Black hole mass estimates in quasars – A comparative analysis of high- and low-ionization lines. (arXiv:1905.00617v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Marziani_P/0/1/0/all/0/1">P. Marziani</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Olmo_A/0/1/0/all/0/1">A. del Olmo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Martinez_Carballo_M/0/1/0/all/0/1">M. A. Martinez-Carballo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Martinez_Aldama_M/0/1/0/all/0/1">M. L. Martinez-Aldama</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stirpe_G/0/1/0/all/0/1">G. M. Stirpe</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Negrete_C/0/1/0/all/0/1">C. A. Negrete</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dultzin_D/0/1/0/all/0/1">D. Dultzin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Onofrio_M/0/1/0/all/0/1">M. D' Onofrio</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bon_E/0/1/0/all/0/1">E. Bon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bon_N/0/1/0/all/0/1">N. Bon</a>
The inter-line comparison between high- and low-ionization emission lines has
yielded a wealth of information on the quasar broad line region (BLR) structure
and dynamics, including perhaps the earliest unambiguous evidence in favor of a
disk + wind structure in radio-quiet quasars. We carried out an analysis of the
CIV 1549 and Hbeta line profiles of 28 Hamburg-ESO high luminosity quasars and
of 48 low-z, low luminosity sources in order to test whether the
high-ionization line CIV 1549 width could be correlated with Hbeta and be used
as a virial broadening estimator. We analyze intermediate- to high-S/N,
moderate resolution optical and NIR spectra covering the redshifted CIV and
H$beta$ over a broad range of luminosity log L ~ 44 – 48.5 [erg/s] and
redshift (0 – 3), following an approach based on the quasar main sequence. The
present analysis indicates that the line width of CIV 1549 is not immediately
offering a virial broadening estimator equivalent to H$beta$. At the same time
a virialized part of the BLR appears to be preserved even at the highest
luminosities. We suggest a correction to FWHM(CIV) for Eddington ratio (using
the CIV blueshift as a proxy) and luminosity effects that can be applied over
more than four dex in luminosity. Great care should be used in estimating
high-L black hole masses from CIV 1549 line width. However, once corrected
FWHM(CIV) values are used, a CIV-based scaling law can yield unbiased MBH
values with respect to the ones based on H$beta$ with sample standard
deviation ~ 0.3 dex.
The inter-line comparison between high- and low-ionization emission lines has
yielded a wealth of information on the quasar broad line region (BLR) structure
and dynamics, including perhaps the earliest unambiguous evidence in favor of a
disk + wind structure in radio-quiet quasars. We carried out an analysis of the
CIV 1549 and Hbeta line profiles of 28 Hamburg-ESO high luminosity quasars and
of 48 low-z, low luminosity sources in order to test whether the
high-ionization line CIV 1549 width could be correlated with Hbeta and be used
as a virial broadening estimator. We analyze intermediate- to high-S/N,
moderate resolution optical and NIR spectra covering the redshifted CIV and
H$beta$ over a broad range of luminosity log L ~ 44 – 48.5 [erg/s] and
redshift (0 – 3), following an approach based on the quasar main sequence. The
present analysis indicates that the line width of CIV 1549 is not immediately
offering a virial broadening estimator equivalent to H$beta$. At the same time
a virialized part of the BLR appears to be preserved even at the highest
luminosities. We suggest a correction to FWHM(CIV) for Eddington ratio (using
the CIV blueshift as a proxy) and luminosity effects that can be applied over
more than four dex in luminosity. Great care should be used in estimating
high-L black hole masses from CIV 1549 line width. However, once corrected
FWHM(CIV) values are used, a CIV-based scaling law can yield unbiased MBH
values with respect to the ones based on H$beta$ with sample standard
deviation ~ 0.3 dex.
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