Oral Presentation

Cosmology from the Diffuse Emission in the Extragalactic Background Light

Author(s): Yun-Ting Cheng (JPL/Caltech)

Presenter: Yun-Ting Cheng (JPL/Caltech)

In conventional galaxy surveys, the large-scale structure (LSS) is probed by performing photo-z and spec-z on bright sources and use them to trace the 3D density field, which leaves the information from faint sources largely unexplored. Intensity mapping has emerged as an alternative method to study the LSS and statistical properties of emission sources. By measuring fluctuations of aggregate emission from all sources without individually resolving them, intensity mapping is well-suited for studying the faint / diffuse emission and the high-redshift universe, where only brightest sources can be detected individually. In this talk, I will first give an overview on intensity mapping. Next, I will present a new data-driven technique to study cosmology from multi-band large-scale intensity maps. Without detecting individual sources or imposing any prior knowledge, our method can simultaneously determine the spectral and spatial distribution of all emitting sources and the underlying LSS traced by them. This method will be widely applicable to upcoming cosmological surveys (LSST, Euclid, Roman, SPHEREx, etc), and can provide complementary information to the detection-based galaxy redshift surveys.