Wednesday, August 10, 2011

Finally was able to put together and show my data in a more effective way.
I reorganized my code so that for all the samples that I considered to be active, four plots will be created, 1) Ha equivalent widths vs. time of exposure, 2) Ha equivalent widths vs. adjusted dM radial velocity, 3) adjusted dM radial velocity vs. time of exposure, and 4) spectra for each exposure in Ha emission region.


I like this one because it illustrates the benefits of having multiple exposures. You can also see the hint of periodic motion. I was pleased that most of the samples that I have singled out have had periodic motion. I didn't have a lot of time to prepare before group meeting, so I quickly just printed out a few of the ones at the beginning of my file.

With just a couple more days at the office, there are a few important things that MUST get done:

- create read me file (and put code that is useful/important in one directory that is easily accessible)
- go through important codes and more thoroughly comment on it
- put all calculated data into a structure
- finish latex document (so far it looks good - just need to write up about the last few weeks)
- pull out nice plots that I would want to use in my poster for the KINSC symposium
- write up summary for KINSC Summer Stipend and submit it
- write up abstract for KINSC Research Symposium and submit it

Had our last group meeting today. Andrew mentioned about a paper he just read that looked at a sample that is similar to Dylan's with multiple exposure spectra and analyzed "fractional variability" of Ha emission over time (apparently it's pretty much the same across early and late types). They determined that around 6 hours or so is enough time to determine the variability of the Ha emission for these stars. Pretty interesting considering that our spectra is taken over about an hour or so. Anyways, I'm glad I had some plots to show, but wish I had more time to pick some cool ones.

Monday, August 8, 2011

I spent the past couple of days reworking my code so that I would be able to more easily sort out the active binaries in my sample.

From West, et al (2011), active is defined as where:
- equivalent width is greater than .75 Angstroms
- s/n is greater than 3
- height of spectral line is greater than 3x noise

One of the great things about the data set that I'm working with, is that is has a time component; for fast binaries, from exposure to exposure, we can see a difference in the Ha emissions for the M dwarfs.

To illustrate this, I went through the spectra of the samples that had been categorized as active, and if they had velocity shifts of about 30 km/s over the course of their exposures, I would then make two plots. 1) equivalent width vs. time difference b/w exposures, and 2) equivalent width vs. dM radial velocity.


It's been pretty slow going, but I think I'm finally getting somewhere.

I ran into a little problem with the the time listed for some of my exposures. A few of the times listed for each exposure have been rounded, causing small errors in the time exposure of each sample. I think I have it figured out, but will finish fixing it up tomorrow.

I also have to start wrapping up my work. This week is my last week here in Boston at the West lab.

Things that MUST get done by the end of the week:
-short summary for KINSC
-poster for symposium
-write-up for records
-categorize/organize directories

Wednesday, August 3, 2011

very productive day!

I feel like I accomplished so much today (finally!)

I started out the morning working on my error calculation for my equivalent widths. After writing out a long code, I realized that I didn't need to do this by hand and that I could just use TSUM with my flux error array and go from there. After that it wasn't too difficult, and my values look pretty reasonable.

I moved on to recreate a plot that Dylan has for his sample. It's a plot of activity vs. separation as seen in log-log space, with activity being measured through Lbol/LHa. In order to do this, I needed to calculate Lbol/LHa, and go back and fix my pesky separation calculation.

Also team West dinner at Andrew's tonight. So excited!

Tuesday, August 2, 2011

It's been a while since I last posted, so I'm going to have to recap.

My equivalent widths are finally figured out. I made a lot of plots last week that are currently kind of wonky, but once I update them with my new equivalent widths, I think we'll see some really cool plots. I also reformatted my code to now take into account the s/n ratios for both continuum A and B and to take into account the 3x noise level that is necessary to be considered active. Dylan helped me out this afternoon (issues with some of my splining with the redder ends of my spectra) and now my spectra have clearer H alpha regions. YES!

Cool trick I learned: If you want to just click through multiple plots, put this in you plotting code:
cursor, x, y, /down

On a super cool note, I may be writing up something for Dylan's upcoming paper. So exciting!

Monday, July 25, 2011

Equivalent Widths -- Error calculations and more!

I worked on my equivalent width errors -- still really high, but consulted with Jan Marie who had a similar issue. I redid the calculation and they look much better. I went back to my equivalent widths and widened my area around the H alpha emission region to be 10 Angstroms. Plotted the spectra from 6500-6000 Angstroms and then overplotted the selected range around the H alpha region. At first it looked a little wonky (hence enlarging the region). But now it looks really good, and even for the spectra that look like they have a strong H alpha region, the calculation still seems to underestimate the EW. Currently fixing that problem.

After I fix that, on to plotting the the equivalent widths vs. spectral type. There are two plots that I hope to make by Wednesday afternoon. 1) Mean EW per spectral type vs. spectral type, and 2) fraction of active binaries vs. spectral type. In order to do this second plot (and also for just good measure), I need to determine sigma for my equivalent widths (...and then make a histogram and calculate sigma). I was having trouble with the plothist procedure -- it says that one of the called procedures doesn't exist in my library. I downloaded it and put it in the right folder, but it still isn't working so well. I'll check further into it by tomorrow.

BUT this means that I need to get my EW calculation figured out.

Red Sox game tonight!

Friday, July 22, 2011

review of the day

-Worked on error calculation for equivalent widths -- currently have it written up, and in the middle of implementing it into my code. Need to check on error calculation when dividing by constants.
-Fixed equivalent widths -- took into account dM radial velocity and thereby shifted H alpha region over
-Worked on separation calculation - check with Dylan on monday

Thursday, July 21, 2011

...and I made possibly the most stupid mistake I've made in a very long time.

Binary separation should be the same for each pair (duh). My calculation does not show that. Not quite sure how this went by me at first, but it did.

I also corrected my equivalent width calculation.

Here are some plots that I made that show a possible correlation between equivalent width along with the velocities at each exposure.