Archiv: intergalactic / circumgalactic medium

15.11.2019 - 17:47 [ ]

The large-scale ionization cones in the Galaxy


Our time-dependent Seyfert flare models adequately explain the observations and indicate the Seyfert flare event took place T_o = 3.5 +/- 1 Myr ago.

15.11.2019 - 17:32 [ ]

Something in The Centre of Our Galaxy Colossally Erupted 3.5 Million Years Ago


In 2013, astrophysicist Joss Bland-Hawthorn of the University of Sydney and the ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) and colleagues estimated that the event occurred between 1 and 3 million years ago.

Now, more observations taken using the Hubble Space Telescope – and therefore a bigger dataset – have provided even more compelling evidence for the event. And the team has been able to narrow down a timeframe for both when the event occurred, as well as its duration.

15.11.2019 - 17:29 [ ]

Fossil imprint of a powerful flare at the Galactic Centre along the Magellanic Stream


Thus it is likely that the Stream emission arose from a `Seyfert flare‘ that was active 1-3 Myr ago, consistent with the cosmic ray lifetime in the Fermi bubbles. Sgr A* activity today is greatly suppressed (70-80 dB) relative to the Seyfert outburst…

15.11.2019 - 17:16 [ Forbes ]

The Milky Way’s Supermassive Black Hole Erupted Two Million Years Ago


The key the astronomers found was actually discovered 20 years old, in the form of a strange glow that astronomers had noticed in the Magellanic Stream. The Magellanic Stream is composed of large clouds of gas – mostly hydrogen – that stretch for light years in the wake of the Milky Way’s two companion Galaxies, the Large and Small Magellanic Clouds. The Stream is about 2 billion years old.

„We didn’t understand the cause. Then suddenly we realised it must be the mark, the fossil record, of a huge outburst of energy from the centre of our Galaxy,“ remarked researcher Joss Bland-Hawthorn in a press release.