TY - JOUR
T1 - Shedding New Light on Weak Emission-line Quasars in the C iv-H β Parameter Space
AU - Ha, Trung
AU - Dix, Cooper
AU - Matthews, Brandon M.
AU - Shemmer, Ohad
AU - Brotherton, Michael S.
AU - Myers, Adam D.
AU - Richards, Gordon T.
AU - Maithil, Jaya
AU - Anderson, Scott F.
AU - Brandt, W. N.
AU - Diamond-Stanic, Aleksandar M.
AU - Fan, Xiaohui
AU - Gallagher, S. C.
AU - Green, Richard
AU - Lira, Paulina
AU - Luo, Bin
AU - Netzer, Hagai
AU - Plotkin, Richard M.
AU - Runnoe, Jessie C.
AU - Schneider, Donald P.
AU - Strauss, Michael A.
AU - Trakhtenbrot, Benny
AU - Wu, Jianfeng
N1 - Publisher Copyright:
© 2023. The Author(s). Published by the American Astronomical Society.
PY - 2023/6/1
Y1 - 2023/6/1
N2 - Weak emission-line quasars (WLQs) are a subset of type 1 quasars that exhibit extremely weak Lyα + N v λ1240 and/or C iv λ1549 emission lines. We investigate the relationship between emission-line properties and accretion rate for a sample of 230 "ordinary"type 1 quasars and 18 WLQs at z < 0.5 and 1.5 < z < 3.5 that have rest-frame ultraviolet and optical spectral measurements. We apply a correction to the Hβ-based black hole mass (M BH) estimates of these quasars using the strength of the optical Fe ii emission. We confirm previous findings that WLQs' M BH values are overestimated by up to an order of magnitude using the traditional broad-emission-line region size-luminosity relation. With this M BH correction, we find a significant correlation between Hβ-based Eddington luminosity ratios and a combination of the rest-frame C iv equivalent width and C iv blueshift with respect to the systemic redshift. This correlation holds for both ordinary quasars and WLQs, which suggests that the two-dimensional C iv parameter space can serve as an indicator of accretion rate in all type 1 quasars across a wide range of spectral properties.
AB - Weak emission-line quasars (WLQs) are a subset of type 1 quasars that exhibit extremely weak Lyα + N v λ1240 and/or C iv λ1549 emission lines. We investigate the relationship between emission-line properties and accretion rate for a sample of 230 "ordinary"type 1 quasars and 18 WLQs at z < 0.5 and 1.5 < z < 3.5 that have rest-frame ultraviolet and optical spectral measurements. We apply a correction to the Hβ-based black hole mass (M BH) estimates of these quasars using the strength of the optical Fe ii emission. We confirm previous findings that WLQs' M BH values are overestimated by up to an order of magnitude using the traditional broad-emission-line region size-luminosity relation. With this M BH correction, we find a significant correlation between Hβ-based Eddington luminosity ratios and a combination of the rest-frame C iv equivalent width and C iv blueshift with respect to the systemic redshift. This correlation holds for both ordinary quasars and WLQs, which suggests that the two-dimensional C iv parameter space can serve as an indicator of accretion rate in all type 1 quasars across a wide range of spectral properties.
UR - http://www.scopus.com/inward/record.url?scp=85163802915&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/acd04d
DO - 10.3847/1538-4357/acd04d
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AN - SCOPUS:85163802915
SN - 0004-637X
VL - 950
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 97
ER -