A photometric redshift sample of Luminous Red Galaxies ( hereafter LRGs ) obtained from The DECam Legacy Survey ( DECaLS ) is analysed to probe cosmic distances by exploiting the wedge approach of the two-point correlation function .
Although the cosmological information is highly contaminated by the uncertainties existing in the photometric redshifts from the galaxy map , an angular diameter distance can be probed at the perpendicular configuration in which the measured correlation function is minimally contaminated .
An ensemble of wedged correlation functions selected up to a given threshold based on having the least contamination was studied in the previous work \citep Srivatsan_2019 using simulations , and the extracted cosmological information was unbiased within this threshold .
We apply the same methodology for analysing the LRG sample from DECaLS which will provide the optical imaging for targeting two-thirds of the DESI footprint and measure the angular diameter distances at z = 0.69 and z = 0.87 to be D _ { A } ( 0.697 ) = ( 1499 \pm 77 \mathrm { Mpc } ) ( r _ { d } / r _ { d,fid } ) and D _ { A } ( 0.874 ) = ( 1680 \pm 109 \mathrm { Mpc } ) ( r _ { d } / r _ { d,fid } ) with a fractional error of 5.14 % and 6.48 % respectively .
We obtain a value of H _ { 0 } = 67.59 \pm 5.52 km/s/Mpc which supports the H _ { 0 } measured by all other BAO results and is consistent with \Lambda CDM model .