I guess it is similar to hunting season. Lots of targets and options around, but probably less sitting still and quiet. In fact, quite the opposite!
Proposals for the Westerbork Synthesis Radio Telescope in the Netherlands are due in a bit over 8 hours. I just sent the draft of our proposal back to my advisor for more edits and comments. Fortunately it seems to have converged rather quickly. I suspect there will be one more round before we submit. We should get it in comfortably, with plenty of time.
That is just the beginning though. Upcoming deadlines include those for telescopes operated by the National Radio Astronomy Observatory (Very Large Array, Very Long Baseline Array, Green Bank Telescope), the space-based X-ray telescope XMM-Newton, the Gemini optical telescopes, and a slew of other optical and infrared telescopes. It should be a busy few weeks! These upcoming rounds of proposals are exciting as they will likely form the basis for my dissertation. Always exciting to see that take shape.
Now back to editing!
As I write this, we are just getting on-sky with the Green Bank Telescope to do some neutral hydrogen (HI) observations. We are remotely observing and David is at the controls getting things going. The first step is to focus the telescope (easy to do at L-band!), determine pointing offsets (difference between where the telescope thinks it’s pointing, and where it actually is pointing), and balance the IF rack (ensure the system responds linearly to incoming signal). This first portion takes about 10 minutes or so. Once that is done, we will move to a strong calibrator source, generally a radio loud quasar or a radio galaxy which is unresolved by the GBT. We will do quick observations of a calibrator so we can later calibrate our data to accurate measurements.
Once the setup and calibration is completed, we will move to our source and begin taking data. This evening’s observations are part of a modest survey to look for HI in compact groups of galaxies. They are an interesting selection of objects, much smaller than large galaxy clusters or groups. There is a mix of elliptical galaxies and spiral galaxies, although elliptical galaxies seem to be more prevalent. We only have a 1.5 hour observing block tonight, so with calibrations and overhead (slewing the telescope, etc), we will only be observing a single compact group. We have already observed a number of groups, and will observe more during future runs, including one tomorrow and one on Wednesday.
But, soon it’s off to the calibrator!
As noted before, the semester is winding down here at UVa. As a result, a good chunk of the weekend has been spent grading the flood of labs that always appears at the end of the semester. Pretty much all day yesterday was absorbed grading the labs for the Intro to Observing class. As I am head TA for that class, I am intimately involved in helping assign final grades for the semester. With a somewhat complicated set of deadlines, it will involve lots of checking to make sure the labs have been properly dated.
On Friday I put in a good chunk of work reducing the GBT data I had acquired in March. I am about 90% done with the first galaxy, just a bit of double-checking to do for quality control. I think we have made the first measurement of the neutral hydrogen gas in this particular galaxy. While that is nothing special in and of itself, I believe we have also detected absorption of the radio source by another component of neutral hydrogen. Unfortunately, due to the fact that we used the GBT and the beam is significantly larger than the galaxy, we can’t localize any of it. However, the existing data will be included in a paper currently being finished up (and hopefully published soon).
Continuing with the working theme, this morning was spent on the take-home portion of the final exam for the Extragalactic Astronomy II class. Fortunately it turned out to be fairly straightforward. Since then I have been writing my thesis defense talk. It is just over a week away and I must admit I found the prospect of writing a 45 minute talk somewhat daunting. However, now that I’ve actually started working on it, I feel better about it. It is probably easier since I can use my thesis for an outline to guide the talk. There are already 18 slides and I am still working on background information. At ~1 min/slide I should manage to get it around 45 minutes without too much trouble.
I’ll spend the rest of the afternoon working on the slides. My last final (ever?) is tomorrow afternoon so this evening and tomorrow morning will be devoted to studying. Then, back to grading and working on the defense.
The next week and a half will be quite busy, but at least there’s a light at the end of the tunnel! On May 14th I will get to see my brother graduate from Notre Dame! Following that, I’ll be joining my family for a vacation. Looking forward to the break!
Newly edited and uploaded pictures from observing in Green Bank have been uploaded to flickr. The Green Bank pictures are included with pictures from a trip in the fall.
I had a bit of two worlds this evening… I headed out to Moorman’s boulders after work to do a bit of climbing before the sun went down. I was feeling pretty mellow today, so I didn’t push things too hard. Worked some problems that I’d been trying before, tried some new ones, and sent some “old friends”. I went with another graduate student at UVa (though not in the astro dept!), who showed me a couple other problems there that I hadn’t tried before.. Good times all around, and minimal pain to the fingers.
After bouldering, I finished up some lab grading I’d been working on during the afternoon. Still have another lab to grade as well as a midterm for a 100 level class. Should be a busy weekend.
I’ve just wrapped up my night’s effort to reduce the data taken at the Green Bank Telescope. I am using the GBTIDL software package to reduce the data. So far I’ve only been flagging bad data in the scans of our targets. Due to the low amount of radio frequency interference (RFI) in Green Bank, only ~1 minute of total data was severely affected in the several hours of data taken! Now that I’ve got the hang of flagging obviously bad data, the next step is to calibrate the spectra using the flux calibrators observed during the run. This involves a conversion of antenna temperature (T_A which measures the strength of the signal measured by the receiver) to an actual flux value with the gain and any atmospheric opacity taken into account…
But I think it’s time to call it a night. Have a full day of meetings, classes, and talks planned for tomorrow!
