University of New Mexico Department of Physics and Astronomy Distinguished Professor Greg Taylor recently took a group of students to build antennas at the third Long Wavelength Array (LWA) station. The LWA is a telescope that helps collect radio wave data from celestial bodies. The effort was part of a $1 million grant received by the department from the Air Force Research Laboratory (AFRL).
Taylor and the students traveled down to the North Arm site, located in central New Mexico about 25 km north of the first LWA station (LWA1) and the Very Large Array (VLA), to build these antennas. In collaboration, this new station being built will partner with the other two stations (LWA1 and LWA-SV) already built by this department in New Mexico to search for transient sources. While constructing these antennas students learned about radio astronomy instrumentation and signal analysis.
Along with students from UNM, Hillsdale College students also collaborated on this project and traveled from Michigan to gain hands-on experience with building the antennas. The ultimate goal for this project is for students to build these instruments in order to utilize them properly to discover something new about the universe.
Taylor points out that this new site, LWA-NA, operates at low frequencies, meaning they are using dipole arrays, which do not involve massive antennas. Dipoles can take a couple of students about half an hour to assemble the whole dipole antenna. Unlike the VLA’s antennas which weigh around 250 tons, students are able to easily assemble the dipole antenna based on their labor alone.
“That's the great thing about this project is that it is very approachable for students. They don't just build antennas, we get them involved in everything, even very advanced digital processing techniques, learning how to write the software, how to really understand the signals, how we're combining the signals and how we put it all together, and making images of the sky. They really get a terrific experience,” expressed Taylor.
The students gained first-hand experience with building the new antennas at the third station. The entire station was built by students and faculty. Students get to participate in laying out the site, pouring the concrete pad for the electronics shelter, setting up the power, installing electronics, building the antennas, and so much more. Once the shelter was in place, power was running, and antennas were functioning, the team held a mini ribbon-cutting ceremony at the shelter to celebrate their progress.
"We are one of the last remaining university radio observatories where students can actually go out and be part of every aspect of construction and operations of a radio telescope." – Distinguished professor Greg Taylor
After building the shelter students needed to install instrumentation including a lightning detector and a weather station. This involved running cables in trenches, and ultimately making sure everything was hooked up properly. In order to achieve this students had to physically dig trenches, install conduit, and then run the cables for the electronics and computers. At the end of the day the shelter is where these scientists will process all of the signals that are received by the North Arm station.
Once the antennas begin to be assembled they must all face the same way. The team is set out to build around 65 antennas in total for this site. Taylor states how this is a rare opportunity for students to participate in due to the high professionalism in the field. Students across most other universities are not gaining these same opportunities, and Taylor points out that the University of New Mexico is one of the last remaining universities in the country for students to participate in something like this.
“It's getting more and more difficult to have astronomy instrumentation projects, such as building telescopes, that are actually accessible to students because so much of astronomy now is done by these facilities that cost hundreds of millions of dollars. And the students don't get the opportunity to participate in these national scale facilities,” stated Taylor, “You have professional engineers and technicians that build these big antennas and you have regulations and OSHA. And I mean, not that we aren't safety-conscious, but it's hard for students to be allowed to participate in these large construction projects. And so we are one of the last remaining university radio observatories where students can actually go out and be part of every aspect of construction and operations of a radio telescope."
Taylor emphasized the importance of student involvement in advancing the project. The team added 16 antennas during their recent trip in September and hope to have all 65 antennas installed by mid-November. This new site will work with the existing stations to provide much higher resolution observations of the sky.
At the North Arm site UNM will conduct astronomy, and AFRL will conduct space research such as space weather and ionospheric studies. The Air Force also has an antenna stationed there to receive radar signals, however they are partnering with UNM in conjunction with their radar and want to utilize this technology that UNM is building.
While students get first hand opportunities on how to build these instruments, they are also gaining knowledge on how to properly utilize them. Many students at other universities may use radio telescopes like the VLA or the LWA, but for them it’s a black box. They put in a schedule, and collect some data, but they don’t understand all the pieces that make it work.
“I think it's interesting. It's another view of the universe. You see what's up in the sky, right? And so what we're used to is we look with our eyes and we see, you know, stars. But when you look at low frequencies, you get a very different view of the sky, one that is more dominated by the Milky Way, and also active galaxies, but not stars. This gives you a new perspective of our place in the universe and what's out there,” said Taylor.