5 research outputs found
Optical Images and Source Catalog of AKARI North Ecliptic Pole Wide Survey Field
We present the source catalog and the properties of the , and
band images obtained to support the {\it AKARI} North Ecliptic Pole Wide
(NEP-Wide) survey. The NEP-Wide is an {\it AKARI} infrared imaging survey of
the north ecliptic pole covering a 5.8 deg area over 2.5 -- 6 \micron
wavelengths. The optical imaging data were obtained at the Maidanak Observatory
in Uzbekistan using the Seoul National University 4k 4k Camera on the
1.5m telescope. These images cover 4.9 deg where no deep optical imaging
data are available. Our , and band data reach the depths of
23.4, 23.1, and 22.3 mag (AB) at 5, respectively. The
source catalog contains 96,460 objects in the band, and the astrometric
accuracy is about 0.15\arcsec at 1 in each RA and Dec direction.
These photometric data will be useful for many studies including identification
of optical counterparts of the infrared sources detected by {\it AKARI},
analysis of their spectral energy distributions from optical through infrared,
and the selection of interesting objects to understand the obscured galaxy
evolution.Comment: 39 pages, 12 figure
Seoul National University Bright Quasar Survey in Optical (SNUQSO). II. Discovery of 40 Bright Quasars Near the Galactic Plane
We report the discovery of 40 bright quasars and active galactic nuclei
(AGNs) at low Galactic latitude (b<20deg). The low Galactic latitude region has
been considered a place to avoid when searching for extragalactic sources,
because of the high Galactic extinction, as well as a large number of stars
contaminating the sample selection. Bright quasars (R<~17) suffer more from
such difficulties because they look like bright stars, which are numerous at
low b, yet their surface number density is very low. In order to find quasars
in this region of the sky less explored for extragalactic sources, we have
started a survey of low Galactic latitude bright quasars as a part of the Seoul
National University Quasar Survey in Optical (SNUQSO). Quasar candidates have
been selected from radio and near-infrared (NIR) data. Out of 88 targets, we
identify 29 bright quasars/AGNs around the antigalactic center, and 11 bright
quasars/AGNs in the outskirts of the Galactic center, from two observing runs
in 2006 at the Bohyunsan Optical Astronomical Observatory (BOAO) in Korea. Our
finding demonstrates that quasars/AGNs can be discovered effectively, even at
low Galactic latitude, using multiwavelength data.Comment: 16 pages, 3 figure