Hubble Space Telescope Uncovers Ancient Quasar Duo in Colliding Galaxies

The NASA/ESA Hubble Space Telescope has revealed a pair of quasars, known as J0749+2255, dating back to when the universe was just 3 billion years old. These quasars are nestled within colliding galaxies and separated by a distance smaller than a single galaxy. Fueled by voracious supermassive black holes, quasars emit powerful energy streams as they devour surrounding matter. Eventually, these black holes will merge.

This groundbreaking discovery hinged on the combined efforts of the Hubble Space Telescope, W.M. Keck Observatories in Hawaii, International Gemini Observatory in Hawaii, NSF's Karl G. Jansky Very Large Array in New Mexico, and NASA's Chandra X-ray Observatory. ESA's Gaia space observatory also played a crucial role in identifying the double quasar.

Hubble's findings confirm the presence of two authentic supermassive black holes, rather than a gravitational lens effect. Tidal features caused by merging galaxies create two tails of stars, visible in Hubble images. Gaia's extensive database allowed researchers to pinpoint potential double-quasar candidates, revealing a subtle "jiggle" that indicates alternating brightness between the quasar pair.

As Hubble observes the distant past, this double quasar no longer exists. Over the last 10 billion years, the colliding galaxies have likely evolved into a giant elliptical galaxy, with the quasars merging into a colossal, supermassive black hole at its core. These findings were published in the journal Nature on 5 April 2023.

Credit:

NASA, ESA, Yu-Ching Chen (UIUC), Hsiang-Chih Hwang (IAS), Nadia Zakamska (JHU), Yue Shen (UIUC)