Red quasars are candidate young objects in an early transition stage of
massive galaxy evolution. Our team recently discovered a population of
extremely red quasars (ERQs) in the Baryon Oscillation Spectroscopic Survey
(BOSS) that has a suite of peculiar emission-line properties including large
rest equivalent widths (REWs), unusual "wingless" line profiles, large NV/Lya,
NV/CIV, SiIV/CIV and other flux ratios, and very broad and blueshifted OIII
5007. Here we present a new catalog of CIV and NV emission-line data for
216,188 BOSS quasars to characterize the ERQ line properties further. We show
that they depend sharply on UV-to-mid-IR color, secondarily on REW(CIV), and
not at all on luminosity or the Baldwin Effect. We identify a "core" sample of
97 ERQs with nearly uniform peculiar properties selected via i-W3 > 4.6 (AB)
and REW(CIV) > 100 A at redshifts 2.0-3.4. A broader search finds 235 more red
quasars with similar unusual characteristics. The core ERQs have median
luminosity log L (ergs/s) ~ 47.1, sky density 0.010 deg^-2, surprisingly
flat/blue UV spectra given their red UV-to-mid-IR colors, and common outflow
signatures including BALs or BAL-like features and large CIV emission-line
blueshifts. Their SEDs and line properties are inconsistent with normal quasars
behind a dust reddening screen. We argue that the core ERQs are a unique
obscured quasar population with extreme physical conditions related to powerful
outflows across the line-forming regions. Patchy obscuration by small dusty
clouds could produce the observed UV extinctions without substantial UV
reddening.
cite arxiv:1609.07241Comment: 36 pages, 18 figures, accepted for publication in the MNRAS. The emission-line catalog described in this paper, along with supplemental tables and figures, can be downloaded from the University of California Digital Libraries at the URL https://dx.doi.org/10.6086/D1H59V (digital object identifier DOI:10.6086/D1H59V)
%0 Generic
%1 hamann2016extremely
%A Hamann, Fred
%A Zakamska, Nadia L.
%A Ross, Nicholas
%A Paris, Isabelle
%A Alexandroff, Rachael M.
%A Villforth, Carolin
%A Richards, Gordon T.
%A Herbst, Hanna
%A Brandt, W. Niel
%A Cook, Ben
%A Denney, Kelly D.
%A Greene, Jenny E.
%A Schneider, Donald P.
%A Strauss, Michael A.
%D 2016
%K extinction quasars red uv
%T Extremely Red Quasars in BOSS
%U http://arxiv.org/abs/1609.07241
%X Red quasars are candidate young objects in an early transition stage of
massive galaxy evolution. Our team recently discovered a population of
extremely red quasars (ERQs) in the Baryon Oscillation Spectroscopic Survey
(BOSS) that has a suite of peculiar emission-line properties including large
rest equivalent widths (REWs), unusual "wingless" line profiles, large NV/Lya,
NV/CIV, SiIV/CIV and other flux ratios, and very broad and blueshifted OIII
5007. Here we present a new catalog of CIV and NV emission-line data for
216,188 BOSS quasars to characterize the ERQ line properties further. We show
that they depend sharply on UV-to-mid-IR color, secondarily on REW(CIV), and
not at all on luminosity or the Baldwin Effect. We identify a "core" sample of
97 ERQs with nearly uniform peculiar properties selected via i-W3 > 4.6 (AB)
and REW(CIV) > 100 A at redshifts 2.0-3.4. A broader search finds 235 more red
quasars with similar unusual characteristics. The core ERQs have median
luminosity log L (ergs/s) ~ 47.1, sky density 0.010 deg^-2, surprisingly
flat/blue UV spectra given their red UV-to-mid-IR colors, and common outflow
signatures including BALs or BAL-like features and large CIV emission-line
blueshifts. Their SEDs and line properties are inconsistent with normal quasars
behind a dust reddening screen. We argue that the core ERQs are a unique
obscured quasar population with extreme physical conditions related to powerful
outflows across the line-forming regions. Patchy obscuration by small dusty
clouds could produce the observed UV extinctions without substantial UV
reddening.
@misc{hamann2016extremely,
abstract = {Red quasars are candidate young objects in an early transition stage of
massive galaxy evolution. Our team recently discovered a population of
extremely red quasars (ERQs) in the Baryon Oscillation Spectroscopic Survey
(BOSS) that has a suite of peculiar emission-line properties including large
rest equivalent widths (REWs), unusual "wingless" line profiles, large NV/Lya,
NV/CIV, SiIV/CIV and other flux ratios, and very broad and blueshifted [OIII]
5007. Here we present a new catalog of CIV and NV emission-line data for
216,188 BOSS quasars to characterize the ERQ line properties further. We show
that they depend sharply on UV-to-mid-IR color, secondarily on REW(CIV), and
not at all on luminosity or the Baldwin Effect. We identify a "core" sample of
97 ERQs with nearly uniform peculiar properties selected via i-W3 > 4.6 (AB)
and REW(CIV) > 100 A at redshifts 2.0-3.4. A broader search finds 235 more red
quasars with similar unusual characteristics. The core ERQs have median
luminosity log L (ergs/s) ~ 47.1, sky density 0.010 deg^-2, surprisingly
flat/blue UV spectra given their red UV-to-mid-IR colors, and common outflow
signatures including BALs or BAL-like features and large CIV emission-line
blueshifts. Their SEDs and line properties are inconsistent with normal quasars
behind a dust reddening screen. We argue that the core ERQs are a unique
obscured quasar population with extreme physical conditions related to powerful
outflows across the line-forming regions. Patchy obscuration by small dusty
clouds could produce the observed UV extinctions without substantial UV
reddening.},
added-at = {2016-09-26T10:17:53.000+0200},
author = {Hamann, Fred and Zakamska, Nadia L. and Ross, Nicholas and Paris, Isabelle and Alexandroff, Rachael M. and Villforth, Carolin and Richards, Gordon T. and Herbst, Hanna and Brandt, W. Niel and Cook, Ben and Denney, Kelly D. and Greene, Jenny E. and Schneider, Donald P. and Strauss, Michael A.},
biburl = {https://www.bibsonomy.org/bibtex/2071ff7d2edc14a063bef7b985727fd0e/miki},
description = {[1609.07241] Extremely Red Quasars in BOSS},
interhash = {b6f355376b535fede45650a4e2301830},
intrahash = {071ff7d2edc14a063bef7b985727fd0e},
keywords = {extinction quasars red uv},
note = {cite arxiv:1609.07241Comment: 36 pages, 18 figures, accepted for publication in the MNRAS. The emission-line catalog described in this paper, along with supplemental tables and figures, can be downloaded from the University of California Digital Libraries at the URL https://dx.doi.org/10.6086/D1H59V (digital object identifier DOI:10.6086/D1H59V)},
timestamp = {2016-09-26T10:17:53.000+0200},
title = {Extremely Red Quasars in BOSS},
url = {http://arxiv.org/abs/1609.07241},
year = 2016
}