MICE Galaxy Catalogue J. Carretero F. Castander M. Crocce P. Fosalba E. Gaztañaga www.ice.cat/mice domingo 8 de julio de 2012 1
MOCK GALAXY CATALOGUE • Generating mock galaxy catalogues from N-body haloes using HOD prescription + all sky lensing maps • Constraints: • Luminosity function • Colour-magnitude diagram • Clustering as a function of colour and luminosity domingo 8 de julio de 2012 2
MOCK GALAXY CATALOGUE • MICE Grand Challenge simulation 70 billions particles, 3 Gpc/h box, m p =3 × 10 10 M • Lightcone without repetition up to z ~ 1.4 • FoF haloes with b=0.2 (150 millions, n part ≥ 10) • 1 octant (5000 sq.deg.) • 117M galaxies • Contents: - Positions (RA, DEC, z) - Magnitudes - SEDs - Lensing (convergence & shear) domingo 8 de julio de 2012 3
HALO CATALOGUE z = 0 z = 1.4 domingo 8 de julio de 2012 4
LENSING IN MICE SIMS “ The onion universe: all sky light-cone simulations in spherical shells ” Fosalba et al, MNRAS, 391 , 435 (2008) • Split the data into thin shells. • Interpolate into (Healpix) pixels • Combine to produce convergence maps • From this, it is possible to obtain other lensing observables, e.g. shear, magnification, flexion, etc in the Born approximation domingo 8 de julio de 2012 5
LENSING IN MICE SIMS • Shear power spectrum for sources at z=1 (sub arc-min resolution) domingo 8 de julio de 2012 6
HALO OCCUPATION DISTRIBUTION • Large N-body MICE simulation provides haloes • Each halo contains one central galaxy and maybe some satellite galaxies • Compute how many satellite galaxies populate each halo (HOD) <N sat > = (M/M 1 ) α • Assign luminosities to central and satellite galaxies conserving the luminosity function domingo 8 de julio de 2012 7
LUMINOSITY FUNCTION domingo 8 de julio de 2012 8
HALO OCCUPATION DISTRIBUTION • Large N-body MICE simulation provides haloes • Each halo contains one central galaxy and maybe some satellite galaxies • Compute how many satellite galaxies populate each halo (HOD) <N sat > = (M/M 1 ) α • Assign luminosities to central and satellite galaxies conserving the luminosity function • Assign colours to central and satellite galaxies reproducing the colour-magnitude diagram domingo 8 de julio de 2012 9
COLOUR-MAGNITUDE DIAGRAM domingo 8 de julio de 2012 10
HALO OCCUPATION DISTRIBUTION • Compute positions and velocities for centrals and satellites within the halo. NFW and Virial Theorem • Compute the projected correlation function as a function of colour and magnitude and compare with observations • Tune HOD parameters and the assignment of luminosities and colours to fit the correlation function domingo 8 de julio de 2012 11
GALAXY CLUSTERING RED BLUE domingo 8 de julio de 2012 12
GALAXY CLUSTERING domingo 8 de julio de 2012 13
GALAXY CLUSTERING domingo 8 de julio de 2012 14
LENSING APPLIED TO GALAXIES • All-sky convergence maps computed in 3D in the LC • Compute shear in this 3D grid • Assign convergence and shear to galaxies domingo 8 de julio de 2012 15
HALO OCCUPATION DISTRIBUTION METHOD • Compute positions and velocities for centrals and satellites within the halo. NFW and Virial Theorem • Compute the projected correlation function as a function of colour and magnitude and compare with observations • Tune HOD parameters and the assignment of luminosities and colours to fit the correlation function • Assign full SEDs • Tune model parameters at higher redshift • Assing sizes and ellipticities domingo 8 de julio de 2012 16
CURRENT CATALOGUE’s CAVEATS • Incomplete at low luminosity at low redshift (z<0.8) because of the mass resolution M halo > 2.9 × 10 11 M • Local luminosity & colour recipes + lightcone yields wrong magnitudes at high redshift • Triaxial NFW (clusters?) • No shear errors domingo 8 de julio de 2012 17
DM particles Lightcone 3072 Mpc/h / z ~1.4 Thanks for your attention! ) n o i t a c i l p e r o n ( N=4096 3 m p ~ 3 e10 M sun /h domingo 8 de julio de 2012 18
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