N/A Feb-00 60.93 1140.6 235079 56836 23.8 N/A Mar-00 60.72 1132.8 234174 54661 22.9 N/A Apr-00 61.10 1147.0 235252 58348 22.2 N/A May-00 61.00 1143.1 234569 57445 21.2 N/A Jun-00 61.19 1150.3 235622 58946 22.8 N/A Jul-00 61.96 1179.3 238114 66905 19.3 N/A Aug-00 61.27 1153.4 236108 59965 56.9 / 2 21.7 N/A Sep-00 61.08 1146.2 235644 58449 22.1 N/A Oct-00 61.44 1159.5 237142 61667 23.1 N/A Nov-00 60.99 1142.7 235849 57271 24.2 N/A Dec-00 61.59 1165.2 237454 63656 23.8 / 2 21.8 N/A Jan-01 61.64 1167.3 238962 62922 22.2 N/A Feb-01 61.84 1174.6 239218 65324 23.5 N/A Mar-01 61.89 1176.7 239128 65898 23.1 N/A Apr-01 61.92 1177.5 239784 66169 22.6 N/A May-01 62.25 1189.9 240631 69412 22.8 N/A Jun-01 62.17 1187.1 240572 68588 21.6 N/A Jul-01 62.75 1208.8 241519 74670 22.5 / 2 22.7 N/A Aug-01 62.77 1209.6 241443 75645 22.3 N/A Sep-01 62.58 1202.3 241033 73720 22.0 N/A NOTES: * The dark current calculations are using full half resolution 2.668 sec images not taken in during the SAA. The dark current rate assumes a "fat zero" of 30.5 DN and a gain of 100 e/DN. * The entrance filter failure of 13-Nov-92 eliminated the capability of taking optical images, so the optical transmission is not available after Nov-92. It also caused an increase in the dark current signal, however some of the increase shown here is an increase in the readout noise and is not a function of exposure duration. Page 6 PERSONNEL TRAVEL SXT Foreign Travel between 1-SEP-01 and 30-SEP-01 BARTUS 1-SEP-01 * 30-SEP-01 * 30 (total of 30 days) FLETCHER 8-SEP-01 30-SEP-01 * 23 (total of 23 days) HUDSON 1-SEP-01 * 16-SEP-01 16 21-SEP-01 30-SEP-01 * 10 (total of 26 days) TAKEDA 1-SEP-01 * 15-SEP-01 15 (total of 15 days) ---------------------------------------------------------------- Grand Total of 94 days for 4 people NOTE: The "*" signifies travel that actually ends after 30-SEP-01 SXT Foreign Travel between 1-OCT-01 and 31-OCT-01 BARTUS 1-OCT-01 * 31-OCT-01 * 31 (total of 31 days) FLETCHER 1-OCT-01 * 5-OCT-01 5 (total of 5 days) HUDSON 1-OCT-01 * 7-OCT-01 7 (total of 7 days) NITTA 18-OCT-01 31-OCT-01 * 14 (total of 14 days) TAKEDA 6-OCT-01 31-OCT-01 * 26 (total of 26 days) ---------------------------------------------------------------- Grand Total of 83 days for 5 people NOTE: The "*" signifies travel that actually ends after 31-OCT-01 Respectfully submitted, Thomas R. Metcalf Frank Friedlaender Page 7 ================================================================= Montana State Univ Activity Report for June 1998-July 1998 ================================================================= (J. Sato) INTRODUCTION The MSU group carried out data analysis, graduate and undergraduate research, and performed outreach activities. Within this period, almost of the MSU group were working for Yohkoh 10th meeting although the meeting was postponed by a tragic affair on September 11. We also passed the Yohkoh/SXT senior Review and got a grant to continue the Yohkoh mission and SXT operation by NASA. This is very good news for all Yohkoh people and we will get many scientific results from Yohkoh. The Yohkoh is a unique satellite having high spatial resolution of soft X-rays. YOHKOH AND SXT OPERATIONS No operations by MSU people. Canfield reformatted the SXT Chief Observer's weekly report at http://solar.physics.montana.edu/nuggets/ MEETINGS No meetings related to SXT activities. Yohkoh 10 th meeting was postponed until 2002/01. Probably, the meeting will be a good chance to see the first result obtained from HESSI. RESEARCH Acton continued to improve the straylight correction for the SXT Science Composite database. Although the reason for straylight intensity bifurcation remains obscure, he has learned a great deal about the SXT shutter operation and mechanical layout of the SXT focal plane assemblies through this work. Canfield with Bob Leamon and Alex Pevtsov studied sigmoids and magnetic clouds. The study shows that the large-scale dipole leading-field paradigm for magnetic clouds, developed for filament-associated eruptions, does not work for active-region eruptions from sigmoids. Rather, they follow a weak solar-cycle (Hale-polarity) rule. Also, rather than the strong hemispheric handedness rule shown by magnetic clouds associated with erupting filaments, only a weak hemispheric handedness rule is shown by magnetic clouds associated with erupting active-region sigmoids. Finally, independent of handedness, erupting sigmoids tend to produce at least moderate geomagnetic storms. Also, he resumed work on the Whole Sun Month 3 Flare Topology Working Group paper on NOAA AR 8668. Martens helped grad student Jonathan Cirtain with a new JOP for coordinated observations (CDS, EIT, TRACE, SXT) to determine the DEM's of limb loops. He continued working with Becca McMullen on band ratio temperatures for TRACE. He also attended (parts of) the MOSES kick-off meeting at MSU, and presented a short talk. He and Dave worked on two proposals for the NASA SR&T proposals (see Dave's part). He is working on in-orbit determination of the SXT Point Spread Function with Szymon Gburek, a Polish grad student of Janosz Sylwester. He and Dave were working on a MidEx proposal with Don Hassler and Leon Golub, called "ESSEX". It contains several high resolution EUV telescopes and a SUMER-like spectrometer. He also refereed two papers for A&A. McKenzie worked on two NASA SR&T proposals, dealing with (a) spikey arcades and the magnetic network, and (b) coronal hole temperatures. He prepared material and some SXT data for himself and Becca McMullen at the Yohkoh 10 meeting. With Dana Longcope, he started designing a 3D model of a CSHKP-type arcade with patchy discrete reconnection. He worked on a MidEx proposal with Piet Martens and other people, primarily by helping to estimate the capabilities of EUV imagers in various wavelength passbands, to be applied to appropriate scientific targets. Also, He found one more apparent supra-arcade downflow event: the 27-sep-01 M flare displays an X-ray emitting loop which seems to shrink downward into the top of the spikey arcade. Sato tried to do a data analysis using Yohkoh Flare Image Catalogue (tentative title). Some interesting events were found within the catalogue. Especially, he studied flares showing a large structure in SXT and a small source in HXT. Such a flare may reveal characteristics of energetic electrons due to the small thermal emission in HXT energy range. The spectral characteristics of hard X-ray sources seem to be similar to that of double sources which are studied in my footpoint source paper. Also, he studied some limb flares using a fanbeam data to confirm an existence of high coronal emission. Some events showed high coronal emission and the region is not synthesized due to the limited dynamic range of the HXT. Also, he continued to revise his old paper of footpoint source spectrum. SERVICE AND OUTREACH Martens and Acton, with the invaluable help of LOC members McMullen, Noonan, and Halvarson, made great progress in the organization of the Yohkoh 10th Anniversary Meeting in August. But the meeting was postponed and therefore they started re-organization for the meeting held on 2002/01. Martens got NSF grant to have 4 students participate in the Yohkoh 10 th meeting. Canfield worked with Nitta and Hudson on a press release associated with their GRL paper on the dramatic flux emergence, X-flares, ejecta, and CMEs from AR9236. McKenzie maintained and updated the SXT website. He collaborated with Michelle Larson and David Alexander on a poster for the Yohkoh 10th Anniversary meeting. He worked on press releases related to the tenth anniversary of Yohkoh. The material was released on September 10, and then re-released the following week. It was covered by local news (with Acton's face on TV), space.com, MSU website, and NASA website. He began discussions with Annette Trinity-Stevens about a TV project. This would be one of a series of 2-3 minute "fillers" called "MSU Research Highlights", and would introduce the MSU solar group to PBS viewers in Montana. He continued collaboration with MSU's master of fine arts program's film school, in regards to a film project about Yohkoh, solar research, etc. Sato improved image database of SXT and HXT images. All images can be accessed within a flare list. The flare list is similar to that of YOHKOH HXT IMAGE CATALOGUE. Also, Sato fixed many bugs seen in the database. Now, the database gives us correct information of the alignment. PUBLICATIONS Martens had two papers: "Origin and Evolution of Filament-Prominence Systems", P.C.H. Martens and C. Zwaan 2001, Astrophys. J., 558, 872-887, and "Chromospheric Damping of Alfven Waves", B. De Pontieu, P.C.H. Martens, and H.S. Hudson 2001, Astrophys. J., 558, 859-871. Sato had a paper: "Observation of the coronal hard X-ray sources of the 1998 April 23 Flare", J. Sato, ApJL, 558, 137-140 (2001) McKenzie had two papers: "Downflows and structure above LDE arcades: Possible signatures of reconnection?", McKenzie, D. E., and Hudson, H. S., Earth Planets Space 52, 577-580 (2000) "Hard X-rays from slow flares", Hudson, H. S., and McKenzie, D. E., Earth Planets appeared in Space 52, 581-584 (2000). ============================================================= Univ of Hawaii Activity Report for June 1998-July 1998 ============================================================= (J. Li) Our activities included support of Yohkoh operations and data analysis at ISAS, coordinated ground-based data acquisition (including designated Yohkoh campaigns) at Mees, collaborative analysis of Yohkoh/Mees data, and preparation of manuscripts. Operational support for SXT was provided by G. Nitta at Mees and LaBonte and Li in Manoa. Our colleagues, Canfield at Montana State University, Wuelser and Metcalf at Lockheed, and Hudson at Solar Physics Research Corporation aided in advice and oversight of Mees operations. LaBonte has relocated to Johns Hopkins University, Applied Physics Lab. He will continue to have a daily role in overseeing Mees operations and data analysis. Weather at Mees was average during these months. Observations were obtained on 72% of all scheduled days in August and 90% in September. Total coverage was limited by the number of holidays and vacations. The Sun became more active in September, with several large active regions. Mees observed a number of events, but the weekends occurred during X flares. Special observations were made. Vector magnetograms in H-alpha were made for several dates in early August with the IVM. The Quicklook analysis shows real signal, and in the best cases interesting structure. The Ca II 8542 A line was observed with the MCCD in August, in a search for signatures of Ellerman bombs. Numerous small flares were seen. Li finished the paper on coronal streamers and sunspot clusters, and the paper has been accepted for publication. She has resumed the work with Zhang to understand the match of magnetic field azimuths from Mees and Huairou instruments. Papers accepted for publication: Persistent Coronal Streamers and the Identification of Sunspot Clusters by Jing Li, Barry LaBonte, Loren Acton, and Greg Slater Astrophys. J. ============================================================ Stanford Univ Activity Report for June 1998-July 1998 ============================================================ (P. Sturrock) Peter Sturrock and Mark Weber have continued their comparative analysis of Yohkoh/SXT data, solar neutrino data, and data for the Sun's internal rotation. Mark has recently extended his reduction of the SXT data-base to cover the interval 1991 through 2000, which now covers almost a solar cycle. We have now spectrum-analyzed each of nine latitude bins, each with a width of 15 degrees. The most striking periodicity is found at the highest latitudes - 60N and 60S. The peaks occur at 12.91 y^-1 for 60N and at 12.86 y^-1 for 60S. Taken together (by forming the joint spectrum statistic), the peak is found at 12.88 y^-1. In our analysis of the Homestake neutrino data (Sturrock, Walther & Wheatland , 1997, ApJ, 491, 409), we identified a prominent periodicity at precisely the same frequency. In the previous bi-monthly report, we stated that the most prominent periodicity in the equatorial SXT data occurs near 13.6 y^-1, close to the value [13.56 y^-1] of a prominent peak in the GALLEX-GNO neutrino data (Sturrock & Weber, 2001, ApJ, in press). However, this association is not as striking as that which we find for the high-latitude X-ray flux. It appears that the high-latitude corona exhibits rigid rotation more strongly than the low-latitude corona. The only known mechanism that can lead to rotational modulation of the solar neutrino flux is flavor and/or chirality oscillation due to magnetic field. (This requires neutrinos to have a small but nonzero magnetic moment, a property which is not generally attributed to neutrinos.) We therefore attribute the rigid rotation of the corona to localized, long-lived magnetic regions, which also influence the solar neutrino flux. From a comparison of the frequencies of the peaks in the power spectra with estimates of the solar internal rotation, as determined from MDI helioseismology data, we infer that the magnetic region influencing the low-latitude corona is situated deep in the convection zone, and that the magnetic region influencing the high-latitude corona is located at or near the tachocline. Neutrino data offer a hint as to the difference in these two magnetic regions. Most of the neutrinos detected by Homestake originate within a sphere of radius 0.05 solar radii, whereas most of the neutrinos detected by GALLEX-GNO originate within a sphere of radius 0.15 solar radii. Hence it seems likely that the magnetic region in the convection zone which influences the low-latitude corona and the Homestake neutrino flux has dimensions of order 0.05 solar radii or less. On the other hand, the magnetic region in the tachocline which influences the Homestake and GALLEX-GNO neutrinos and the high-latitude corona may have a much larger latitudinal extent. We plan to pursue this research further by comparing the longitude distributions of X-ray emission (taking the northern and southern hemispheres separately) with the longitude distribution of neutrino measurements. In this context, the longitudes will be referred to the rotating coordinate system identified by our power spectrum analysis. We plan also to examine the variation of these patterns with phase of the solar cycle. In his analysis of latitudinally binned SXT time-series, Mark has shown that it only takes about 20 degrees of freedom, or 10 harmonic signals, to model the midhigh-latitude corona over a ten year period, to two-sigma agreement with the data. The implication is that the midhigh-latitudes (45--70 degrees latitude) are relatively simple to model. A more sophisticated model which takes time-evolution into account, perhaps using wavelets or analyzing shorter time runs, might reduce the required model size to a mere handful of important signals. The low latitudes are expected to be more complex, and Mark is currently looking to see how much more. Mark also performed some maintenance on the Yohkoh-10 Meeting's LaTeX template. =========================================================================== Solar Physics Research Corp. Activity Report for June 1998-July 1998 =========================================================================== (Karen L. Harvey and Hugh S. Hudson) KAREN L. HARVEY: Activities for August and September: (1) Continued the analysis of the 18 December 1998 HAO/CHIP He I 10830 data in collaboration with Terry Forbes to measure the magnetic flux as a function of time within an area bounded by the flare ribbons and the polarity inversion separating them and within the associated transient coronal holes. The objectives of this study are to determine the reconnection rate of a flare and as an addendum to our original goal, to investigate the role of the transient coronal holes in the accompanying CME. Unfortunately, the SXT data for this event, made available with the help of Hugh Hudson, are not of good enough quality nor are the SXT images taken early enough in the flare for these data to be of use for this particular event. We have had to rely on the few EIT observations for comparison with coronal images. We find that the combined magnetic flux in the flare ribbon and transient coronal hole in the positive flux is equal to that in the unsigned negative polarity, although individually the magnetic flux in the two flare ribbons and in the two coronal holes is not balanced. EIT images were used to estimate the position of the loop footpoints as we suspect that the overlying coronal flare loops `shadow' the boundary of the flare and transient coronal hole in the eastern portion of the flare. It is somewhat difficult to be absolutely sure of the location of the coronal loop footpoints as this depends to some extent on the intensity scale used to display the coronal images. First estimates, however, indicate that the loop footpoints overcorrect for the imbalance of flux in the flare ribbons. We have found a two part structure to the distribution of He I 10830 equivalent width within the bounds of the transient coronal holes. We are trying to determine the validity of this finding and how to establish their separation using an objective method and to see how this relates to the dimmings seen in the EIT coronal and chromospheric images. (2) Continuing with a comparison of the coronal holes identified in NSO/KP He I 10830 rotation maps and with corresponding Yohkoh/SXT rotation maps to determine if the structures identified as coronal holes in He I 10830 all are associated with low emission areas. Plans for October and November: Continued analysis (1) with T. Forbes of the reconnection rate of magnetic fields during long-duration arcade events/He I 10830 2-ribbon flares and comparison of the transient coronal holes with X-ray/EUV dimmings; (2) of the association of coronal holes observed in He I 10830 spectroheliograms and the SXT full-frame and synoptic images; this includes isolated, non-polar coronal holes, as well as the transient coronal holes; of particular interest is the formation of coronal holes and of polar extensions; (3) return to a collaborative project with Keith Strong on the solar cycle variation of XBP started in 1995 for a paper presented the 1996 Bath meeting. HUGH S. HUDSON Activities for August and September: The paper on the April 18 event was submitted and accepted. The referee requested a longer paper, which we've been hoping also to do; certainly the Nobeyama data have not been displayed properly and there is much more that can be done with the Yohkoh observations. The Aurass et al. poster from CESRA continued to be of interest, leading to a journal-club presentation at Berkeley August 22 and a retrospective science nugget on the April 7, 1997 flare event. I agreed to help with a program to compare Yohkoh hard X-ray and gamma-ray observations with the submillimeter observations from the Bern group; in the meanwhile the August 25 X-class flare turns out to have excellent Brazilian submillimeter data too. An overview of this event appears in the August 31 science nugget. We had planned to have an ad-hoc session on it during the Yohkoh 10 meeting in September. The major project continues to be global waves, specifically the paper on the May 6, 1998 event. We now have several X-ray wave observations, so this is no longer the first (see the nugget http://solar.physics.montana.edu/nuggets/ 2001/010907/010907.html, which shows off a new X-ray detection). The May 6 paper is an important one, though, because it addresses the question of why it is so hard to see these waves with SXT. Franta Farnik arrived at ISAS from Ondrejov with data from the Czech hard X-ray instrument instrument HXRS on board the MTI spacecraft. It has novel design features, some of which work, and we can probably make good use of these data at some times within the databases - a replacement for BATSE. Incidentally, I had initial discussions at Berkeley about getting Ulysses data in the same framework, and will follow up on this in October. Even though HXRS is shielded by a 1 mm Al entrance window, it still sees thermal leakage. Plans for October and November: After getting the May 6 paper submitted ... I have become seriously interested in the wonderful TRACE observations of seventeen (17!) cases of coronal loop oscillation; the list doesn't seem to be comprehensive in spite of this huge number. With Joe Khan's help, we found that 8 or maybe 9 out of the 17 events were accompanied by Type II bursts, pointing squarely at the fast-mode flare waves as an excitation mechanism. Unless the TRACE group has already recognized this and written their own paper, we will probably write this up with an eye towards learning more about the nature of the fast-mode wave exciter from the behavior of the oscillations. There is a splendid pre-flare observation from one of the joint HXRS/Yohkoh events Farnik and I are studying, September 24, 2001. Please see the nugget for 010928. If this can be worked up promptly, it has a chance to compete for the Warren Prize (minimum time between event and journal publication date, current record holder for Yohkoh being Harry P. Warren). PUBLIC SERVICE: Refereed for Solar Physics. Wrote or helped with Yohkoh science nuggets. The CD-ROM edition of the science nuggets has now appeared in Solar Physics, vol. 200. PUBLICATIONS Papers Published Watanabe, T., Sterling, A. C., Hudson, H. S., and Harra, L. K., "Energetics of an Active Region Observed from Helium-Like Sulphur Lines": Solar Phys. 201, 71-91 (2001). McKenzie, D. E., and Hudson, H. S., "Downflows and Structure Above LDE Arcades: Possible Signatures of Reconnection?": Earth Planets Space 52, 577-580 (2000). Hudson, H. S., and McKenzie, D. E., "Hard X-rays from Slow Flares": Earth Planets Space 52, 581-584 (2000). Paper Accepted Hudson, H. S., Kosugi, T., Nitta, N. V., and Shimojo, M., "Hard X-Radiation from a Fast Coronal Ejection": ApJL Paper Submitted Kahler, S. W., and Hudson, H. S., "Boundary Structures and Changes in Long-Lived Coronal Holes": ApJ TAKEDA AKI: Activities for August and September: I worked the following five full weeks as an SXT_CO. week 31 (30-Jul through 5-Aug): SXT_CO week 32 (6-Aug through 12-Aug): SXT_CO week 33 (13-Aug through 19-Aug): SXT_CO week 34 (20-Aug through 26-Aug): SXT_CO week 35 (27-Aug through 2-Sep): SXT_CO According to L. Acton's proposition and H. Hudson's suggestion, I prepared a couple of special tables to carry out the stray-light calibration during the week 34. The tables were uploaded on the 21th during KSC contacts and on the 22th during DSN passage. Images obtained are reviewed by L. Acton. A hard X-ray spectrometer was launched with a balloon on the 28 August, and successfully observed the solar spectrum from 23:00 UT to 2:00 UT on 29 August. The project was lead by S. Tsuneta (Tokyo Univ). I supported them by reporting the recent solar activity in discussing the timing of the launch and preparing a special SXT table for the coordinated observation during the balloon flight. As for the Science Nugget, the following entry is my contribution. http://isass1.solar.isas.ac.jp/sxt_co/010810.html "A vague giant region -- it was gentle but great! --". It looks back at the activity produced by the NOAA region 9544, during its disk passage on 10-23 July 2001. There were no large enhancements in the GOES flux, but the region is thought to be a source of some eruptive events observed by SoHO/LASCO. I am preparing another nugget on the X2.6 flare on 24 September for the next week (the 5-Oct edition). Since, during September, L. Fletcher and H. Hudson were at ISAS and worked as SXT_COs, and since the Yohkoh 10th anniversary meeting was unfortunately postponed, I concentrated my scientific research on the 'gorgeous' coronal hole which appeared in September through December 2000. Examining a series of synoptic maps of the magnetic fields obtained at Kitt Peak, I found the coronal hole consists of several parts which came from separate unipolar regions, and those unipolar regions were the remnant of active regions which appear to develop during CR 1964, that is, four Carrington rotations before the appearance of the coronal hole. With a help of L. Fletcher, I have started to handle the TRACE and EIT images as well as those with SXT. JANOS BARTUS Activities for August and September: - getting through many difficulties I managed to find out a final working operation system/hardware configuration for the videoserver. From the new sss files we prepared suitable images that I could use to create the special video files needed for the real time video analysis. With those files we could demonstrate a fast and easy replacement of the obsolete video disks. The full mission video can be looked through quickly with some mouse clicks. The video output can be seen on the computer screen as well as on a separate (big) TV screen simultaneously. The video editor software enables us to assemble video clips from the arbitrary part of the mission in real time or even incorporate video files from other solar missions. We also managed to use the DVD authoring system and prepare a prototype of the DVD video disks containing the full mission SXT movies. - hackers attacked isass5's mailing system. I had to replace and securely configure the very old sendmail package with its latest release on this machine. - due to the reparation of ISAS's electric system the full computer system had to be brought down and restarted after the work was finished. - after the 2nd external security scan in ISAS some security holes and deficiency was found on our machines. I fixed those problems. - I developed a secured, php based go_go_toban web interface for the sxt_co's. - everyday sysadmin works. Plans for October and November: - complete the video file database, and handing the videoserver over to the researchers, assembling and using video files from other missions too, DVD creation - within 2 months we probably move to the new ISAS A building. Most of the computers will be transferred to the new building as well. Many sysadmin tasks will be necessarily attached to this rearrangement. - Globus software kit installation on pollux, isass0/1 - further go_go_toban www interface improvements according to sxt co's requests =========================================================================== University of California Activity Report for June 1998-July 1998 =========================================================================== (G. Fisher) Work continues on the paper describing our new efforts at Big Bear solar observatory to detect proton beams in flares. Yohkoh data is used to constrain the number and location of accelerated particles in these events. The title and abstract for the paper are given below. The paper will be submitted to solar physics within the next 6 weeks. A Search for Linear Polarization in the Core of H-alpha During Solar Flares, C.M. Johns-Krull, G.H. Fisher, J. Varsik, and W. Marquette The role of low energy (E < 1 MeV) proton beams in solar (and stellar) flares is uncertain. Claims in the literature range from there being a negligible influence on flare phenomena due to protons; to claims that proton beams may be the primary agent carrying energy released by coronal magnetic fields to the solar surface resulting in intense heating of the transition region, chromosphere, and possibly the photosphere as well. Much of the confusion over the role protons play in flares arises from the paucity of observational evidence implicating protons, which is in turn due to the fact that proton beams are expected to produce very few distinguishing types of detectable emissions. However, one such characteristic emission from protons impacting the solar chromosphere is linear polarization in the H-alpha line with both a specific orientation and center--to--limb variation. Here, we describe modifications to the Big Bear Solar Observatory's Video Magnetograph system and the beginning of an observational program to look for linear polarization in H-alpha emission from solar flares characteristic of proton beams. We present observations two flares well observed with this system: (1) a GOES class C3.8 flare observed on 5 March 1999 and (2) a GOES class M1.9 flare observed on 5 August 1999. The second flare, in particular, is an ideal candidate for polarization observations due to its long duration and close proximity to the limb of the Sun. We describe the importance of accounting for seeing induced polarization signals, and show that we detect no significant polarization from this flare in excess of 1.5%, which is below the expected level based on previously reported observations of H-alpha linear polarization. Page 7 ------------------------------------------------------------------------------- NASA REPORT DOCUMENTATION PAGE (IN LIEU OF NASA FORM 1626) --------------------|--------------------------|------------------------------- 1. REPORT NO. | 2. GOVERNMENT | 3. RECIPIENT'S DR-01 | ACCESSION NO. | CATALOG NO. --------------------|--------------------------|------------------------------- 4. TITLE AND SUBTITLE | 5. REPORT DATE Monthly progress report - for the month of | 10 October 2001 September 2001 |------------------------------- | 6. PERFORMING ORG | CODE: O/L9-41 -----------------------------------------------|------------------------------- 7. AUTHOR(S) | 8. PERFORMING ORGANIZA- T. R. Metcalf | TION REPORT NO: F. M. Friedlaender | |------------------------------- -----------------------------------------------|10. WORK UNIT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS | Lockheed Martin Missiles and Space |------------------------------- Advanced Technology Center, O/L9-41, B/252 |11. CONTRACT OR GRANT NO. 3251 Hanover Street, Palo Alto Ca. 94304 | NAS8 - 00119 -----------------------------------------------|------------------------------- 12. SPONSORING AGENCY NAME AND ADDRESS |13. TYPE OF REPORT AND Marshall Space Flight Center (Explorer Program)| PERIOD COVERED Huntsville Alabama 35812 | Progress report for the month Contact: Larry Hill | of September 2001 |------------------------------- |14. SPONSORING AGENCY | CODE MSFC / AP32 -----------------------------------------------|------------------------------- 15. SUPPLEMENTARY NOTES ------------------------------------------------------------------------------- 16. ABSTRACT The SOLAR-A Mission is a program of the Institute of Space and Astronautical Science (ISAS), the Japanese agency for scientific space activity. The SOLAR-A satellite was launched on August 30, 1991, to study high energy phenomena in solar flares. As an international cooperative agreement, Lockheed, under NASA contract, is providing a scientific investigation and has prepared the Soft X-ray Telescope (SXT), one of the two primary experiments of the mission. --------------------------------------|---------------------------------------- 17. KEY WORDS (SUGGESTED BY | 18. DISTRIBUTION STATEMENT AUTHOR(S)) Solar-A, X-ray, CCD, | Space Science, Solar Physics ------------------------|-------------|----------|-----------------|----------- 19. SECURITY CLASSIF. | 20. SECURITY CLASSIF. | 21. NO OF PAGES |22. PRICE (OF THIS REPORT) | (OF THIS PAGE) | | None | None | 19 | ------------------------|------------------------|-----------------|-----------