Indian astronomers have discovered the longest intergalactic beam, stretching for more than a million light years, that might help to reveal how such jets of matter bind themselves together. The discovery emerged from a large elliptical galaxy called CGCG 049-033, which is about 600 million light years away.
GMRT maps at 1.28 GHz, showing (left): Intensity contours: -0.18,0.18, 0.36, 0.72, 1.44, 3 and 6 mJy/beam; rms noise: ~ 60 Jy/beam, and the pseudo-colour image (centre), both with a 11 beam. The details of the inner ~ 2 region (inset) are visible in the 3 resolution 1.28 GHz GMRT image (shown in red) overlaid on the optical r-band SDSS image (shown in blue).
An intergalactic particle beam stretching for more than a million light years is the longest ever seen. According to the team that discovered this record breaker, it could help reveal how such jets of matter bind themselves together. Jets are seen all over the cosmos squirting out of many different types of object, including stars that are just beginning to form. The most powerful ones come from the cores of active galaxies, where gas falling towards a giant black hole generates a mixture of heat, high-energy particles and magnetic fields. In some cases, these elements combine to spit out narrow columns of hot gas laced with high-energy particles, which drill though the galaxy and on out into space. The latest discovery emerges from a large elliptical galaxy called CGCG 049-033, which is about 600 million light years away. A team led by Joydeep Bagchi of Pune University in Maharashtra, India, noticed emission from this galaxy during a broad search for radio sources, and then took a closer look using the Giant Metrewave Radio Telescope near Pune and the 100-metre Effelsberg radio dish in Germany. The jet they saw is nearly 1.5 million light years long, twice the length of the previous record holder. If this jet sprang instead from the centre of the Milky Way, it would loom over us like a skyscraper and would stretch halfway to the Andromeda galaxy.
Title: A Giant Radio Jet Ejected by an Ultramassive Black Hole in a Singlelobed Radio Galaxy Authors: Joydeep Bagchi, GopalKrishna, Marita Krause, and Santosh Joshi1
We report the discovery of a very unusual, highly asymmetric radio galaxy whose radio jet, the largest yet detected, emits strongly polarized synchrotron radiation and can be traced all the way from the galactic nucleus to the hot spot located ~440 kpc away. This jet emanates from an extremely massive black hole (>10^9 solar masses ) and forms a strikingly compact radio lobe. No radio lobe is detected on the side of the counterjet, even though it is similar to the main jet in brightness up to a scale of tens of kiloparsecs. Thus, contrary to the nearly universal trend, the brightness asymmetry in this radio galaxy increases with distance from the nucleus. With several unusual properties, including a predominantly toroidal magnetic field, this FanaroffRiley type II megajet is an exceptionally useful laboratory for testing the role of magnetic field in jet stabilization and radio lobe formation.