17 March 2026
Konkoly Observatory
Europe/Budapest timezone
Supported by the Lendület Programme of the Hungarian Academy of Sciences

Little Red Dots - What's behind the name?

17 Mar 2026, 10:15
15m
Detre Hall (Konkoly Observatory)

Detre Hall

Konkoly Observatory

Speaker

Krisztina Perger (Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences)

Description

A new population of high-redshift sources was discovered by the James Webb Space Telescope, referred to as little red dots (LRDs). These are a mysterious class of objects that appear to be extremely compact in size, show excess ultraviolet emission, have a red optical continuum in the rest-frame, and exhibit broad-line spectral features. Collecting a sample of 919 LRDs from the literature, we found no associated radio counterparts in catalogues of large radio surveys. To uncover possible sub-millijansky-level weak radio emission, we performed mean and median image stacking analyses of empty-field radio image cutouts centred on the LRD positions. As no underlying emission could be recovered down to ~10 uJy levels, the nature of these extremely radio-quiet LRDs is discussed with respect to `regular' active galactic nuclei at high redshifts.

Author

Krisztina Perger (Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences)

Co-authors

Judit Fogasy (Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences) Krisztina Gabányi (Department of Astronomy, Institute of Physics and Astronomy, ELTE) Sándor Frey (Konkoly Observatory, HUN-REN Research Centre for Astronomy and Earth Sciences)

Presentation materials