In a momentous discovery, astronomers have unlocked the secrets of 53 new quasars fueled by supermassive black holes, which unleash jets of matter at relativistic speeds, stretching up to 7.2 million light-years, making them 20 to 50 times wider than the Milky Way. These colossal Radio Quasars, as they are known, have been recently unveiled by Indian astronomers as part of a trove of 369 such quasars. The data was collected by the Giant Meterwave Radio Telescope (GMRT), an array of 30 parabolic dishes nestled near Pune, India, as part of the TIFR GMRT Sky Survey (TGSS). It has been observed that the TGSS ensured a comprehensive coverage of approximately 90% of the celestial sphere above Earth.
To power the immense energy of a quasar, a supermassive black hole must be surrounded by a dense supply of gas and dust, which it devours like a cosmic beast. This matter spirals around the black hole in flattened cloud structures called accretion disks. The powerful tidal forces generated within this spiraling matter ultimately result in brightly emitted radiation across the electromagnetic spectrum.
Sabyasachi Pal, an astronomer at Midnapore City College and team leader, said, "These enormous radio jets from these quasars are invaluable for understanding both the late stages of their evolution and the intergalactic medium in which they expand, the rennous gas that confines their radio lobes millions of light-years from the central black hole."
The research team delved into the environments of these Giant Radio Quasars and found that approximately 14% of them are colossal objects located within galaxy groupings and clusters near intergalactic medium filaments of gas, dust, and dark matter. The environment plays a pivotal role in shaping how these radio jets evolve. In denser regions, the jets might be agitated or slowed by the surrounding gas; conversely, in less dense regions like the intergalactic medium, they can grow freely.
Scientists demonstrated that while most quasars feature twin jets, these jets are uneven in terms of length or brightness, a disparity called radio jet asymmetry. This asymmetry serves as a telltale sign that these jets are grappling with an uneven cosmic environment.
Moreover, the research findings suggest that giant quasars at greater cosmological distances seem to be more powerful than those closer to the Milky Way. This could be due to the quasars moving away from us, with the early cosmos being more tumultuous and filled with denser gas that distorted the path of these jets.
