Intrinsic alignment as an RSD contaminant in the DESI survey

Journal Article · 10 April 2023 · Monthly Notices of the Royal Astronomical Society

DOI: https://doi.org/10.1093/mnras/stad950 · OSTI ID:1969773

Lamman, Claire  ^[1]; Eisenstein, Daniel  ^[1]; Aguilar, Jessica Nicole ^[2]; Brooks, David ^[3]; de la Macorra, Axel ^[4]; Doel, Peter ^[3]; Font-Ribera, Andreu  ^[5]; Gontcho A Gontcho, Satya ^[2]; Honscheid, Klaus  ^[6]; Kehoe, Robert ^[7]; Kisner, Theodore ^[2]; Kremin, Anthony ^[2]; Landriau, Martin ^[2]; Levi, Michael ^[2]; Miquel, Ramon ^[8]; Moustakas, John ^[9]; Palanque-Delabrouille, Nathalie ^[10]; Poppett, Claire ^[11]; Schubnell, Michael ^[12]; Tarlé, Gregory ^[12]

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1. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
2. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
3. University College London (United Kingdom)
4. Universidad Nacional Autonoma de Mexico (UNAM), Mexico City (Mexico)
5. The Barcelona Institute of Science and Technology (Spain)
6. The Ohio State University, Columbus, OH (United States)
7. Southern Methodist University, Dallas, TX (United States)
8. The Barcelona Institute of Science and Technology (Spain); Institució Catalana de Recerca i Estudis Avançats, Barcelona (Spain)
9. Siena College, Loudonville, NY (United States)
10. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Université Paris-Saclay. Gif-sur-Yvette (France)
11. Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); University of California, Berkeley, CA (United States)
12. University of Michigan, Ann Arbor, MI (United States)

We measure the tidal alignment of the major axes of luminous red galaxies (LRGs) from the Legacy Imaging Survey and use it to infer the artificial redshift-space distortion signature that will arise from an orientation-dependent, surface-brightness selection in the Dark Energy Spectroscopic Instrument (DESI) survey. Using photometric redshifts to downweight the shape–density correlations due to weak lensing, we measure the intrinsic tidal alignment of LRGs. Separately, we estimate the net polarization of LRG orientations from DESI’s fibre-magnitude target selection to be of order 10^–2 along the line of sight. Using these measurements and a linear tidal model, we forecast a 0.5 per cent fractional decrease on the quadrupole of the two-point correlation function for projected separations of 40–80 h^–1 Mpc. We also use a halo catalogue from the ABACUSSUMMIT cosmological simulation suite to reproduce this false quadrupole.

• Research Organization: Univ. of Michigan, Ann Arbor, MI (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP); USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF); USDOE
• Grant/Contract Number: SC0019193; AC02-05CH11231; SC0013718
• OSTI ID: 1969773
• Alternate ID(s): OSTI ID: 2234142; OSTI ID: 2352628
• Journal Information: Monthly Notices of the Royal Astronomical Society, Vol. 522, Issue 1; ISSN 0035-8711
• Publisher: Oxford University PressCopyright Statement
• Country of Publication: United States
• Language: English