Detecting Multiple DLAs per Spectrum in SDSS DR12 with Gaussian Processes. (arXiv:2003.11036v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Ho_M/0/1/0/all/0/1">Ming-Feng Ho</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bird_S/0/1/0/all/0/1">Simeon Bird</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Garnett_R/0/1/0/all/0/1">Roman Garnett</a>
We present a revised version of our automated technique using Gaussian
processes (GPs) to detect Damped Lyman-$alpha$ absorbers (DLAs) along quasar
(QSO) sightlines. The main improvement is to allow our Gaussian process
pipeline to detect multiple DLAs along a single sightline. Our DLA detections
are regularised by an improved model for the absorption from the Lyman-$alpha$
forest which improves performance at high redshift. We also introduce a model
for unresolved sub-DLAs which reduces mis-classifications of absorbers without
detectable damping wings. We compare our results to those of two different
large-scale DLA catalogues and provide a catalogue of the processed results of
our Gaussian process pipeline using 158 825 Lyman-$alpha$ spectra from SDSS
data release 12. We present updated estimates for the statistical properties of
DLAs, including the column density distribution function (CDDF), line density
($dN/dX$), and neutral hydrogen density ($Omega_{textrm{DLA}}$).
We present a revised version of our automated technique using Gaussian
processes (GPs) to detect Damped Lyman-$alpha$ absorbers (DLAs) along quasar
(QSO) sightlines. The main improvement is to allow our Gaussian process
pipeline to detect multiple DLAs along a single sightline. Our DLA detections
are regularised by an improved model for the absorption from the Lyman-$alpha$
forest which improves performance at high redshift. We also introduce a model
for unresolved sub-DLAs which reduces mis-classifications of absorbers without
detectable damping wings. We compare our results to those of two different
large-scale DLA catalogues and provide a catalogue of the processed results of
our Gaussian process pipeline using 158 825 Lyman-$alpha$ spectra from SDSS
data release 12. We present updated estimates for the statistical properties of
DLAs, including the column density distribution function (CDDF), line density
($dN/dX$), and neutral hydrogen density ($Omega_{textrm{DLA}}$).
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