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

{getToc} $title={Table of Contents}

Summary

The James Webb Space Telescope (JWST) has discovered "little red dots" (LRDs) that are reshaping our understanding of the early universe. A bright LRD, RUBIES-BLAGN-1, was observed with JWST/NIRSpec, revealing broad emission lines and a red continuum. The data suggest that the object is a dust-reddened active galactic nucleus (AGN) with a stellar mass of 109 M and a black hole mass of 108 M.

Highlights

• RUBIES-BLAGN-1 is a bright LRD with broad emission lines and a red continuum.
• The object is likely a dust-reddened AGN with a stellar mass of 109 M.
• The black hole mass is estimated to be 108 M.
• The AGN is thought to be the dominant source of the red continuum.
• The object's size is compact, with an effective radius of 0.2 kpc.
• The inferred star-formation history resembles that of a post-starburst galaxy.
• The object's redshift is z = 3.1034.

Key Insights

• The discovery of RUBIES-BLAGN-1 provides new insights into the nature of LRDs, suggesting that they may be dust-reddened AGNs rather than dusty star-forming galaxies.
• The object's compact size and high stellar density suggest that it may be a unique phase in the early formation of massive galaxies and their supermassive black holes.
• The lack of hot dust emission in RUBIES-BLAGN-1 is puzzling, as it is expected to be a common feature of AGNs.
• The object's red continuum is thought to be dominated by the AGN, but the exact nature of the continuum is still uncertain.
• The black hole mass of RUBIES-BLAGN-1 is lower than expected for a typical UV-selected quasar at z = 3.
• The object's Eddington luminosity suggests that the black hole may be radiating at 40% of the Eddington limit, potentially indicating a high accretion rate.
• The detection of a blue-shifted Hei absorption feature suggests the presence of an ionized outflow, which may be a common feature among LRDs.

Mindmap

Citation

Wang, B., de Graaff, A., Davies, R. L., Greene, J. E., Leja, J., Brammer, G. B., Goulding, A. D., Miller, T. B., Suess, K. A., Weibel, A., Williams, C. C., Bezanson, R., Boogaard, L. A., Cleri, N. J., Hirschmann, M., Katz, H., Labbe, I., Maseda, M. V., Matthee, J., … Whitaker, K. E. (2024). RUBIES: JWST/NIRSpec Confirmation of an Infrared-luminous, Broad-line Little Red Dot with an Ionized Outflow (Version 3). arXiv. https://doi.org/10.48550/ARXIV.2403.02304