UAT Workshop 2012: Seeing Science Strive

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.

 

Update on the hunt for “dark galaxies”

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!!!

 

The Weather is Our Nemesis

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!

 

Let the hunt begin….

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.

 

Dreaming about the Future: What science will come after ALFALFA?

This post is by Martha Haynes

As we wind up 2011 with about 95% of the ALFALFA survey observations completed, we are already starting actively to think about what science we want to do when we have finished the ALFALFA survey. That of course won’t be for some time; we won’t get the final observations until Fall 2012, and then we will still have to process and analyze the data to produce the final ALFALFA legacy catalog. But, already, we can imagine starting a new survey in a few years, and as was the case with ALFALFA itself, advanced planning (and a bit of dreaming) is critical to pushing the frontiers of science forward. What science do we want to do and what observational and computational capabilities will be required in order to achieve that science? What new instrumentation might be available in a few years? In the last few months, we’ve been thinking seriously about what will come after ALFALFA.

One of the science frontier questions related to “Understanding the Cosmic Order” identified in the Astro 2010 decadal survey asks how baryons cycle in and out of galaxies. A number of papers have shown that dark matter halos of mass below log M_tot/M_sun < 10 are baryon-poor. Studying the process(es) which impose this depletion requires advances in (g)astrophysics (reionization, feedback, etc) and better observational constraints on the baryon content of low mass dwarfs. ALFALFA has discovered a set of ultracompact HI clouds which might be associated with low mass dark matter halos in the Local Group, but determining their distances and thus proving their extragalactic nature by detecting their associated stellar counterparts is very difficult. We realize that the clinching evidence that the lowest HI mass clouds are in fact the cores of isolated low mass dark matter halos will require a deep census of several very nearby groups of galaxies. At distances of 5-10 Mpc, low HI mass dwarfs will separate in velocity from the range of galactic and perigalactic phenomena, thereby allowing a direct estimate of distance without requiring the detection of stellar counterparts. Besides exploring the baryon content of low mass halos, an accurate counting of such dwarfs in nearby groups may potentially constrain dark matter decay models (decay injects kinetic energy that can unbind dwarfs).

A survey with 10 times ALFALFA’s sensitivity covering several hundred square degrees in 2-3 nearby groups would deliver the required sampling. To undertake such a survey with ALFA and its 7 feed horns would, however, take an enormous amount of telescope time. We need more pixels! The exciting news is that a 40-beam focal plane phased array feed (PAF) is now in development. A PAF on a single dish can be cooled, and Arecibo’s unmatched instantaneous sensitivity is optimal for local universe detection experiments. So, besides working on ALFALFA in the next years, we will also start the advanced planning for a new survey with this new device dubbed “AO40″, perhaps to start in 2014. You can read more about our thinking on this survey here.

We started the advanced planning for ALFALFA in 2002, and the survey observations themselves began in 2005. So it seems about the right time to start laying the foundations for the next generation survey. Dreaming about the future is always fun, especially when you realize that the future isn’t so far away.

 

An ALFALFA Thanksgiving

This posting is by Lauren Bearden and the Colgate UAT who spent Thanksgiving conducting the A2010 observing on site at the Arecibo Observatory.

November 22, 2011

Greetings from Arecibo Observatory! The Colgate University Astronomy community is so happy to be here in Puerto Rico over Thanksgiving break with Professor Tom Balonek as a part of the Undergraduate ALFALFA Team. Our group includes senior Ajay Chahar (Physics), juniors Michael Fusco (Astrogeophysics), Danny Roesler (Astronomy-Physics), and Katie Iadanza (Astronomy-Phsyics), and sophomores Lauren Bearden (Astronomy-Physics) and Kevin McCullough (Physics) of Colgate University in Hamilton, NY. We are all enrolled in Astronomy 212: Observational Techniques with Professor Balonek this semester. And so our story begins…

After a long night of trying to finish up our schoolwork before the break, we met at Colgate’s Hall of Presidents, bags packed, and ready to go. The ride to Syracuse airport was snug in Katie’s minivan, but went smoothly, and before we knew it we were on the plane headed to JFK airport. Once we got to JFK, we had a delicious multi-ethnic lunch of donuts, lo mein, pad thai, pizza, and Stromboli. Once we got to Puerto Rico, we got picked up by a “Taxi Turistico” and went grocery shopping, buying anything we could find that didn’t require microwavable cooking or complicated preparations. This turned out to be just about soup, chips, bread, cold cuts, cereal, and juice. After arriving in the town of Arecibo, we stopped for dinner at Martin’s Barbecue and got some local food: rice, beans, chicken, and pork. We finally made it to the observatory around 9:30 local time (that’s Atlantic Standard Time, AST = UT-4). We got settled into our rooms in the North VSQ (Visiting Science Quarters), and immediately set off to look around. After a leisurely ten minute walk to the control room, we met students from Siena College who told us a little about what they were doing (and what we would be doing) [see their earlier blog]. We went down to the road that circles the dish to look around, but couldn’t see much because it was so dark. Oh, how we can’t wait until daylight tomorrow to really appreciate the immense size of the telescope. Then, we went back to our rooms, and immediately fell asleep after a long day of travel. Co-QUI!

November 23, 2011

We met up around 10:00 and went on a tour of the platform and dome of the telescope, given by engineer (and pro tour guide) Dana Whitlow. We spent about two and a half hours looking around, asking questions, and learning how a radio telescope actually works from Dana. At first, we were a bit intimidated by the elevation of the catwalk, especially when it was slanted halfway through, but we eventually learned not to let the height get to us, and ended up learning so much. We took tons of pictures… in fact Professor Balonek managed to take over 2,000. We then got some lunch and after a short rest, went back up the hill to look around the visitor center. We were sad that the gift store was closed, but the stations at the museum were interesting and we took many more pictures. Later, we talked to telescope operator Israel Cabrera for a pretty long time in the control room. He told us some great stories of his experiences at the Observatory. He told us about the different people he’s met by working here, how much he’s learned from the visitors, and about his own personal astronomical technology that he keeps at his home. Talking over coffee (Puerto Rican coffee, of course) really does have a way of bringing two groups from different backgrounds together; he was so friendly and willing to share his stories, Israel probably could’ve talked to anyone easily. We went up to the computer rooms after that and practiced starting up the telescope control program (CIMA) for tomorrow night. We made our cheat sheets and after a little more practice tomorrow, will be quick and ready to observe for Martha. We’re so excited!

Some shots of the control room can be seen at this link recommended by Israel entitled “hardworking pulsar astronomers at Arecibo” during an observing run by Dan Stinebring and his students from Carleton College.

November 24, 2011

Happy Thanksgiving! Though not with our immediate families, the Colgate community was sure to have our own feast here on the picnic tables behind our rooms at Arecibo with our “observing family” as Mike called it. We had a great lunch of Turkey sandwiches, Lays and Tostitos chips, guava and cranberry juice, and pumpkin and apple pie. It was, by far, the most unique Thanksgiving I’ve ever had, with minimal preparation and no football game in the background. We then went up to the control room and continued working on perfecting the start up process of observing. We finally got control of the telescope around 6 pm, and after a successful start up by Danny, we got into the rhythm of recording the observations. Observing was fun, especially because looking at and identifying the spectral lines was new to a lot of us. While observing, we noticed the spike in our spectrum from the FAA radar network and the corresponding harmonic frequency from San Juan. We also saw a major signal from galactic HI. Professor Balonek was sure to point out quasars (continuum sources) every once in awhile, also. We learned how to save and transfer the data after observations. We knew that Martha would be checking our results early the next morning.

November 25, 2011

The gift shop was finally open today! We got pina coladas at the stand on the way up the steep hill, hotdogs, ice cream, and lots of presents for people at home. We eventually went up to the Observatory, worked for a while, and then started observing. Awhile after Katie’s successful start up, Danny noticed a galaxy in the spectra! After looking online based on the RA and dec, we identified it as NGS 925! So naturally, we did a celebratory dance. We realized just how much data we were taking, and also how much the survey as a whole would gather total… 56000 data points are taken per second in ten minute scans (with 1 second between scans to calibrate), 6 hours or so of scanning per night, and 4 nights of scanning. But that’s just our data! The survey has been going like this for 6 years! That’s about 3,000,000,000,000 data points! It’s so amazing to be part of such of an important and broad study.

November 26, 2011

We woke up at the crack of dawn (which equates to 11 am for astronomers) and decided it was a great day to explore the surrounding area. We began this endeavor by going way down under the dish, and going up to the towers onsite. We were amazed at how the dish was held into place in its spherical shape by primarily just the tie-downs. The towers were enormous and we enjoyed the hike up and down the hills, though we came back sweating and ready to collapse. WE HAD BETTER THINGS TO DO THAN COLLAPSE, THOUGH! We ventured out into the town of Arecibo in search of some more groceries. On the way, we happened upon a local restaurant, where the food was delicious, but didn’t sit very well in our stomachs. We went straight up to the control room after we returned and began work. We had a successful start up by Kevin, and continued our research throughout the night. At this point, we pretty much know how to handle the computer and know what to look out for in the spectrum on the control screen of the data we’ve taken. One thing that we realized tonight is that the red error messages that have come up the past 2 nights have always happened at 00:00:00 UT time. Because the message never actually affects the images, and it happens at the exact same time every night, we think this might be an error in the computer system, rather than an error with the machinery, and therefore is not something for us to worry about too much. Another successful night complete! Coqui, coqui.

November 27, 2011

Today, our last full day in Puerto Rico, we went to the beach. The weather was beautiful, the waves were big, and we had a great time swimming and enjoying the weather and scenery. We got some local pizza on the way home, which was delicious. Then, we went up to the control room for our last night of observing. Because we’ve been observing for the past few nights, tonight we were able to start up and shut down the operating system almost entirely without the instruction of Professor Balonek. This was fairly exciting, and a confirmation that we are in fact learning. Tonight was also unusual because the FAA radar signals were higher in some of the quicklooks randomly. We noted these changes in our log. The way that we work our observing is that we ordinarily have three students in the control room: one typing in the information from the calibrations and exposures, one checking the quicklooks, and a third person there for company. We did an excellent job of switching in and out of these positions tonight. I guess the 4th night is a charm for us…

Tomorrow we head back to Colgate. While we’re all happy to go back to school (though dreading final papers and exams coming up), we’ll most certainly always remember the time we spent here in Puerto Rico, learning all we can about radio astronomy. WE HOPE TO BE BACK AGAIN SOON!

 

Observing at Arecibo: More impressive than remote observing!

This posting is by Martha Haynes, thanks to the UAT at Siena College.

While most of the observing for ALFALFA is conducted remotely, it is a lot more impressive to do the observing from the Arecibo control room. For one thing, you can’t really appreciate just how big the Arecibo antenna is until you walk around and underneath it and take a trip up to the platform. Even at night, you can see the lights of the towers and the platform from the control room, and so you get a better sense of just how immense and complex the whole telescope system is. You also get to interact with the telescope operator, hear the sounds of the motors (and the coquis) and watch even more monitors. Fortunately, members of the Undergraduate ALFALFA team do get to travel to Arecibo to experience for themselves the awesome site of the “Big Dish in the Jungle”.

The ALFALFA observations on Nov 21-22, 2011 were conducted on site by 6 students and 2 faculty members from Siena College. The students were Laura Apicello and Amy McCann (junior physics majors), Alissa Earle and Thad Savery (junior Physics and Math majors) and Ian Gilchrest and Steve Atkinson (senior physics majors). The faculty were Rose Finn and Michele McColgan; it was Michele’s first trip to Arecibo too. The students were all enrolled in an observational astronomy class Physics 380 and had learned about and conducted remote observations for ALFALFA prior to travelling to Arecibo. They arrived in Puerto Rico on Sun Nov 20th. While at the Observatory, they stayed in the VSQ “family units” at the top of one of the hills on site. These units have three beds, one bathroom, a living room, and a kitchen.

The students were asked to comment on some of their impressions, and here are some of their answers:

What were you first impressions when you arrived in Puerto Rico?

• Laura writes “The weather in Puerto Rico was the first thing I experienced when I arrived. It was very hot and humid as we came out of the airport. On our car ride to the Observatory, we drove through some of the more populated area and were soon traveling through the more rural areas. There were a lot of hills and valleys that we passed through and a lot of animals.”
• Thad writes “The landscape is what I first noticed. The country is filled with hills throughout, rather than being relatively flat with an occasional mountain here and there. Also, for being a territory of the United States it is extremely different from any place I have been in the U.S. from the structure of the homes, to the way streets are organized.”
• Alissa writes “This is my second time coming down to Arecibo (I was here for the UAT workshop in January). The major differences this time are that we are staying up in the family units this time, a part of the observatory I didn’t get a chance to explore during my last visit, and we have had more down time to wonder around the observatory and visit the city of Arecibo.”

What are your impressions of the Arecibo telescope?

• Alissa writes “Even though it is my second time down here I am still amazed by just how huge the telescope is.”
• Thad writes “The immense scale of the telescope. I knew it was big, but seeing it in person makes you wonder who came up with this design and how has it stood the test of time and is still up and running with few problems.”
• Laura writes “The telescope was larger than I expected. Being able to go under the dish and onto the platform gave us a better idea of the make up of the telescope. We were able to go inside the Gregorian dome and see the secondary and tertiary mirrors. We also had the opportunity to see the ALFA detector.”

What are your impressions of the Observatory overall?

• Alissa writes “I really enjoy the scenery at the observatory and enjoyed working in the control room and hiking under the dish.”
• Laura writes “The control room and telescope were very impressive. The area was very nice and the scenery was great. It was very peaceful and remote to be staying the the cabin located in the observatory.”

What are your impressions of the observing for ALFALFA? Is it what you expected?

• Laura writes: “Since we had done the remote observing during our lab, I knew what to expect when observing the ALFALFA Survey. Doing the observing in the actual control room was much more exciting.”
• Alissa writes: “It has been pretty similar to my experience last time, but since it is a smaller group and we have longer runs we have all been able to have more hands on time while observing.”

What is the most interesting or surprising thing that you have learned while you’ve been on this trip?

• Thad writes: “The tour of the elevated part of the telescope was both the most exciting and most surprising thing we did and learned about. Our tour guide gave us an in depth description of how the telescope worked, while we were on it. I was terrified for a while since we were so high up, but it was an experience I will never forget. Both the experience and the information we learned while on the telescope was definitely the most interesting part of this trip.”
• Laura writes: “The size of the radio telescope was something that surprised me on this trip. Not until I was able to be in close contact with the telescope was I able to put the telescope into scale.”
• Alissa writes: “It has been interesting staying in the VSQ “family units” this time because they are made of plywood (with no insulation) and the windows just have screens and shutters with no glass. It is really different from anything you would see in upstate New York.”

The chance to visit and conduct observing on site really does make bring the Arecibo telescope and Observatory into perspective! Members of the Undergraduate ALFALFA team are grateful to the National Science Foundation and their respective institutions for the funding support which makes possible these observing trips and to the Arecibo Observatory staff for their assistance and hospitality. Thanks especially to Dana Whitlow for the platform tour!

 

The AO staff to the rescue!

The following post is by Martha Haynes.

Last night, Derek Fertig and Jessica O’Connor, graduate students in the Department of Physics and Astronomy at George Mason University, were the A2010 observers, their 3rd night in a row. They were ready to go at 9:15pm …. but alas, the system wasn’t, and immediate ominous messages began appearing in the CIMA message window when they tried to run the calibration script command file for the TOGS program (we do the observing for the TOGS team as well as for ALFALFA). After running through his own quick check, Derek gave me a call, and I quickly logged in from my laptop at home (the only difficulty being the cat sleeping in my lap).  After my own quick look at the error messages and the total power monitors — two of which read “nan” (“not a number”…. not a good sign!), I told Derek to contact the telescope operator to alert him that there was clearly a serious hardware problem….  That got an immediate response first from Arun, who was able to isolate the problem to one of the WAPPs, and then from Luis, who rushed in from home to diagnose and fix the problem (issue was a bad filter overloading a power supply). Derek and Jessica were able to restart observing at 11pm and had a successful completion of the rest of the night.

The ALFALFA survey is all about team work,  not just of us astronomers but also of the technical staff who keep the instrumentation, hardware and software running day after day after day. Muchas gracias to the incredibly committed and expert staff of the Arecibo Observatory for making sure that ALFALFA catches all those photons!

 

Yes, [Virginia], real observing requires more than a cellphone.

The following post is by Martha Haynes.

Last night was the first night of ALFALFA observing since April. The ALFA receiver was taken down in July and reinstalled just on Tuesday (a bit late, thanks to Hurricane Irene). There hasn’t really been enough time to check it out completely and we were warned that there could be problems. Additionally, we were going to cover a drift very close to the Arecibo zenith. Betsey and Martha  (along with Luke, Manolis, Melissa, Ani and Riccardo) were ready at the start. Then the big test: could we get the telescope to move to the right position for our almost-at-the-zenith declination strip (part of this is a test of the telescope software and part is a test of our ability to get the spherical geometry right). It worked!  But one of the beams showed very low power, although we had been told it was ok. We double checked our setup, and in the absence of being able to do anything further, we just kept on observing.

Betsey stayed the night, but Martha came home around 12:30. She was back in the office early in the morning to check the calibration and take a quick look at the night’s dataset. She verified quickly that in fact the power in the bad beam was really low and its Tsys was too high. And so she emailed the observatory staff and they went to check (even though it was Saturday). And voila, they found the problem and fixed it. Hooray, tonight should be ok!

So, the ALFALFA team is always on duty during ALFALFA observations, because we appreciate having the chance to use the awesome Arecibo telescope and we certainly love our data. The reward today is that, in the very first drift, in the very noisy beam, there is a very bright galaxy that hasn’t been catalogued before. It’s got a lot of gas and is very blue. Now, that’s what makes ALFALFA fun!

 

The ALFALFA 40% catalog is done!

The following post is by Martha Haynes.

After a lot of blood and sweat (no tears, but insert here: coffee, sleep deprivation, mild cursing, graying of the hair… and HARD WORK!), we are publishing a catalog containing almost 16,000 HI sources detected in the course of the ALFALFA survey. And we estimate we are only 40% done, so that this is called the α.40 catalog.

So, what does it take to make up a catalog that is of real legacy value? In an era when datasets are made public and used by many people, I wonder if everyone appreciates how much work, meticulous attention, and true cleverness is required of a core group of people to make a survey really useful. In this discussion, I should clarify two important points right away: (1) ALFALFA is not a mega-survey like others (SDSS for example) and (2) The ALFALFA team includes no full-time professional staff.  We are teaching faculty and a lot of the heavy ALFALFA lifters are graduate students (especially the fearless Cornell EGGs Amélie, Brian, Sabrina, Ann, Betsey, Shan, Manolis and Greg). But, also, ALFALFA is not the first survey Riccardo and I have been involved in, so we had some idea from the start of what would be required: standardized data and data processing, designed from the outset; careful monitoring of the data at every step along the way; lots of documentation/commenting/verification, including some by individuals where feasible; careful design of data products and access tools which are understandable, documented, simple to use and easily transportable; a philosophy that the success of the survey is measured by how many other people use the survey’s data for their own science. As they say in real estate, it’s all about: quality, quality, quality… and documentation, documentation, documentation.

So, how many hours have gone into making up the 40% catalog? I have no idea, but I know it is a lot, not just for me, but for every single one of the co-authors, who have spent time observing (and learning to observe), flagging, making grids, extracting sources, identifying optical counterparts, testing/verifying, analyzing completeness and worrying about what might have gone wrong. For me, the best part of ALFALFA is working with these amazing, smart and fun folks. And now, with α.40 done, I am reminded of what Wing Comdr. Gibson said to Group Capt. Whitworth in the the classic 1955 film The Dam Busters: “…Have a drink to celebrate. We’ve done the trick! “

The α.40 catalog will be posted on the main ALFALFA website once its associated data paper (Haynes et al. 2011) is accepted for publication… which should be very soon!