We present the discovery of eight quasars at z~6 identified in the Sloan
Digital Sky Survey (SDSS) overlap regions. Individual SDSS imaging runs have
some overlap with each other, leading to repeat observations over an area
spanning >4000 deg^2 (more than 1/4 of the total footprint). These overlap
regions provide a unique dataset that allows us to select high-redshift quasars
more than 0.5 mag fainter in the z band than those found with the SDSS
single-epoch data. Our quasar candidates were first selected as i-band dropout
objects in the SDSS imaging database. We then carried out a series of follow-up
observations in the optical and near-IR to improve photometry, remove
contaminants, and identify quasars. The eight quasars reported here were
discovered in a pilot study utilizing the overlap regions at high galactic
latitude (|b|>30 deg). These quasars span a redshift range of 5.86<z<6.06 and a
flux range of 19.3<z_AB<20.6 mag. Five of them are fainter than z_AB=20 mag,
the typical magnitude limit of z~6 quasars used for the SDSS single-epoch
images. In addition, we recover eight previously known quasars at z~6 that are
located in the overlap regions. These results validate our procedure for
selecting quasar candidates from the overlap regions and confirming them with
follow-up observations, and provide guidance to a future systematic survey over
all SDSS imaging regions with repeat observations.
Description
[1504.01741] Discovery of Eight z ~ 6 Quasars in the Sloan Digital Sky Survey Overlap Regions
%0 Generic
%1 jiang2015discovery
%A Jiang, Linhua
%A McGreer, Ian D.
%A Fan, Xiaohui
%A Bian, Fuyan
%A Cai, Zheng
%A Clement, Benjamin
%A Wang, Ran
%A Fan, Zhou
%D 2015
%K high-z qso selection
%T Discovery of Eight z ~ 6 Quasars in the Sloan Digital Sky Survey Overlap
Regions
%U http://arxiv.org/abs/1504.01741
%X We present the discovery of eight quasars at z~6 identified in the Sloan
Digital Sky Survey (SDSS) overlap regions. Individual SDSS imaging runs have
some overlap with each other, leading to repeat observations over an area
spanning >4000 deg^2 (more than 1/4 of the total footprint). These overlap
regions provide a unique dataset that allows us to select high-redshift quasars
more than 0.5 mag fainter in the z band than those found with the SDSS
single-epoch data. Our quasar candidates were first selected as i-band dropout
objects in the SDSS imaging database. We then carried out a series of follow-up
observations in the optical and near-IR to improve photometry, remove
contaminants, and identify quasars. The eight quasars reported here were
discovered in a pilot study utilizing the overlap regions at high galactic
latitude (|b|>30 deg). These quasars span a redshift range of 5.86<z<6.06 and a
flux range of 19.3<z_AB<20.6 mag. Five of them are fainter than z_AB=20 mag,
the typical magnitude limit of z~6 quasars used for the SDSS single-epoch
images. In addition, we recover eight previously known quasars at z~6 that are
located in the overlap regions. These results validate our procedure for
selecting quasar candidates from the overlap regions and confirming them with
follow-up observations, and provide guidance to a future systematic survey over
all SDSS imaging regions with repeat observations.
@misc{jiang2015discovery,
abstract = {We present the discovery of eight quasars at z~6 identified in the Sloan
Digital Sky Survey (SDSS) overlap regions. Individual SDSS imaging runs have
some overlap with each other, leading to repeat observations over an area
spanning >4000 deg^2 (more than 1/4 of the total footprint). These overlap
regions provide a unique dataset that allows us to select high-redshift quasars
more than 0.5 mag fainter in the z band than those found with the SDSS
single-epoch data. Our quasar candidates were first selected as i-band dropout
objects in the SDSS imaging database. We then carried out a series of follow-up
observations in the optical and near-IR to improve photometry, remove
contaminants, and identify quasars. The eight quasars reported here were
discovered in a pilot study utilizing the overlap regions at high galactic
latitude (|b|>30 deg). These quasars span a redshift range of 5.86<z<6.06 and a
flux range of 19.3<z_AB<20.6 mag. Five of them are fainter than z_AB=20 mag,
the typical magnitude limit of z~6 quasars used for the SDSS single-epoch
images. In addition, we recover eight previously known quasars at z~6 that are
located in the overlap regions. These results validate our procedure for
selecting quasar candidates from the overlap regions and confirming them with
follow-up observations, and provide guidance to a future systematic survey over
all SDSS imaging regions with repeat observations.},
added-at = {2015-04-09T09:59:21.000+0200},
author = {Jiang, Linhua and McGreer, Ian D. and Fan, Xiaohui and Bian, Fuyan and Cai, Zheng and Clement, Benjamin and Wang, Ran and Fan, Zhou},
biburl = {https://www.bibsonomy.org/bibtex/210d83369819ed478ba624b763d8679d6/miki},
description = {[1504.01741] Discovery of Eight z ~ 6 Quasars in the Sloan Digital Sky Survey Overlap Regions},
interhash = {5303546b27437ece12f7bab6b69ddc01},
intrahash = {10d83369819ed478ba624b763d8679d6},
keywords = {high-z qso selection},
note = {cite arxiv:1504.01741Comment: AJ in press (8 pages)},
timestamp = {2015-04-09T09:59:21.000+0200},
title = {Discovery of Eight z ~ 6 Quasars in the Sloan Digital Sky Survey Overlap
Regions},
url = {http://arxiv.org/abs/1504.01741},
year = 2015
}