Galaxies

The center of the Milky Way seen in detail by the MWA radio telescope

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Three articles published in the journal “Publications of the Astronomical Society of Australia (PASA)” report some results of the GaLactic and Extragalactic All-sky MWA (GLEAM) survey. A team of researchers created some images obtained thanks to the Murchison Widefield Array (MWA) radio telescope showing the center of the Milky Way. Thanks to the low-frequency radio emissions detected, it was possible to generate an image that reproduces both the larger structures and the details. This means that it was possible to obtain an overall image and images of individual objects such as 27 supernova remnants.

The image of an ancient galaxy multiplied by a gravitational lens

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An article published in the journal “Science” reports a study of a galaxy nicknamed Sunburst Arc observed through a gravitational lensing effect that leads to multiplying its image obtaining at least 12 distorted copies in four large arcs. The Hubble Space Telescope detected the light from that galaxy, about 11 billion light years from Earth, thanks to that effect, which also made it between 10 and 30 times brighter. Studying such an ancient galaxy allows to gather information on the early universe and on what’s called the epoch of reionization.

A study of 20 radio galaxies offers new information on the activity of the supermassive black holes at their center

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An article published in the journal “Astronomy & Astrophysics” reports a study on the properties of the ionized gas that surrounds supermassive black holes in 20 galaxies selected as a sample. A team of researchers led by Barbara Balmaverde of the Italian National Institute of Astrophysics, Turin, used the MUSE spectrograph mounted on ESO’s VLT in Chile to carry out the MURALES (MUse RAdio Loud Emission line Snapshot) survey, which includes the 20 galaxies studied. These are powerful sources of radio emissions thanks to their active galactic nuclei. The mapping of the ionized gas and its interaction with the relativistic jet produced by central black holes helps to understand the mechanisms of growth and interaction with their host galaxies.

A map of the four galaxy clusters merging in Abell 1758

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An article published in “The Astrophysical Journal” reports a study on Abell 1758, a quadruple galaxy cluster formed by two pairs that are in different merger phases. A team of researchers used NASA’s Chandra X-ray Observatory and other telescopes to map this gigantic group of galaxies. Each pair is made up of hundreds of galaxies embedded in enormous amounts of hot gas and invisible dark matter. These accurate observations will help to better assess how long it will take for mergers to occur in the two pairs of clusters, which in the future will in turn merge to form a super cluster that will be one of the most massive objects in the universe.

Artist's concept of a quasar (Image ESO/M. Kornmesser)

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An article published in the journal “Astronomy & Astrophysics” reports an analysis of 48 quasars in the early universe to detect the outflows of materials they produce. A team of researchers led by Manuela Bischetti of the Italian National Institute of Astrophysics in Rome used the ALMA radio telescope to confirm for the first time the common existence of those outflows, which act as powerful winds inside those early galaxies heavily interfering in the formation of new stars.