Gargantuan Black Hole Jets Are Biggest Seen Yet
Astronomers have spotted the biggest pair of black hole jets ever seen, spanning 23 million light-years in total length. That’s equivalent to lining up 140 Milky Way galaxies back to back.
Second-Generation Starlink Satellites Leak 30 Times More Radio Interference, Threatening Astronomical Observations
Observations with the LOFAR (Low Frequency Array) radio telescope last year showed that first generation Starlink satellites emit unintended radio waves that can hinder astronomical observations. New observations with the LOFAR radio telescope, the biggest radio telescope on Earth observing at low frequencies, have shown that the second generation ’V2-mini’ Starlink satellites emit up to 32 times brighter unintended radio waves than satellites from the previous generation, potentially blinding radio telescopes and crippling vital research of the Universe.
European grant allows ASTRON astronomer Joe Callingham to study the space weather of other worlds
Dr Joe Callingham has received an ERC Starting Grant worth 1.5 million euros.
Top marks for ASTRON
ASTRON has been assessed by the Strategy Evaluation Protocol (SEP) committee as a research institute that produces excellent research both on astronomy and in technology and innovations.
Colloquium: MHONGOOSE: searching for low-column density gas with MeerKAT
© Erwin de Blok (ASTRON/UCT/RuG)
With these deepest resolved HI observations of nearby galaxies to date, we want to detect cold gas accretion. This is the process by which galaxies replenish their gas reservoirs from the cosmic web, enabling them to continue forming stars throughout cosmic time.
The survey is now 90% complete, and is routinely reaching its target HI column density sensitivity of a few times 10^17 atoms cm-2, two orders of magnitude lower than the typical values found in galaxy HI disks.
Our full-depth data show that the outskirts of our galaxies are complex and dynamic environments, with many potential accretion and interaction features that only now become visible due to the excellent column density sensitivity. We detect a significant number of uncatalogued low-mass dwarf galaxies, which enable us to do the kind of science in environments at tens of Mpc distance that was so far only possible in the Local Group.
A first comparison of the MHONGOOSE galaxies with simulated HI data extracted from recent cosmological simulations shows a marked difference in kinematics and morphology, indicating that cold gas accretion is not happening in the form simulations predict.
This discrepancy between observations and simulations is a challenge but also points the way to a better understanding of the role of gas accretion in galaxy evolution and identifies opportunities for new HI surveys with the upcoming SKA-MID telescope.
Open Dag: 6 oktober/Open Day: October 6th
Sun 06 Oct 2024
English follows Dutch Bezoek ons tijdens onze open dag op 6 oktober Hoe klinkt een dode ster? Hoe maak je onzichtbaar licht zichtbaar? Hoe werkt een zwart gat? Waarom kun je met een radiotelescoop terug in de tijd kijken? Achter al deze en nog veel meer interessante dingen kom je tijdens onze open dag […]