Detection of “Plunging Regions” Around Black Holes: A team from Oxford University has provided the first observational evidence of the “plunging regions” around black holes, where matter from a star falls into the black hole at near-light speeds. Dr. Andrew Mummery, who led the study, described this process as observing a “river turning into a waterfall,” offering the first look at the final descent of plasma into a black hole. This discovery confirms a key prediction of Einstein’s theory of general relativity about the behavior of matter under the strongest gravitational fields known in the universe. Dr. Mummery emphasized that this breakthrough represents a significant advance in understanding black hole dynamics and gravity at its most extreme University of Oxford and Space.com
The Event Horizon Telescope (EHT) collaboration has set a new benchmark for Earth-based astronomical observations by achieving the highest resolution observation of a black hole from the planet’s surface. This groundbreaking accomplishment offers a sharper view of black holes and is expected to provide deeper insights into their enigmatic behaviors.
The EHT is a global network of telescopes that work together using a technique called very-long-baseline interferometry (VLBI), creating a virtual Earth-sized telescope. In this latest observation, the EHT successfully detected light from distant galaxies at an unprecedented frequency of 345 GHz, which corresponds to a wavelength of 0.87 millimeters. This achievement marks the highest frequency observation ever conducted using the VLBI technique.
Event Horizon Telescope makes highest-resolution black hole detections from Earth: https://t.co/9UHAjWig9e
— Ken Gusler (@kgusler) August 27, 2024
The advancement promises significantly sharper images of black holes, with the EHT expecting future images to be 50% clearer than previous ones. Alexander Raymond, co-lead of the paper detailing this breakthrough, explained, “With the EHT, we saw the first images of black holes by detecting radio waves at 230 GHz. However, the bright ring formed by light bending in the black hole’s gravity appeared blurry because we were at the absolute limits of our imaging capabilities. At 345 GHz, our images will be sharper and more detailed, likely revealing new properties, some anticipated and others unexpected.”
Simulated images of the supermassive black hole M87*, located in the center of the M87 galaxy, demonstrate the improvement in clarity and resolution when moving from 230 GHz to 345 GHz. The EHT is well-known for capturing the first image of M87* in 2019 and later the Milky Way’s black hole, Sgr A*, in 2022.
Observations from the James Webb Space Telescope (JWST): The JWST has observed a mature quasar from the early universe, shedding light on the growth of supermassive black holes. This observation revealed that early quasars were “shockingly normal,” with similar characteristics to those found in more modern counterparts. According to astrophysicist Sarah E. I. Bosman, this suggests that supermassive black holes and their feeding mechanisms were already fully developed when the universe was just 5% of its current age. These findings challenge existing models of black hole growth and suggest that these massive structures formed very early with significant initial masses Phys.org
The increase in observation frequency presented significant challenges, primarily due to atmospheric water vapor, which absorbs signals more strongly at 345 GHz than at 230 GHz. To overcome these obstacles, the EHT team enhanced the sensitivity of their instruments, improved technological components like bandwidth, and meticulously planned observations around optimal weather conditions at each site.
The EHT network includes some of the most powerful telescopes globally, such as the Atacama Large Millimeter/submillimeter Array (ALMA), the Atacama Pathfinder Experiment (APEX), the IRAM, the Northern Extended Millimeter Array (NOEMA), the Submillimeter Array (SMA), and the Greenland Telescope. By combining these advanced telescopes, the EHT achieved an impressive resolution of 19 microarcseconds.
Nimesh Patel, an astrophysicist at the Center for Astrophysics | Harvard & Smithsonian, highlighted the importance of high-altitude observatories where atmospheric transparency and stability are optimal for such detailed observations. “With high-bandwidth systems that process wider swaths of the radio spectrum, we are starting to overcome basic sensitivity issues, like weather,” Patel noted.
Event Horizon Telescope Makes Highest-Resolution Black Hole Detections from Earth
https://t.co/3yex73sjUe pic.twitter.com/wtHV1Mfc8e
— Paul Jones (@Z00KY) August 27, 2024
Looking ahead, the EHT’s recent accomplishment brings scientists closer to creating detailed movies of black holes, specifically capturing the event horizon region—the boundary beyond which nothing can escape a black hole’s gravitational pull. The future of black hole imaging is promising, with plans for the next-generation Event Horizon Telescope (ngEHT) project, which aims to expand the current network with additional antennas and upgraded technology.
More
- Gravitational Wave Background Discovery: Researchers from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) have detected the first evidence of a gravitational wave background, which consists of low-frequency gravitational waves created by slowly merging supermassive black holes or possibly from the early universe. Chiara Mingarelli from Yale University, a key member of the NANOGrav team, highlighted that these findings provide a new window into understanding the universe’s evolution and confirm standard models of galaxy formation and black hole growth. This discovery opens up new avenues for exploring how supermassive black holes merge and grow over time YaleNews
Key Points:
i. The Event Horizon Telescope (EHT) has achieved the highest resolution observation of a black hole from Earth using a frequency of 345 GHz.
ii. This breakthrough allows for sharper images of black holes, offering new insights into their properties and behaviors.
iii. The EHT used a global network of advanced telescopes and overcame significant challenges, such as atmospheric interference, to achieve this feat.
iv. Future advancements with the ngEHT project are expected to enhance the capabilities of the EHT, including creating detailed movies of black holes.
v. The EHT’s achievement marks a significant step forward in the study of black holes and their event horizons.
RM Tomi – Reprinted with permission of Whatfinger News