A worldwide network of telescopes has produced an image of a beam of radio waves that seems to come out the center of one supermassive black hole with more than 15 times the speed of light.
A year agoscientists from observatories around the world worked together to first ever image of the shadow of a black hole. But the Event Horizon Telescope collaboration can yield more than just an image of one cosmic donut. During the observation run of April 2017, a picture was also taken of one blazar- a supermassive black hole that shoots a beam of radiation at it Earth, allow astronomers look inside and present the radio jet in the best resolution yet.
Understanding these black hole jets and how they form is critical for astrophysicists today, and a popular way to study them is very long basic interferometry (VLBI). VLBI is a method that combines the observations of radio telescopes all over the world – in fact creating a much larger telescope—around the general resolution with which they can distinguish distant objects. Each telescope records the radiation coming in from a source and the exact time when the radiation arrived. Computer algorithms combine and, in a way, the data in a high-resolution image.
The best known use of VLBI came from the Event Horizon Telescope, a worldwide effort to image the dark circle in the center of a black hole. Eight radio telescopes recorded data for two weeks back in 2017, and the collaboration presented the now iconic image of the center of Galaxy M87 last April. Although the M87 image helped scientists better understand jet formation, it didn’t directly link the black hole to its jet, according to the study published today in astronomy and astrophysics. But they also observed other targets, including a bright source of radio waves called blazar 3C 279, billions of light years away.
Today scientists publish the results of their analysis of 3C 279, led by Jae-Young Kim of the Max Planck Institute for Radio Astronomy in Germany. The EHT captured the object on April 5, 6, 10, and 11, 2017, and scientists in the following years worked to combine the observations to combine and analyze the actual data.
These observations visualized the beam up to half a light.years in resolution. The structure seemed twisted at the base and had smaller substructural components that moved perpendicular to our field of view. It even changed over the course of a few days of the to observe window. Two of the jet components seemed to move faster than the speed of light, 15 and 20 times light speed, in fact. They are not really faster than the speed of light; they just seem to do it in the air, an effect I explain it here. Together, the observations suggest that the jet can be one bent or rotating emission of shock waves caused by instability in being plasma.
A physicist who was not involved in the study, postdoctoral researcher Konstancja Satalecka at DESY in Germany told Gizmodo that the measurements themselves are compelling but will be even more exciting in combination with other radiation wavelengths, such as gamma rays. Gamma-ray emissions from jets are associated with the formation of new functions and can also be correlated with more mysterious eruptions such as neutrinos and cosmic rays.
“Since the EHT observations were made at a time when 3C 279 showed high variability in gamma shine, I am very excited about the next publication where the multi-wavelength data will be used to model the processes in the jet, ”she told Gizmodo in an email. “Hopefully we can lockpinpoint the location of the gamma radiation emission range and learn about the acceleration and emission mechanisms responsible for their production. “
This jet is just one example, Satalecka explained a family of objects that can display enormous variation. This means that the results here cannot be generalized to other active galactic nuclei – galaxies whose centers also radiate radiation. Yet it is a step in the direction understand how these jets form.
Scientists continue to analyze the data from the April 2017 run and hope to eventually produce an image or even a video from the center of our own galaxy black hole. The ongoing covid-19 pandemic has suspended this month’s EHT run, so EHT scientists are working to further analyze the data collected in 2017 and 2018. An extended run with 11 observatories is scheduled for March 2021.