Tag Archives: Centaurus A

Behold: the warped magnetic fields of Centaurus A – not one galaxy, but two. To wit:

When galaxies collide — what happens to their magnetic fields? To help find out, NASA pointed SOFIA, its flying 747, at galactic neighbour Centaurus A to observe the emission of polarized dust — which traces magnetic fields. Cen A’s unusual shape results from the clash of two galaxies with jets powered by gas accreting onto a central supermassive black hole. In the resulting featured image, SOFIA-derived magnetic streamlines are superposed on ESO (visible: white), APEX (submillimeter: orange), Chandra (X-rays: blue), and Spitzer (infrared: red) images. The magnetic fields were found to be parallel to the dust lanes on the outskirts of the galaxy but distorted near the centre. Gravitational forces near the black hole accelerate ions and enhance the magnetic field. In sum, the collision not only combined the galaxies’ masses — but amplified their magnetic fields. These results provide new insights into how magnetic fields evolved in the early universe when mergers were more common.

(Image: Optical: European Southern Observatory (ESO) Wide Field Imager; Submillimeter: Max Planck Institute for Radio Astronomy/ESO/Atacama Pathfinder Experiment (APEX)/A.Weiss et al; X-ray and Infrared: NASA/Chandra/R. Kraft; JPL-Caltech/J. Keene; Text: Joan Schmelz (USRA))


Behold: vast jets emanating from the Centaurus A galaxy, aka Caldwell 77, each one more than a million light years long. To wit:

These jets of streaming plasma, expelled by a giant black hole in the centre of this spiral galaxy, light up this composite image of Cen A. Exactly how the central black hole expels infalling matter remains unknown. After clearing the galaxy, however, the jets inflate large radio bubbles that likely glow for millions of years. If energised by a passing gas cloud, the radio bubbles can even light up again after billions of years. X-ray light is depicted in the featured composite image in blue, while microwave light is coloured orange. The base of the jet in radio light shows details of the innermost light year of the central jet.

(Image: ESO/WFI (visible); MPIfR/ESO/APEX/A. Weiss et al. (microwave); NASA/CXC/CfA/R. Kraft et al. (X-ray)