Year: 2019
Type: article
Abstract: The galaxy catalogs generated from low-resolution emission-line surveys often contain both foreground and background interlopers due to line misidentification, which can bias the cosmological parameter estimation. In this paper, we present a method for correcting the interloper bias by using the joint analysis of auto- and cross-power spectra of the main and the interloper samples. In particular, we can measure the interloper fractions from the cross-correlation between the interlopers and survey galaxies, because the true cross-correlation must be negligibly small. The estimated interloper fractions, in turn, remove the interloper bias in the cosmological parameter estimation. For example, in the Hobby–Eberly Telescope Dark Energy Experiment low-redshift (z < 0.5) [O ii] λ3727Å emitters contaminate high-redshift (1.9 < z < 3.5) Lyα line emitters. We demonstrate that the joint-analysis method yields a high signal-to-noise ratio measurement of the interloper fractions while only marginally increasing the uncertainties in the cosmological parameters relative to the case without interlopers. We also show that the same is true for the high-latitude spectroscopic survey of the Wide-field Infrared Survey Telescope mission where contamination occurs between the Balmer-α line emitters at lower redshifts (1.1 < z < 1.9) and oxygen ([O iii] λ5007Å) line emitters at higher redshifts (1.7 < z < 2.8).
Source: The Astrophysical Journal
Authors: Henry S. Grasshorn Gebhardt, Donghui Jeong, Humna Awan, Joanna S. Bridge, Robin Ciardullo, Daniel Farrow, Karl Gebhardt, Gary J. Hill, Eiichiro Komatsu, Mallory Molina, Ana Paulino-Afonso, Shun Saito, Donald P. Schneider, Greg Zeimann
Institutions: Pennsylvania State University, Rutgers, The State University of New Jersey, University of Louisville, Max Planck Institute for Extraterrestrial Physics, The University of Texas at Austin, McDonald Observatory, Kavli Institute for the Physics and Mathematics of the Universe, Max Planck Institute for Astrophysics, The University of Tokyo
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: Cosmology with the galaxy bispectrum: galaxy bias, redshift-space distortion, and primordial non-Gaussianity, WE PROPOSE A RESEARCH PROGRAM THE AIMING AT EXPLOITING THE DATASET FROM THE UPCOMING SPACE MISSIONS: SPHEREX WFIRST AND EUCLID. IN PARTICULAR WE WILL STUDY THE TWO OBSERVABLES THAT ARE NOT PARTS OF THE CURRENT COSMOLOGICAL ANALYSIS: 1) THE GALAXY THREEPOINT CORRELATION FUNCTION AND 2) CLUSTERING FOSSILS. EXPLOITING THE GALAXY THREE-POINT CORRELATION FUNCTION (3PCF) WILL IMPROVE THE DARK ENERGY CONSTRAINT (BOTH GEOMETRICAL AND DYNAMICAL) BY A FACTOR OF TWO COMPARED TO THE CONVENTIONAL ANALYSIS USING ONLY THE TWO-POINT CORRELATION FUNCTION. THE CLUSTERING FOSSILS MEASUREMENT CAN POTENTIALLY BE A POWERFUL TEST OF INFLATIONARY THEORY BY SEARCHING FOR SIGNATURES OF SPECTATOR FIELDS WITH GENERAL-SPIN (THIS INCLUDES THE PRIMORDIAL GRAVITATIONAL WAVES) THAT MIGHT HAVE EXISTED IN THE EARLY UNIVERSE. BY USING THE ANALYTICAL THEORY BASED ON THE GENERAL THEORY OF RELATIVITY AS WELL AS RECENTLY DEVELOPED TOTAL ANGULAR MOMENTUM WAVE METHOD WE PLAN TO INCORPORATE THE RELATIVISTIC PROJECTION EFFECT AS WELL AS WIDE-ANGLE EFFECT. FOR BOTH OBSERVABLES THE KEY THEORETICAL CHALLENGE IS TO MODEL THE COUPLING BETWEEN LONG-WAVELENGTH MODES AND SHORT-WAVELENGTH MODES. WE PLAN TO DEVELOP A THEORETICAL MODEL BY USING THE PERTURBATION THEORY TECHNIQUES AND COMPARE THE VALIDITY OF THE MODELS AGAINST COSMOLOGICAL N-BODY SIMULATIONS. PARALLEL TO THE THEORETICAL STUDIES WE ALSO PLAN TO STUDY THE METHOD TO IDENTIFYING AND MODELING THE SURVEY SYSTEMATICS INDUCED BY DUST CONTAMINATION BRIGHT STARS AS WELL AS OVERLAPPING SPECTRA. FOR THIS STUDY WE SHALL GENERATE THE LOG-NORMAL MOCK CATALOGUES FOR WHICH WE KNOW COMPLETE UNDERLYING STATISTICS. AS AN END PRODUCT OF THE RESEARCH PROGRAM WE WILL HAVE AN END-TO-END DATA ANALYSIS TOOLKIT FOR THE GALAXY 3PCF AND CLUSTERING FOSSILS. THE TOOLKITS INCLUDE FROM THE OPTIMAL ESTIMATOR OF THE SIGNATURE TO ACCURATE THEORETICAL TEMPLATE FOR THE COSMOLOGICAL INTERPRETATION.
OpenAlex ID: W2901969841