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Baryon acoustic oscillations from the complete SDSS-III Lyα-quasar cross-correlation function at z = 2.4

Citation:

du Mas des Bourboux H, Le Goff J-M, Blomqvist M, Busca NG, Guy J, Rich J, Yèche C, Bautista JE, Burtin É, Dawson KS, et al. Baryon acoustic oscillations from the complete SDSS-III Lyα-quasar cross-correlation function at z = 2.4. Astronomy and Astrophysics. 2017;608.

Date Published:

December 1, 2017

Abstract:

We present a measurement of baryon acoustic oscillations (BAO) in thecross-correlation of quasars with the Lyα-forest flux transmissionat a mean redshift of z = 2.40. The measurement uses the complete SloanDigital Sky Survey (SDSS-III) data sample: 168 889 forests and 234 367quasars from the SDSS data release DR12. In addition to the statisticalimprovement on our previous study using DR11, we have implementednumerous improvements at the analysis level enabling a more accuratemeasurement of this cross-correlation. We have also developed the firstsimulations of the cross-correlation that allow us to test differentaspects of our data analysis and to search for potential systematicerrors in the determination of the BAO peak position. We measure the tworatios DH(z = 2.40) /rd = 9.01 ± 0.36 andDM(z = 2.40) /rd = 35.7 ± 1.7, where theerrors include marginalization over the non-linear velocity of quasarsand the cross-correlation of metals and quasars, among other effects.These results are within 1.8σ of the prediction of theflat-ΛCDM model describing the observed cosmic microwavebackground anisotropies. We combine this study with the Lyα-forestauto-correlation function, yielding DH(z = 2.40)/rd = 8.94 ± 0.22 and DM(z = 2.40)/rd = 36.6 ± 1.2, within 2.3σ of the sameflat-ΛCDM model.

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