EHT Tracks Cosmic Jet to M87* Black Hole Source
Astronomers utilizing the Event Horizon Telescope (EHT) have tracked a 3,000 light-years-long cosmic jet to its source, the supermassive black hole M87*.
This development could enhance understanding of how these powerful jets of charged particles, which travel at near-light speeds, are generated.
M87*: A Supermassive and Active Black Hole
M87* is located at the center of the galaxy Messier 87 (M87), approximately 55 million light-years from Earth. It was the first black hole ever imaged by humanity, with its historic image captured by the EHT in 2017 and released in April 2019.
M87* possesses a mass equivalent to 6.5 billion suns, making it significantly more massive than the Milky Way's central black hole, Sagittarius A (Sgr A)**, which has about 4 million solar masses.
As an active black hole, M87* actively consumes surrounding gas and dust while launching powerful jets from its poles. The precise mechanism powering these jets and their exact origin around black hole central engines have been subjects of ongoing scientific inquiry.
Connecting the Jet to its Source
To investigate the jet, astronomers employed EHT observations of M87* conducted in 2021, using Very Long Baseline Interferometry (VLBI). This technique allows for the resolution of structures around supermassive black holes at small scales, such as the glowing ring of super-hot matter visible in the 2019 image, which represents the black hole's "shadow."
Through these newer observations, the research team successfully linked the glowing material ring around M87* to the base of the jet, identifying a probable origin point.
Saurabh of the Max Planck Institute for Radio Astronomy (MPIfR), who led the team, stated that this study is an initial step in connecting theoretical concepts of jet launching with direct observational evidence.
He emphasized that pinpointing the jet's origin and its connection to the black hole's shadow contributes a crucial element to understanding the central engine's operation.
Further Observations and Future Understanding
Saurabh's modeling of the supermassive black hole indicated that radio emissions, which were absent in EHT observations from 2017-2019 but present in 2021, likely originated from a compact region situated less than a tenth of a light-year from the black hole. This region corresponds to the base of the M87* jet and aligns with the southern arm of another observed radio jet.
Hendrik Müller of the National Radio Astronomy Observatory (NRAO), a team member, noted the progression toward integrating these observations across multiple frequencies to complete the understanding of the jet launching region.
The team plans to conduct additional observations of M87* to further investigate the jet's structure and fine details. This continued research is anticipated to provide deeper insights into how supermassive black holes influence their surrounding environments.