Abstract

Finding and characterizing the earliest systems are pivotal for answering critical cosmological questions such as first galaxies and black holes (BHs), as well as the cosmic reionization process. The advent of JWST has dramatically advanced our capability to detect and analyze systems from the early galaxies, now serving the candidates out to z~17. Simultaneously, submm/mm observations have gained prominence, providing complementary insights into the cold dust and gas characteristics and verifying the authenticity of ultra-high-redshift galaxy candidates against dusty lower-redshift interlopers. In my talk, I will overview my recent quest for the first light in the universe. My strategy synergizes JWST, ALMA, and Gravitational Lensing for the most sensitive and comprehensive investigations of the earliest epochs. My systematic JWST spectroscopic survey corroborates the high abundance of z > 9 galaxies recently claimed from photometric measurements, and I will discuss its possible origins from their initial characterizations. I also derive the infrared luminosity function by establishing the largest faint ALMA mm sample ever, enabling the first direct attempt to quantify the total (=unobscured + dust-obscured) cosmic star formation history up to z~8. Looking ahead, I will also present my vision in the next few years to decade. A unique ensemble of ~160 hours PI JWST, ALMA, and MUSE programs targeting strongly lensed galaxies at z=6-7 forms the cornerstone of my plan. This will facilitate in-depth characterizations of chemical enrichment, mass assembly (stars, dust, gas, and dark matter), and kinematics down to ~10 pc in the lensed systems at z=6-7. Building upon this, I also will introduce a pioneering 220-hour program of JWST’s first wide lensing cluster survey and future prospects on the first light studies in the era of next generation extremely large telescopes.