A recent study of black hole jets from NASA’s Chandra X-ray Observatory has identified bright formations or “knots” in these jets, with each showing unexpected variations in speed. This analysis, led by David Bogensberger, an astrophysicist at the University of Michigan, examined decades-old Chandra data on the supermassive black hole at the heart of the Centaurus A galaxy, located around 12 million light-years from Earth.
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Observations of Bright ‘Knots’ Moving at Variable Speeds
The findings, which was published in The Astrophysical Journal, reveal that the knots within these jets, which emit energy from the black hole, are moving faster in X-ray observations compared to radio wavelengths. For instance, some knots recorded speeds of 94 per cent of light in the X-ray band, which exceeded the 80 per cent speed of light observed in radio wavelengths. As per the study, these discoveries provide a unique view of black hole jet mechanics, as the X-ray wavelengths reveal elements unseen in other spectral bands.
Funding Challenges for NASA’s X-ray Programme
This research arises as NASA faces potential budget cuts that could affect the Chandra Observatory’s operations. With the U.S. presidential election and government budget discussions ongoing, Chandra’s funding future remains uncertain. Despite these challenges, the telescope—currently operating with 2024 funding levels—continues to provide crucial insights, highlighting its role in studying distant cosmic phenomena.
Centaurus A Galaxy and Black Hole Jet Mechanics
First detected in the 1800s, Centaurus A’s jets were later mapped with radio telescopes in the 20th century. Of these, one jet points towards Earth, while the fainter “counterjet” extends away from it. The movement and brightness changes in Centaurus A’s knots echo findings from previous observations of M87 galaxy jets, where brightness increased before dimming over time.
The study brings new insights into how magnetic fields and spin near black holes influence jet formation, offering astronomers fresh approaches for understanding such mechanisms across different galaxies. Future studies may further clarify whether the knot behaviour is due to internal jet dynamics or external forces such as interstellar materials.
