Shedding New Light on Weak Emission-Line Quasars in the C$_{rm IV}$-H$beta$ Parameter Space. (arXiv:2304.04783v1 [astro-ph.GA])

Shedding New Light on Weak Emission-Line Quasars in the C$_{rm IV}$-H$beta$ Parameter Space. (arXiv:2304.04783v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Ha_T/0/1/0/all/0/1">Trung Ha</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Dix_C/0/1/0/all/0/1">Cooper Dix</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Matthews_B/0/1/0/all/0/1">Brandon M. Matthews</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Shemmer_O/0/1/0/all/0/1">Ohad Shemmer</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Brotherton_M/0/1/0/all/0/1">Michael S. Brotherton</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Myers_A/0/1/0/all/0/1">Adam Myers</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Richards_G/0/1/0/all/0/1">Gordon T. Richards</a> (3), <a href="http://arxiv.org/find/astro-ph/1/au:+Maithil_J/0/1/0/all/0/1">Jaya Maithil</a> (4), <a href="http://arxiv.org/find/astro-ph/1/au:+Anderson_S/0/1/0/all/0/1">Scott F. Anderson</a> (5), <a href="http://arxiv.org/find/astro-ph/1/au:+Brandt_W/0/1/0/all/0/1">W. N. Brandt</a> (6), <a href="http://arxiv.org/find/astro-ph/1/au:+Diamond_Stanic_A/0/1/0/all/0/1">Aleksandar M. Diamond-Stanic</a> (7), <a href="http://arxiv.org/find/astro-ph/1/au:+Fan_X/0/1/0/all/0/1">Xiaohui Fan</a> (8), <a href="http://arxiv.org/find/astro-ph/1/au:+Gallagher_S/0/1/0/all/0/1">Sarah C. Gallagher</a> (9), <a href="http://arxiv.org/find/astro-ph/1/au:+Green_R/0/1/0/all/0/1">Richard F. Green</a> (8), <a href="http://arxiv.org/find/astro-ph/1/au:+Lira_P/0/1/0/all/0/1">Paulina Lira</a> (10), <a href="http://arxiv.org/find/astro-ph/1/au:+Luo_B/0/1/0/all/0/1">Bin Luo</a> (11), <a href="http://arxiv.org/find/astro-ph/1/au:+Netzer_H/0/1/0/all/0/1">Hagai Netzer</a> (12), <a href="http://arxiv.org/find/astro-ph/1/au:+Plotkin_R/0/1/0/all/0/1">Richard Plotkin</a> (13), <a href="http://arxiv.org/find/astro-ph/1/au:+Runnoe_J/0/1/0/all/0/1">Jessie C. Runnoe</a> (14), <a href="http://arxiv.org/find/astro-ph/1/au:+Schneider_D/0/1/0/all/0/1">Donald P. Schneider</a> (6), <a href="http://arxiv.org/find/astro-ph/1/au:+Strauss_M/0/1/0/all/0/1">Michael A. Strauss</a> (15), <a href="http://arxiv.org/find/astro-ph/1/au:+Trakhtenbrot_B/0/1/0/all/0/1">Benny Trakhtenbrot</a> (12), <a href="http://arxiv.org/find/astro-ph/1/au:+Wu_J/0/1/0/all/0/1">Jianfeng Wu</a> (16) ((1) U. North Texas, (2) U. Wyoming, (3) Drexel U., (4) CfA, (5) U. Washington, (6) Penn State U., (7) Bates College, (8) U. Arizona, (9) U. Western Ontario, (10) U. Chile, (11) Nanjing U., (12) Tel Aviv U., (13) U. Nevada-Reno, (14) Vanderbilt U., (15) Princeton U., (16) Xiamen U.)

Weak emission-line quasars (WLQs) are a subset of Type 1 quasars that exhibit
extremely weak Ly$alpha +$N V $lambda$1240 and/or C IV $lambda$1549 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 H$beta$-based black-hole
mass ($M_{rm BH}$) estimates of these quasars using the strength of the
optical Fe II emission. We confirm previous findings that WLQs’ $M_{rm BH}$
values are overestimated by up to an order of magnitude using the traditional
broad emission-line region size-luminosity relation. With this $M_{rm BH}$
correction, we find a significant correlation between H$beta$-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.

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