Defines a sample of ~1300 SDSS quasars as Local Red Dots matching LRD photometric colors at z~0.4-0.8, with a V-shaped subset showing Balmer absorption and [NeV] emission, and SEDs modeled as reddened AGN plus host galaxy that match LRD stacks.
Do little red dots really form a distinct class of astronomical objects?
5 Pith papers cite this work. Polarity classification is still indexing.
5
Pith papers citing it
abstract
JWST observations have identified a class of enigmatic sources known as "Little Red Dots" (LRDs). These have been interpreted as a distinct class of active galactic nuclei (AGN) and host galaxies, potentially involving "quasi-stars" or Black Hole stars (BH*). However, two questions remain: is there a clear discontinuity between LRDs and field galaxies, and do LRDs form a homogeneous population? In this work, we address these issues by introducing a continuous metric to evaluate the "LRDness" of galaxies. We measure their compactness ($\delta_{compact}$), the sharpness of the V-shaped spectral energy distribution ($\delta_{v-shape}$), and the strength of the broad Balmer line emission. We apply this approach to a sample of ~48,000 galaxies with photometric and ~5,000 with spectroscopic information, selected over ~750 arcmin^2. We find that V-shape prominence correlates strongly with morphology without a clear transition at common LRD selection thresholds: the fraction of compact galaxies rises continuously with V-shape intensity. Similarly, broad H$\alpha$ strength increases with both V-shape sharpness and compactness. The [N II] deficit is not an exclusive feature of LRDs but a global property of compact, metal-poor galaxies. Only the 3% most extreme LRDs present a prominent Balmer break (>3) of potentially non-stellar origin. LRDs and non-LRDs follow similar trends in the evolution of the Balmer decrement with V-shape sharpness, suggesting a shared physical origin, likely dust attenuation. Estimated dust masses (~4-7 x 10^4 M_{sun}) and luminosities are low enough to account for their non-detection by ALMA. We conclude that most LRDs do not represent a separate class of objects, but rather the extreme tail of a continuous distribution of galaxies and broad H$\alpha$ emitters, consistent with a classical broad line region and dust attenuation.
fields
astro-ph.GA 5years
2026 5verdicts
UNVERDICTED 5representative citing papers
LRDs are reinterpreted as intermediate-mass super-Eddington systems with wind-driven pseudo-photospheres that explain their spectra and imply engine masses below 10^5 solar masses rather than overmassive black holes.
JWST data on LRDs and LBDs show AGN-like excitation, strong Lyα with broad components, and X-ray weakness, implying clumpy or equatorial geometries around growing black holes rather than complete gas envelopes.
Quasi-star models using Cloudy radiative transfer reproduce the UV-NIR continuum shape, Balmer break, and hydrogen line luminosities in some LRDs when combined with host galaxy emission, but fail to account for broad helium lines and hot dust without added components.
Little red dots are the dust-reddened, high-inclination counterparts of little blue dots under a super-Eddington unification model, with luminosity-dependent fractions peaking near 20% and obscured systems showing systematically higher black hole masses due to selection.
citing papers explorer
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A Population of Little Red Dot-like Quasars in SDSS
Defines a sample of ~1300 SDSS quasars as Local Red Dots matching LRD photometric colors at z~0.4-0.8, with a V-shaped subset showing Balmer absorption and [NeV] emission, and SEDs modeled as reddened AGN plus host galaxy that match LRD stacks.
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Little Red Dots as Intermediate Mass, Super-Eddington Engines: Insights from Type IIn Supernovae and The 1837-1856 Great Eruption of $\eta$ Carinae
LRDs are reinterpreted as intermediate-mass super-Eddington systems with wind-driven pseudo-photospheres that explain their spectra and imply engine masses below 10^5 solar masses rather than overmassive black holes.
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Little Red and Blue Dots: AGN-excited narrow lines, Lyman-$\alpha$ emission, and resemblance to standard quasars
JWST data on LRDs and LBDs show AGN-like excitation, strong Lyα with broad components, and X-ray weakness, implying clumpy or equatorial geometries around growing black holes rather than complete gas envelopes.
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The quasi-star model for Little Red Dots: potential and challenges
Quasi-star models using Cloudy radiative transfer reproduce the UV-NIR continuum shape, Balmer break, and hydrogen line luminosities in some LRDs when combined with host galaxy emission, but fail to account for broad helium lines and hot dust without added components.
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Little red dots as obscured little blue dots: relative abundances, luminosities, and black-hole masses
Little red dots are the dust-reddened, high-inclination counterparts of little blue dots under a super-Eddington unification model, with luminosity-dependent fractions peaking near 20% and obscured systems showing systematically higher black hole masses due to selection.