Lyman-α Cosmology with BOSS Julián Bautista University of Utah. Rencontres du Vietnam Cosmology 2015

Lyman-α Cosmology with BOSS Julián Bautista University of Utah Rencontres du Vietnam Cosmology 2015

Lyman-α Forest of a Quasar (by Andrew Pontzen) F ( obs )= Observed flux Unabsorbed flux ( obs) 2

Lyman-α Forest of a Quasar (by Andrew Pontzen) F ( obs )= Observed flux Unabsorbed flux ( obs) 3

Survey of Lyman-α Forests Tracers of matter distribution in the Universe Quasars IGM blog.sdss3.org 4 Earth

BOSS Baryon Oscillation Spectroscopic Survey DR12 190 000 quasars at 2 < z <3.5 15% more than DR11 Measuring BAO when the Universe was one fifth of its age BAO Expansion rate Dark Energy BAO scale 5

Measuring BAO with forests Quasar redshifts: visual inspection of all targets (Paris++2014) Redshift z 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3 Redshift z 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3 BAO scale ~150 Mpc Continuum level amount of absorption Compute correlation function (~r) =h i j i Measure the BAO scale 6 r? r k ~r obs [nm] 350 400 450 500 350 400 450 500 obs [nm] BOSS spectral coverage

Lyman-α auto-correlation function DR11 r 2 (r?,r k ) r k j i r? r k [h -1 Mpc] r? [h -1 Mpc] (Delubac, JB, ++ 2015)

Lyman-α auto-correlation function r k DR11 (~r) r? (Delubac, JB, ++ 2015) 8

Quasar Lyman-α cross-correlation function DR11 j (Font-Ribera++2014) 9

Fitting BAO model BAOfit package with continuum distortion model (Kirkby++ 2013, Blomqvist++ 2015) model (~r, k,? )= cosmo (~r, k,? )+ broadband (~r) k = D H( z)/r d and? = D A( z)/r d [D H ( z)/r d ] fid [D A ( z)/r d ] fid Radial BAO Transverse BAO r k DR11 k Bias 0? r? 10 Redshift-space distortions

Tests on Mock Catalogs Log-normal absorption fields 1.0 (JB++2015) Correlation functions Transmission F ( ) 0.8 0.6 0.4 0.2 DR11 Mocks 0.0 360 370 380 390 400 Wavelength [nm] f [erg s 1 cm 2 Å 1 ] 10 8 6 4 2 0 2 350 400 450 500 550 Wavelength [nm] BOSS like spectrua 11 BAO best-fits 100 realizations

350 400 450 500 obs [nm] r k j Lyman-α i r? auto-correlation function Preliminary DR12 r k [h 1 Mpc] 150 100 50 0 50 r 2 (r?,r k ) 2.0 1.6 1.2 0.8 0.4 0.0 0.4 0.8 r 2 µ 0.4 0.2 0.0 0.2 0.4 0.6 100 150 150 100 50 0 50 100 150 r? [h 1 Mpc] 1.2 1.6 2.0 0.8 1.0 JB++ 12 in prep 0 <µ<0.5 0.5 <µ<0.8 0.8 <µ<1.0 40 60 80 100 120 140 160 180 r [h 1 Mpc]

350 400 450 500 obs [nm] i Quasar Lyman-α cross-correlation function Preliminary DR12 r k [h 1 Mpc] 150 100 50 0 50 r 2 (r?,r k ) 30 24 18 12 6 0 6 12 r 2 µ 8 6 4 2 0 2 0 <µ<0.5 1 <µ< 0.5 and 0.5 <µ<1.0 100 150 150 100 50 0 50 100 150 r? [h 1 Mpc] 18 24 30 4 6 40 60 80 100 120 140 160 180 r [h 1 Mpc] JB++ 13 in prep

BAO Results DR11 and DR12 Preliminary 2 Auto-correlation = 1499.1/(1515-13) 1479.2 / (1515-13) 2 Cross-correlation = 1957.93 / (1926-20) 426.4/420 k? = 1.054(32) = 0.973(56) 1.030(26) 1.018(45) k? = 1.050(30) = 0.916(29) 1.042(34) 0.930(36) DR12 Planck 2015 Delubac, JB++2015 14 JB++ in prep

Cosmology DR11 Expansion rate Angular distance (Aubourg++2014) 15

What is new in DR12 16

What is new in DR12 190 000 quasars at 2 < z <3.5 15% more than DR11 17

What is new in DR12 Work in progress! - Improved modelling of metal contamination in the forest - New CCD extraction algorithm - Throughput correction (Margala++2015) - Null tests 18

What is new in DR12 Work in progress! - Improved modelling of metal contamination 1D 0.006 0.005 0.004 0.003 0.002 0.001 0.000 Line of sight correlations SiII(1193)/SiII(1190) Lya/SiIII SiIII/SiII(1193) SiIII/SiII(1190) Lya/SiII(1193) Lya/SiII(1190) SiII(1260)/Lya SiII(1260)/SiIII SiII(1260)/SiII(1193) SiII(1260)/SiII(1190) Mock Data (nm) Lyα 121.6 SiIII 120.6 SiII 119.0 SiII 119.3 SiII 126.0 Mocks ( WithMet NoMet )[ 10 4 ] 0.001 0.002 0.003 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1/ 2 Metal line contaminating the BAO peak Use of metal templates while fitting for BAO 19

What is new in DR12 Work in progress! - New CCD extraction algorithm Unbiased estimator of counts More accurate propagation of errors (5% increase) Cleaner mean transmission Less sky residuals 20

What is new in DR12 - Throughput correction (Margala++2015) Due to different focal plane configurations between stars and quasars Uncorrected Corrected 21

- Null tests Build fake forests Compute correlations What is new in DR12 Expectation Measurement Work in progress! 22

What is new in DR12 - Systematics Contributions from sky model, calibration and galactic absorption Work in progress! No significant shift in the BAO peak estimates! 23

CONCLUSIONS Lyman-α forest BAO allows us to access expansion at z ~ 2.3 DR12 analysis: 15% more data Robust estimate of astrophysical and instrumental systematics Stay tuned! 24

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Large-scale structure of Lyman-α emission intensity (First optical intensity mapping result) Quasar BOSS$ LRG$fiber$$ spectra$ minus$lrgs$ Cross7correla9on$ Cro:,$Miralda7Escude,$Zheng$et$al.$ (2015)$arXiv:1504.04088$ Quasar&Lya)emission)cross&correla1on:) ))))Shape)=)Lambda)CDM) ))))Amplitude))prop.)to))bias)X)mean)) ))))))))))))))))))))))))intensity)of)lya)emission.) 26