Close galaxy pairs with accurate photometric redshifts

Abstract

Context. Studies of galaxy pairs can provide valuable information to jointly understand the formation and evolution of galaxies and galaxy groups. Consequently, taking into account the new high precision photo-z surveys, it is important to have reliable and tested methods that allow us to properly identify these systems and estimate their total masses and other properties. Aims. In view of the forthcoming Physics of the Accelerating Universe Survey (PAUS) we propose and evaluate the performance of an identification algorithm of projected close isolated galaxy pairs. We expect that the photometric selected systems can adequately reproduce the observational properties and the inferred lensing mass - luminosity relation of a pair of truly bound galaxies that are hosted by the same dark matter halo. Methods. We develop an identification algorithm that considers the projected distance between the galaxies, the projected velocity difference and an isolation criteria in order to restrict the sample to isolated systems. We apply our identification algorithm using a mock galaxy catalog that mimics the features of PAUS. To evaluate the feasibility of our pair finder, we compare the identified photometric samples with a test sample that considers that both members are included in the same halo. Also, taking advantage of the lensing properties provided by the mock catalog, we apply a weak lensing analysis to determine the mass of the selected systems. Results. Photometric selected samples tend to show high purity values, but tend to misidentify truly bounded pairs as the photometric redshift errors increase. Nevertheless, overall properties such as the luminosity and mass distributions are successfully reproduced. We also accurately reproduce the lensing mass - luminosity relation as expected for galaxy pairs located in the same halo.

10 pages, 12 Figures. Accepted for publication in A&A

References in corpus (17)

• zCOSMOS: A Large VLT/VIMOS redshift survey covering 0 < z < 3 in the COSMOS field
• Galaxies in the Hubble Ultra Deep Field: I. Detection, Multiband Photometry, Photometric Redshifts, and Morphology
• CLASH: Weak-Lensing Shear-and-Magnification Analysis of 20 Galaxy Clusters
• Lensing is Low: Cosmology, Galaxy Formation, or New Physics?
• A calibration of the relation between the abundance of close galaxy pairs and the rate of galaxy mergers
• Minor Galaxy Interactions: Star Formation Rates and Galaxy Properties
• An algorithm to build mock galaxy catalogues using MICE simulations
• A Halo Model of Galaxy Colors and Clustering in the SDSS
• The onion universe: all sky lightcone simulations in spherical shells
• A filament of dark matter between two clusters of galaxies
• The L_X--M relation of Clusters of Galaxies
• The ALHAMBRA survey: Accurate merger fractions by PDF analysis of photometric close pairs
• Massive Dark Matter Halos around Bright Isolated Galaxies in the 2dFGRS
• The Physics of the Accelerating Universe Camera
• SARCS strong-lensing galaxy groups: II - mass-concentration relation and strong-lensing bias
• CFHTLenS: A Gaussian likelihood is a sufficient approximation for a cosmological analysis of third-order cosmic shear statistics
• A catalog of UGC isolated galaxy pairs with accurate radial velocities

Cited by in corpus (8)

• A Census of WISE-selected Dual and Offset AGN Across the Sky: New Constraints on Merger-Driven Triggering of Obscured AGN
• The PAU Survey: Intrinsic alignments and clustering of narrow-band photometric galaxies
• TOPz: Photometric redshifts for J-PAS
• On the weak lensing masses of a new sample of galaxy groups
• Statistical deprojection of intervelocities, interdistances and masses in the Isolated Galaxy Pair Catalog
• The PAU Survey: Close galaxy pairs identification and analysis
• Structure and large scale environment of galaxy pairs in the S-PLUS DR4
• ODIN: Using multiplicity of Lyman-Alpha Emitters to assess star formation activity in dark matter halos