We present neutrino mass bounds using 900,000 luminous galaxies with photometric redshifts measured from Sloan Digital Sky Survey III Data Release Eight ( SDSS DR8 ) .
The galaxies have photometric redshifts between z = 0.45 and z = 0.65 , and cover 10,000 square degrees and thus probe a volume of 3 h ^ { -3 } Gpc ^ { 3 } , enabling tight constraints to be derived on the amount of dark matter in the form of massive neutrinos .
A new bound on the sum of neutrino masses \sum m _ { \nu } < 0.26 eV , at 95 % confidence level ( CL ) , is obtained after combining our sample of galaxies , which we call ” CMASS ” , with WMAP 7 year Cosmic Microwave Background ( CMB ) data and the most recent measurement of the Hubble parameter from the Hubble Space Telescope ( HST ) .
This constraint is obtained with a conservative multipole range choice of 30 < \ell < 200 in order to minimize non-linearities , and a free bias parameter in each of the four redshift bins .
We study the impact of assuming this linear galaxy bias model using mock catalogs , and find that this model causes a small ( \sim 1 - 1.5 \sigma ) bias in \Omega _ { DM } h ^ { 2 } .
For this reason , we also quote neutrino bounds based on a conservative galaxy bias model containing additional , shot noise-like free parameters .
In this conservative case , the bounds are significantly weakened , e.g . \sum m _ { \nu } < 0.36 eV ( 95 % confidence level ) for WMAP+HST+CMASS ( \ell _ { max } = 200 ) .
We also study the dependence of the neutrino bound on multipole range ( \ell _ { max } = 150 vs \ell _ { max } = 200 ) and on which combination of data sets is included as a prior .
The addition of supernova and/or Baryon Acoustic Oscillation data does not significantly improve the neutrino mass bound once the HST prior is included .

A companion paper ( ) describes the construction of the angular power spectra in detail and derives constraints on a general cosmological model , including the dark energy equation of state w and the spatial curvature \Omega _ { K } , while a second companion paper presents a measurement of the scale of baryon acoustic oscillations from the same data set .
All three works are based on the catalog by .