Where did all the Little Red Dots go? The abundance of LRD analogues among objects with broad lines at z < 0.35
Abstract
One of the most puzzling discoveries since the launch of the James Webb Space Telescope is a numerous population of sources at high redshift nicknamed ``Little Red Dots'' (LRDs). Characterized by broad Balmer emission lines, compact morphologies and v-shaped spectral energy distributions (SEDs) in the rest-frame optical, the nature of LRDs remains elusive. A major challenge is the high redshift nature of LRDs, which makes observations very expensive and difficult. Finding local LRD analogues is a crucial step in unravelling the physical processes giving rise to LRDs, as cheaper observations with many facilities would become available. In this paper, we conduct a search for local LRD analogues by starting from an unbiased parent catalogue of all SDSS objects with broad Hα or Hβ emission lines (both galaxies and quasars) at 0 < z < 0.35, complemented by archival photometry and spectroscopy. We find that among broad-line objects, 19% show a v-shaped SED. We then select objects whose SED is well described by a modified black body (MBB), and identify nine local LRD analogues. After accounting for selection limitations we get an abundance of 0.08% of all objects with broad lines. Among only objects which match the typical continuum and emission line luminosities of LRDs, 5% display a v-shape and 0.37% display a MBB-like SED. We recover one previously-identified local LRD analogue (the so-called ``Egg''), validating our methodology. Among the other eight analogues, one (J0302−0101) shows all the hallmarks of an LRD despite being visibly embedded in the core of a galaxy; another object is ambiguous, and the remaining six may have alternative explanations for their peculiar SEDs. Our study highlights that LRDs are extremely rare at z < 0.35; we find very few objects with broad lines which have LRD-like SEDs, even without attempting to match the compactness of LRDs.
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BibTeX
@misc{seyberlich2026where,
title = {{Where did all the Little Red Dots go? The abundance of LRD analogues among objects with broad lines at $z < 0.35$}},
author = {Lasse Seyberlich and Sarah E. I. Bosman},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2608.05267},
eprint = {2608.05267},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.05267},
}
RIS
TY - UNPB
TI - Where did all the Little Red Dots go? The abundance of LRD analogues among objects with broad lines at z < 0.35
AU - Lasse Seyberlich
AU - Sarah E. I. Bosman
PY - 2026
DA - 2026/10/26
PB - arXiv
DO - 10.48550/arxiv.2608.05267
UR - https://arxiv.org/abs/2608.05267
AB - One of the most puzzling discoveries since the launch of the James Webb Space Telescope is a numerous population of sources at high redshift nicknamed ``Little Red Dots'' (LRDs). Characterized by broad Balmer emission lines, compact morphologies and v-shaped spectral energy distributions (SEDs) in the rest-frame optical, the nature of LRDs remains elusive. A major challenge is the high redshift nature of LRDs, which makes observations very expensive and difficult. Finding local LRD analogues is a crucial step in unravelling the physical processes giving rise to LRDs, as cheaper observations with many facilities would become available. In this paper, we conduct a search for local LRD analogues by starting from an unbiased parent catalogue of all SDSS objects with broad Hα or Hβ emission lines (both galaxies and quasars) at 0 < z < 0.35, complemented by archival photometry and spectroscopy. We find that among broad-line objects, 19% show a v-shaped SED. We then select objects whose SED is well described by a modified black body (MBB), and identify nine local LRD analogues. After accounting for selection limitations we get an abundance of 0.08% of all objects with broad lines. Among only objects which match the typical continuum and emission line luminosities of LRDs, 5% display a v-shape and 0.37% display a MBB-like SED. We recover one previously-identified local LRD analogue (the so-called ``Egg''), validating our methodology. Among the other eight analogues, one (J0302−0101) shows all the hallmarks of an LRD despite being visibly embedded in the core of a galaxy; another object is ambiguous, and the remaining six may have alternative explanations for their peculiar SEDs. Our study highlights that LRDs are extremely rare at z < 0.35; we find very few objects with broad lines which have LRD-like SEDs, even without attempting to match the compactness of LRDs.
ER -