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All articles tagged with #vlbi

27-year video reshapes understanding of a distant blazar jet
astronomy17 days ago

27-year video reshapes understanding of a distant blazar jet

Scientists created a 27-year video reconstruction of the jet from blazar 3C 345, using very long baseline interferometry (VLBI) and a deep‑learning model called Kine to map brightness over time. The continuous video reveals that the bright jet features move at speeds nearly equal to the bulk plasma flow, challenging the idea that knots are faster shocks, and suggesting revisions to jet dynamics models. The method, which delivers two orders of magnitude better dynamic range and four times better resolution, will be applied to other blazars, with the study published in Nature (August 2026).

via Space|
#3c-345#astronomy#black-hole-jet
AI stitches 116 VLBI observations into a continuous, ultra-high-resolution view of the 3C 345 jet
science24 days ago

AI stitches 116 VLBI observations into a continuous, ultra-high-resolution view of the 3C 345 jet

AI-based neural-field reconstruction (kine) combines 116 MOJAVE VLBA epochs of blazar 3C 345 into a time-continuous, high‑resolution map, achieving ~113 microarcsecond effective resolution and ~500,000:1 dynamic range. It shows apparent jet speeds of 10–13 times light (bulk flow ~9–12c) due to geometry, not actual superluminal motion; interpolation between sparse epochs remains reliable for up to ~6 months. The knots may arise from overdense or emissive regions rather than strong shocks, and the method provides a new way to analyze long-running VLBI data that could be applied to other programs, without creating extra observations.

via Space Daily|
#3c-345#neural-fields#radio-interferometry
Optical Combs Tie Radio Telescopes Together With Higher Timing Precision
science8 months ago

Optical Combs Tie Radio Telescopes Together With Higher Timing Precision

Scientists demonstrated using optical frequency combs to transmit timing signals for very-long-baseline interferometry (VLBI), boosting synchronization among dispersed radio telescopes (e.g., Korea’s VLB Yonsei) beyond hydrogen-maser clocks. The proof-of-concept achieved up to 50 GHz with commercial photodiodes, and the fiber-based approach can carry multiple wavelengths to better correct atmospheric fluctuations, enabling more precise coordinated observations.

via Hackaday|
#atmospheric-fluctuations#optical-frequency-combs#radio-telescopes
Shadow to Jet: Astronomers Tie a 3,000‑Light‑Year Outflow to M87*’s Shadow
science8 months ago

Shadow to Jet: Astronomers Tie a 3,000‑Light‑Year Outflow to M87*’s Shadow

Using the Event Horizon Telescope’s VLBI observations of M87*, researchers traced the base of the galaxy’s 3,000‑light‑year jet to a region near the black hole’s shadow, linking jet launching to the accretion flow around the supermassive black hole (about 6.5 billion suns) and connecting theory to observation. The finding, based on 2021 data and building on the 2019 image of M87*, was published in Astronomy & Astrophysics.

via Yahoo|
#black-hole#event-horizon-telescope#jet