Speaker
Description
Deep IR observations by JWST have discovered a new population of high-redshift compact objects known as "little red dots" (LRDs) with a characteristic V-shape SED. Based on the detection of broad Balmer emission lines, previous studies suggested that LRDs are low-luminosity AGNs, possibly linked to super-Eddington accretion shortly after seed BH formation. In this study, we propose a new color selection technique for identifying LRDs at z~10, utilizing both NIRCam and MIRI photometry to extend the redshift frontier of LRD studies. Applying this method to COSMOS-Web, the largest NIRCam-MIRI joint survey, we find one solid candidate with a compact morphology, a clear F115W dropout, and a V-shape SED. This candidate with the photometric redshift of ~10.5 may represent one of the most distant SMBH so far, potentially representing the era just after seed BH formation. In the talk, we will present the first constraints on the luminosity function of LRDs at z~10 and discuss the implications of this discovery for our understanding of SMBH evolution in the early Universe.
