Photo of orbits of the G objects at the center of our galaxy

Astronomers discover class of strange objects near our galaxy’s enormous black hole

Photo of orbits of the G objects at the center of our galaxy

Orbits of the G objects at the center of our galaxy, with the supermassive black hole indicated with a white cross. Stars, gas and dust are in the background. Photo: Anna Ciurlo, Tuan Do/UCLA Galactic Center Group

Astronomers from UCLA’s Galactic Center Orbits Initiative have discovered a new class of bizarre objects at the center of our galaxy, not far from the supermassive black hole called Sagittarius A*. They published their research in the Jan. 16 issue of the journal Nature.

“These objects look like gas and behave like stars,” said co-author Andrea Ghez, UCLA’s Lauren B. Leichtman and Arthur E. Levine Professor of Astrophysics and director of the UCLA Galactic Center Group.

The new objects look compact most of the time and stretch out when their orbits bring them closest to the black hole. Their orbits range from about 100 to 1,000 years, said lead author Anna Ciurlo, a UCLA postdoctoral researcher.

Ghez’s research group identified an unusual object at the center of our galaxy in 2005, which was later named G1. In 2012, astronomers in Germany made a puzzling discovery of a bizarre object named G2 in the center of the Milky Way that made a close approach to the supermassive black hole in 2014. Ghez and her research team believe that G2 is most likely two stars that had been orbiting the black hole in tandem and merged into an extremely large star, cloaked in unusually thick gas and dust.

“At the time of closest approach, G2 had a really strange signature,” Ghez said. “We had seen it before, but it didn’t look too peculiar until it got close to the black hole and became elongated, and much of its gas was torn apart. It went from being a pretty innocuous object when it was far from the black hole to one that was really stretched out and distorted at its closest approach and lost its outer shell, and now it’s getting more compact again.”

“One of the things that has gotten everyone excited about the G objects is that the stuff that gets pulled off of them by tidal forces as they sweep by the central black hole must inevitably fall into the black hole,” said co-author Mark Morris, UCLA professor of physics and astronomy. “When that happens, it might be able to produce an impressive fireworks show since the material eaten by the black hole will heat up and emit copious radiation before it disappears across the event horizon.”

But are G2 and G1 outliers, or are they part of a larger class of objects? In answer to that question, Ghez’s research group reports the existence of four more objects they are calling G3, G4, G5 and G6. The researchers have determined each of their orbits. While G1 and G2 have similar orbits, the four new objects have very different orbits.

Ghez believes all six objects were binary stars — a system of two stars orbiting each other — that merged because of the strong gravitational force of the supermassive black hole. The merging of two stars takes more than 1 million years to complete, Ghez said.

“Mergers of stars may be happening in the universe more often than we thought, and likely are quite common,” Ghez said. “Black holes may be driving binary stars to merge. It’s possible that many of the stars we’ve been watching and not understanding may be the end product of mergers that are calm now. We are learning how galaxies and black holes evolve. The way binary stars interact with each other and with the black hole is very different from how single stars interact with other single stars and with the black hole.”

Ciurlo noted that while the gas from G2’s outer shell got stretched dramatically, its dust inside the gas did not get stretched much. “Something must have kept it compact and enabled it to survive its encounter with the black hole,” Ciurlo said. “This is evidence for a stellar object inside G2.”

“The unique dataset that Professor Ghez’s group has gathered during more than 20 years is what allowed us to make this discovery,” Ciurlo said. “We now have a population of ‘G’ objects, so it is not a matter of explaining a ‘one-time event’ like G2.”

The researchers made observations from the W.M. Keck Observatory in Hawaii and used a powerful technology that Ghez helped pioneer, called adaptive optics, which corrects the distorting effects of the Earth’s atmosphere in real time. They conducted a new analysis of 13 years of their UCLA Galactic Center Orbits Initiative data.

In September 2019, Ghez’s team reported that the black hole is getting hungrier and it is unclear why. The stretching of G2 in 2014 appeared to pull off gas that may recently have been swallowed by the black hole, said co-author Tuan Do, a UCLA research scientist and deputy director of the Galactic Center Group. The mergers of stars could feed the black hole.

The team has already identified a few other candidates that may be part of this new class of objects, and are continuing to analyze them.

Ghez noted the center of the Milky Way galaxy is an extreme environment, unlike our less hectic corner of the universe.

“The Earth is in the suburbs compared to the center of the galaxy, which is some 26,000 light-years away,” Ghez said. “The center of our galaxy has a density of stars 1 billion times higher than our part of the galaxy. The gravitational pull is so much stronger. The magnetic fields are more extreme. The center of the galaxy is where extreme astrophysics occurs — the X-sports of astrophysics.”

Ghez said this research will help to teach us what is happening in the majority of galaxies.

Other co-authors include Randall Campbell, an astronomer with the W.M. Keck Observatory in Hawaii; Aurelien Hees, a former UCLA postdoctoral scholar, now a researcher at the Paris Observatory in France; and Smadar Naoz, a UCLA assistant professor of physics and astronomy.

The research is funded by the National Science Foundation, W.M. Keck Foundation and Keck Visiting Scholars Program, the Gordon and Betty Moore Foundation, the Heising-Simons Foundation, Lauren Leichtman and Arthur Levine, Jim and Lori Keir, and Howard and Astrid Preston.

In July 2019, Ghez’s research team reported on the most comprehensive test of Einstein’s iconic general theory of relativity near the black hole. They concluded that Einstein’s theory passed the test and is correct, at least for now.

► Watch a four-minute film about Ghez’s research

►View an animation below of the orbits of the G objects, together with the orbits of stars near the supermassive black hole. Credit: Advanced Visualization Lab, National Center for Supercomputing Applications, University of Illinois

This article originally appeared in the UCLA Newsroom.

Photo of group of volunteers at first mobile health clinic.

Student launches mobile health clinic to increase access to care

Photo of group of volunteers at first mobile health clinic.

Ahmad Elhaija, center, with International Collegiate Health Initiative medical staff, volunteers and student team members at the organization’s first mobile health clinic. Photo: Reed Hutchinson/UCLA

On a sunny autumn Saturday at the Southeast-Rio Vista YMCA in the city of Maywood, kids colored drawings and played Jenga while their parents and other family members underwent basic health screenings conducted by volunteer nurses.

After their bloodwork and other tests were done, the people met with doctors from medical centers in southeast Los Angeles County to discuss their results. Aided by Spanish-language translators, the doctors also gave advice about everything from medications to old injuries — anything the patients wanted to know.

The free event, attended by about 40 community members plus their children, was the first mobile community health clinic hosted by the International Collegiate Health Initiative. Founded two years ago by UCLA junior psychobiology major Ahmad Elhaija, the initiative aims to increase access to affordable, high-quality medical care in low-income and refugee communities in Los Angeles through mobile community health clinics and social advocacy.

“I thought, what can we do here that’ll make a big impact, where we can affect the statistics of a community, their health outcomes?” he said.

Elhaija drew inspiration for the project from two aspects of his youth in Anaheim — growing up frequently sick without consistent health insurance and his volunteer work assisting Arab and Muslim refugees.

Given the need for this kind of service, Elhaija applied for the annual Donald A. Strauss Foundation scholarship to help implement his vision. Each year, the Strauss Foundation awards 10 to 15 students from across 14 California colleges a $15,000 scholarship which is divided between the student’s educational costs and a grant for the public service project they propose in their application.

Elhaija was the only UCLA student to win the $15,000 scholarship in 2019. In 2018, two UCLA students won the Strauss scholarship; their projects helped transfer students prepare for doctoral programs, and provided therapy and support for K-12 students who stutter.

Photo of Ahmad Elhaija

Ahmad Elhaija Photo: Reed Hutchinson/UCLA

As part of the scholarship, Elhaija was assigned a mentor to advise him on his project. Elhaija’s mentor, Marc Anthony Branch, is a program officer for sustainable development for the United Methodist Committee on Relief and an expert in grant writing. Elhaija relied on Branch’s knowledge to improve his grant writing skills.

“I set him up with my grant-writing team, and he was really pivotal in actually getting us moving forward,” Elhaija said. “Before him, we didn’t really have much progress in grant writing, so having him on board and him giving his expertise was really cool. He knows what grant-giving organizations are looking for and he has some good contacts in that realm as well.”

Growing up in a low-income neighborhood in Anaheim, Elhaija was frequently sick from asthma and a rare blood disorder called cyclic neutropenia. His family didn’t always have health insurance, and although they worked hard to support and care for him, they were often left with high hospital bills.

While his family’s difficulty navigating his health care opened his eyes to the importance of providing affordable care, as a teenager Elhaija also volunteered at the nonprofit Access California Services, which provides support and resources to Arab and Muslim refugees in Anaheim. He said that volunteering with the organization and seeing the services for refugees that were still lacking inspired him to think of ways he could help.

So when Elhaija got to UCLA in 2017, he formed the International Collegiate Health Initiative with the goal to provide medical care to refugees in countries like Syria and Palestine. Through his volunteer work and visiting his own family in the Middle East, Elhaija learned that college campuses would be the safest places to provide medical services in the region.

However, finances and logistics made it more productive for Elhaija to focus his efforts on refugee and low-income communities closer to home. So he switched the initiative’s focus to offering mobile community health clinics in southeast Los Angeles.

The initiative is managed by a team of 20 students, a board of directors and professional advisers who offer guidance and medical services for the clinics. The clinic in Maywood, held on Nov. 16, was the organization’s first mobile health clinic. Another is planned for the city of Bell in February.

The ICHI’s ultimate goal is to raise enough money for a mobile clinic van, and to expand to other cities in California or even overseas.

“The idea is that we could have our full blown mobile clinic running in the fall of next year, where we can provide basically every type of care that a standard clinic can provide,” Elhaija said.

This article originally appeared in the UCLA Newsroom.

Image of Kabuki actor performing

UCLA receives $25 million from Uniqlo founder for Japanese literature and culture studies

Image of Kabuki actor performing

Renowned Kabuki actor Nakamura Kyozo performing the role of a lion in “Shujaku jishi” at the Glorya Kaufman Dance Theater in an event for students co-sponsored by the Yanai Initiative and the Japanese Ministry of Culture (November 14, 2019). (Credit: Ning Wong Studios)

UCLA has received a $25 million gift from Tadashi Yanai, the chair, president and CEO of Japan-based Fast Retailing and founder of clothing company Uniqlo. The funds will endow the Tadashi Yanai Initiative for Globalizing Japanese Humanities, which will bolster UCLA’s status as a leading center for the study of Japanese literature, language and culture.

The gift is the largest from an individual donor in the history of the UCLA College’s humanities division. A previous donation of $2.5 million from Yanai in 2014 created the Yanai Initiative, a collaboration between UCLA and Waseda University, one of Japan’s most prestigious universities. The program supports academic and cultural programming and enables student and faculty exchanges between the two universities. This latest gift will ensure the initiative’s long-term future.

“Mr. Yanai’s extraordinary gifts are a testament to UCLA’s long-standing commitment to educate global citizens who can thrive in careers — and cultures — anywhere in the world,” said UCLA Chancellor Gene Block. “The Tadashi Yanai Initiative for Globalizing Japanese Humanities will have a profound and lasting impact on this campus.”

Photo of Tadashi Yanai

UCLA has received a $25 million gift from Tadashi Yanai, the chair, president and CEO of Japan-based Fast Retailing and founder of clothing company Uniqlo. (Credit: Fast Retailing Co., Ltd.)

The Yanai Initiative is housed in the UCLA College department of Asian languages and cultures and directed by Professor Michael Emmerich. The latest gift will fund and establish an endowed chair in Japanese literature and will fund conferences, public lectures, faculty research, cultural performances and community outreach. It will support graduate and postdoctoral fellowships and undergraduate awards.

“It has been inspiring to see all of the creative, innovative programming — both academic and cultural — that this project has realized over the past five years,” Yanai said. “Now that we are making it permanent, I’m excited to see how it will continue to transform the Japanese humanities in a global context. At the same time, I hope this gift will give others a chance to remember how crucial the humanities are, and, in their own way, to recommit.”

The gift also triggers matching funds from the Humanities Centennial Match and the UCLA Centennial Scholars Match to support UCLA graduate students in Japanese humanities and other areas of study.

“Mr. Yanai’s gift is a visionary investment in a field of increasing interest to humanities scholars, students and people everywhere,” said David Schaberg, UCLA’s dean of humanities. “Thanks to his generosity, UCLA will lead the way in research and teaching in Japanese humanities, bringing new attention to a rich culture that has captured people’s imaginations for centuries.”

Schaberg said another benefit of the gift is that it will deepen UCLA’s partnership with Waseda.

In addition to funding fellowships, symposia, lectures and academic workshops, Yanai’s previous donation supported a range of cultural programs, including a five-day series of events featuring actor Nomura Mansaku, who was designated a “living national treasure” by the Japanese government; a retrospective of films by Palme d’Or recipient Hirokazu Kore-eda; and “The Art of the Benshi,” which introduced Los Angeles audiences to the early 20th century performance art in which narrators bring silent movies to life with live music accompaniment.

“During the past five years, Mr. Yanai’s generosity has enabled us to do so much for students and for the Japanese humanities not just at UCLA, but across the country and around the world,” Emmerich said. “We’ve been able to organize major cultural events across Los Angeles, drawing thousands of participants. I never imagined I would be able to say that all this was only the beginning. I can’t express how grateful we all are to Mr. Yanai for his generosity, his incisive advice and his commitment.”

The gift was facilitated through a designated donations program run by the Japan Foundation, which is dedicated to promoting cultural and intellectual exchange with Japan. Over the past three decades, the foundation has helped advance and fund numerous cultural programs at UCLA.

View this release in Japanese

Unearthing Easter Island’s Moai

Two Moai are shown during excavations by Jo Anne Van Tilburg and her team at Rano Raraku quarry on Rapa Nui, better known as Easter Island. Photo credit: Easter Island Statue Project

Rapa Nui (or Easter Island, as it is commonly known) is home to the enigmatic Moai, stone monoliths that have stood watch over the island landscape for hundreds of years. Their existence is a marvel of human ingenuity — and their meaning a source of some mystery.

Ancient Rapanui carvers worked at the behest of the elite ruling class to carve nearly 1,000 Moai because they, and the community at large, believed the statues capable of producing agricultural fertility and thereby critical food supplies, according to a new study from Jo Anne Van Tilburg, director of the Easter Island Statue Project, recently published in Journal of Archaeological Science.

Van Tilburg and her team, working with geoarchaeologist and soils specialist Sarah Sherwood, believe they have found scientific evidence of that long-hypothesized meaning thanks to careful study of two particular Moai excavated over five years in the Rano Raraku quarry on the eastern side of the Polynesian island.

Van Tilburg’s most recent analysis focused on two of the monoliths that stand within the inner region of the Rano Raraku quarry, which is the origin of 95 percent of the island’s more than 1,000 Moai. Extensive laboratory testing of soil samples from the same area shows evidence of foods such as banana, taro and sweet potato.

Van Tilburg said the analysis showed that in addition to serving as a quarry and a place for carving statues, Rano Raraku also was the site of a productive agricultural area.

“Our excavation broadens our perspective of the Moai and encourages us to realize that nothing, no matter how obvious, is ever exactly as it seems. I think our new analysis humanizes the production process of the Moai,” Van Tilburg said.

Van Tilburg has been working on Rapa Nui for more than three decades. Her Easter Island Statue Project is supported in part by UCLA’s Cotsen Institute of Archaeology. Tom Wake, a Cotsen Institute colleague, analyzes small-animal remains from the excavation site. Van Tilburg also serves as director of UCLA’s Rock Art Archive.

Van Tilburg, in partnership with members of the local community, heads the first legally permitted excavations of Moai in Rano Raraku since 1955. Cristián Arévalo Pakarati, a noted Rapanui artist, is project co-director.

The soils in Rano Raraku are probably the richest on the island, certainly over the long term, Sherwood said. Coupled with a fresh-water source in the quarry, it appears the practice of quarrying itself helped boost soil fertility and food production in the immediate surroundings, she said. The soils in the quarry are rich in clay created by the weathering of lapilli tuff (the local bedrock) as the workers quarried into deeper rock and sculpted the Moai.

A professor of earth and environmental systems at the University of the South in Sewanee, Tenn., Sherwood joined the Easter Island Project after meeting another member of Van Tilburg’s team at a geology conference.

She wasn’t originally looking for soil fertility, but out of curiosity and research habit, she did some fine-scale testing of samples brought back from the quarry.

“When we got the chemistry results back, I did a double take,” Sherwood said. “There were really high levels of things that I never would have thought would be there, such as calcium and phosphorous. The soil chemistry showed high levels of elements that are key to plant growth and essential for high yields. Everywhere else on the island the soil was being quickly worn out, eroding, being leeched of elements that feed plants, but in the quarry, with its constant new influx of small fragments of the bedrock generated by the quarrying process, there is a perfect feedback system of water, natural fertilizer and nutrients.”

She said it also looks like the ancient indigenous people of Rapanui were very intuitive about what to grow — planting multiple crops in the same area, which can help maintain soil fertility.

The Moai that Van Tilburg’s team excavated were discovered upright in place, one on a pedestal and the other in a deep hole, indicating they were meant to remain there.

“This study radically alters the idea that all standing statues in Rano Raraku were simply awaiting transport out of the quarry,” Van Tilburg said. “That is, these and probably other upright Moai in Rano Raraku were retained in place to ensure the sacred nature of the quarry itself. The Moai were central to the idea of fertility, and in Rapanui belief their presence here stimulated agricultural food production.”

Van Tilburg and her team estimate the statues from the inner quarry were raised by or before A.D. 1510 to A.D.1645. Activity in this part of the quarry most likely began in A.D.1455. Most production of Moai had ceased in the early 1700s due to western contact.

The two statues Van Tilburg’s team excavated had been almost completely buried by soils and rubble.

“We chose the statues for excavation based on careful scrutiny of historical photographs and mapped the entire Rano Raraku inner region before initiating excavations,” she said.

Van Tilburg has worked hard to establish connections with the local community on Rapa Nui. The project’s field and lab teams are made up of local workers, mentored by professional archeologists and geologists.

The result of their collective efforts is a massive detailed archive and comparative database that documents more than 1,000 sculptural objects on Rapa Nui, including the Moai, as well as similar records on more than 200 objects scattered in museums throughout the world. In 1995, UNESCO named Easter Island a World Heritage Site, with most of the island’s sacred sites protected within Rapa Nui National Park.

This is the first definitive study to reveal the quarry as a complex landscape and to make a definitive statement that links soil fertility, agriculture, quarrying and the sacred nature of the Moai.

Van Tilburg and her team are working on another study that analyzes the rock art carvings that exist on only three of the Moai.

This article originally appeared in the UCLA Newsroom.

That Supermassive Black Hole in our Galaxy? It has a Friend.

Two black holes are entwined in a gravitational tango in this artist’s conception. Photo Credit: NASA/JPL-Caltech/SwRI/MSSS/Christopher Go

Smadar Naoz is an associate professor of physics and astronomy in the UCLA College. She wrote this article for The Conversation.

Do supermassive black holes have friends? The nature of galaxy formation suggests that the answer is yes, and in fact, pairs of supermassive black holes should be common in the universe.

I am an astrophysicist and am interested in a wide range of theoretical problems in astrophysics, from the formation of the very first galaxies to the gravitational interactions of black holes, stars and even planets. Black holes are intriguing systems, and supermassive black holes and the dense stellar environments that surround them represent one of the most extreme places in our universe.

The supermassive black hole that lurks at the center of our galaxy, called Sgr A*, has a mass of about 4 million times that of our sun. A black hole is a place in space where gravity is so strong that neither particles or light can escape from it. Surrounding Sgr A* is a dense cluster of stars. Precise measurements of the orbits of these stars allowed astronomers to confirm the existence of this supermassive black hole and to measure its mass. For more than 20 years, scientists have been monitoring the orbits of these stars around the supermassive black hole. Based on what we’ve seen, my colleagues and I show that if there is a friend there, it might be a second black hole nearby that is at least 100,000 times the mass of the sun.

Supermassive black holes and their friends

Almost every galaxy, including our Milky Way, has a supermassive black hole at its heart, with masses of millions to billions of times the mass of the sun. Astronomers are still studying why the heart of galaxies often hosts a supermassive black hole. One popular idea connects to the possibility that supermassive holes have friends.

To understand this idea, we need to go back to when the universe was about 100 million years old, to the era of the very first galaxies. They were much smaller than today’s galaxies, about 10,000 or more times less massive than the Milky Way. Within these early galaxies the very first stars that died created black holes, of about tens to thousand the mass of the sun. These black holes sank to the center of gravity, the heart of their host galaxy. Since galaxies evolve by merging and colliding with one another, collisions between galaxies will result in supermassive black hole pairs – the key part of this story. The black holes then collide and grow in size as well. A black hole that is more than a million times the mass of our sun is considered supermassive.

If indeed the supermassive black hole has a friend revolving around it in close orbit, the center of the galaxy is locked in a complex dance. The partners’ gravitational tugs will also exert its own pull on the nearby stars disturbing their orbits. The two supermassive black holes are orbiting each other, and at the same time, each is exerting its own pull on the stars around it.

The gravitational forces from the black holes pull on these stars and make them change their orbit; in other words, after one revolution around the supermassive black hole pair, a star will not go exactly back to the point at which it began.

Using our understanding of the gravitational interaction between the possible supermassive black hole pair and the surrounding stars, astronomers can predict what will happen to stars. Astrophysicists like my colleagues and me can compare our predictions to observations, and then can determine the possible orbits of stars and figure out whether the supermassive black hole has a companion that is exerting gravitational influence.

Using a well-studied star, called S0-2, which orbits the supermassive black hole that lies at the center of the galaxy every 16 years, we can already rule out the idea that there is a second supermassive black hole with mass above 100,000 times the mass of the sun and farther than about 200 times the distance between the sun and the Earth. If there was such a companion, then I and my colleagues would have detected its effects on the orbit of SO-2.

But that doesn’t mean that a smaller companion black hole cannot still hide there. Such an object may not alter the orbit of SO-2 in a way we can easily measure.

The physics of supermassive black holes

Supermassive black holes have gotten a lot of attention lately. In particular, the recent image of such a giant at the center of the galaxy M87 opened a new window to understanding the physics behind black holes.

The proximity of the Milky Way’s galactic center – a mere 24,000 light-years away – provides a unique laboratory for addressing issues in the fundamental physics of supermassive black holes. For example, astrophysicists like myself would like to understand their impact on the central regions of galaxies and their role in galaxy formation and evolution. The detection of a pair of supermassive black holes in the galactic center would indicate that the Milky Way merged with another, possibly small, galaxy at some time in the past.

That’s not all that monitoring the surrounding stars can tell us. Measurements of the star S0-2 allowed scientists to carry out a unique test of Einstein’s general theory of relativity. In May 2018, S0-2 zoomed past the supermassive black hole at a distance of only about 130 times the Earth’s distance from the sun. According to Einstein’s theory, the wavelength of light emitted by the star should stretch as it climbs from the deep gravitational well of the supermassive black hole.

The stretching wavelength that Einstein predicted – which makes the star appear redder – was detected and proves that the theory of general relativity accurately describes the physics in this extreme gravitational zone. I am eagerly awaiting the second closest approach of S0-2, which will occur in about 16 years, because astrophysicists like myself will be able to test more of Einstein’s predictions about general relativity, including the change of the orientation of the stars’ elongated orbit. But if the supermassive black hole has a partner, this could alter the expected result.

Finally, if there are two massive black holes orbiting each other at the galactic center, as my team suggests is possible, they will emit gravitational waves. Since 2015, the LIGO-Virgo observatories have been detecting gravitational wave radiation from merging stellar-mass black holes and neutron stars. These groundbreaking detections have opened a new way for scientists to sense the universe.

Any waves emitted by our hypothetical black hole pair will be at low frequencies, too low for the LIGO-Virgo detectors to sense. But a planned space-based detector known as LISA may be able to detect these waves which will help astrophysicists figure out whether our galactic center black hole is alone or has a partner.

This article originally appeared in the UCLA Newsroom.