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Testing HOD model Yu Liang

Testing HOD model Yu Liang. Tsinghua University & Instituto de Física Teórica (IFT), Universidad Autónoma de Madrid (UAM). Background. Five parameter HOD model . Motivation-testing HOD model. Varying the five parameters to fit the correlation function.

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Testing HOD model Yu Liang

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  1. Testing HOD modelYu Liang Tsinghua University & Instituto de FísicaTeórica (IFT), Universidad Autónoma de Madrid (UAM)

  2. Background • Five parameter HOD model

  3. Motivation-testing HOD model • Varying the five parameters to fit the correlation function. • After the correlation is fitted well, we check how it will be in power spectrum. • We guess HOD model with five parameters can fit any correlation but it won’t be so well even though correlation function is well fitted.

  4. Catalogs • CatalgoAccSm.a.0.65.DAT (get from Anatoly , some one named peter created sub-sub-halo, original from BDMV) • BDMV (whole catalog and with 6.3E13 mass cut to select distinct halo) • BDMW (whole catalog and with 6.3E13 mass cut to select distinct halo) • FOF with particles (whole catalog and with 6.3E13 mass cut to select distinct halo)

  5. Get data by Query the MultiDarkDatabase (few days) haloid=$((62000000000+$i)) sql=“ select top 5 fofId, p.particleId, snapnum, x, y, z, vx, vy, vz, phkey from MDR1..FOFParticles62 as fp inner join MDR1..particles62 as p on fp.particleId = p.particleId where fp.fofId = $haloid order by newid()"

  6. Get data by Query the MultiDarkDatabase (few hours) with tmp as ( select row_number() over ( partition by fofId order by newid() ) as 'rownum', fofId, particleId from MDR1..FOFparticles62 where fofId between 62000400000 $plus $i $times 1e3 and 62000400999 $plus $i $times 1e3 ) select fp.fofId , p.* from tmpas fp , MDR1..particles62 as p Where fp.particleId = p.particleId and fp.rownum <= 5 Order by fofId, particleId

  7. Correlation function

  8. Check what’s going on with the subhalo • Compute the correlation function of subhalos "only“ • Compute the distance between each subhalo and its parent distinct halo, and then make a distribution

  9. Check what’s going on with the subhalo • The typical size of a halo is smaller than 1 Mpc/h and it is why we have very large power at first bin. • The subhalo picked in my way would boost the power of the correlation function. In addition, we found the subhalos are living very close to distinct halos (i.e. < 1Mpc/h) and that is why we have large power at first two bins (r < 2Mpc/h)

  10. Use HOD to assign galaxy

  11. HOD model • Difference between papersa, No central galaxy, no satellite galaxy.b, Satellite galaxies can exist without central galaxy.c, Nsat=[(M-M0)/M1]^alpha (astro-ph/0408564 ZhengZheng et al) d, Nsat=Ncen*[(M-M0)/M1]^alpha (astro-ph/0703457 ZhengZheng et al) e, Nsat=(M/M1)^alpha * exp(-Mcut/M1) (arXiv 1202:6057V4)

  12. Varying five parameters

  13. The mean occupancy of all haloes in our MultiDark sample Fig 8. Nuza et al 2013

  14. Thank you!

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