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Title: A map-based method for eliminating systematic modes from galaxy clustering power spectra with application to BOSS

Journal Article · · Monthly Notices of the Royal Astronomical Society
 [1];  [2];  [3];  [3];  [4];  [5]; ORCiD logo [6];  [1]
  1. Univ. of Barcelona, Barcelona (Spain)
  2. Univ. of Waterloo, ON (Canada); Perimeter Inst. for Theoretical Physics, Waterloo, ON (Canada); Univ. of Portsmouth (United Kingdom). Inst. of Cosmology and Gravitation
  3. Univ. of Portsmouth (United Kingdom). Inst. of Cosmology and Gravitation
  4. Univ. of Portsmouth (United Kingdom). Inst. of Cosmology and Gravitation; Kansas State Univ., Manhattan, KS (United States); Ilia State Univ., Tbilisi (Georgia). National Abastumani Astrophysical Observatory
  5. Univ. of Barcelona, Barcelona (Spain); Catalan Inst. for Research and Advanced Studies (ICREA), Barcelona (Spain)
  6. The Ohio State Univ., Columbus, OH (United States). Center for Cosmology and AstroParticle Physics

We develop a practical methodology to remove modes from a galaxy survey power spectrum that are associated with systematic errors. We apply this to the BOSS CMASS sample, to see if it removes the excess power previously observed beyond the best-fitting ΛCDM model on very large scales. We consider several possible sources of data contamination, and check whether they affect the number of targets that can be observed and the power spectrum measurements. We describe a general framework for how such knowledge can be transformed into template fields. Mode subtraction can then be used to remove these systematic contaminants at least as well as applying corrective weighting to the observed galaxies, but benefits from giving an unbiased power. Even after applying templates for all known systematics, we find a large-scale power excess, but this is reduced compared with that observed using the weights provided by the BOSS team. This excess is at much larger scales than the BAO scale and does not affect the main results of BOSS. However, it will be important for the measurement of a scale-dependent bias due to primordial non-Gaussianity. The excess is beyond that allowed by any simple model of non-Gaussianity matching Planck data, and is not matched in other surveys. We show that this power excess can further be reduced but is still present using ‘phenomenological’ templates, designed to consider further potentially unknown sources of systematic contamination. As all discrepant angular modes can be removed using ‘phenomenological’ templates, the potentially remaining contaminant acts radially.

Research Organization:
Kansas State Univ., Manhattan, KS (United States)
Sponsoring Organization:
USDOE Office of Science (SC), High Energy Physics (HEP); National Aeronautics and Space Administration (NASA); European Union (EU); Ministry of Economic Affairs and Digital Transformation of Spain (MINECO)
Grant/Contract Number:
SC0011840; 12-EUCLID11-0004; 725327; 614030; ST/N000668/1
OSTI ID:
1479162
Alternate ID(s):
OSTI ID: 1611673; OSTI ID: 1656951
Journal Information:
Monthly Notices of the Royal Astronomical Society, Vol. 482, Issue 1; ISSN 0035-8711
Publisher:
Royal Astronomical SocietyCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 21 works
Citation information provided by
Web of Science

Cited By (2)

A blind method to recover the mask of a deep galaxy survey journal April 2019
Redshift-weighted constraints on primordial non-Gaussianity from the clustering of the eBOSS DR14 quasars in Fourier space journal September 2019