Planck 2013 results. XXX. Cosmic infrared background measurements and implications for star formation (1309.0382v1)

Abstract: We present new measurements of CIB anisotropies using Planck. Combining HFI data with IRAS, the angular auto- and cross frequency power spectrum is measured from 143 to 3000 GHz, and the auto-bispectrum from 217 to 545 GHz. The total areas used to compute the CIB power spectrum and bispectrum are about 2240 and 4400 deg^2, respectively. After careful removal of the contaminants, and a complete study of systematics, the CIB power spectrum and bispectrum are measured with unprecedented signal to noise ratio from angular multipoles ell~150 to 2500, and ell~130 to 1100, respectively. Two approaches are developed for modelling CIB power spectrum anisotropies. The first approach takes advantage of the unique measurements by Planck at large angular scales, and models only the linear part of the power spectrum, with a mean bias of dark matter halos hosting dusty galaxies at a given redshift weighted by their contribution to the emissivities. The second approach is based on a model that associates star-forming galaxies with dark matter halos and their subhalos, using a parametrized relation between the dust-processed infrared luminosity and (sub-)halo mass. The two approaches simultaneously fit all auto- and cross- power spectra very well. We find that the star formation history is well constrained up to z~2. However, at higher redshift, the accuracy of the star formation history measurement is strongly degraded by the uncertainty in the spectral energy distribution of CIB galaxies. We also find that CIB galaxies have warmer temperatures as redshift increases. The CIB bispectrum is steeper than that expected from the power spectrum, although well fitted by a power law; this gives some information about the contribution of massive halos to the CIB bispectrum.

Analysis of Planck 2013 Results: Cosmic Infrared Background Measurements and Their Implications for Star Formation

This paper presents a comprehensive analysis of cosmic infrared background (CIB) anisotropies using data from the Planck HFI combined with IRAS data, focusing on measurements from 143 to 3000 GHz. The paper significantly improves the signal-to-noise ratio of the CIB power spectrum and provides new insights into the star formation history and CIB-galaxy clustering.

Key Findings

1. High Signal-to-Noise Measurements: Measurements of the CIB power spectrum were conducted with exceptional precision across a wide range of angular multipoles, providing unprecedented insights particularly between $\ell \sim150$ to $2500$.
2. Bispectrum Analysis: The paper reports on the bispectrum due to clustering of dusty, star-forming galaxies from $\ell \sim130$ to $1100$, with noticeable signal-to-noise ratios at 217, 353, and 545 GHz.
3. Modelling Approaches: Two distinct models were developed and employed:
   • A linear model focusing on large-scale measurements which constrains the redshift evolution of bias and SFRD (star-formation rate density).
   • An extended halo model integrating a luminosity-mass relation to fit data across all scales, providing insights into galaxy formation processes.
4. Star Formation Redshift History: The research successfully models the star formation history of the Universe, presenting robust estimates up to redshift $z \sim 2$. Beyond this, the accuracy diminishes due to uncertainties in CIB galaxy SEDs.
5. Biasing and Halo Mass: The effective bias is constrained significantly, showing consistency within halo masses of log$(M_{\rm eff}/) = 12.6$, aligning well with independent analyses of efficient star-forming masses.
6. Temperature Evolution: An important finding is the increase in CIB galaxy temperatures as redshift increases, supporting the hypothesis of a more intense radiation field at higher redshifts.

Implications

The research poses significant implications for understanding galaxy formation and the nature of the large-scale Universe:

• Constraining Star Formation and Bias: The clarity in modelling the star formation rate and understanding the associated bias evolution enhances our comprehension of cosmic structures formation.
• Halo Models and Substructure: The work advances the comprehension of dark matter halo occupation models and the mass-luminosity relations critical to modern cosmology, enabling more detailed predictions of galaxy clustering.
• Future Directions in CIB Studies: Such precise measurements challenge and refine current models of galaxy evolution further refining the linkage between observed CIB and underlying matter structures. Future studies can leverage these findings to refine techniques in separating the CIB signal from other cosmic foregrounds.

In summary, this paper portrays a meticulous and rigorous approach to understanding the cosmic infrared background and its implications for cosmology and galaxy formation theories. The results highlight the utility of CIB data in probing not only the early Universe's star formation but also the larger dark matter structure distribution, providing a roadmap for future cosmological and astrophysical investigations.