| 29th of June 2021 |
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| The Northern Clump of the Abell 3391/3395 cluster |
| by Veronica et al. |
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The concept that gas filaments connect clusters of galaxies across
the universe has been difficult to prove until recently, because the
matter in these filaments is so sparse it eluded the gaze of even the
most sensitive instruments.
An international team has made observations of the
the Abell 3391/95 galaxy cluster system,
combining data from the ASKAP
radio telescope, the SRG/eROSITA, XMM-Newton and Chandra X-ray satellites, and
DECam optical data.
They detected a large galaxy at
the centre of the Northern Clump in the cluster system with a black hole at its centre.
The swept-back radio lobes of this "wide angle tail" galaxy
indicate that it is moving towards Abell 3391.
The leader of the ASKAP EMU project, Andrew Hopkins of Australian Astronomical Optics, Macquarie University, says, "The excellent sensitivity of the ASKAP telescope to faint extended radio emission is the key that allows the detection of these jets of radio emission from the supermassive black hole. The shape and orientation of these jets in turn provide important clues to the motion of the galaxy hosting the black hole." The observations agree with the result of the Magneticum computer simulations developed by researchers of the eROSITA consortium. They can therefore also be taken as an argument that the current assumptions about the origin and evolution of the Universe are correct. This includes the view that a large part of matter is invisible to our measuring instruments. About 85 percent of our universe is believed to consist of this ‘dark matter’. In the standard model of cosmology, it plays an important role as a condensation nucleus that caused gaseous matter to condense into galaxies after the Big Bang. The image above shows the Northern Clump as it appears in X-rays (blue, XMM-Newton satellite), in visual light (green, DECam), and at radio wavelengths (red, ASKAP/EMU). (Image credit: Veronica et al., Astronomy & Astrophysics) |