Roland de Putter, Olga Mena, Elena Giusarma, Shirley Ho, Antonio Cuesta, Hee-Jong Seo, Ashley Ross, Martin White, Dmitry Bizyaev, Howard Brewington, David Kirkby, Elena Malanushenko, Viktor Malanushenko, Daniel Oravetz, Kaike Pan, Will J. Percival, Nicholas P. Ross, Donald P. Schneider, Alaina Shelden, Audrey Simmons, Stephanie Snedden
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 $\Omega_{\rm DM} h^2$. 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 ($\ell_{\rm max}=200$). We also study the dependence
of the neutrino bound on multipole range ($\ell_{\rm max}=150$ vs $\ell_{\rm
max}=200$) 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.
[abridged]
View original:
http://arxiv.org/abs/1201.1909
No comments:
Post a Comment