Zach Gallegos: The Man Behind HVAC at the Very Large Array

Zach Gallegos, a native of Socorro, New Mexico, is the HVAC and Plumbing lead at the Very Large Array (VLA). He is a dedicated professional who has carved a niche for himself in the field of HVAC and plumbing.

Zach’s journey into the HVAC field was not a planned one. After graduating from Doña Ana Community College, he was searching for a job when HVAC came across his path. His love for tinkering with things since childhood made him a natural fit for the job. He started his career at the National Radio Astronomy Observatory (NRAO) as a security guard, where his dedication and hard work saw him quickly rise through the ranks, first as a track operator, then as the HVAC team lead.

A typical day for Zach involves a variety of tasks, from instrument readings to checking emails and ensuring the functionality of antennas. His role is crucial to the VLA, as he is responsible for all HVAC, plumbing, and compressors, essentially anything that has a motor. HVAC also controls the chiller for the supercomputer, a critical component of the VLA. HVAC takes care of 28 vertex air conditioners and 28 ped room air conditioners. These are highly modified, and thus are made and designed in house. Zach takes care of air conditioning for all the buildings at the VLA site. HVAC also takes care of all the plumbing, from fixing a faucet to repairing both sewer and fresh water lines. They also manage the water treatment system and all sewage. Additionally, HVAC is responsible for the air compressors in each building – there are seven total. They maintain and monitor the fuel system on site, as well as the gas station. They manage all the ventilation systems, and they repair and maintain all the air conditioners on the over 100 vehicles at the VLA. Zach’s responsibilities extend beyond the VLA site. He also manages and maintains all of the Pie Town Very Long Baseline Array (VLBA) site’s air conditioners and hot water heaters. 

Despite the demanding nature of his job, Zach loves his work, especially the people he works with and the opportunity to work four days a week, enjoying a three-day weekend. However, like any job, Zach’s role comes with its challenges. He has been the only person in HVAC for the past two years, making it difficult to manage all the responsibilities single-handedly. He wishes to recruit and train more skilled tradespeople in the field to ease the workload and ensure the smooth functioning of the VLA.

Zach Gallegos is a shining example of dedication and hard work. His journey from a security guard to the HVAC and Plumbing lead at the VLA is inspiring. Despite the challenges, he continues to serve with grit and determination, ensuring the smooth operation of the VLA. His story serves as a reminder that with passion and dedication, one can achieve great heights in any field.

About the People Behind the Very Large Array: 

Highly-skilled individuals work behind the scenes day in and day out to make our magnificent Array the very best it can be. The People Behind the VLA project aims to highlight the stories of these workers and share their stories, so that everyone may get a glimpse of the wonderful people that make the Very Large Array work.

The post The People Behind the Very Large Array appeared first on National Radio Astronomy Observatory.

One of the primary goals of the Atacama Large Millimeter/submillimeter Array (ALMA) is to study the formation and evolution of planetary systems. Young stars are often surrounded by a disk of gas and dust, out of which planets can form. One of the first high resolution images that ALMA captured was of HL Tauri, a young star just 480 light-years away surrounded by a protoplanetary disk. The disk has visible gaps which could be where young protoplanets are forming. Planetary formation is a complex process that we still don’t fully understand. During this process, dust grains in the disk are growing in size as they collide and stick to each other, causing them to slowly grow to potentially become objects similar to those within our solar system.

One of the ways to study dust grains in these complex structures is to look at the orientation of the light waves they emit, which is known as polarization. Earlier studies of HL Tauri have mapped this polarization, but a new study from Stephens, et al. has captured a polarization image of HL Tauri in unprecedented detail. The resulting image is based on 10x more polarization measurements than of any other disk, and 100x more measurements than most disks. It is by far the deepest polarization image of any disk captured thus far, according to research published today in Nature.

The image was captured at a resolution of 5 AU, which is about the distance from the Sun to Jupiter. Previous polarization observations were at a much lower resolution and didn’t reveal the subtle patterns of polarization within the disk. For example, the team found the amount of polarized light to be greater on one side of the disk than the other, which is likely due to asymmetries in the distribution in the dust grains or their properties across the disk. Dust grains aren’t often spherical. They can be oblate like a thick pancake, or prolate like a grain of rice. When light is emitted by or scatters off these dust grains, it can become polarized, meaning that the waves of light are oriented in a particular direction rather than just randomly. These new results suggest that grains behave more like prolate grains, and they put strong constraints on the shape and size of dust grains within the disk.

A surprising result of the study is that there is more polarization within the gaps of the disk than the rings, even though there is more dust in the rings. The polarization within the gaps is more azimuthal, which suggests the polarization comes from aligned dust grains within the gaps. The polarization of the rings is more uniform, suggesting the polarization largely comes from scattering. In general, the polarization comes from a mix of scattering and dust alignment. Based on the data, it is unclear what is causing the dust grains to align, but they are likely not aligned along the magnetic field of the disk, which is the case for most dust outside of protoplanetary disks. Currently, it is thought that the grains are aligned mechanically, perhaps by their own aerodynamics, as they revolve around the central young star.

What will studies of HL Tau reveal next? This new publication makes clear that high resolution is needed for polarization observations to learn the details about the dust grains. As the world’s most powerful millimeter/ submillimeter telescope, ALMA will be a fundamental instrument for continuing this research.

About ALMA & NRAO

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

NRAO is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

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Jill Malusky, NRAO & GBO News & Public Information Manager

jmalusky@nrao.edu

304-460-5608

The post ALMA Observation of Young Star Reveals Details of Dust Grains appeared first on National Radio Astronomy Observatory.

An international team of astronomers has collaborated to improve the capabilities of the Atacama Large Millimeter/submillimeter Array (ALMA), one of the world’s most powerful telescopes. Scientists from the National Science Foundation’s National Radio Astronomy Observatory (NRAO), the Joint ALMA Observatory, the National Astronomical Observatory of Japan (NAOJ), and European Southern Observatory have achieved the highest resolution observation since ALMA began operations,  in one of the most challenging array configurations. The results are published today in the Astrophysical Journal.

ALMA has 66 parabolic dish antennas. Combinations of these antennas are used together as an interferometer, where the observations of many instruments are combined as one giant telescope. Each antenna is equipped with receivers that allow it to observe radio waves in different frequency ranges, or bands. The many signals collected by the individual antennas are synthesized together in a correlator.

The array’s highest resolution is achieved when it is configured to its maximum extent, or widest antenna baseline, and observes at its highest frequency. When arranged in different configurations, such as Band 10 (which was used with approximately 50 antennas for this test) there can be up to 10 miles between the location of each dish. The weather, atmosphere, and minute differences between individual antennas must be accounted for and corrected to make observing possible. To help correct for these errors, a bright target is set to calibrate the antennas. However, when observing at higher frequencies, the availability of bright calibrator is scarce and hence severely hampers the calibration process.

To solve this problem, astronomers tried the “Band-to-Band” (B2B) method, which was first developed in the 1990s by the Nobeyama Radio Observatory of NAOJ. When ALMA was constructed, hardware and software infrastructure was put in place to one day try this method, which was first tested in 2020 using Band 9 receivers and an array baseline of just over 8 ½ miles. The B2B observing technique consists of observing a bright calibrator at a lower frequency, and applying the calibration solutions from that data to the higher frequency, in which the science target is observed.

Results from this latest test, using B2B at Band 10 with the longest distance between the antennas, have achieved the highest resolution of 5 milli-arcsec (=1/720000 degrees) ever captured, the equivalent of being able to see a single human hair two and a half miles away. For this test, astronomers observed R Leporis, a star in its final stage of evolution, located approximately 1,535 light-years away from Earth in the Milky Way galaxy. The B2B calibration used a nearby bright galactic core, which, while distant, appears nearby R Leporis in the sky.

Antonio Hales, NRAO Scientist and Deputy Manager of the North American ALMA Regional Center, also part of the team that achieved these results, highlights the importance of these results: “By achieving this unparalleled resolution through the Band-to-Band method, we’ve pushed ALMA’s capabilities to their absolute limit, unveiling a new window to the cosmos. This breakthrough allows astronomers to probe cosmic phenomena with a precision once thought unattainable, marking a significant testament to ALMA’s power and paving the way for future discoveries that will undoubtedly deepen our understanding of the Universe’s most profound secrets.”

See the press release from the National Astronomical Observatory of Japan.

See the press release from European Southern Observatory.

This result was presented in a paper titled “ALMA High-frequency Long Baseline Campaign in 2021: Highest Angular Resolution Submillimeter Wave Images for the Carbon-rich Star R Lep” to appear in the Astrophysical Journal (doi:10.3847/1538-4357/acf619).

The team is composed of Y. Asaki (JAO; NAOJ; SOKENDAI), L. Maud (ESO; Leiden University), H. Francke (JAO), H. Nagai (NAOJ), D. Petry (ESO), E. B. Fomalont (NRAO), E. Humphreys (JAO; ESO), A. M. S. Richards (University of Manchester), K. T. Wong (IRAM; Uppsala University), W. Dent (JAO), A. Hirota (JAO; NAOJ), J. M. Fernandez (Lowell Observatory), S. Takahashi (NAOJ), and A. S. Hales (JAO; NRAO).

About ALMA & NRAO

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

The NRAO is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

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Jill Malusky, NRAO & GBO News & Public Information Manager

jmalusky@nrao.edu

304-460-5608

The post World’s Most Powerful Millimeter/Submillimeter Telescope Captures Highest Resolution Observations—Ever appeared first on National Radio Astronomy Observatory.

The National Science Foundation’s National Radio Astronomy Observatory (NRAO) and the National Astronomical Observatory of Japan (NAOJ) are joining efforts to expand the capabilities of the world’s most powerful millimeter/ submillimeter telescope, the Atacama Large Millimeter/submillimeter Array (ALMA). In a little over two years, this collaboration will deliver high performance receiver components for Band 2, and accelerate the development of the significantly upgraded version of Band 6 receivers, known as Band 6v2, which are part of the ongoing Wideband Sensitivity Upgrade.

“This agreement speeds the development of ALMA’s Wideband Sensitivity Upgrade and establishes the groundwork for a promising longer term collaboration between NRAO and NAOJ,” shares Phil Jewell, NRAO North American ALMA Director. “ALMA is made possible by a major international collaboration, and it’s important to all partners that our telescope array remains a fundamental instrument for international astronomy for decades to come.”

Drawing upon the technical design, fabrication, and testing expertise of both organizations, new receiver components will be developed, fabricated, integrated, and tested. As part of these efforts, NRAO and NAOJ will collaborate in a design for a Superconductor-Insulator-Superconductor (SIS) mixer to be fabricated at NAOJ’s in-house facility, their Advanced Technology Center. This technology will greatly enhance the sensitivity of ALMA’s receivers.

NAOJ has already been collaborating with the European Southern Observatory to develop the initial six units of the Band 2 receiver. This agreement with NRAO will strengthen this partnership to deliver the rest. NRAO will use NAOJ’s relationship with specialized manufacturers to produce receiver components, including corrugated feed horns, waveguides and orthomode transducers. This will complete the second phase of the NAOJ/ESO project, to outfit the entire ALMA telescope array with Band 2 receivers.

For Band 6v2, NRAO and NAOJ engineers will investigate the performance of receiver optics, along with the design and fabrication of SIS mixers, with the intention of producing NRAO designs at the NAOJ facility. NAOJ will also design, test and produce prototypes of orthomode transducers for potential use in the Band 6v2 receivers.

“Through this agreement, NAOJ and NRAO will deepen our collaboration to make the most of our expertise for the production of the Band 2 receiver and the development of the Band 6v2 receiver, which are both key pieces of the ALMA2030 Wideband Sensitivity Upgrade,” adds Alvaro Gonzalez, NAOJ ALMA Project Director. “Joint efforts like this are crucial for sustainable long-term development in radio astronomy.”

About ALMA & NRAO

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

The NRAO is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

The post New US & Japan Partnership Will Make the World’s Most Powerful Telescope Even More Sensitive appeared first on National Radio Astronomy Observatory.

The Event Horizon Telescope (EHT) collaboration has published new results that describe for the first time how light from the edge of the supermassive black hole M87* spirals as it escapes the black hole’s intense gravity, a signature known as circular polarization. The way light’s electric field prefers to rotate clockwise or counterclockwise as it travels carries information about the magnetic field and types of high-energy particles around the black hole. The new paper, published today in Astrophysical Journal Letters, supports earlier findings from the EHT that the magnetic field near the M87* black hole is strong enough to occasionally stop the black hole from swallowing up nearby matter.

The Atacama Large Millimeter/submillimeter Array (ALMA) is the world’s most powerful millimeter/ submillimeter telescope, and a key instrument for the EHT. The spiraling light at the heart of this research is actually made up of low frequency radio waves—light that can’t be seen by the human eye or optical telescopes, but can be observed by the many radio telescopes, including ALMA, working together across the EHT.

“Circular polarization is the final signal we looked for in the EHT’s first observations of the M87 black hole, and it was by far the hardest to analyze,” says  Andrew Chael, an associate research scholar at the Gravity Initiative at Princeton University, who coordinated the project.  “These new results give us confidence that our picture of a strong magnetic field permeating the hot gas surrounding the black hole is the right one. The unprecedented EHT observations are allowing us to answer long-standing questions about how black holes consume matter and launch jets outside their host galaxies.”

In 2019, the EHT released its first image of a ring of hot plasma close to the event horizon of M87*.  In 2021, EHT scientists released an image showing the directions of the oscillating electric fields across the image. Known as linear polarization, this result was the first sign that the magnetic fields close to the black hole were ordered and strong. The new measurements of the circular polarization – which indicate how light’s electric fields spiral around the linear direction from the 2021 analysis – provide yet more conclusive evidence for these strong magnetic fields.

ALMA provided both data and calibration for these results, and served as the array reference antenna for the EHT. Without the much greater sensitivity of ALMA as the reference antenna, circular polarization could not have been detected.

About ALMA & NRAO

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

The National Radio Astronomy Observatory (NRAO) is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

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Associated Universities, Inc. (AUI) and the National Radio Astronomy Observatory (NRAO) have awarded the 2023 Karl G. Jansky Lectureship to Dr. Paul A. Vanden Bout, Senior Scientist, Emeritus at NRAO. The Jansky Lectureship is an honor established by the trustees of AUI to recognize outstanding contributions to the advancement of radio astronomy.

After earning his Ph.D. from the University of California, Berkeley, Dr. Vanden Bout pioneered work in millimeter-wavelength astronomy at McDonald Observatory. He was the Director of NRAO from 1985 to 2002, and oversaw the completion of the Very Long Baseline Array, Green Bank Telescope, Expanded  Very Large Array, now the Jansky Very Large Array, and the start of the Atacama Large Millimeter/submillimeter Array (ALMA).  He was Interim Director of ALMA from 2002 – 2003, and Interim Head of the North American ALMA Science Center from 2004 – 2005. ALMA is one of the largest astronomical projects in the world, a complex array of 66 radio telescopes located high in the Chilean desert. One of the biggest challenges was simply ensuring ALMA was successful. “Every big project has funding difficulties and touch-and-go situations.  ALMA was no exception,” Dr. Vanden Bout said. Beyond his service as NRAO Director, Dr. Vanden Bout has published nearly 100 research articles. He is also the first author of “The ALMA Telescope: The Story of a Science Mega-Project,” published by Cambridge University Press in Fall 2023.

Dr. Vanden Bout will deliver his Jansky Lecture, entitled “Millimeter Astronomy at NRAO – Some Personal Remembrances, “ in Charlottesville, VA on Wednesday November 8; at the Green Bank Observatory in Green Bank, WV on Thursday November 9; and in Socorro, NM on Friday November 17. Learn more about these event times and locations.

First awarded in 1966, the Jansky Lectureship is named in honor of the man who, in 1932, first detected radio waves from a cosmic source. Karl Jansky’s discovery of radio waves from the central region of the Milky Way started the science of radio astronomy.

Other recipients of the Jansky award include eight Nobel laureates (Drs. Subrahmanyan Chandrasekhar, Edward Purcell, Charles Townes, Arno Penzias, Robert Wilson, William Fowler, Joseph Taylor, and Reinhard Genzel) as well as Jocelyn Bell-Burnell, discoverer of the first pulsar, and Vera Rubin, discoverer of dark matter in galaxies.

See a list of past recipients.

The National Radio Astronomy Observatory and the Green Bank Observatory are facilities of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

The post Five Decades of Groundbreaking Millimeter Astronomy—From Discovering Molecules in Space to Imaging New Solar Systems appeared first on National Radio Astronomy Observatory.

Gravity can focus light like a lens, allowing astronomers to see distant galaxies and explore dark matter. Join our host Summer Ash of the National Radio Astronomy Observatory as she talks about how astronomers use gravitational lensing to study the universe.

The post The Baseline #17: Gravitational Lensing: Focusing On The Cosmos appeared first on National Radio Astronomy Observatory.

Usually it’s Octoberfest that draws a crowd to Germany this time of year. For hundreds of folks gathered at mtex antenna technology in Schkeuditz, it’s a first look at a prototype radio telescope that may one day be part one of the world’s largest and most sensitive radio telescopes in the world, the National Radio Astronomy Observatory’s (NRAO) next generation Very Large Array (ngVLA). The prototype antenna was unveiled to an excited crowd of government and business leaders, scientists, engineers, and the press from Germany and US.

The prototype antenna’s 18-meter dish, just under the height of a six-story building, is composed of 76 individual aluminum panels assembled in a striking 8-sided shape. “This design allows the surface of the dish to withstand whatever the environment throws at it—extreme temperature, wind, gravity—the reflector will maintain its precise shape within several microns, the equivalent of three human hairs,” explained Lutz Stenvers, managing director of mtex antenna technology. “The structure has 724 pieces, held together with 2,500 screws, weighing in at 43 tons. This design can be shipped in multiple containers to anywhere in the world, and assembled in very little time.”

Time and distance are important factors in ngVLA’s development. A total of 244 dishes are planned for  the massive instrument, with a core array of telescopes working together throughout New Mexico and the American southwest, along with a longer baseline across the US, Mexico and Canada.

The ngVLA has received funding for design and project review from the National Science Foundation (NSF), who supports the majority of NRAO’s operations, with oversight from Associated Universities, Inc. (AUI.)

This preview of the antenna was the closing event for scientists and AUI, NRAO, and NSF staff attending a workshop exploring research opportunities for the ngVLA held at Max Planck Institute for Mathematics in the Sciences in Leipzig.

mtex has been awarded a $1 million state grant from the New Mexico Local Economic Development Act (LEDA) job-creation fund to assist with land, building, and infrastructure costs for their new Albuquerque facility. The City has pledged an additional $300,000 from its municipal LEDA funds.

NRAO’s partnerships with New Mexico Tech and the University of New Mexico are crucial to the ngVLA’s future. NRAO recently signed a new memo of understanding with the University of New Mexico to explore data housing, internships and training for astronomy, engineering, and other fields of STEM education.

Learn more about the ngVLA https://ngvla.nrao.edu/

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under a cooperative agreement by Associated Universities, Inc.

The post German tech factory reveals antenna prototype—ngVLA will open a new window into the Universe appeared first on National Radio Astronomy Observatory.

Many objects in the Universe have magnetic fields. Planets such as Earth and Jupiter, the Sun and other stars, even galaxies billions of light years away. But these magnetic fields don’t typically emit light astronomers can see, not even in radio. So how do astronomers study the magnetic fields of distant stars and galaxies?

Although magnetic fields don’t emit light, charged particles moving in these magnetic fields often do. For example, aurora on Earth are caused by charged particles from the solar wind that are captured by Earth’s magnetic field. They spiral along the magnetic field lines until they strike our atmosphere near the north and south magnetic poles, which can create both visible and radio light. We can see the aurora on Earth and Jupiter as a beautiful curtain of colors. Astronomers have even observed the radio glow of the aurora of a brown dwarf.

When magnetic fields are extremely strong, charged particles caught in these fields can be accelerated to incredible speeds. As they accelerate around the magnetic field, the charges can emit light directly. It’s known as synchrotron radiation, and it’s often seen coming from the heated accretion disks of black holes. Astronomers can use synchrotron radiation to measure how fast the charges are moving, and how strong the magnetic field is. It has helped us understand how black holes can tear apart and consume stars and also lets astronomers determine the size of distant black holes.

Astronomers can also map weak magnetic fields. The magnetic field of the Milky Way isn’t as strong as Earth’s, but it permeates our entire galaxy. Our galaxy is filled with charged particles in the form of ionized interstellar gas. This ionized gas doesn’t emit much light on its own, but it does affect light passing through it, particularly polarized light such as that emitted by pulsars. When polarized light passes through an ionized gas, its orientation rotates. The amount the polarization rotates depends on the frequency of the light. By comparing the polarization of pulsar light at different frequencies, astronomers can map the distribution of ionized gas in the galaxy. And since this gas aligns with the galactic magnetic field, they can map the field.

We can even measure the magnetic field of a galaxy billions of light-years away. Recently the Atacama Large Millimeter/submillimeter Array (ALMA) measured the magnetic field of a galaxy so distant its light took 11 billion years to reach us. This galaxy is particularly dusty, so ALMA observed light reflected and emitted by this dust. This light is polarized along the orientation of the dust grains, and since dust grains tend to align along magnetic field lines, astronomers could use this to map the galaxy’s magnetic field. It is the most distant galaxy known to have a magnetic field.

Astronomers don’t always need to see something to know that it’s there. They just need to see the effect they have on things they can see. From dark matter and dark energy to black holes and magnetic fields, radio astronomy helps us bring these invisible things to light.

The post How Radio Astronomy Sees Magnetic Fields appeared first on National Radio Astronomy Observatory.

An event will be held onsite at the National Radio Astronomy Observatory (NRAO) Dominici Science Operations Center in Socorro, New Mexico and at the Very Large Array (VLA) next week to celebrate the release of the new book, “Joe Pawsey and the Founding of Australian Radio Astronomy: Early Discoveries, from the Sun to the Cosmos” by W.M. Goss (National Radio Astronomy Observatory, Socorro, New Mexico), Claire Hooker (Health and Medical Humanities, Sydney Health Ethics, Sydney, Australia) and Ronald D. Ekers (Commonwealth Scientific and Industrial Research Organization,  Space and Astronomy, Sydney, Australia). This book was more than 15 years in the making, and it is a collaboration of three authors across two continents who worked together to bring to light the story of Joe Pawsey, a key figure in Australian science and, especially, radio astronomy.

The book is an innovative biography of Joe Pawsey, where the biographical structure is used to reexamine the early years of radio astronomy research, as the field emerged from radar research after WWII. Goss, Hooker and Ekers explore the scientific and social context in which Pawsey forged a career that culminated in his leading the first radio astronomy research group in Australia, one of only three worldwide. The authors are interested in different perspectives and include analysis of personalities and motivations to their discussion of how radio astronomy transformed understanding of the universe.  

The authors emphasize Pawsey’s groundbreaking research, particularly his work on solar radio astronomy. Pawsey’s experiments in the 1940s led to the discovery of the association of solar radio bursts with sunspots, which revolutionized our understanding of the Sun’s activity. His innovative use of the interference between radio waves to study celestial objects laid the foundation for future development of the interferometer arrays such as the Very Large Array (VLA). 

Pawsey’s vision and determination led to the establishment of the radio astronomy group of the Radiophysics Laboratory at CSIR, now CSIRO – Australia’s national science agency, in Sydney, Australia. This group became a hub for radio astronomy research, attracting scientists from around the world. Pawsey’s leadership and collaborative approach fostered an environment of innovation, resulting in numerous significant discoveries.

One of Pawsey’s most notable contributions was his participation in the Parkes Radio Observatory (opened in 1961) under the leadership of E.G. Bowen. Bowen provided the entrepreneurial role while Pawsey provided the scientific inspiration with major contributions to the design and future science program of this ground-breaking instrument. The 64-meter Parkes radio telescope, Murriyang, has produced major scientific discoveries in the intervening six decades.

“Joe Pawsey and the Founding of Australian Radio Astronomy” by Goss, Hooker and Ekers provides a comprehensive account of Joe Pawsey’s remarkable journey and his significant contributions to the field of radio astronomy. This book serves as a testament to Pawsey’s enduring legacy and his invaluable contributions to our understanding of the universe. W.M. Goss stated, “Pawsey’s influence on astronomy has now persisted over six decades well into the 21th century. If I might modify Issac Newton’s statement to Robert Hook in 1675: ‘If I have seen further it is by standing on the shoulders of Pawsey, the original Giant’.”

On the 28th July 2023, an Australian book launch was held at the Pawsey Supercomputing Research Centre in Perth. An Australian supercomputing centre, named after Joe Pawsey, which now plays a key role in the phenomenal success of the aperture synthesis radio astronomy imaging technique, a technique which was invented by Pawsey’s group and is now used throughout the world, including the Very Large Array (VLA). It will be key to the success of future telescopes such as the Next Generation VLA and the Square Kilometre Array (SKA).

“This open access book examines not only the life of a radio astronomy pioneer, but also the birth and growth of the field of radio astronomy and the state of science itself in twentieth century Australia. The book explains how an isolated continent with limited resources grew to be one of the international leaders in the study of radio astronomy and the design of instruments to do so‌,” Ronald Ekers. 

If you would like to read “Joe Pawsey and the Founding of Australian Radio Astronomy” by Claire Hooker, Ronald D. Ekers, and W. M. Goss you can access a digital copy of the open access book here. You can also purchase a hardback or soft cover version at the Springer web site ( https://link.springer.com with keyword “pawsey”)

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