Wednesday, August 17, 2022

The photon ring: a black hole ready for its close-up

Artist’s conception of the accretion flow and jet – the near-lightspeed outflow of plasma and electromagnetic fields along the polar axis – near the black hole in M87.  Near the event horizon, the rotation of the black hole drags everything, including space itself, around the black hole, twisting the magnetic fields (magenta lines) that ultimately launch the jet.  As a result, the plasma in the jet spins about its axis, slowing as the jet expands (like the figure skater as she opens her arms).  The bottom of the jet has now been observed, exhibiting the tell-tale rotation that betrays the black hole’s role in its creation. Photo credit: Perimeter Institute / University of Waterloo

When scientists unveiled humanity’s historic first image of a black hole in 2019 – depicting a dark core encircled by a fiery aura of material falling toward it – they believed even richer imagery and insights were waiting to be teased out of the data.

Simulations predicted that, hidden behind the glare of the diffuse orange glow, there should be a thin, bright ring of light created by photons flung around the back of the black hole by its intense gravity.

A team of researchers led by astrophysicist Avery Broderick used sophisticated imaging algorithms to essentially “remaster” the original imagery of the supermassive black hole at the centre of the M87 galaxy.

“We turned off the searchlight to see the fireflies,” explains Broderick, an associate faculty member at Perimeter Institute and the University of Waterloo. “We have been able to do something profound – to resolve a fundamental signature of gravity around a black hole.”

By essentially “peeling off” elements of the imagery, says co-author Hung-Yi Pu, an assistant professor at National Taiwan Normal University, “the environment around the black hole can then be clearly revealed.”

To accomplish this, the team employed a new imaging algorithm within the EHT analysis framework THEMIS to isolate and extract the distinct ring feature from the original observations of the M87 black hole – as well as detect the telltale footprint of a powerful jet blasting outward from the black hole.

The researchers’ findings both confirm theoretical predictions and offer new ways to explore these mysterious objects, which are believed to reside at the heart of most galaxies.

Black holes were long considered unseeable until scientists coaxed them out of hiding with a globe-spanning network of telescopes, the Event Horizon Telescope (EHT). Using eight observatories on four continents, all pointed at the same spot in the sky and linked together with nanosecond timing; the EHT researchers observed two black holes in 2017.

The EHT collaboration first unveiled the supermassive black hole in M87 in 2019, and then in 2022, the comparatively small but tumultuous black hole at the heart of our own Milky Way galaxy, called Sagittarius A* (or Sgr A*). Supermassive black holes occupy the centre of most galaxies, packing an incredible amount of mass and energy into a small space. The M87 black hole, for example, is two quadrillion (that’s a two followed by 15 zeros) times more massive than Earth.

The M87 image scientists unveiled in 2019 was a landmark, but the researchers felt they could sharpen the image and glean new insights by working smarter, not harder. They applied new software techniques to reconstruct the original 2017 data in search of phenomena that theories and models predicted were lurking beneath the surface. The new, resulting image depicts the photon ring, comprised of a series of increasingly sharp sub-rings, which the team then stacked to get the full image.

“The approach we took involved leveraging our theoretical understanding of how these black holes look to build a customized model for the EHT data,” says Dominic Pesce, a team member based at the Center for Astrophysics | Harvard & Smithsonian. “This model decomposes the reconstructed image into the two pieces that we care most about, so we can study both pieces individually rather than blended together.”

The result was possible because the EHT is a “computational instrument at its heart,” says Broderick, who holds the Delaney Family John Archibald Wheeler Chair at Perimeter. “It is as dependent on algorithms as it is upon steel. Cutting-edge algorithmic developments have allowed us to probe key features of the image while rendering the remainder in the EHT's native resolution.”

The researchers’ findings were published on August 16 in The Astrophysical Journal.

UWaterloo Oral History Pilot Project launches

A message from the University of Waterloo Library.

Oral histories allow us to gather, preserve, and interpret voices and memories of people, communities and participants of past events and can be a source of rich and important information when researching. The Library’s Special Collections & Archives is working on a pilot project to capture the lived experiences of UWaterloo staff, faculty and students to add to the University of Waterloo Archives.

Learn more by visiting https://bit.ly/SCAoralhistory.

Games Institute Seed Grant funds interdisciplinary cross campus collaborations

By Emma Vossen. This article was originally published on the Games Institute website.

The Games Institute (GI) is pleased to announce the recipients of its first-ever seed grant funding competition. In total, the GI Seed Program will support eight interdisciplinary initiatives for a total of $110,000 over the next year. The competition promoted interdisciplinary collaborations in teams of researchers spanning many different disciplines and research areas.

The seed grant recipients will combine their varied expertise to tackle real-world problems facing indigenous communities, health care workers, children with speech difficulties, mothers facing homelessness, citizen scientists, and VR, XR and social media consumers.

GI leadership gratefully acknowledges the hard work of the seed grant adjudication committee. Says Executive Director Dr. Neil Randall, "This seed grant program fulfills a goal the GI has had for quite some time. As a research centre, the GI always supports research, but rarely do we get an opportunity to initiate it through direct funding. We're very pleased to fund this set of proposals, all of which were excellent in conception and quality. I congratulate the recipients, and I thank them sincerely." 

Congratulations to the following award recipients:

Dementia-friendly First Responders Edu-Action: An Interactive Participatory and Co-Designed Training Course for Indigenous First Responders

Dr. Hector Perez (School of Public Health Sciences), Dr. Lili Liu (School of Public Health Sciences) Dr. Antonio Miguel-Cruz (University of Alberta), Dr. Noelannah Neubauer (School of Public Health Sciences), Isabella Rose Chawrun (School of Public Health Sciences), and Cathy Conway (Project Manager).

“Dementia is over-represented among First Nations. First responders lack awareness that dementia-related missing incidents differ from other types of missing occurrences. Search and rescue training for Indigenous communities is delivered by organizations like SAR-1. Education about dementia and how to address risks of persons with dementia going missing would increase awareness, capacity and competence among First Nations personnel. We will use storytelling and gamification to co-create a virtual training course to support Indigenous first responders and search and rescue personnel. We will collaborate with first responders (e.g., police and paramedics) in two Indigenous communities, the Games Institute, and SAR-1. “

Empowering Meaningful Customizations in Social Virtual Reality

Dr. Eugene Kukshinov (Stratford School of Interaction Design and Business), Dr. Daniel Harley (Stratford School of Interaction Design and Business), Jonathan Baltrusaitis (English Language and Literature), and Dr. Lennart Nacke (Stratford School of Interaction Design and Business and Communication Arts).

“As an emerging technologically-mediated social environment, social virtual reality (SVR) is said to provide improved opportunities for creative, physical, and social interactions in virtual spaces. While Meta has recently released new avatars to improve diverse representation, current VR research is biased towards white male participants, and little is known about how more diverse demographics interact within SVR. Focusing on avatar use and customization, we will apply a critical, intersectional approach to better understand how diverse demographics of participants navigate social virtual reality, examining how the potential benefits of these spaces can become more available to everyone by design.”

Exploring Digital Feminist Futures: Creating Media Tools and Interventions for the Resistance

Dr. Brianna I. Wiens (English Language & Literature), Dr. Shana MacDonald (Communication Arts), Dr. Cayley MacArthur (Stratford School of Interaction Design and Business), Sid Heeg (Environment, Enterprise, and Development), Kate Bradley (History), and Thuvaraka Mahenthiran (Psychology).

“Over the last two decades, both feminist and antifeminist sentiments––including racist, imperialist, queerphobic, transphobic, and ableist sentiments––have been on the rise, with the technologies we use daily responsible for circulating these media toxicities by their very design. Despite repeated calls for regulations and protections, few exist. As such, there remains a need for everyday people to harness the potential of the internet to learn not only how to protect themselves but how to fight back. This project directly addresses this need through an explicit research-creation approach to studying and designing public digital toolkits for resistance via public programming, archiving, and designing workshops informed by data feminist principles.”

Free-Range Gamesourcing Annotated Rhetorical Figure Data

Dr. Randy Allen Harris (English Language and Literature), and Dr. Olga Vechtomova (Management Sciences).

“This proposal is to adapt for free-range release an existing Citizen Science game developed within the GI ecosystem, to harvest instances of language exhibiting extra-grammatical patterns known as rhetorical figures in order to build training sets for Machine Learning algorithms.”

Interactive Training Tool for Injury Assessment of a Human Joint

Dr. Oliver Schneider (Management Sciences), Dr. Mark Hancock (Management Sciences), Rob Burns (Kinesiology), Marco Moran-Ledesma (Systems Design Engineering), and Emily Shiu (Psychology).

“Manual musculoskeletal assessments allow rehabilitation practitioners to identify soft tissue injuries (e.g., knee ligament sprains) through visual and haptic cues. However, becoming proficient at assessing patients’ joint integrity through manual physical exams is difficult due to 1) the wide range of joint conditions and 2) the limited practice opportunities on injured clients both clinically and in an academic setting. Novice students find themselves limited to practicing on their peers’ healthy joints or relying on non-tactile learning materials, such as lectures, videos, or demonstrations. This model, and the XR environment we have planned, will provide students with exposure to various joint conditions and injury grades.”

Marillac Place - Gamifying the "Praise with a Raise" Program

Dr. Cayley MacArthur (Stratford School of Interaction Design and Business), Dr. James Wallace (Public Health Sciences), and Veen Wong (Public Health Sciences).

“Marillac Place is a women’s shelter whose mission is: to support new mothers and mothers-to-be facing homelessness in Waterloo Region by providing a safe living environment, teaching parenting & life skills and developing supportive relationships. Its residents participate in the Praise with a Raise Program. Marillac Place collects data on how effectively residents accomplish their program goals. Currently, Marillac Place does not have an interface for their residents to review their own goals and performance. The team, with Marillac Place, will develop an app that residents can use to build essential life, parenting, and social skills for independent living. The app will also be used by Marillac Place staff to access individual performance in the program. The app will consider trauma-informed computing and include gamification elements to promote engagement and encourage task completion.”

Privacy In Extended Reality

Hilda Hadan (Systems Design Engineering), Dr. Lennart Nacke (Stratford School of Interaction Design and Business and Communication Arts), and Dr. Leah Zhang-Kennedy (Stratford School of Interaction Design and Business).

“Our project focuses on the privacy implication of XR, a newly emerged and rapidly evolving game-related technology. As social interactions are now moving into XR, the immersion of XR creates unique challenges for human privacy. We aim to investigate people’s existing knowledge of privacy issues of XR and how the knowledge influences their privacy concerns and privacy-seeking behaviors. XR technology and gamification of social interactions using it are still in their infancy, creating this opportunity to develop solutions for potential privacy issues of the technology proactively.”

VR Speech Therapy Kit

Emily Shiu (Psychology), Dr. Oliver Schneider (Management Sciences), Jing Hao Yao (Software Engineering), Karthik Prasad (Management Sciences,) and Thomas Mastantuono (Management Sciences).

“Children with autism or certain other communicative disorders struggle to communicate their wants and needs, either due to difficulty understanding intentions and social cues, or because of struggles in verbalizing their thoughts. This often results in reduced quality-of-life for these children and their parents. Receiving speech therapy teaches these kids the communicative skills needed to thrive and getting therapy earlier results in better outcomes. However, speech therapy is costly, limiting accessibility for those with lower income. Additionally, availability is limited by how many speech therapists are in a region. We are developing a VR speech therapy kit to either supplement existing speech therapy, or to provide an accessible option for people who cannot afford or allot time for dedicated speech therapy.”