3.3.9.2  :  Blaizot2006_AllSky

This dataset contains 6 all-sky mock catalogues (tables Blaizot_AllSky_RT_x, with x = 1-5 and Blaizot_AllSky_PT_1). They are all limited at an apparent AB magnitude of 18 in the r filter from SDSS, in an attempt to reproduce (with some margin) the SDSS spectroscopic selection. The catalogues include apparent magnitudes in the 8 filters from both SDSS and 2MASS (namely u,g,r,i,z,J,H, and K).

These light-cones were made using the MoMaF code (see Blaizot et al. 2005, MNRAS 360, 159) and the semi-analytic model presented in De Lucia & Blaizot 2006 (astro-ph/0606519), the results of which are stored in the MPAGalaxies..DeLucia2006a table.

Light-cones 'Blaizot_AllSky_RT_1' to 'Blaizot_AllSky_RT_5' use the random tiling technique described in Blaizot et al. (2005), and each of these mock catalogues was generated with a different seed for the random number generator. In practice, the main effect of this here is that the "observer" sits in different parts of the simulation volume for each light-cone, thus allowing estimates of cosmic variance in the very local universe.

The light-cone 'Blaizot_AllSky_PT_1' preserves the periodicity of the density field (i.e. it does not use *random* tiling). The price to pay is that replications do introduce spatial correlations on very large scales. The gain is that the density field is indeed almost continuous across the whole light-cone volume.

The tables contain not only the "observable" information for the mock catalogues, but also all the attributes(columns) of the underlying galaxy obtained from DeLucia2006a. This information could in principle be obtained using a join on the galaxyId column, however for large subsets this can easily cause a degradation in query speed to beyond the current timeout limits. Hence we have added this information for you already.

Credits : on top of the normal credits for using the Millennium database (see here), please also refer to the MoMaF paper (Blaizot et al. 2005, MNRAS 360, 159) if you use these mock catalogues for publication.

Example queries :

redshift distribution

select floor(cosmo_redshift*500)/500 as z 
,      count(*) as n 
  from mpamocks..blaizot2006_allsky_rt_1 
 group by floor(cosmo_redshift*500)/500 
 order by z 

mass distribution of a random subsample

select floor(log10(stellarmass)*10)/10 as lmstar
,      count(*) as n
  from mpamocks..Blaizot2006_AllSky_RT_1
group by floor(log10(stellarmass)*10)/10
  order by lmstar