We have two (more) visitors this week. Suk Sien Tie and Jiaxi Yu are visiting Wednesday – Friday and both will give talks tomorrow at 1pm in PRB 4138 (time/location of the cosmology group meeting).
Suk Sien will be based in 4008 McPherson and her email is sstie@physics.ucsb.edu. Jiaxi will be based in CCAPP and her email is jiaxi.yu@epfl.ch. Here are the titles and abstracts for the talks tomorrow:
Here are the titles and abstracts for the talks tomorrow:
Clustering of the metal-line forest as a probe of cosmic reionization enrichment
Suk Sien Tie (UC Santa Barbara)
I will introduce using metal-line absorptions, specifically their clustering properties as measured through the correlation function, as a tool to probe cosmic reionization and enrichment. I will first present this idea from a theoretical simulation point of view and then discuss the results of some ongoing work in applying this method to a set of ground-based measurements.
The galaxy-halo connection inferred from the DESI Early-Data Release
Jiaxi Yu (EPFL)
In the spectroscopic survey, we observe millions of spectra of galaxies and quasars (QSO) to study the nature of dark energy and the growth of dark matter. Meanwhile, high-resolution N-body simulations can reproduce the theoretically predicted LSS and provide properties of dark matter haloes. The relation between galaxy/quasar-haloes is highly non-linear and subject to the local environment, and is crucial for accurate cosmological measurements. SubHalo Abundance Matching (SHAM) is an empirical method to assign galaxies to dark matter haloes from N-body simulations. However, its classical version only works for luminous red galaxies (LRGs, most of which are quiescent). In this talk, we introduce an inclusive SHAM for LRGs, emission line galaxies (ELGs, mostly star-forming) and QSOs in DESI EDR, accounting for the massive (sub)halo incompleteness, the redshift uncertainty and the satellite fraction. Its model galaxies reproduce the clustering of observation on scales of 5-30Mpc/h and at 0.4<z<3.5. Besides SHAM, we have variants of Abundance Halo Occupation Distribution (HOD) that is able to reproduce 2PCF down to 0.03Mpc/h, extracting interesting features like assembly bias, conformity and satellite fraction. The LRG-ELG cross correlation would also provide new information on the galaxy-halo connection studies.