Presentation #410.06D in the session “Cosmology 2”.
The extragalactic background light (EBL) refers to the integrated emission from sources outside of the Milky Way. In the near infrared window, the EBL traces star formation history from the Epoch of Reionization (EOR) and places tight constraints on cosmological models. The measured EBL has been reported to fluctuate more than predicted by models in various studies including those using data from the first Cosmic Infrared Background ExpeRiment (CIBER-1) observations at 1.1 and 1.6 um. To explain the difference, many sources have been considered in the literature including the intra-halo light (IHL) from faint stars stripped from their host galaxies during merging. Best-fitting models suggest an IHL level as bright as the integrated light from galaxies. To confirm this model and to disentangle IHL from EOR signals, CIBER-2 has wavelength coverage over 0.5 - 2.5 um in six wavebands and increases the light-gathering power to 10 times CIBER-1. In this talk, I will present CIBER-2 design and characterization, focusing on the detector performance to provide crucial benchmark for upcoming missions. Next, I will report new progress on the EBL fluctuation analysis using unpublished CIBER-1 data. Built on the pipeline established in the first three flights, this revised analysis captures the hardware changes while also laying the groundwork for future CIBER-2 pipeline.