TY - JOUR
T1 - Optically detected galaxy cluster candidates in the AKARI North Ecliptic Pole field based on photometric redshift from the Subaru Hyper Suprime-Cam
AU - Huang, Ting-Chi
AU - Matsuhara, Hideo
AU - Goto, Tomotsugu
AU - Santos, Daryl Joe D.
AU - Ho, Simon C-C
AU - Kim, Seong Jin
AU - Hashimoto, Tetsuya
AU - Ikeda, Hiroyuki
AU - Oi, Nagisa
AU - Malkan, Matthew A
AU - Pearson, William J.
AU - Pollo, Agnieszka
AU - Serjeant, Stephen
AU - Shim, Hyunjin
AU - Miyaji, Takamitsu
AU - Hwang, Ho Seong
AU - Durkalec, Anna
AU - Poliszczuk, Artem
AU - Greve, Thomas R.
AU - Pearson, Chris
AU - Toba, Yoshiki
AU - Lee, Dongseob
AU - Kim, Helen K
AU - Toft, Sune
AU - Jeong, Woong-Seob
AU - Enokidani, Umi
PY - 2021
Y1 - 2021
N2 - Galaxy clusters provide an excellent probe in various research fields in
astrophysics and cosmology. However, the number of galaxy clusters
detected so far in the AKARI North Ecliptic Pole (NEP) field is limited. In this work, we provide galaxy cluster candidates in the AKARI NEP field with the minimum requisites based only on the coordinates and photometric redshift (photo-z) of galaxies. We used galaxies detected in five optical bands (g, r, i, z, and Y) by the Subaru Hyper Suprime-Cam (HSC), with additional data from the u band obtained from the Canada-France-Hawaii Telescope (CFHT) MegaPrime/MegaCam, and from the IRAC1 and IRAC2 bands from the Spitzer space telescope for photo-z
estimation. We calculated the local density around every galaxy using
the 10th-nearest neighbourhood. Cluster candidates were determined by
applying the friends-of-friends algorithm to over-densities. A total of
88 cluster candidates containing 4390 member galaxies below redshift 1.1
in 5.4 deg2 were identified. The reliability of our method
was examined through false-detection tests, redshift-uncertainty tests,
and applications on the Cosmic Evolution Survey (COSMOS) data, giving
false-detection rates of 0.01 to 0.05 and a recovery rate of 0.9 at high
richness. Three X-ray clusters previously observed by ROSAT and Chandra
were recovered. The cluster galaxies show a higher stellar mass and
lower star formation rate compared with the field galaxies in two-sample
Z-tests. These cluster candidates are useful for environmental
studies of galaxy evolution and future astronomical surveys in the NEP,
where AKARI has performed unique nine-band mid-infrared photometry for tens of thousands of galaxies.
AB - Galaxy clusters provide an excellent probe in various research fields in
astrophysics and cosmology. However, the number of galaxy clusters
detected so far in the AKARI North Ecliptic Pole (NEP) field is limited. In this work, we provide galaxy cluster candidates in the AKARI NEP field with the minimum requisites based only on the coordinates and photometric redshift (photo-z) of galaxies. We used galaxies detected in five optical bands (g, r, i, z, and Y) by the Subaru Hyper Suprime-Cam (HSC), with additional data from the u band obtained from the Canada-France-Hawaii Telescope (CFHT) MegaPrime/MegaCam, and from the IRAC1 and IRAC2 bands from the Spitzer space telescope for photo-z
estimation. We calculated the local density around every galaxy using
the 10th-nearest neighbourhood. Cluster candidates were determined by
applying the friends-of-friends algorithm to over-densities. A total of
88 cluster candidates containing 4390 member galaxies below redshift 1.1
in 5.4 deg2 were identified. The reliability of our method
was examined through false-detection tests, redshift-uncertainty tests,
and applications on the Cosmic Evolution Survey (COSMOS) data, giving
false-detection rates of 0.01 to 0.05 and a recovery rate of 0.9 at high
richness. Three X-ray clusters previously observed by ROSAT and Chandra
were recovered. The cluster galaxies show a higher stellar mass and
lower star formation rate compared with the field galaxies in two-sample
Z-tests. These cluster candidates are useful for environmental
studies of galaxy evolution and future astronomical surveys in the NEP,
where AKARI has performed unique nine-band mid-infrared photometry for tens of thousands of galaxies.
KW - Methods: data analysis
KW - Galaxies: clusters: general
KW - Galaxies: distance and redshifts
KW - Galaxies: evolution
KW - galaxies: groups: general
U2 - 10.1093/mnras/stab2128
DO - 10.1093/mnras/stab2128
M3 - Journal article
SN - 0035-8711
VL - 506
SP - 6063
EP - 6080
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -