RUBIES: JWST/NIRSpec Confirmation of an Infrared-luminous, Broad-line Little Red Dot with an Ionized Outflow

Abstract The JWST discovery of “little red dots” (LRDs) is reshaping our picture of the early Universe, yet the physical mechanisms driving their compact size and UV-optical colors remain elusive. Here, we report an unusually bright LRD ( z spec = 3.1) observed as part of the RUBIES program. This LRD exhibits broad emission lines (FWHM ∼ 4000 km s −1 ), a blue UV continuum, a clear Balmer break, and a red continuum sampled out to rest-frame 4 μ m with MIRI. We develop a new joint galaxy and active galactic nucleus (AGN) model within the Prospector Bayesian inference framework and perform spectrophotometric modeling using NIRCam, MIRI, and NIRSpec/Prism observations. Our fiducial model reveals a M * ∼ 10 9 M ⊙…

• NA
  National Aeronautics and Space Administration

  Award: JWST-GO-04233.009-A
• ST
  Space Telescope Science Institute
• AG
  Australian Government
• NR
  National Research Foundation
• DG
  Danmarks Grundforskningsfond
• IF
  Institute for Computational and Data Sciences, Pennsylvania State University