The Observer Vol 1 Issue 2 – April 2017
The last few months have seen many exciting developments at the Green Bank Observatory. Two new 3-mm wavelength instruments are having an excellent first full high frequency season – ARGUS, a 16-pixel spectroscopy contend, and MUSTANG-2, a 223-pixel feedhorn bolometer – and we are looking forward to publication of the instrument’s science results. World-class science coming from both our NSF-funded “open skies” time and the telescope time used by our partner organizations continues to be outstanding. Pressure for use of the GBT’s time also continues to increase, and with 17% of the proposers being new to the GBT! We also have a major new educational initiative underway, First Two, which works to increase retention of STEM students in their first two years of college, with a particular focus on first generation college students.
Looking forward, we are preparing for the many and varied educational programs coming up, which range from REU students arriving for the summer, the PING (Physicist Inspiring the Next Generation) camp for students, a new Research Experience for Teachers program, and many, many more activities. And, of course, we are beginning to ramp up our plans for the fall workshop “Transformative Science for the Next Decades with the Green Bank Observatory,” and the accompanying 60th anniversary of sciences from our facility.
Hope to see many of you at one or more of these exciting events!
Green Bank Observatory Director
Our new SETI Tour celebrates Green Bank’s historic Search for Extra Terrestrial Intelligence. Piloted last summer, the tour sold out all but three offerings. The tour lasts about 3 hours and takes guests into the telescope control rooms where Project OZMA and Phoenix took place-just to name a few!
Check out our summer tour schedule for 2017 online at: greenbankobservatory.org/events/
Chautauqua Short Courses
May 22nd-25th, 2017
This 2.5 day course is designed to celebrate more than 50 years of contributions to the forefront of astronomy by the telescopes of the Green Bank Observatory and is open to educators of all disciplines. Presentations will emphasize recent research at Green Bank in two areas: pulsar studies, that could lead in the near future to direct detection of gravitational radiation and hydrogen studies that reveal the structure and evolution of galaxies and their dark matter halos.
Learn more: greenbankobservatory.org/education/teachers
June 9th-11th, 2017
It’s a festival. It’s a race. It’s group rides. It’s a clinic. It’s a fundraiser. It’s a tradition. The 6th Annual Space Race Rumpus is a 3-day family music and cycling festival hosted by the Northern Pocahontas Wellness Center at the Green Bank Observatory. If you’ve ever wanted to bring your bike to explore the site trails or miles of scenic roads in Pocahontas County, now’s the time! Registration is now open. Find out more: www.spaceracerumpus.org
ESS Teacher’s Passport
June 18th-July 1st, 2017
ESS Passport is an amazing professional development program for West Virginia science teachers to prepare them to teach Earth and Space Science. Funded by the West Virginia Math Science Partnership program, the Earth/Space Science Passport workshop provides West Virginia science teachers with professional development in Geology, Meterology and Astronomy concepts that will enable them to teach a new mandated ninth grade Earth/Space Science course. Over a twoweek residential workshop teacher groups rotate through three-day directed studies in each of these content areas. The Green Bank Observatory provides the Astronomy course.
Learn more at greenbankobservatory.org/education/teachers/
Pulsar Search Collaboratory Camp
July 10th-17th, 2017
The Pulsar Search Collaboratory (PSC) is a joint project between the Green Bank Observatory and West Virginia University (WVU), funded by the National Science Foundation (NSF). The goal of the PSC is to give high school students, and their teachers experience doing real research.
Learn more at greenbankobservatory.org/education/student_research/
Just last year, a new documentary (www.lgmfilm.com) called “Little Green Men” was released. The film follows PSC high school students searching for pulsars using data from the Green Bank Telescope.
Physics Inspiring the Next Generation: Investigating the Cosmos Summer Camp Experience
Current 8th graders (rising 9th-graders) will be on location in Green Bank, WV, at NRAO’s world famous Green Bank Telescope. Students will be immersed in the research activities of this national research center. While in residence, students will work in small teams supported by an undergraduate student mentor and an NRAO staff scientist (astronomer, physicist, engineer, etc.) to conduct research by observing the universe with a 40-foot diameter radio telescope.
For more details, visit: greenbankobservatory.org/education/student_research/
Observer Training Workshop
September 18 – 23, 2017
The Green Bank Telescope (GBT) Observer Training Workshop series provides the essential skills and knowledge needed to use the GBT and maximize its scientific output. We’ve reached capacity for the Spring 2017 training, but there will be plenty of openings for the next session, set for the week of September 18th, 2017.
A separate announcement will be made when registration opens for this event.
Transformative Science for the Next Decades with the Green Bank Observatory
October 16 – 20, 2017
Big Questions, Large Programs, and New Instruments: With new instruments and excellent performance, the 100m Green Bank Telescope is only just reaching its full potential. On this 60th anniversary of the ground breaking for the Green Bank Observatory, we are holding a workshop looking toward the next 10, 20, and even 60 years of the Green Bank Observatory, and invite the community to attend and aid us in planning the future.
For more information, please visit our Web site at greenbankobservatory.org/transformative-science/
ARGUS camera for GBT 3mm spectroscopy swings into action
Throughout the winter months of 2016-2017 the new ARGUS 16-pixel camera for 3mm spectroscopy has been in regular use on the GBT. The camera was developed by Sarah Church (Stanford University) and collaborators under a grant from the NSF. The first map made during commissioning was shown in the previous GBO newsletter (http://greenbankobservatory.org/green-bank-observer-vol-1-issue-1/). Data from a number of projects are now in the hands of the PIs for reduction and analysis.
Read full article online:
In October 2016, the Green Bank Observatory received an award from the INCLUDES initiative (NSF #1649323), to build the First Two Network. The problem First Two addresses is post-secondary attrition. Degree completion is key to producing a diverse STEM workforce: Increasing the retention of STEM majors by 25% will “generate three quarters of the targeted 1 million additional STEM degrees needed over the next decade” (PCAST, 2012). Well-shy of half of all undergraduate students who enter STEM majors complete degrees in STEM, and that it is during the first two years of college that most students drop out of the STEM The effects are worse with First Generation College (FGC) students, who not only leave STEM programs but often quit their post-secondary education altogether. Since roughly one third of all post-secondary students are FGC students, addressing the underlying challenges they face could significantly broaden participation in the STEM workforce.
The First Two Network targets rural first generation students who major in a STEM related course of study. Beginning summer 2017, we pilot two early research experiences (for rising freshmen), and an academic year course that builds science process skills, communication skills and leadership expertise. An innovative component of FIRST TWO is the creation of Hometown STEM ambassadors—students who participate will be prepared to mentor their peers, and also conduct outreach in their home school districts.
Finally, there are many studies that inquire into the factors that correlate with post-secondary retention in general, and with STEM attrition specifically but few that focus on rural students. One of our working groups is developing a rigorous educational research project that can advance understanding of the factors affecting rural students’ entry into and persistence in STEM career pathways. For more information about our INCLUDES program, please visit our Education pages at greenbankobservatory.org/education
GBT helps find Lost Spacecraft
Finding a tiny lost space-craft at a distance of 270,000 miles away may seem impossible, but NASA scientists have done just that. Using a new radar technique, they have located India’s Chandrayaan-1 spacecraft which has been lost since August 2009, the last time any communication was received from it.
Read full story here: greenbankobservatory.org/newscontent/observer04.17.html
GBT Observations Compound Intersellar Helium Ionization Problem
Warm ionized gas is a major constituent of the Galactic interstellar medium, observable through both optical and radio emission lines. To maintain its ionization it requires about 80% of the ionizing radiation from all OB stars in the Galaxy; this is presumably supplied by UV photons leaking from HII regions.
This UV leakage should be sufficient to fully ionize Helium in the diffuse ionized gas, but instead, the fractional ionization of He appears to be relatively low, in the range of 10-20%.
Recent observations with the Green Bank Telescope (GBT) compound this problem. A set of H and He recombination lines was observed toward the envelopes of three ultra-compact HII regions that are still embedded in their molecular clouds. The envelopes have emission measures an order of magnitude greater than that of the warm ionized gas, and are just a few parsecs away from the central stars, which have type O5 or earlier. The data indicate that He is not uniformly ionized in the HII region envelopes. In two cases helium in the envelope is only 30% and 50% ionized. After ruling out the possibility that the helium may be doubly ionized, the authors conclude that the most likely explanation for the discrepancy is selective absorption of helium-ionizing photons by dust.
“Helium Ionization in the Diffuse Ionized Gas Surrounding UCHHII Regions” D. Anish Roshi, E. Churchwell and L. D. Anderson, accepted by the Astrophysical Journal.
GBT hits new performance milestone at 109 GHz
With the installation of the Argus 16-pixel receiver covering 75-115 GHz on the Green Bank Telescope (GBT), it is now possible to characterize the antenna beam above 100 GHz, where the use of the active surface and out-of-focus holography are critical to the telescope’s performance. A recent measurement (2017 March 23) in good weather conditions at 109.4 GHz yielded a FWHM beam of 6.7 arcsec and 6.4 arcsec in azimuth and elevation, respectively. This corresponds to 1.16 Lambda/D at 109.4 GHz, which agrees well with the low-frequency value measured at 9.0 GHz. After applying the standard antenna corrections (focus and active surface), we find no measurable degradation of the beam of the GBT at its highest operational frequencies.
These results are discussed in more detail in the GBT Memo #296: library.nrao.edu/public/memos/gbt/GBT_296.pdf
GBO Post-doc Jennifer Weston Wins dissertation prize
Jennifer Weston has just won the 2016 Robert L. Brown Outstanding Doctoral Dissertation Award. The award presentation, and her talk on the research which led to the award, will be in Charlottesville on April 13.
The Robert L. Brown Outstanding Doctoral Dissertation Award is administered by AUI and the NRAO on behalf of Bob Brown’s friends and family to honor Bob’s life and career. The Award is given each year to a recent recipient of a doctoral degree from any recognized degree granting institution in the United States, and is substantially based on new observational data obtained at any AUI operated facility and considered to be of an exceptionally high scientific standard.
Featured Receiver – ASIAA 800 MHz HIM Receiver Array
In November of last year, a collaborative effort involving representatives of the Academia Sinica Institute of Astronomy and Astrophysics, University of Wisconsin, NRAO, and the Green Bank Observatory gathered to review designs for a proposed focal plane array for the GBT. The proposed receiver system improves the observing efficiency in the 700 to 900 MHz band by replacing the single corrugated prime focus feed with seven short backfire antennas each with an individually cooled cryogenic dewar. The group faced many technical challenges, especially the weight and moment limits of the GBT prime focus feed arm. Some of the margins were razor thin and thus the group plans more modeling of the structure for a better understanding of the wind load analysis.
Read full story online: greenbankobservatory.org/newscontent/observer04.17.html
New Phased Array Feed Successfully Commissioned on the GBT
The L-band cryogenic Phased Array Feed (PAF) receiver, with nineteen dual-polarization crossed dipoles located in the focal plane of a reflector antenna, was commissioned on the GBT in March 2017. The testing has confirmed the predicted excellent performance of the PAF, and has also commissioned the unformatted digital link technology developed by NRAO’s Central Development Lab.
Phased Arrays employ a technique in which many small antennas can be combined together to perform the function of a single large antenna. By combining the small antennas together with adjustable phase and amplitude, the properties of the composite antenna beam can be changed (beamwidth and beam direction). Since the beamforming is accomplished by FPGA-based digital signal processing, multiple beams can be simultaneously formed increasing telescope throughput (in this case seven beams in each polarization were formed).
The PAF was developed as part of a collaboration consisting of NRAO, GBO, West Virginia University, and Brigham Young University. More information will be forthcoming as data results are analyzed.
Students track anomalies in the fading of Cassiopeia A
Every summer since 1992, Prof. Dan Reichart of the University of North Carolina (UNC) and a small group of astronomy faculty have taken 15 mostly undergraduate students through an intense, one-week workshop at the Green Bank Observatory called “Educational Research in Radio Astronomy” (ERIRA). While on site the students are engaged in several observing projects with the 40 Foot Telescope including observations of Cassiopeia A, Taurus A, and Cygnus A.
Read Full Story online: greenbankobservatory.org/newscontent/observer04.17.html
Student Art Exhibit
To show support for the Green Bank Telescope, Green Bank Middle School students created some amazing 2-D and 3-D art projects. From intricate Popsicle-stick GBT models to precise blueprint-style charcoal drawings, works included a wide variety in chosen mediums. This project was lead by the art teacher, Alison Flegal, who created the project as a way for students to voice their support for the Green Bank Telescope in response to 2016’s Environmental Impact Statement (EIS) Call for Public Comments. In fact, a few of the works were submitted formally and included among the hundreds of letters. In March, the Green Bank Science Center hosted an art exhibit opening for these works, which are now on display in the lobby. During the opening, these young artists presented their work to both staff and the public. The Green Bank Observatory is an education partner of the Green Bank Elementary Middle School as part of our outreach program.
New online reservation system coming soon!
Coming Soon! The Green Bank Software Development Division will soon release the new Green Bank Observatory Reservation System (GBORS), replacing the previous BOS system and offering expanded capabilities. GBORS will accept reservation requests for everything from an overnight stay to planning a conference. When launched, look for it on our website!
Upcoming call for GBT proposals (18A)
The Green Bank Observatory (GBO) will invite scientists to participate in the next Call for Proposals for the Green Bank Telescope (GBT). The deadline is August 1st, 2017 for Semester 2018A.
Response to the 17B Call for GBT proposals
The 1 February 2017 call for proposals to use the GBT beginning the second semester of 2017 elicited requests for 6647 hours in 100 individual proposals. In the 3mm band there were requests for 1,148 hours for spectroscopy and continuum using the new ARGUS and MUSTANG2 cameras, as well as an additional 191 hours for spectroscopy and VLBI with the 2-pixel”W band” receiver which covers the lower part of the band. Demand for the7-pixel “K-band” camera that covers 18-26 GHz continued to be strong, at 645 hours. More than 3,000 hours were also requested at frequencies below 2 GHz for programs of spectroscopy and pulsar studies.
There were a number of proposals for joint observations with ALMA, the JVLA,Fermi, and other instruments.
More than 17% of the proposers had not previously been on a GBT proposal, showing the continued strong growth of the scientific community’s interest in the GBT. Proposals are now undergoing review and results should be available in early May.
A bit of history: The Green Bank Interferometer confirmed Einstein’s theory
Einstein’s theory of gravity (also known as General Relativity) predicts that the path of a ray of light (or that of a radio wave) will bend when it passes near a massive object. This was first tested in 1919 by Sir Arthur Eddington, who organized an expedition to observe star positions during an eclipse of the Sun from islands near the coast of Africa.
Observing stars close to the edge of the Sun is normally impossible, but during an eclipse, the Sun is blocked out and stars nearby can be observed. The 1919 experiment confirmed the theory and made an instant celebrity of Einstein and of General Relativity.
Read full story online: greenbankobservatory.org/newscontent/observer04.17.html
MEET THE STAFF
Thomas Chamberlain, Software Engineer
How long have you worked at GBO?
Just under two years now; I started February 23rd, 2015, right after I graduated.
What led you to applying for the position?
Well, I guess there’s some backstory here. My grandfather worked here in the late fifties and early sixties as an operator before moving on to JPL, Socorro, and later Charlottesville. My mother was actually born in Marlinton in 1961, although they left early enough that she doesn’t remember it. She’s an accountant and she was looking for jobs online when, as she tells it, just happened to think of checking out the NRAO for any openings. She’s wanted to get out of the Atlanta suburbs for a while, and I think she has fond memories of this area, going to the summer picnic as a kid and such. She saw a software engineering position open, thought “I think Thomas does that”, and passed it along to me.
Learn more about Thomas here:
Become a Member
Want to help support the Green Bank Observatory? We now have a new Membership and Donation program! Check out the variety of opportunities found at greenbankobservatory.org/engage/
The Green Bank Observatory employs 100 people on a year round basis, and an additional 40 people in the summer time. While most people tend to think of Green Bank as hiring scientists and astronomers, it takes a village to run the scientific and educational programs. While we have staff from all around the world, the majority of our employees (80%) were born in West Virginia, and roughly 60% of the staff are from Pocahontas County. Of the astronomy staff, 40% are female (compared to the national average of less than 30%). We are committed to a diverse and inclusive work place culture that accepts and appreciates all individuals.
Career opportunities can be found at a new website!Please check out our current listings here: greenbankobservatory.org/careers/