Extragalactic Background Fluctuation from the Numerical Galaxies

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Extragalactic Background Fluctuationfromthe
Numerical Galaxies

• Hideki Yahagi DTAP, NAOJ
• Masahiro Nagashima Univ. of Durham
• Yuzuru Yoshii IoA, Univ. of Tokyo

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Cosmic Background Radiation
Hauser Dwek (2002)
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Cosmic Microwave Background

• WMAP

Benett et al. (2003)
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Cosmic far-IR Background

• ISO

Matsuhara et al. (2000)
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Cosmic near-IR Background

• ISO

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?GC N-body SAM

• Dark matter carries most of mass in the Universe
• Galaxies are baryonic components accumulated at
  the bottom of the potential well generated by
  dark matter
• We can treat the evolution of dark matter
  distribution (by N-body method) and evolution of
  galaxies (by Semi-analytic model SAM) separately
• Spatial distribution ?N-body
• Other observable quantities ?SAM
• Kauffmann et al. (1999)

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Parameters of N-body simulation

• Computer VPP-5000 (_at_ ADAC/NAOJ)
• Number of particles 5123
• Cosmological parameters
• W0.3, l0.7, s81.0
• Box size 70h-1 Mpc
• Movie

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Mass Function of Dark Halos

• Effective mass resolution is several 1010M8
• (L 70h-1Mpc)
• Well-fitted by Sheth-Tormen type mass function

Yahagi, Nagashima, and Yoshii (2003)
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Semi-Analytic Model

• Nagashima et al. (2001)

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Semi-Analytic Model
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Semi-Analytic Model
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Semi-Analytic Model
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Semi-Analytic Model
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Distribution of Dark Matter and Galaxies

• z0

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Distribution and Colors ofGalaxies in the Cluster

• Cluster at z0

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Distribution and Colors ofGalaxies in the Cluster

• Cluster _at_z0.5

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Distribution and Colors ofGalaxies in the Cluster

• Cluster at z1

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Applications of ?GC

• Angular correlation function of galaxies
• Yahagi, Nagashima, Miyazaki, Gouda, Yoshii
• Extragalactic background fluctuation
• Nagashima, Yahagi, Yoshii
• Cosmic string search
• Japanese Virtual Observatory groups

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Angular Correlation Function

• Wedge diagram

40x40 arcmin2
RClt22
22ltRClt24
24ltRClt26
26ltRC
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Angular Correlation Function

• Field-to-field variation

(DD-2DRRR)/RR (Landy Szalay 1993)
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Angular Correlation Function

• Integral Constraints

1wtruelt1wtruegt lt1wobsgtlt(n/ltngt)2 gt
1ltwobsgts2
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Angular Correlation Function

• Limiting magnitude

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Angular Correlation Function

• Subaru Suprime-Cam
• GTO 2.2 deg2 field
• S. Miyazaki (Subaru telescope, NAOJ) et al.

Suprime-Cam (National Astronomical Observatory)
Subaru Telescope (National Astronomical
Observatory of Japan)
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Angular Correlation Function

• Comparison with observational data

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Extragalactic Background Fluctuation

• Two-body correlation function of galaxies
• Correlation function of galaxies brighter than
  the limiting magnitude
• Edxtra-galactic background fluctuation
• Correlation function of galaxies dimmer than the
  limiting magnitude

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Extragalactic Background Fluctuation

• Diffuse extra-galactic background light (EBL)
• Superposition of unresolved galaxies ?(NIR)
• Expected outcome from EBL anisotropy
• Source of EBL
• Number of unresolved galaxies
• IR Satellite projects
• SIRTF
• Astro-F, SPICA

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Extragalactic Background Fluctuation
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Extragalactic Background Fluctuation
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Extragalactic Background Fluctuation

• Kashlinsky et al. (2002)

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Summary

• N-body SAM ?GC
• High mass resolution
• Parallelized AMR N-body simulation code
• Comparison with observation
• Angular correlation function
• Our catalog realizes the observational data
• Extragalactic background light
• Our catalog fits the 2MASS results quite well
• What is the origin of the excess at 10minslt ?