Publications de Anand Stéphane Raichoor

Validation of the Scientific Program for the Dark Energy Spectroscopic Instrument

Eduardo Sanchez, Zhifeng Ding, Sun Hee Kim, Hua Zhang, Stewart Cole, Jiangyan Yang, Jean-Paul Richard Kneib, Anand Stéphane Raichoor, Andrei Variu, Ting Tan, Daniel Felipe Forero Sanchez, Cheng Zhao, Arjun Dey, David Schlegel, Zheng Zheng, Xin Chen

The Dark Energy Spectroscopic Instrument (DESI) was designed to conduct a survey covering 14,000 deg(2) over 5 yr to constrain the cosmic expansion history through precise measurements of baryon acoustic oscillations (BAO). The scientific program for DESI ...

Iop Publishing Ltd2024

The DESI Survey Validation: Results from Visual Inspection of Bright Galaxies, Luminous Red Galaxies, and Emission-line Galaxies

Stewart Cole, Yi Zhang, Anand Stéphane Raichoor, Jiaxi Yu, Arjun Dey

The Dark Energy Spectroscopic Instrument (DESI) Survey has obtained a set of spectroscopic measurements of galaxies to validate the final survey design and target selections. To assist in these tasks, we visually inspect DESI spectra of approximately 2500 ...

IOP Publishing Ltd2023

First detection of the BAO signal from early DESI data

Anand Stéphane Raichoor, Andrei Variu, Cheng Zhao, David Schlegel

We present the first detection of the baryon acoustic oscillations (BAOs) signal obtained using unblinded data collected during the initial 2 months of operations of the Stage-IV ground-based Dark Energy Spectroscopic Instrument (DESI). From a selected sam ...

Oxford Univ Press2023

Abundance matching analysis of the emission-line galaxy sample in the extended Baryon Oscillation Spectroscopic Survey

Johan Comparat, Anand Stéphane Raichoor

We present the measurements of the small-scale clustering for the emission-line galaxy (ELG) sample from the extended Baryon Oscillation Spectroscopic Surv e y (eBOSS) in the Sloan Digital Sk y Surv e y IV (SDSS-IV). We use conditional abundance matching m ...

OXFORD UNIV PRESS2023

Model BOSS and eBOSS luminous red galaxies at 0.2 < z < 1.0 using SubHalo Abundance Matching with three parameters

Jean-Paul Richard Kneib, Anand Stéphane Raichoor, Jiaxi Yu, Cheng Zhao, Ginevra Favole

SubHalo Abundance Matching (SHAM) is an empirical method for constructing galaxy catalogues based on high-resolution N-body simulations. We apply SHAM on the UNIT simulation to simulate SDSS BOSS/eBOSS luminous red galaxies (LRGs) within a wide redshift ra ...

OXFORD UNIV PRESS2022

Angular systematics-free cosmological analysis of galaxy clustering in configuration space

Anand Stéphane Raichoor, Cheng Zhao

Galaxy redshift surveys are subject to incompleteness and inhomogeneous sampling due to the various constraints inherent to spectroscopic observations. This can introduce systematic errors on the summary statistics of interest, which need to be mitigated i ...

OXFORD UNIV PRESS2022

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: measurement of the BAO and growth rate of structure of the emission line galaxy sample from the anisotropic power spectrum between redshift 0.6 and 1.1

Johan Comparat, Claudio Gorgoni, Amélie Tamone, Anand Stéphane Raichoor, Cheng Zhao, Yuting Wang

We analyse the large-scale clustering in Fourier space of emission line galaxies (ELG) from the Data Release 16 of the Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey. The ELG sample contains 173736 galaxies covering 1170deg(2) ...

OXFORD UNIV PRESS2021

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: N-body mock challenge for the eBOSS emission line galaxy sample

Johan Comparat, Amélie Tamone, Anand Stéphane Raichoor, Cheng Zhao

Cosmological growth can be measured in the redshift space clustering of galaxies targeted by spectroscopic surveys. Accurate prediction of clustering of galaxies will require understanding galaxy physics, which is a very hard and highly non-linear problem. ...

OXFORD UNIV PRESS2021

Tightening weak lensing constraints on the ellipticity of galaxy-scale dark matter haloes

Anand Stéphane Raichoor

Cosmological simulations predict that galaxies are embedded into triaxial dark matter haloes, which appear approximately elliptical in projection. Weak gravitational lensing allows us to constrain these halo shapes and thereby test the nature of dark matte ...

EDP SCIENCES S A2021

Baryon acoustic oscillations in the projected cross-correlation function between the eBOSS DR16 quasars and photometric galaxies from the DESI Legacy Imaging Surveys

Anand Stéphane Raichoor, Cheng Zhao

We search for the baryon acoustic oscillations in the projected cross-correlation function binned into transverse comoving radius between the SDSS-IV DR16 eBOSS quasars and a dense photometric sample of galaxies selected from the DESI Legacy Imaging Survey ...

OXFORD UNIV PRESS2021

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: large-scale structure catalogues and measurement of the isotropic BAO between redshift 0.6 and 1.1 for the Emission Line Galaxy

Johan Comparat, Claudio Gorgoni, Jean-Paul Richard Kneib, Amélie Tamone, Anand Stéphane Raichoor, Cheng Zhao, Arjun Dey, David Schlegel

We present the Emission Line Galaxy (ELG) sample of the extended Baryon Oscillation Spectroscopic Survey from the Sloan Digital Sky Survey IV Data Release 16. We describe the observations and redshift measurement for the 269 243 observed ELG spectra, and t ...

OXFORD UNIV PRESS2021

Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological implications from two decades of spectroscopic surveys at the Apache Point Observatory

Johan Comparat, Jean-Paul Richard Kneib, Amélie Tamone, Anand Stéphane Raichoor, Andrei Variu, Cheng Zhao, Yuting Wang, Zheng Zheng

We present the cosmological implications from final measurements of clustering using galaxies, quasars, and Ly alpha forests from the completed Sloan Digital Sky Survey (SDSS) lineage of experiments in large-scale structure. These experiments, composed of ...

American Physical Society2021

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: 1000 multi-tracer mock catalogues with redshift evolution and systematics for galaxies and quasars of the final data release

Jean-Paul Richard Kneib, Amélie Tamone, Anand Stéphane Raichoor, Cheng Zhao

We produce 1000 realizations of synthetic clustering catalogues for each type of the tracers used for the baryon acoustic oscillation and redshift space distortion analysis of the Sloan Digital Sky Surveys-IV extended Baryon Oscillation Spectroscopic Surve ...

OXFORD UNIV PRESS2021

The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: a multitracer analysis in Fourier space for measuring the cosmic structure growth and expansion rate

Jean-Paul Richard Kneib, Anand Stéphane Raichoor, Cheng Zhao, Yuting Wang

We perform a joint BAO and RSD analysis using the eBOSS DR16 LRG and ELG samples in the redshift range of z is an element of [0.6, 1.1], and detect an RSD signal from the cross-power spectrum at a similar to 4 sigma confidence level, i.e., f sigma(8) = 0.3 ...

OXFORD UNIV PRESS2021

The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: measurement of the BAO and growth rate of structure of the luminous red galaxy sample from the anisotropic power spectrum between redshifts 0.6 and 1.0

Amélie Tamone, Anand Stéphane Raichoor, Cheng Zhao, Yuting Wang

We analyse the clustering of the Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey Data Release 16 luminous red galaxy sample (DR16 eBOSS LRG) in combination with the high redshift tail of the Sloan Digital Sky Survey III Baryon ...

OXFORD UNIV PRESS2020

The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: exploring the halo occupation distribution model for emission line galaxies

Amélie Tamone, Anand Stéphane Raichoor, Cheng Zhao

We study the modelling of the halo occupation distribution (HOD) for the eBOSS DR16 emission line galaxies (ELGs). Motivated by previous theoretical and observational studies, we consider different physical effects that can change how ELGs populate haloes. ...

OXFORD UNIV PRESS2020

Removing imaging systematics from galaxy clustering measurements with Obiwan: application to the SDSS-IV extended Baryon Oscillation Spectroscopic Survey emission-line galaxy sample

Johan Comparat, Anand Stéphane Raichoor, Cheng Zhao

This work presents the application of a new tool, Obiwan, which uses image simulations to determine the selection function of a galaxy redshift survey and calculate three-dimensional (3D) clustering statistics. Obiwan relies on a forward model of the proce ...

OXFORD UNIV PRESS2020

Validation of emission-line galaxies target selection algorithms for the Dark Energy Spectroscopic Instrument using the MMT Binospec

Anand Stéphane Raichoor

The forthcoming Dark Energy Spectroscopic Instrument (DESI) experiment plans to measure the effects of dark energy on the expansion of the Universe and create a 3D map of the Universe using galaxies up to z similar to 1.6 and QSOs up to z similar to 3.5. I ...

OXFORD UNIV PRESS2020

The completed SDSS-IV extended baryon oscillation spectroscopic survey: growth rate of structure measurement from anisotropic clustering analysis in configuration space between redshift 0.6 and 1.1 for the emission-line galaxy sample

Johan Comparat, Claudio Gorgoni, Jean-Paul Richard Kneib, Amélie Tamone, Anand Stéphane Raichoor, Cheng Zhao, Yuting Wang

We present the anisotropic clustering of emission-line galaxies (ELGs) from the Sloan Digital Sky Survey IV (SDSS-IV) extended Baryon Oscillation Spectroscopic Survey (eBOSS) Data Release 16 (DR16). Our sample is composed of 173 736 ELGs covering an area o ...

OXFORD UNIV PRESS2020

The completed SDSS-IV extended baryon oscillation spectroscopic survey: pairwise-inverse probability and angular correction for fibre collisions in clustering measurements

Amélie Tamone, Anand Stéphane Raichoor, Cheng Zhao

The completed extended Baryon Oscillation Spectroscopic Survey (eBOSS) catalogues contain redshifts of 344 080 quasars at 0.8 < z < 2.2, 174 816 luminous red galaxies between 0.6 < z < 1.0, and 173 736 emission-line galaxies over 0.6 < z < 1.1 in order to ...

OXFORD UNIV PRESS2020