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Kristin Rosenau
Solar Physics REU @ Montana State University in Bozeman, MT
Summer 2009
Dr. Jiong Qiu's Daily Log
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07.27.09

I also plotted the different UV light curves on top of the X-Ray intensity for each pole. The first UV light curve is where total >.5 of the max, the second is total >10% of the med, third is mean >.5 of the max, and the fourth is total >10% of the med. The positive pole 1 is used as an example below:



07.23.09

I finished up the REU webpage today. Check it out: http://solar.physics.montana.edu/home/www/reu/2009/index.html. Masha has helped quite in bit in the automation of making plots to analzye data. I will now give data for the poles that make up the major contenders in magnetic reconnection.

       12-25 keV:
   
       25-50 keV:
 

Positive poles
       12-25 keV:

       25-50 keV:

Negative poles
       12-25 keV:


       25-50 keV:



07.20.09

I am working towards creating plots of HXR versus UV for each of the four stages and each of the four ways I have found to calculate the UV lightcurve. Today, I managed to create a plot combining all four stages, but looking at the four ways to define the UV lightcurve. I'm not yet sure if this is the way these graphs are actually supposed to look. I have my doubts, but I shall see tomorrow.

UV lightcurve four definitions

07.17.09

Today I was able to create a plot of x-ray intensity for the primary pole regions involved in mangetic reconnection (all for the 25-50 keV energy range). The positive poles are as follows:

Pole 1Pole 2Pole 3Pole 4

The negative poles are as follows:

Pole -1Pole -2Pole -3Pole -4Pole -5
Pole -8Pole -10Pole -13Pole -18

07.16.09

With the help of Masha and her programming skills,  I was able to create data cubes for each energy level from the fits files taken during the evolution of the solar flare. With these, I then produced the following graphs (12-25 keV on left, 25-50 keV on right):

X-Ray Intensity 12-25 keV      X-Ray Intensity 25-50 keV

This is for cell N28. I'm working on trying to figure out how to get this to work so I can define the cells that actually matter (the ones directly involved in magnetic reconnection).  From there, I will be able to directly compare X-ray versus UV.

07.13.09

I made 6 pixon images to act as representatives for the 4 stages of the solar flare in the 25-50 keV range. The first image represents the first stage . The second and third image represent the second stage (rise). The fourth image represents the third stage (peak). The fifth and sixth image represent the fourth stage (decay).



07.09.09

Again, today I worked on making a more complete visual evolution of the solar flare. This time, I sampled roughly 12-20 seconds each minute for the 12-25keV energy range to continue in following the evolution. I also sampled a few images from the 50-100 keV energy range. The 12-25 keV range:



The 50-100 keV range:


I also completed the table for the stages of the 25-50 keV energy range. It seems that the rise of the solar flare (stage 2) and the decay phase (stage 4) encompass a majority of the time and data. Stage 3 is the peak of the solar flare.


Images Time
Stage 1 1-6
16:38:00 -- 16:39:30
Stage 2 7-33
16:39:30 -- 16:42:45
Stage 3
34-41
16:42:45 -- 16:43:24
Stage 4
42-79
16:43:24 -- 16:53:12


07.08.09

I worked on making more images today for the 25-50 keV energy range as a continuation of the image range on June 30.





I also looked at the 25-50 KeV energy range to sort the solar flare into stages. I did this by viewing the contours of the images over a magnetogram and observing the flare's progression. The stages are as follows:


Images Time
Stage 1 1-6
16:38:00 -- 16:39:30
Stage 2 7-33
16:39:30 -- 16:42:45
Stage 3
34-41
16:42:45 -- 16:43:24
Stage 4
42-54
16:43:24 -- 16:44:30


06.30.09

Images, images, so many images. This time I followed the rise and peak of the solar flare evolution through tiny time increments (aka between 5000 and 10000 counts). I'll begin with the 12-25 keV range:








And here is the 25-50 keV range:







06.29.09

Today I worked to include the UV light curve for each flux cell exhibiting significant activity.
There are nine active negative flux regions (left) and four active positive flux regions (right). The 25-50 keV HXR light curve is included for comparison.

UVHXR Neg   UVHXR Pos

I completed the same graphs, but re-scaled the UV light curve so the peaks could be seen.

UV HXR Negative   UV HXR POS

I next plotted UV and HXR (25-50 keV) on the same graph. The goal was to try to get the UV light curve to most match up with the HXR curve. The UV light curve increases in percentage from 50 to 80% (left to right). This was done with the mean of the UV light curve.

UV @ 50%UV @ 60%UV @ 70%UV @ 80%

Again, I plotted UV and HXR (25-50 keV) on the same graph.  The UV light curve increases in percentage from 50 to 80% (left to right). This was done with the total of the UV light curve.

UV @ 50% TotUV @ 60% TotUV @ 70% TotUV @ 80% Tot
  
It was decided that the total at 50% was the best representation of the beginning of the flare and, as such, these specifications were used with the UV light curve below:

     UV HXR Tot Neg      UV HXR Tot Pos
 

06.26.09

This morning I worked to create plots of reconnection rate for the flux regions with significant activity. There were nine active negative flux regions (left) and four active positive flux regions (right). The 25-50 keV HXR light curve is included for comparison.

Recon HXR Negative    Recon HXR Positive

06.25.09

I added a legend to the plot so you can actually understand what is going on this time, instead of the plot just being a pretty image.

HXR Contours with Legend

I also plotted the HXR contours (both 12-25 keV and 25-50 keV) onto the UV image of a solar flare to show the evolution of the footpoints for the energy ranges involved.

UVHXR -1UVHXR -2UVHXR -3UVHXR -4UVHXR -5UVHXR -6UVHXR -7UVHXR -8UVHXR -9UVHXR -10

An animated movie of the evolution of the HXR footpoints of the solar flare can be found by clicking on the image below. Alternatively, the movie can be downloaded here.

Solar flare evolution

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06.24.09

I spent the morning working on writing a program to put the 25-50 keV HXR contour lines on top of the magnetogram with mask. It took a good long while to get everything to line up properly, but is not the result just charming?

HXR Contours

06.23.09

I used the time segment from each section of the solar flare evolution and plotted it on the light curve graph to make it easy to see which light curve segment corresponds to the images created the previous day. The right picture is simply a zoomed in picture of the light curve graph.

Rain  Rain 2

06.22.09

I spent the morning making images for the evolution of the solar flare for the 12-25 keV and 25-50 keV energy ranges.

Evol 12-25-1Evol 12-25-2Evol-12-25-3


Evol 25-50-1Evol 25-50-2Evol 25-50-3

The afternoon was spent making a more detailed image progression of the evolution of the solar flare. The energy ranges are 12-25 keV and 25-50 keV, respectively.

12-25-112-25-212-25-312-25-412-25-5
12-25-612-25-712-25-812-25-912-25-10

25-50-125-50-225-50-325-50-425-50-5
25-50-625-50-725-50-825-50-925-50-10
Top

06.19.09

This morning Dana Longcope gave the solar physics lecture. It was all about understanding the interior of the sun. I found the formation of sunspots to be the most interesting part. Afterward, I met with Jiong to go over some of the problems I had been having this week. The lightcurve problem now makes sense (I hadn't been scaling correctly and needed to reverse the obs_times and obs_data) and we talked a bit about why spectra are so important for understanding the energy involved in solar activity.

Good Light Curve

The positive and negative reconnection rates are green and white, respectively, the UV light curve is blue, and the red (12-25 keV) and yellow (25-50 keV) lines represent the HXR energy ranges.

I also now understand how to get around the problems of low counts for the imaging the evolution of the solar flare and will spend the rest of the day working on making
(hopefullly) clear images.

06.18.09

Today is the day of confusion, questions, and frustration. I have run into roadblocks in every task I have tried to do. After a rather unproductive morning, I talked with Angela this afternoon and I now have a better grasp on what I need to do to accomplish for my tasks this week. I finally managed to save a counts corrected HXR light curve as a .sav file and was able to plot it to make proper curves. However, when trying to combine it with the reconnection rates and UV light curve from before, again, I ran into problems. Although I shifted the coordinate system to make up with the reconnection rates, for some reason the HXR is still too small to be seen properly:

Bad HXR light curve

The red and yellow line off to the left side represent the 12-25 keV and 25-50 keV. For some reason, they are not scaling properly and the time scale does not appear to match up either. I'm not sure how to fix this, so I will put it off until I have a chance to talk it over with Jiong tomorrow.

There are also problems in trying to capture the evolution of the solar flare over varied energy regions. The light curve and the image are having a bit of trouble agreeing with one another on how many counts there are. The light curve believes there are roughly 500 at the time of the peak, whereas the image reckons there are about 10,000, if not more. Either I managed to break the RHESSI data or something very curious is going on here. The PROOF that I am not crazy:

Light Curve                 No Counts

The counts for the 25-50 keV range are not enough to make an image for the timespan directly before and for the entire time period after the flare. The 12-25 keV range is only enough to make images after 16:58 UT. But look! The images below clearly say otherwise. The image overestimates 8,000 counts for the 12-25 keV data range and 1,500 for the 25-50 keV data range. The real question here is whether the image or the light curve is telling the truth.

Bad Image                Bad Image 2

I feel like a detective. However, knowing this information doesn't help my problem with imaging in the slightest. It's just a peculiar, troublesome feature. Oh, joy.

06.17.09

I re-made images of the solar flare for multiple energy ranges because you can barely tell where the peak was in the first batch. The
ranges are as follows, from left to right: 6-12, 12-25, 25-50, 50-100 keV.

SF 6-12SF 12-25SF 25-50SF 50-100

I also tried again to find the counts corrected light curve. Apparently, the counts corrected button just needs to be selected. I guess I thought it would be more complicated than simply clicking a button.

Counts corrected lightcurve

06.16.09

I found images of the solar flare for multiple energy ranges. The ranges are as follows, from left to right: 6-12, 12-25, 25-50, 50-100 keV. It is best to have a few thousand counts per image (these produce the clearest and most accurate images). However, there are only a thousand counts for the 25-50 keV image and much less for the 50-100 keV image, making both of these images fairly inaccurate and meaningless because the details of the image are not present. The 12-25 keV image provides the clearest image of the footprints of the solar flare.

LC 6-12LC 12-25LC 25-50LC 50-100

I spent the remainder of the afternoon attempting to work with plot_map and combining images. This resulted in making a very wrong, hideous looking plot. I almost wish I had saved a picture of the atrocity.

06.15.09

I finally got the RHESSI data to work on my computer. Apparently I needed to delete some programs from my .cshrc file, because it was confusing commands between the programs. At least it works! I messed around with the GUI interface and did a couple tutorials. Here are the results of my messing around:

GUI Image

This is a clean image of the May 13, 2005 solar flare. The yellow arc across the image represents the position of the sun's limb. The image itself seems to be fairly meaningless (there are no significant flare footprints or sources of information), but at least it looks pretty.

Secondly, I created a light curve for the energy ranges between 6 keV and 300 keV. The curve itself does not have abrupt peaks and dips as it would appear. The attenuators affect how large the curve appears depending on whether a filter is turned on or off. The curve is fairly smooth, in reality.

 Lightcurve GUI

Once I understood the basics in creating plots and saving files, I began to work on the first goal assigned to me by Jiong. This involves deriving counts-corrected light curves in a few energies - at least two energies, one below 25 keV, and the other above 25 keV and figuring out from GUI how to save the data for the light curve, as well as restore and display it in a general IDL window:

HXR lightcurve

Then, as an end result, I am supposed to plot the RHESSI HXR light curves together with the reconnection rates and UV light curve I found earlier. This part is proving the most difficult.

06.12.09

By isolating the region of the solar flare, I am best able to analyze the ribbon speed in multiple directions. The negative ribbon speed is on the left and the positive ribbon speed is on the right:

Negative Ribbon Speed        Positive Ribbon Speed

The most curious result from this is that the ribbon speed grows much faster in one direction than the other. In fact, the difference is approximately 70 km/s faster. Jiong explained that this is just another unknown in the field of solar physics. From today onwards, I will be working with hard x-rays instead of UV light. The goal for the rest of today is to familiarize myself with RHESSI and the GUI interface.


06.11.09

This morning we had a lecture on the instrumentation involved in looking at the sun and examining the sun in various wavelengths (Visible, FUV, EUV, Soft X-ray, Hard X-ray, Gamma Ray, etc). I had no idea how difficult it is to view the sun in any wavelength besides visible. As the filters are increased, the efficiency of the detector goes down--much more than I expected it to. I also finally learned how CCD cameras operate, which was really interesting in and of itself. Afterward, I met with Jiong to work with the program to find out the magnetic reconnection ribbon speed. I had to re-find the PIL line (I didn't extend the line far enough the first time). I think it turned out fairly smooth, but, when trying to fit a line to it, the polynomials seem to disagree with me and don't provide the nicest fit:

PIL Line

06.10.09

There is a linear correlation between the observed and modeled reconnection flux:

Observed vs Modeled Reconnection Flux

The observed data is off by approximately 30%. This is because the data is observed at the top of the chromosphere, whereas the data is modeled from the photosphere. Thus, because the observed data is taken higher in the sun than the modeled, it has a lower reconnection flux. I also determined the PIL (polarity inversion line) of the magnetogram. This is essentially the line dividing the positive and negative flux regions. From here, I am working on debugging the program to find the ribbon speed of the magnetic reconnection.

06.09.09

This morning we started the first of many solar physics lectures. Today's lecture gave a background of the sun, including topics like hydrostatic equilibrium and quantum tunneling. Afterwards, I spent some time with Jiong discussing where my project was going and what the next steps to take would be. The next task is to find the reconnection sequence of the solar flare. To do this, I first plotted the reconnection flux of each positive and negative flux region in relation to time (top graph):

Reconnection Sequence

I then identified the 6 distinct stages of the solar flare to find which flux regions were going through magnetic reconnection at a particular point in time. This table can be seen below:
Episodes
(min after 16 UT)
25-31
31-34
34-42
42-55
55-64
64-72
Correlation Pairs
P3
P4
P4
P4
P3
P4

P1
P3
P3
P3
P1
P1

N10
P1
P2
P2
N3
N4

N5
N18
P1
P1
N2
N3

N2
N5
N10
N18




N2
N8
N10




N1
N5
N8





N4
N5





N3
N4





N2
N3





N1
N2






N1



I also spent a long while trying to make a scatter plot of the observed and modeled reconnection flux to see if they have a linear correlation. I keep stumbling into roadblocks, so I'll try to finish this up tomorrow morning and hopefully I'll have better luck.

06.08.09

I spent some time reading up on the Encyclopedia of the Sun for our lectures tomorrow. I had no idea the corona extended past the solar system. There is still so much to learn. I also plotted the UV light curve from my IDL project together with the reconnection rate to see the correlation, if any:

Light Curve with Reconnection Rate

There is a correlation between the light curve and the reconnection rates. The two peaks of the light curve (blue line) match up with two peaks on the reconnection rate (green line). From here, I was going to look back at the positive and negative flux regions to see if I could find the order in which the regions experienced magnetic reconnection. This can be done by looking at the overall flux and each individual regions flux. When a particular feature of the individual flux region matches up with the overall flux, it can be inferred that the particular flux region was experiencing magnetic reconnection at that moment in time. From there, the rest of the flux regions can be examined for magnetic reconnection at the same instant. Thus, the flux regions can be matched up in the order they experience magnetic reconnection.

The program files I was trying to use to do this were experiencing problems, so I couldn't plot anything meaningful today. Tomorrow, I should have better luck.

06.05.09

This morning I gave my IDL presentation and met with Jiong to go over how to find reconnection flux and reconnection rates. The reconnection flux is the flux during magnetic reconnection. The magnitude is about 10^21 Mx. The reconnection flux can only increase because it is the flux of the solar flare over time--it doesn't make sense for it to decrease:

Reconnection Flux

The reconnection rate is the derivative of the reconnection flux with respect to time.  It is on a magnitude of about 10^18 Mx/s:

Reconnection Rate

After lunch, the Solar Flare Group (Meghan, William, Theresa, and our respective advisors) met for the first time to go over our progress this week and to answer any questions we may have. I had magnetic reconnection explained to me in a different way and it made more sense the second time around. Here it goes:

Magnetic Reconnection

The lowest energy for the magnetic field lines is to be directly connected to the one across from it (left side) and the highest energy is when the lines are when the lines are bent (right side)--you can also think of this like a rubber band. The magnetic field lines bend accordingly to follow the rest of the lines. I realize this probably makes sense to absolutely no one but myself. I'm working on it. I also plotted the brightness of the magnetic flux regions (P1, P2, N1, N2, etc) of the magnetogram as the solar flare progresses over time. The challenge was to figure out what ntim to set to get the most balanced brightness progress (aka, not all black color); the most balanced graph was when ntim=300. It's a little bit hard to read, but the top plot shows the flux regions on the magnetogram, and the bottom plot shows the brightness of the solar flare over time:

Flux cell

06.04.09

I worked on finishing up my IDL project by creating a light curve and mapping the bright pixels of the May 13, 2005 solar flare (10759) to the magnetogram. The light curve can be seen below:

Light Curve    

The small commands in IDL keep tripping me up, like how to open multiple plot windows at once, or scaling graphs to be legible. These tasks seem like they should be easy and intuitive, but they're not. Well, not yet, anyway.  Jiong also gave me a paper to read up on, explaining two-ribbon flares. Interesting things to note:

- Solar flares are composed of two magnetic regions, one positive and the other negative. Both the positive and negative regions are composed of "flux cells" of varied flux and size. Each positive flux cell corresponds to a negative flux cell. However, the flux cells do not necessarily connect to the nearest corresponding flux cell. The negative flux cell can connect to any positive cell regardless of location, making the magnetic field lines between these cells twisted and entangled. These connections can change at any time. Hence, magnetic reconnection in all its messy glory.

-The most accepted model for a solar flare is CSHKP model:

Flare Rec

06.03.09

I spent a good portion of the day writing up some code for our IDL projects due for Friday. I'm creating a "light curve" of the image of a solar flare. To do this, I need to find the median values of the 406 images of the flare, and the number of pixels with counts 10 times larger than the median for each of the 406 images. From here, the sum of the brightness of the pixels can be plotted against time to make the Light Curve of Awesome. Then, I've got to transfer this to a magnetogram and find the reconnection flux, but that's for another day. Like tomorrow.
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