TY - JOUR
T1 - The High Av Quasar Survey
T2 - A z=2.027 metal-rich damped Lyman-alpha absorber towards a red quasar at z=3.21
AU - Fynbo, Johan Peter Uldall
AU - Krogager, Jens-Kristian
AU - Heintz, Kasper Elm
AU - Geier, S.
AU - Moller, p
AU - Noterdaeme, P.
AU - Christensen, Lise Bech
AU - Leloudas, Georgios
AU - Jakobsson, P.
PY - 2017/10/1
Y1 - 2017/10/1
N2 - It is important to understand the selection effects behind the quasar samples to fully exploit the potential of quasars as probes of cosmic chemical evolution and the internal gas dynamics of galaxies; in particular, it is vital to understand whether the selection criteria exclude foreground galaxies with certain properties, most importantly a high dust content. Here we present spectroscopic follow-up from the 10.4 m GTC telescope of a dust-reddened quasar, eHAQ0111+0641, from the extended High AV Quasar (HAQ) survey. We find that the z = 3.21 quasar has a foreground damped Lyman-α absorber (DLA) at z = 2.027 along the line of sight. The DLA has very strong metal lines due to a moderately high metallicity with an inferred lower limit of 25% of the solar metallicity, but a very large gas column density along the line of sight in its host galaxy. This discovery is further evidence that there is a dust bias affecting the census of metals, caused by the combined effect of dust obscuration and reddening, in existing samples of z > 2 DLAs. The case of eHAQ0111+0641 illustrates that dust bias is not only caused by dust obscuration, but also dust reddening.
AB - It is important to understand the selection effects behind the quasar samples to fully exploit the potential of quasars as probes of cosmic chemical evolution and the internal gas dynamics of galaxies; in particular, it is vital to understand whether the selection criteria exclude foreground galaxies with certain properties, most importantly a high dust content. Here we present spectroscopic follow-up from the 10.4 m GTC telescope of a dust-reddened quasar, eHAQ0111+0641, from the extended High AV Quasar (HAQ) survey. We find that the z = 3.21 quasar has a foreground damped Lyman-α absorber (DLA) at z = 2.027 along the line of sight. The DLA has very strong metal lines due to a moderately high metallicity with an inferred lower limit of 25% of the solar metallicity, but a very large gas column density along the line of sight in its host galaxy. This discovery is further evidence that there is a dust bias affecting the census of metals, caused by the combined effect of dust obscuration and reddening, in existing samples of z > 2 DLAs. The case of eHAQ0111+0641 illustrates that dust bias is not only caused by dust obscuration, but also dust reddening.
U2 - 10.1051/0004-6361/201730726
DO - 10.1051/0004-6361/201730726
M3 - Journal article
SN - 0004-6361
VL - 606
JO - Astronomy & Astrophysics
JF - Astronomy & Astrophysics
M1 - A13
ER -