The Accretion History of AGN: A Newly Defined Population of Cold Quasars. (arXiv:1908.04795v1 [astro-ph.GA])

The Accretion History of AGN: A Newly Defined Population of Cold Quasars. (arXiv:1908.04795v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Kirkpatrick_A/0/1/0/all/0/1">Allison Kirkpatrick</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Urry_C/0/1/0/all/0/1">C. Megan Urry</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brewster_J/0/1/0/all/0/1">Jason Brewster</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cooke_K/0/1/0/all/0/1">Kevin C. Cooke</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Estrada_M/0/1/0/all/0/1">Michael Estrada</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Glikman_E/0/1/0/all/0/1">Eilat Glikman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hamblin_K/0/1/0/all/0/1">Kurt Hamblin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ananna_T/0/1/0/all/0/1">Tonima Tasnim Ananna</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Carlile_C/0/1/0/all/0/1">Casey Carlile</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Coleman_B/0/1/0/all/0/1">Brandon Coleman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Johnson_J/0/1/0/all/0/1">Jordan Johnson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kartaltepe_J/0/1/0/all/0/1">Jeyhan S. Kartaltepe</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+LaMassa_S/0/1/0/all/0/1">Stephanie M. LaMassa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marchesi_S/0/1/0/all/0/1">Stefano Marchesi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Powell_M/0/1/0/all/0/1">Meredith Powell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sanders_D/0/1/0/all/0/1">Dave Sanders</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Treister_E/0/1/0/all/0/1">Ezequiel Treister</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Turner_T/0/1/0/all/0/1">Tracey Jane Turner</a>

Quasars are the most luminous of active galactic nuclei (AGN), and are
perhaps responsible for quenching star formation in their hosts. The Stripe 82X
catalog covers 31.3 deg$^2$ of the Stripe 82 field, of which the 15.6 deg$^2$
covered with XMM-Newton is also covered by Herschel/SPIRE. We have 2500 X-ray
detected sources with multi-wavelength counterparts, and 30% of these are
unobscured quasars, with $L_X > 10^{44},$erg/s and $M_B < -23$. We define a new population of quasars which are unobscured, have X-ray luminosities in excess of $10^{44},$erg/s, have broad emission lines, and yet are also bright in the far-infrared, with a 250 $mu$m flux density of $S_{rm 250}>30$ mJy. We
refer to these Herschel-detected, unobscured quasars as “Cold Quasars”. A mere
4% (23) of the X-ray- and optically-selected unobscured quasars in Stripe 82X
are detected at 250 $mu$m. These Cold Quasars lie at $zsim1-3$, have $M_{rm
dust} sim10^8-10^9 M_odot$, have $L_{rm IR}>10^{12} L_odot$, and have star
formation rates of $200-2000 M_odot$/yr. Cold Quasars are bluer in the mid-IR
than the full quasar population, and 75% of our Cold Quasars have WISE W3 $<$ 11.5 [Vega], while only 19% of the full quasar sample meets this criteria. Crucially, Cold Quasars have $4-7times$ as much star formation as the unobscured quasar population at similar redshifts. This phase is likely short-lived, as the central engine and immense star formation consume the gas reservoir. Cold Quasars are type-1 blue quasars that reside in starburst galaxies.

Quasars are the most luminous of active galactic nuclei (AGN), and are
perhaps responsible for quenching star formation in their hosts. The Stripe 82X
catalog covers 31.3 deg$^2$ of the Stripe 82 field, of which the 15.6 deg$^2$
covered with XMM-Newton is also covered by Herschel/SPIRE. We have 2500 X-ray
detected sources with multi-wavelength counterparts, and 30% of these are
unobscured quasars, with $L_X > 10^{44},$erg/s and $M_B < -23$. We define a
new population of quasars which are unobscured, have X-ray luminosities in
excess of $10^{44},$erg/s, have broad emission lines, and yet are also bright
in the far-infrared, with a 250 $mu$m flux density of $S_{rm 250}>30$ mJy. We
refer to these Herschel-detected, unobscured quasars as “Cold Quasars”. A mere
4% (23) of the X-ray- and optically-selected unobscured quasars in Stripe 82X
are detected at 250 $mu$m. These Cold Quasars lie at $zsim1-3$, have $M_{rm
dust} sim10^8-10^9 M_odot$, have $L_{rm IR}>10^{12} L_odot$, and have star
formation rates of $200-2000 M_odot$/yr. Cold Quasars are bluer in the mid-IR
than the full quasar population, and 75% of our Cold Quasars have WISE W3 $<$
11.5 [Vega], while only 19% of the full quasar sample meets this criteria.
Crucially, Cold Quasars have $4-7times$ as much star formation as the
unobscured quasar population at similar redshifts. This phase is likely
short-lived, as the central engine and immense star formation consume the gas
reservoir. Cold Quasars are type-1 blue quasars that reside in starburst
galaxies.

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