The Extended Northern ROSAT Galaxy Cluster Survey (NORAS II). I. Survey Construction and First Results
Journal Article
·
· Astronomical Journal (Online)
- Max-Planck-Institut für Extraterrestrische Physik, D-85748 Garching (Germany)
- ESO, D-85748 Garching (Germany)
- Max-Planck-Institut für Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)
- ESAC, Camino Bajo del Castillo, Villanueva de la Cañada, E-28692 Madrid (Spain)
As the largest, clearly defined building blocks of our universe, galaxy clusters are interesting astrophysical laboratories and important probes for cosmology. X-ray surveys for galaxy clusters provide one of the best ways to characterize the population of galaxy clusters. We provide a description of the construction of the NORAS II galaxy cluster survey based on X-ray data from the northern part of the ROSAT All-Sky Survey. NORAS II extends the NORAS survey down to a flux limit of 1.8 × 10{sup −12} erg s{sup −1} cm{sup −2} (0.1–2.4 keV), increasing the sample size by about a factor of two. The NORAS II cluster survey now reaches the same quality and depth as its counterpart, the southern REFLEX II survey, allowing us to combine the two complementary surveys. The paper provides information on the determination of the cluster X-ray parameters, the identification process of the X-ray sources, the statistics of the survey, and the construction of the survey selection function, which we provide in numerical format. Currently NORAS II contains 860 clusters with a median redshift of z = 0.102. We provide a number of statistical functions, including the log N –log S and the X-ray luminosity function and compare these to the results from the complementary REFLEX II survey. Using the NORAS II sample to constrain the cosmological parameters, σ {sub 8} and Ω{sub m}, yields results perfectly consistent with those of REFLEX II. Overall, the results show that the two hemisphere samples, NORAS II and REFLEX II, can be combined without problems into an all-sky sample, just excluding the zone of avoidance.
- OSTI ID:
- 22663695
- Journal Information:
- Astronomical Journal (Online), Journal Name: Astronomical Journal (Online) Journal Issue: 5 Vol. 153; ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
Similar Records
THE SPATIAL CLUSTERING OF ROSAT ALL-SKY SURVEY ACTIVE GALACTIC NUCLEI. III. EXPANDED SAMPLE AND COMPARISON WITH OPTICAL ACTIVE GALACTIC NUCLEI
The Spatial Clustering of ROSAT All-Sky Survey Active Galactic Nuclei. V. The Evolution of Broad-line AGN Clustering Properties in the Last 6 Gyr
CODEX clusters
Journal Article
·
Thu Feb 09 23:00:00 EST 2012
· Astrophysical Journal
·
OSTI ID:22011857
The Spatial Clustering of ROSAT All-Sky Survey Active Galactic Nuclei. V. The Evolution of Broad-line AGN Clustering Properties in the Last 6 Gyr
Journal Article
·
Thu Jul 20 20:00:00 EDT 2023
· The Astrophysical Journal
·
OSTI ID:2425365
CODEX clusters
Journal Article
·
Mon Jun 22 20:00:00 EDT 2020
· Astronomy and Astrophysics
·
OSTI ID:1647240