January 2012


The following blog post was written by Catherine Weigel, an undergraduate at Hartwick College and member of the Undergraduate ALFALFA Team (UAT), during our annual workshop at Arecibo Observatory.

The January 2012 UAT workshop has been a great experience in seeing the progression of science. As the ALFALFA survey is finishing up, we are starting to observe using the L-band wide (LBW) detector. The great part in doing this workshop is that we actually got to spend time observing in which we learned how these follow up observations would work. The really cool part about it is and what is different from the ALFALFA survey’s data collection is that we are able to look at the data we just collected and see how it looks, right away figuring out if there is a source or not. Though a lot of the sources were not detections, there were quite a handful that were. Now the next step is taking those sources and figuring out what they could be and how to verify it.
I find that having gained many experiences through the UAT project and having been a part of the team for a few years that this progression into the follow up study is really quite a fantastic process and a great experience to see. We are really seeing how history is made, how science finds a cause and pursues it and this is an important feature to see. Especially since one of the greatest things about science is finding a project that you see has the potential of gaining knowledge and understanding to the basic nature of the universe. The only way to find the answers is to pursue a way to make the project become a part of the reality of research.
The UAT Workshop has been an exceptional trip. We have learned quite a bit, and it is fantastic that the professors and the observatory share this experience with us. As a student, I feel as though this is a great contribution to my understanding of the scientific process and the scientific community, opening my window of knowledge to the field.

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This contribution was written by Martha Haynes during the 5th annual Undergraduate ALFALFA team workshop at Arecibo Jan 16-19 2012 when we conducted a first set of observations designed to explore the most interesting candidate signals without optical counterparts.

Despite what people might think, our annual trips to Arecibo in January are not spent lying on the beach under a palm tree. We work hard… and sleep little! In addition to full days devoted to lectures and activities centered on radio astronomy and ALFALFA science plus interesting topics presented by Patrick Taylor (“Planetary Radar Astronomy”), Ellen Howell (“The Geology of Puerto Rico”) and Julia Deneva (“Pulsars”) of the Arecibo staff, plus the great tours of the platform (thanks to Dana again!) and the dish itself, we also have conducted 3 nights of observing. Everyone on the UAT has had a chance to participate in the observations for an hour or so on two different nights, so all of us now are a bit sleep deprived.

Cornell ALFALFA grad students Greg and Betsey led the observing runs from midnight until 7am. Unfortunately, there was a power failure before the end of the run on the 3rd morning, so we lost a little time. But, observing on these three nights has given us the change to test and finalize our observing strategy so that we could write up our documentation and develop some routines to schedule, log and undertake quick checks of data quality. And, furthermore, we also have confirmed the reality of some of the “dark galaxy” HI signals, candidate detections found in the main ALFALFA dataset but without any evidence of a stellar counterpart.

These 3 nights are just the first part of a more extensive program we hope to conduct later this spring, and over the next few years. But even with this short run, we have taken a first significant step forward. By making these “follow-up” observations, we have eliminated any possibility of man-made radio interference as the source of the apparent HI signal. Next we will have to go use other telescopes to look harder at the positions where we detect the HI signal for associated starlight, but now we know where to look: the hunt for “dark galaxies” is ready to continue!!!

I’m writing this post from the Arecibo Observatory as we prepare for the 2012 Undergraduate ALFALFA Workshop.

The weather is often our nemesis as observational astronomers. At optical telescopes, clouds of any sort can block the photons from your telescope. As low frequency radio astronomers, we don’t have to worry about clouds, or even rain, as the radio waves travel right through them to our telescope. Strong winds and thunderstorms can still impede our observations, forcing the telescope to be stowed away for safe keeping. The weather can be our foe before observations even start if we have to travel to the telescope. The weather at our departure and arrival locations, plus all along the way, can impede our observations by keeping us from the telescope.

We re-experienced this lesson yesterday morning when traveling to the Arecibo Observatory from Upstate New York. The morning we had to leave for the airport there was lake-effect snow falling. For those of you who haven’t had the joy of experiencing lake-effect snow, it is what happens when cold air moves across a warm lake, picks up the moisture, and dumps it as snow on the other side. Being jaded astronomers experienced with bad weather, we left plenty of extra time for driving to the airport. And it was a good thing we did! The snow itself wasn’t too bad, but we discovered that the plowing strategy for the Interstate involves two side-by-side plows going 35 mph. In the end, it took us much longer than normal to get to the airport, but we made it with time to spare. We had the always fun experience of sitting on the plane while it was de-iced and were then off without a hitch. We’re very glad to be in sunny and warm Puerto Rico now!

This post is by Martha Haynes, just before the 5th annual Undergraduate ALFALFA Team workshop at Arecibo, Jan 15-18, 2012.

The UAT is gearing up for our annual workshop in Arecibo (no problem getting those of us from upstate New York to travel to Puerto Rico in January!). This is the 5th workshop, so things ought to be pretty routine, right?

Well, not really. First of all, every year we have lots of new undergraduate participants and also a few new faculty ones. And, this year, as the ALFALFA main survey observations come to completion, we are starting to gear up for the 2nd phase of observing for ALFALFA: conducting longer observations at the positions of very interesting sources or ones which are just marginally detected. Among the most exciting (to me, at least) are the HI sources that seem to have no optical counterparts and are not near any galaxies at similar redshift. These are the candidate “dark galaxies”: are they real HI detections or were the ALFALFA observations corrupted by (insidious) man-made radio frequency interference (RFI)? We have identified the more egregious or expected RFI, but it can sometimes fool us. So before we get too excited, we will make some short (but still longer than ALFALFA observes a given target — about 40 seconds in total — that’s where the “fast” in ALFALFA comes from) observations with the L-band wide receiver just to confirm that the ALFALFA detection is real. This program requires a different receiver, observing strategy and reduction software, all of which we get to try out during the workshop. So, some of us may not get much sleep. But, I know I’m ready for a little astro-excitement: “A sleepy astronomer is a happy astronomer.” So, let the hunt for dark galaxies begin!

Stay tuned for more once we get assembled in Puerto Rico this weekend.