OMEGA -- OSIRIS Mapping of Emission-line Galaxies in A901/2: I.-- Survey description, data analysis, and star formation and AGN activity in the highest density regions

Abstract

We present an overview of and first results from the OMEGA survey: the OSIRIS Mapping of Emission-line Galaxies in the multi-cluster system A901/2. The ultimate goal of this project is to study star formation and AGN activity across a broad range of environments at a single redshift. Using the tuneable-filter mode of the OSIRIS instrument on GTC, we target Halpha and [NII] emission lines over a ~0.5 X 0.5 deg2 region containing the z~0.167 multi-cluster system A901/2. In this paper we describe the design of the survey, the observations and the data analysis techniques developed. We then present early results from two OSIRIS pointings centred on the cores of the A901a and A902 clusters. AGN and star-forming (SF) objects are identified using the [NII]/Halpha vs. W_Halpha (WHAN) diagnostic diagram. The AGN hosts are brighter, more massive, and possess earlier-type morphologies than SF galaxies. Both populations tend to be located towards the outskirts of the high density regions we study. The typical Halpha luminosity of these sources is significantly lower than that of field galaxies at similar redshifts, but greater than that found for A1689, a rich cluster at z~0.2. The Halpha luminosities of our objects translate into star-formation rates (SFRs) between ~0.02 and 6 Msun/yr. Comparing the relationship between stellar mass and Halpha-derived SFR with that found in the field indicates a suppression of star formation in the cores of the clusters. These findings agree with previous investigations of this multi-cluster structure, based on other star formation indicators, and demonstrate the power of tuneable filters for this kind of study.

MNRAS accepted, 19 pages, 20 figures,1 table

References in corpus (21)

• Mass and environment as drivers of galaxy evolution in SDSS and zCOSMOS and the origin of the Schechter function
• Galaxy Zoo: the dependence of morphology and colour on environment
• The stellar masses of 25000 galaxies at 0.2<z<1.0 estimated by the COMBO-17 survey
• The STAGES view of red spirals and dusty red galaxies: Mass-dependent quenching of star-formation in cluster infall
• The relation between star formation, morphology and local density in high redshift clusters and groups
• Spectroscopic Confirmation of a Large AGN Population in Clusters of Galaxies
• P-MaNGA: Emission Lines Properties - Gas Ionisation and Chemical Abundances from Prototype Observations
• The dark matter environment of the Abell 901/902 supercluster: a weak lensing analysis of the HST STAGES survey
• The AGN fraction - velocity dispersion relation in clusters of galaxies
• STAGES: the Space Telescope A901/2 Galaxy Evolution Survey
• The Different Environmental Dependencies of Star-formation for Giant and Dwarf Galaxies
• The Origin of S0s in Clusters: evidence from the bulge and disc star formation histories
• The Rich Globular Cluster System of Abell 1689 and the Radial Dependence of the Globular Cluster Formation Efficiency
• Environmental dependence of AGN activity in the supercluster A901/2
• The galaxy populations from the centers to the infall regions in z~0.25 clusters
• Retired galaxies: not to be forgotten in the quest of the star formation -- AGN connection
• Revealing components of the galaxy population through nonparametric techniques
• Ram pressure and dusty red galaxies - key factors in the evolution of the multiple cluster system Abell 901/902
• Caught in the act: Cluster `k+a' galaxies as a link between spirals and S0s
• The sizes of disc galaxies in intermediate-redshift clusters
• General Formulation for the Calibration and Characterization of Narrow-gap Etalons: the OSIRIS/GTC Tunable Filters Case

Cited by in corpus (10)

• The environmental dependence of gas accretion onto galaxies: quenching satellites through starvation
• Jellyfish galaxies with the IllustrisTNG simulations -- When, where, and for how long does ram pressure stripping of cold gas occur?
• OMEGA -- OSIRIS Mapping of Emission-line Galaxies in A901/2 -- V. The rich population of jellyfish galaxies in the multi-cluster system Abell 901/2
• Galaxy cluster mergers as triggers for the formation of jellyfish galaxies: case study of the A901/2 system
• OMEGA -- OSIRIS Mapping of Emission-line Galaxies in A901/2: II. -- Environmental influence on integrated star formation properties and AGN activity
• The miniJPAS survey: The galaxy populations in the most massive cluster in miniJPAS, mJPC2470-1771
• OMEGA - OSIRIS Mapping of Emission-line Galaxies in A901/2: III. - Galaxy Properties Across Projected Phase Space in A901/2
• The evolution of galaxy scaling relations in clusters at 0.5<z<1.5
• OMEGA - OSIRIS Mapping of Emission-line Galaxies in A901/2: IV. - Extinction of Star-Formation Estimators with Inclination
• Wavelength Self-Calibration and Sky Subtraction for Fabry-Perot Interferometers: Applications to OSIRIS