[seminar] Astro Journal Club on 25 March

[Oskari Miettinen]

Dear all,

The Astro Journal Club will be held on Wednesday at 10:15 in the seminar
room F-201 of the Physics Department. This time we will discuss about
submillimetre observations of AGNs and their environments.

Presenter: Ivan Delvecchio
Paper title: Submillimetre observations of WISE/radio-selected AGN and
their environments
Authors: Jones, S. F., Blain, A. W., Lonsdale, C., et al.

Abstract:
We present JCMT SCUBA-2 850 micron submillimetre (submm) observations of
30 mid-infrared (mid-IR) luminous active galactic nuclei (AGNs), detected
jointly by the Wide-field Infrared Survey Explorer (WISE) all-sky IR
survey and the NVSS/FIRST radio survey. These rare sources are selected by
their extremely red mid-IR spectral energy distributions (SEDs) and
compact radio counterparts. Further investigations show that they are
highly obscured, have abundant warm AGN-heated dust and are thought to be
experiencing intense AGN feedback. These galaxies appear to be consistent
with a later AGN-dominated phase of merging galaxies, while hot,
dust-obscured galaxies are an earlier starburst-dominated phase. When
comparing the number of submm galaxies detected serendipitously in the
surrounding 1.5 arcmin to those in blank-field submm surveys, there is a
very significant overdensity, of order 5, but no sign of radial clustering
centred at our primary objects. The WISE/radio-selected AGN thus reside in
10-Mpc-scale overdense environments that could be forming in pre-viralized
clusters of galaxies. WISE/radio-selected AGNs appear to be the strongest
signposts of high-density regions of active, luminous and dusty galaxies.
SCUBA-2 850 micron plates, hence the WISE/radio-selected AGNs have either
less cold and/or more warm dust emission than normally assumed for typical
AGN. Most of the targets are not detected, only four targets are detected
at SCUBA-2 850 micron, and have total IR luminosities >=1e13 Lsun, if
their redshifts are consistent with the subset of the 10 SCUBA-2
undetected targets with known redshifts, z=0.44-2.86.

Link to the paper: http://adsabs.harvard.edu/abs/2015MNRAS.448.3325J

See you all on Wednesday!

Best wishes,
Oskari