Double Quasars

Hubble Resolves Two Pairs of Quasars

These two Hubble Space Telescope images reveal two pairs of quasars that existed 10 billion years ago and reside at the hearts of merging galaxies. Each of the four quasars resides in a host galaxy. These galaxies, however, cannot be seen because they are too faint, even for Hubble. The quasars within each pair are only about 10,000 light-years apart—the closest ever seen at this cosmic epoch.

Quasars are brilliant beacons of intense light from the centers of distant galaxies that can outshine their entire galaxies. They are powered by supermassive black holes voraciously feeding on infalling matter, unleashing a torrent of radiation.

The quasar pair in the left-hand image is catalogued as J0749+2255; the pair on the right, as J0841+4825. The two pairs of host galaxies inhabited by each double quasar will eventually merge. The quasars will then tightly orbit each other until they eventually spiral together and coalesce, resulting in an even more massive, but solitary black hole.

The image for J0749+2255 was taken Jan. 5, 2020. The J0841+4825 snapshot was taken Nov. 30, 2019. Both images were taken in visible light with Wide Field Camera 3.

About the colours

These images are a composite of separate exposures acquired by the WFC3/UVIS instrument on the Hubble Space Telescope. Several filters were used to sample narrow wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Cyan: F475W Orange: F814W

About the data

he Hubble image was created from HST data from proposals: 15900 (H. Hwang)