| 14th of June 2015 |
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| A star-forming disc in the host galaxy of a hyper-luminous supermassive black hole |
| by Amy Kimball (CASS) |
| The 1900-GHz carbon [CII] line is an excellent
tracer of gas dynamics in distant galaxies because of its very high luminosity.
Observing this line is one of the best ways to study galaxies that host an
active supermassive black hole (a "quasar") at their center. The particular
[CII] line presented here is from the galaxy that is home to J1554+1937, one
of the most luminous known quasars in the Universe, observed at z = 4.6 (when
the Universe was 10% of its current age). The double-peaked profile of the line
and the gradient across its velocity map are signatures of rotating gas disc
about 2 kpc (6500 light years) in size. The unprecedented broad width of the
line indicates that the disc is rotating with high velocity (~480 km/s), and
that the total mass within the central 2 kpc of the galaxy is 100 billion times
the mass of the Sun. These observations were made in just 5 minutes with the
Atacama Large Millimeter/submillimeter Array (ALMA)! Reference:Amy Kimball, Mark Lacy, Carol J Lonsdale and J-P Macquart 2015, MNRAS, in press |