Colloquium on Mar. 2, 2023

Cosmic star-formation history with cosmic infrared background cross-correlations

Speaker: Ziang Yan (Institut, Ruhr-Universität Bochum Universitätsstr)

Venue: Video Conference

Time: 16:00 PM, Thursday, Mar. 2, 2023

Abstract:

Star formation is traditionally probed with multiwavelength observations by connecting galaxy light with star formation rate. In this work, we present a new method, namely tomographic cross-correlation between the cosmic infrared background (CIB) and galaxy samples. The galaxy samples are from the Kilo-Degree Survey (KiDS), while the CIB map is made from Planck sky maps at 353, 545, and 857 GHz. We measure the cross-correlation in harmonic space within 100 < l < 2000 with a significance of 43σ. We model the cross-correlation with a halo model, which links CIB anisotropies to star formation rates (SFR) and galaxy abundance. We assume that SFR has a lognormal dependence on halo mass, while galaxy abundance follows the halo occupation distribution (HOD) model. The cross-correlations give a best-fit maximum star formation efficiency of ηmax = 0.41+0.09 −0.14 at a halo mass log10(Mpeak/M ) = 12.14 ± 0.36. The derived star formation rate density (SFRD) is well constrained up to z ∼ 1.5. The constraining power at high redshift is mainly limited by the KiDS survey depth. We also show that the constraint is robust to uncertainties in the estimated redshift distributions of the galaxy sample. A combination with external SFRD measurements from previous studies gives consistent while tighter constraints. This validates the use of CIB tomography as an independent probe of the star formation history of the Universe. Finally, we provide a forecast for future galaxy surveys and conclude that, due to their considerable depth, future surveys will yield a much tighter constraint on the evolution of the SFRD.  

Report PPT:  SWIFAR_Ziang Yan.pdf