pith. sign in

arxiv: 2606.09721 · v1 · pith:RJAU3PDWnew · submitted 2026-06-08 · 🌌 astro-ph.GA

NEXUS: Abundance, Environments, and Spectral Diversity of Little Red Dots from the NIRSpec MSA Sample

Zhiwei Pan , Ming-Yang Zhuang , Yue Shen , Feige Wang , Jenny E. Greene , Adam J. Burgasser , Junyao Li , Zachary Stone
show 1 more author
Padmavathi Venkatraman
This is my paper

Pith reviewed 2026-06-27 16:18 UTC · model grok-4.3

classification 🌌 astro-ph.GA
keywords little red dotsLRDshigh-redshift galaxiesactive galactic nucleispace densitygalaxy clusteringNIRSpec spectroscopysupermassive black holes
0
0 comments X

The pith

Little Red Dots show declining space density toward z=2 opposite normal AGNs and inhabit dark matter halos of several times 10^11 solar masses

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper examines Little Red Dots across redshifts 2.3 to 7.4 with NIRCam photometry and NIRSpec spectra, achieving 85 percent completeness but 60 percent purity after removing contaminants. Spectroscopic confirmation of 36 objects reveals diverse spectra with broad emission lines, extreme Balmer breaks, and continua sometimes fit by low-temperature blackbodies, yet these properties show no change with redshift. Space density measurements indicate LRDs become less common at lower redshifts, the reverse of the trend for ordinary active galactic nuclei, while their clustering points to residence in halos of several times 10^11 solar masses. The results support an origin in accreting supermassive black holes inside dense gas envelopes.

Core claim

The spectroscopic sample of 36 LRDs spans the full observed spectral range, including objects with extreme Balmer breaks and moderately reddened continua fittable by blackbody components. Broad H-alpha emission correlates with the 5100 Angstrom continuum while narrow [O III] does not, and none of these spectral traits evolve with redshift. Space density declines toward z approximately 2, opposite the rise seen for normal AGNs, though low-luminosity examples at z 2-4 may exceed current ground-based limits. Clustering measurements imply LRDs occupy dark matter halos of several times 10^11 h^{-1} solar masses, consistent with accreting supermassive black holes enshrouded in dense gas.

What carries the argument

Photometric selection of LRDs followed by NIRSpec MSA/PRISM spectra to quantify space densities, clustering signals, and emission-line properties across the redshift range.

If this is right

  • Space density of LRDs decreases toward z about 2 in contrast to the increase for normal AGNs.
  • Low-luminosity LRDs at z 2-4 may exceed abundances measured by existing ground-based searches.
  • LRDs reside in dark matter halos of several times 10^11 h^{-1} solar masses.
  • Spectral features including Balmer breaks and line-continuum correlations show no redshift evolution.
  • The population is consistent with accreting supermassive black holes inside dense gas envelopes.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Larger samples with improved purity could tighten halo mass constraints and connect LRDs to specific phases of early black hole assembly.
  • If the density decline holds, it may indicate a redshift-dependent transition in the fraction of black holes that remain enshrouded.
  • The lack of spectral evolution suggests the physical conditions around these black holes stabilize early and persist across several billion years.

Load-bearing premise

The photometric selection yields a representative LRD sample despite 60 percent purity and contamination from emission-line galaxies, normal AGNs, and dwarf stars.

What would settle it

A deeper survey at z approximately 2 that measures a space density for LRDs equal to or higher than the extrapolated high-redshift value would contradict the reported decline.

Figures

Figures reproduced from arXiv: 2606.09721 by Adam J. Burgasser, Feige Wang, Jenny E. Greene, Junyao Li, Ming-Yang Zhuang, Padmavathi Venkatraman, Yue Shen, Zachary Stone, Zhiwei Pan.

Figure 1
Figure 1. Figure 1: Color selection of LRD candidates exhibiting V-shaped SEDs, detailed in Section 2.2.1. The upper panel in the leftmost column shows the compactness criterion, defined as fF444W(0.4 ′′)/fF444W(0.2 ′′). The lower panel in the leftmost column illustrates the brown dwarf rejection cut, which is shown to be effective in Section 2.3 and [PITH_FULL_IMAGE:figures/full_fig_p005_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Slope selection of LRD candidates exhibiting V-shaped SEDs, detailed in Section 2.2.2. Left: half-light radius in F444W, rh,F444W versus F444W magnitude for the bright sample (SNRF444W > 12). The dashed and solid pink curves show the stellar half-light radius and 1.5 times that value, respectively; the shaded region marks the compact-source selection. Right: βOPT versus βUV for the same sample. The shaded … view at source ↗
Figure 3
Figure 3. Figure 3: Color selection of LRD candidates exhibiting very red SEDs, detailed in Section 2.2.3. Left: F277W−F444W color versus fF444W(0. ′′2)/fF444W(0. ′′5). The shaded region and dashed lines indicate the adopted selection criteria, requiring 0.5 < fF444W(0. ′′2)/fF444W(0. ′′5) < 0.7 and F277W−F444W > 1.5. Right: F277W−F444W color versus F444W magnitude. The symbol coding is the same as in [PITH_FULL_IMAGE:figure… view at source ↗
Figure 4
Figure 4. Figure 4: Spatial distribution of the LRD population in the NEXUS Deep field. Small gray points show the positions of all NIRSpec MSA targets from the multi-epoch deep spec￾troscopic observations. Photometric LRD candidates are shown in blue, with objects lacking valid spectra plotted as small blue points and those with valid spectroscopic coverage shown as larger blue circles with black outlines. Spectroscop￾ically… view at source ↗
Figure 5
Figure 5. Figure 5: Spectral-slope selection of spectroscopic LRDs exhibiting V-shaped continua. Grey points represent the z > 2 compact sources, while red circles mark the spectro￾scopic LRDs. The shaded pink region indicates the adopted V-shaped continuum selection, defined by βUV < −0.37 and βopt > 0. rest-optical continuum compared to typical blue AGNs. These objects likely lie near the boundary of the pho￾tometric select… view at source ↗
Figure 7
Figure 7. Figure 7: Rest-frame spectral gallery of the spectroscopically confirmed LRD sample with the order of increasing redshift. For each source, the gray curve shows the smoothed JWST/NIRSpec prism spectrum, while the purple points indicate the NIRCam photometry. The blue dashed line marks the Balmer break at 3646 ˚A. The upper-right corner of each panel indicates the SED-shape subclass, where “S”, “V”, and “L” denote th… view at source ↗
Figure 8
Figure 8. Figure 8: Left: spectroscopic and photometric LRD samples in the F444W magnitude–redshift plane. The sample includes 36 spectroscopically confirmed LRDs, marked by red square outlines, and 57 photometrically selected LRD candidates with MSA spectroscopic observations. The three photometric selection methods are encoded simultaneously in the symbol style: diamond and circular markers indicate the V-color selection be… view at source ↗
Figure 9
Figure 9. Figure 9: Hβ+[Oiii] λλ4959,5007 and Hα spectral fits for the spectroscopic LRD sample. In each panel, the black curve shows the continuum-subtracted rest-frame spectrum, the gray curve shows the 1σ uncertainty, and the red curve shows the total best-fit model. The left and right sides of each panel display the Hβ+[O iii] and Hα regions, respectively. In the Hβ+[O iii] region, the fitted Hβ and [O iii] components are… view at source ↗
Figure 10
Figure 10. Figure 10: Left: Broad Hα luminosity as a function of redshift for the LRDs in this work (filled red stars), compared with NEXUS EDR LRDs (pink diamonds; M.-Y. Zhuang et al. 2026a), ASPIRE LRDs (orange triangles; X. Lin et al. 2024), and CEERS+RUBIES BLAGNs (green squares; A. J. Taylor et al. 2025). Right: Rest-frame total Hα equivalent width versus Hα FWHM. Gray contours and shaded regions show the distribution of … view at source ↗
Figure 11
Figure 11. Figure 11: Left: Broad Hα luminosity functions of LRDs at z > 2. Red stars represent the NEXUS DR1 measurements over 2.3 < z < 6.7, and pink diamonds show the NEXUS EDR measurements over 3 < z < 5.1. Cyan crosses, blue crosses, and gold squares show literature results from X. Lin et al. (2026a), J. Matthee et al. (2024), and V. Kokorev et al. (2024a), respectively. Gray curves show the extrapolated AGN bolometric lu… view at source ↗
Figure 12
Figure 12. Figure 12: Angular correlation functions for different sam￾ples, measured over 1 ≲ θ ≲ 100′′. The best-fit power-law models are shown as dashed lines and summarized in [PITH_FULL_IMAGE:figures/full_fig_p018_12.png] view at source ↗
Figure 13
Figure 13. Figure 13: LRD composite spectra of the LRD and comparison samples in NEXUS, normalized by fλ at 4000 ˚A, smoothed, and shifted vertically for clarity. The number of objects included in each stack is listed in the corresponding label. The top panel shows the overall S-shape LRD composite (red) together with two redshift subsamples, z < 4 (purple) and z ≥ 4 (orange). The middle panel shows the V-shape LRD composite. … view at source ↗
Figure 14
Figure 14. Figure 14: The host-galaxy plus blackbody continuum decomposition for each LRD, shown in the same format as [PITH_FULL_IMAGE:figures/full_fig_p022_14.png] view at source ↗
Figure 15
Figure 15. Figure 15: Left: Blackbody temperature versus blackbody flux fraction at 5500 ˚A for the spectroscopic LRD sample. Different symbol shapes denote the three spectral subclasses, S-shape, V-shape, and L-shape, while different colors indicate the two redshift intervals, z < 4 and z > 4. The light-green and dark-green stars show the median values for the z < 4 and z > 4 subsamples, respectively, with error bars indicati… view at source ↗
Figure 16
Figure 16. Figure 16: Left: Rest-frame total Hα equivalent width versus Balmer decrement, LHα/LHβ. Gray contours show the counts-density distribution of SDSS DR16 quasars at z < 0.6, red stars show the NEXUS LRDs, and the purple star marks the LRD median. The black dashed line indicates the Case B value of 2.86. Right: Spearman rank correlation matrix for LRD emission-line and continuum properties, restricted to sources with M… view at source ↗
Figure 17
Figure 17. Figure 17: Search for possible water absorption in LRD ID 93986 at z = 2.346. The rest-frame LRD spectrum is fit￾ted with a two-component dwarf model based on PHOENIX stellar atmosphere templates (F. Allard et al. 2012), where the template grid spans effective temperature T, metallicity [M/H], and surface gravity log g. The gray shaded regions are excluded from the fit. The orange and red curves show the two fitted … view at source ↗
read the original abstract

We present a comprehensive study of Little Red Dots (LRDs) at 2.3 < z < 7.4 using NIRCam photometry and NIRSpec MSA/PRISM spectra from the ongoing NEXUS program. Photometric selection combining several commonly adopted methods yields a high completeness of about 85% for LRD selection over this redshift range and for a flux limit of F444W < 26. The overall purity is about 60%, with contamination from emission-line galaxies and normal active galactic nuclei (AGNs), as well as dwarf stars. Most (>90%) of the spectroscopically confirmed LRDs have robust broad-line detection. Our spectroscopic sample of 36 LRDs displays the full range of spectral diversity of LRDs. It includes objects with extreme Balmer breaks similar to the LRD "Cliff", as well as objects with moderately reddened rest-optical continua that can be fit with low-temperature blackbody components in the recent BH* model framework. The broad H$\alpha$ emission is correlated with the continuum emission at 5100 Angstrom, suggesting common origins for these emission components; the narrow [O III] emission, however, is poorly correlated with the optical continuum. We do not find evidence of redshift evolution in these spectral properties. The space density of LRDs declines toward z about 2, opposite to the trend for normal AGNs, although low-luminosity LRDs at z about 2-4 may be more abundant than currently probed by ground-based searches. The clustering of LRDs suggests that they live in dark matter halos of several times $10^{11}\ h^{-1}$ solar masses, albeit with large uncertainties. Overall, these results are consistent with recent observations of LRDs and with the emerging picture of accreting SMBHs enshrouded in dense gas envelopes as the origin of LRDs.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

3 major / 1 minor

Summary. The manuscript presents a study of Little Red Dots (LRDs) at 2.3 < z < 7.4 using NIRCam photometry and NIRSpec MSA/PRISM spectra from the NEXUS program. Photometric selection combining multiple methods yields ~85% completeness but ~60% purity (contaminants: emission-line galaxies, normal AGNs, dwarf stars). A spectroscopic subsample of 36 LRDs shows spectral diversity (extreme Balmer breaks, reddened continua fit by low-T blackbodies), with broad Hα correlated to 5100Å continuum but narrow [O III] not; no redshift evolution is found in spectral properties. Central claims are a declining LRD space density toward z~2 (opposite normal AGNs) and clustering implying dark matter halos of several ×10^{11} h^{-1} M_⊙.

Significance. If the 60% purity and associated contamination are shown to be correctly subtracted in a redshift- and luminosity-dependent way, the work would supply useful observational constraints on LRD demographics, spectral diversity, and environments, reinforcing distinctions from standard AGNs and supporting dense-gas-envelope models for accreting SMBHs.

major comments (3)
  1. [Abstract] Abstract: the space-density decline toward z~2 and the clustering-derived halo masses are obtained from the photometrically selected parent sample. With only 60% purity, a redshift- and luminosity-dependent correction for the 40% contaminants (ELGs, normal AGNs, dwarf stars) is required; the manuscript must demonstrate that this correction has been applied and quantify residual bias, otherwise both the reported density trend and the two-point correlation function (hence halo mass) can shift systematically.
  2. [Abstract] Abstract: the >90% broad-line confirmation rate applies only to the 36 spectroscopically confirmed objects; the statistical claims on abundance and clustering use the full photometric sample, so the purity and confirmation fraction for that parent sample must be stated explicitly.
  3. [Abstract] Abstract: no uncertainties or error bars are reported on the space densities or clustering measurements; without them the significance of the claimed decline relative to normal AGNs and the halo-mass estimate cannot be assessed.
minor comments (1)
  1. Additional details on the spectral fitting procedures, continuum modeling (including the BH* blackbody components), and any data-exclusion criteria would improve reproducibility.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for their careful and constructive comments. We address each major point below and will revise the manuscript accordingly to improve clarity on the photometric sample properties.

read point-by-point responses

  1. Referee: [Abstract] Abstract: the space-density decline toward z~2 and the clustering-derived halo masses are obtained from the photometrically selected parent sample. With only 60% purity, a redshift- and luminosity-dependent correction for the 40% contaminants (ELGs, normal AGNs, dwarf stars) is required; the manuscript must demonstrate that this correction has been applied and quantify residual bias, otherwise both the reported density trend and the two-point correlation function (hence halo mass) can shift systematically.

    Authors: We agree that a redshift- and luminosity-dependent correction for the 40% contaminants must be demonstrated explicitly for the photometric sample results. We will revise the methods and results sections to detail how this correction was applied and to quantify any residual bias after subtraction. revision: yes

  2. Referee: [Abstract] Abstract: the >90% broad-line confirmation rate applies only to the 36 spectroscopically confirmed objects; the statistical claims on abundance and clustering use the full photometric sample, so the purity and confirmation fraction for that parent sample must be stated explicitly.

    Authors: The abstract already states both the 60% purity of the photometric selection and that the >90% broad-line rate applies specifically to the spectroscopically confirmed objects. We will revise the abstract to state the confirmation fraction and purity applicable to the photometric parent sample even more explicitly. revision: partial

  3. Referee: [Abstract] Abstract: no uncertainties or error bars are reported on the space densities or clustering measurements; without them the significance of the claimed decline relative to normal AGNs and the halo-mass estimate cannot be assessed.

    Authors: We will add explicit error bars to the space density measurements and quantitative uncertainties to the clustering and halo-mass results in the revised manuscript and figures. revision: yes

Circularity Check

0 steps flagged

No circularity; results are direct observational counts and correlations

full rationale

The paper computes space densities from photometric selection (with stated 85% completeness and 60% purity corrections) followed by spectroscopic confirmation of 36 objects, and infers halo masses from measured clustering via standard bias-to-halo-mass mapping. No equations or steps reduce by construction to fitted inputs, self-definitions, or self-citation chains; all load-bearing quantities are measured quantities from the NIRCam/NIRSpec data. The purity caveat is a systematic uncertainty, not a circularity mechanism.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The work rests on standard assumptions in extragalactic astronomy about the interpretation of broad emission lines as AGN signatures and the use of clustering to infer halo masses, with no new free parameters or invented entities introduced.

axioms (2)
  • domain assumption Standard photometric selection criteria for LRDs achieve the stated 85% completeness over 2.3 < z < 7.4
    Invoked to support the sample construction and purity estimate.
  • standard math Clustering statistics can be translated to halo mass using standard cosmology and bias models
    Used for the reported halo mass of several times 10^11 h^{-1} solar masses.

pith-pipeline@v0.9.1-grok · 5924 in / 1523 out tokens · 32940 ms · 2026-06-27T16:18:08.747807+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

90 extracted references · 89 canonical work pages · 11 internal anchors

  1. [1]

    2016, JWST User Documentation (JDox),, JWST User Documentation Website

    2016

  2. [2]

    B., Casey, C

    Akins, H. B., Casey, C. M., Lambrides, E., et al. 2024, arXiv e-prints, arXiv:2406.10341, doi: 10.48550/arXiv.2406.10341

    work page doi:10.48550/arxiv.2406.10341 2024

  3. [3]

    B., Casey, C

    Akins, H. B., Casey, C. M., Lambrides, E., et al. 2025, ApJ, 991, 37, doi: 10.3847/1538-4357/ade984

    work page doi:10.3847/1538-4357/ade984 2025

  4. [4]

    2012, Philosophical Transactions of the Royal Society of London Series A, 370, 2765, doi: 10.1098/rsta.2011.0269

    Allard, F., Homeier, D., & Freytag, B. 2012, Philosophical Transactions of the Royal Society of London Series A, 370, 2765, doi: 10.1098/rsta.2011.0269

    work page doi:10.1098/rsta.2011.0269 2012

  5. [5]

    T., Bogd´ an,´A., Kov´ acs, O

    Ananna, T. T., Bogd´ an,´A., Kov´ acs, O. E., Natarajan, P., & Hickox, R. C. 2024, ApJL, 969, L18, doi: 10.3847/2041-8213/ad5669

    work page doi:10.3847/2041-8213/ad5669 2024

  6. [6]

    2025, MNRAS, 536, 3677, doi: 10.1093/mnras/stae2765 Astropy Collaboration, Robitaille, T

    Arita, J., Kashikawa, N., Onoue, M., et al. 2025, MNRAS, 536, 3677, doi: 10.1093/mnras/stae2765 Astropy Collaboration, Robitaille, T. P., Tollerud, E. J., et al. 2013, A&A, 558, A33, doi: 10.1051/0004-6361/201322068 Astropy Collaboration, Price-Whelan, A. M., Sip˝ ocz, B. M., et al. 2018, AJ, 156, 123, doi: 10.3847/1538-3881/aabc4f Astropy Collaboration, ...

    work page doi:10.1093/mnras/stae2765 2025

  7. [7]

    Baggen, J. F. W., van Dokkum, P., Labb´ e, I., et al. 2023, ApJL, 955, L12, doi: 10.3847/2041-8213/acf5ef

    work page doi:10.3847/2041-8213/acf5ef 2023

  8. [8]

    G., Kocevski, D

    Barro, G., P´ erez-Gonz´ alez, P. G., Kocevski, D. D., et al. 2024, ApJ, 963, 128, doi: 10.3847/1538-4357/ad167e

    work page doi:10.3847/1538-4357/ad167e 2024

  9. [9]

    2025, astropy/photutils: 2.2.0, 2.2.0 Zenodo, doi: 10.5281/zenodo.14889440

    Bradley, L., Sip˝ ocz, B., Robitaille, T., et al. 2025, astropy/photutils: 2.2.0, 2.2.0 Zenodo, doi: 10.5281/zenodo.14889440

    work page doi:10.5281/zenodo.14889440 2025

  10. [10]

    B., van Dokkum, P

    Brammer, G. B., van Dokkum, P. G., & Coppi, P. 2008, ApJ, 686, 1503, doi: 10.1086/591786

    work page internal anchor Pith review doi:10.1086/591786 2008

  11. [11]

    Carnall, A. C. 2017, arXiv e-prints, arXiv:1705.05165, doi: 10.48550/arXiv.1705.05165

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.48550/arxiv.1705.05165 2017

  12. [12]

    2026, MNRAS, 545, staf2131, doi: 10.1093/mnras/staf2131

    Chang, S.-J., Gronke, M., Matthee, J., & Mason, C. 2026, MNRAS, 545, staf2131, doi: 10.1093/mnras/staf2131 NEXUS: MSA LRDs27 de Graaff, A., Rix, H.-W., Carniani, S., et al. 2024, A&A, 684, A87, doi: 10.1051/0004-6361/202347755 de Graaff, A., Rix, H.-W., Naidu, R. P., et al. 2025a, A&A, 701, A168, doi: 10.1051/0004-6361/202554681 de Graaff, A., Hviding, R....

    work page doi:10.1093/mnras/staf2131 2026

  13. [13]

    2026, arXiv e-prints, arXiv:2602.12325, doi: 10.48550/arXiv.2602.12325

    Fei, Q., Fujimoto, S., Brammer, G., et al. 2026, arXiv e-prints, arXiv:2602.12325, doi: 10.48550/arXiv.2602.12325

    work page doi:10.48550/arxiv.2602.12325 2026

  14. [14]

    2025, arXiv e-prints, arXiv:2512.02096, doi: 10.48550/arXiv.2512.02096

    Fu, S., Zhang, Z., Jiang, D., et al. 2025, arXiv e-prints, arXiv:2512.02096, doi: 10.48550/arXiv.2512.02096

    work page doi:10.48550/arxiv.2512.02096 2025

  15. [15]

    J., Zitrin, A., Plat, A., et al

    Furtak, L. J., Zitrin, A., Plat, A., et al. 2023, ApJ, 952, 142, doi: 10.3847/1538-4357/acdc9d

    work page doi:10.3847/1538-4357/acdc9d 2023

  16. [16]

    J., Labb´ e, I., Zitrin, A., et al

    Furtak, L. J., Labb´ e, I., Zitrin, A., et al. 2024, Nature, 628, 57, doi: 10.1038/s41586-024-07184-8

    work page doi:10.1038/s41586-024-07184-8 2024

  17. [17]

    1986, ApJ, 303, 336, doi: 10.1086/164079

    Gehrels, N. 1986, ApJ, 303, 336, doi: 10.1086/164079

    work page doi:10.1086/164079 1986

  18. [18]

    J., Duncan, K

    Gloudemans, A. J., Duncan, K. J., Eilers, A.-C., et al. 2025, ApJ, 986, 130, doi: 10.3847/1538-4357/adddb9 G´ orski, K. M., Hivon, E., Banday, A. J., et al. 2005, ApJ, 622, 759, doi: 10.1086/427976

    work page doi:10.3847/1538-4357/adddb9 2025

  19. [19]

    E., Labbe, I., Goulding, A

    Greene, J. E., Labbe, I., Goulding, A. D., et al. 2024, ApJ, 964, 39, doi: 10.3847/1538-4357/ad1e5f

    work page doi:10.3847/1538-4357/ad1e5f 2024

  20. [20]

    E., Setton, D

    Greene, J. E., Setton, D. J., Furtak, L. J., et al. 2026, ApJ, 996, 129, doi: 10.3847/1538-4357/ae1836

    work page doi:10.3847/1538-4357/ae1836 2026

  21. [21]

    A., Pacucci, F., & Kocevski, D

    Guia, C. A., Pacucci, F., & Kocevski, D. D. 2024, Research Notes of the American Astronomical Society, 8, 207, doi: 10.3847/2515-5172/ad7262

    work page doi:10.3847/2515-5172/ad7262 2024

  22. [22]

    2023, ApJ, 959, 39, doi: 10.3847/1538-4357/ad029e

    Harikane, Y., Zhang, Y., Nakajima, K., et al. 2023, ApJ, 959, 39, doi: 10.3847/1538-4357/ad029e

    work page doi:10.3847/1538-4357/ad029e 2023

  23. [23]

    Harris and K

    Harris, C. R., Millman, K. J., van der Walt, S. J., et al. 2020, Nature, 585, 357, doi: 10.1038/s41586-020-2649-2

    work page doi:10.1038/s41586-020-2649-2 2020

  24. [24]

    Hunter, J. D. 2007, Computing in Science & Engineering, 9, 90, doi: 10.1109/MCSE.2007.55

    work page doi:10.1109/mcse.2007.55 2007

  25. [25]

    , keywords =

    Hviding, R. E., de Graaff, A., Miller, T. B., et al. 2025, A&A, 702, A57, doi: 10.1051/0004-6361/202555816

    work page doi:10.1051/0004-6361/202555816 2025

  26. [26]

    S., & Noda, H

    Inayoshi, K., Kimura, S. S., & Noda, H. 2025, PASJ, 77, 811, doi: 10.1093/pasj/psaf050

    work page doi:10.1093/pasj/psaf050 2025

  27. [27]

    2025, ApJL, 980, L27, doi: 10.3847/2041-8213/adaebd

    Inayoshi, K., & Maiolino, R. 2025, ApJL, 980, L27, doi: 10.3847/2041-8213/adaebd

    work page doi:10.3847/2041-8213/adaebd 2025

  28. [28]

    2025, MNRAS, 544, 3900, doi: 10.1093/mnras/staf1867

    Ji, X., Maiolino, R., ¨Ubler, H., et al. 2025, MNRAS, 544, 3900, doi: 10.1093/mnras/staf1867

    work page doi:10.1093/mnras/staf1867 2025

  29. [29]

    2025, Nature Astronomy, 9, 1890, doi: 10.1038/s41550-025-02676-7

    Jiang, D., Jiang, L., Sun, S., Liu, W., & Fu, S. 2025, Nature Astronomy, 9, 1890, doi: 10.1038/s41550-025-02676-7

    work page doi:10.1038/s41550-025-02676-7 2025

  30. [30]

    2024, A&A, 691, A52, doi: 10.1051/0004-6361/202348857

    Killi, M., Watson, D., Brammer, G., et al. 2024, A&A, 691, A52, doi: 10.1051/0004-6361/202348857

    work page doi:10.1051/0004-6361/202348857 2024

  31. [31]

    D., Finkelstein, S

    Kocevski, D. D., Finkelstein, S. L., Barro, G., et al. 2024, arXiv e-prints, arXiv:2404.03576, doi: 10.48550/arXiv.2404.03576

    work page doi:10.48550/arxiv.2404.03576 2024

  32. [32]

    D., Finkelstein, S

    Kocevski, D. D., Finkelstein, S. L., Barro, G., et al. 2025, ApJ, 986, 126, doi: 10.3847/1538-4357/adbc7d

    work page doi:10.3847/1538-4357/adbc7d 2025

  33. [34]

    2024b, ApJ, 975, 178, doi: 10.3847/1538-4357/ad7d03

    Kokorev, V., Chisholm, J., Endsley, R., et al. 2024b, ApJ, 975, 178, doi: 10.3847/1538-4357/ad7d03

    work page doi:10.3847/1538-4357/ad7d03

  34. [35]

    I., Greene, J

    Kokorev, V., Caputi, K. I., Greene, J. E., et al. 2024c, ApJ, 968, 38, doi: 10.3847/1538-4357/ad4265

    work page doi:10.3847/1538-4357/ad4265

  35. [36]

    2025, ApJ, 995, 24, doi: 10.3847/1538-4357/ae119e

    Kokubo, M., & Harikane, Y. 2025, ApJ, 995, 24, doi: 10.3847/1538-4357/ae119e

    work page doi:10.3847/1538-4357/ae119e 2025

  36. [37]

    Kormendy, J., & Ho, L. C. 2013, ARA&A, 51, 511, doi: 10.1146/annurev-astro-082708-101811 Labb´ e, I., van Dokkum, P., Nelson, E., et al. 2023, Nature, 616, 266, doi: 10.1038/s41586-023-05786-2

    work page internal anchor Pith review doi:10.1146/annurev-astro-082708-101811 2013

  37. [38]

    E., Bezanson, R., et al

    Labbe, I., Greene, J. E., Bezanson, R., et al. 2025, ApJ, 978, 92, doi: 10.3847/1538-4357/ad3551

    work page doi:10.3847/1538-4357/ad3551 2025

  38. [39]

    D., & Szalay, A

    Landy, S. D., & Szalay, A. S. 1993, ApJ, 412, 64, doi: 10.1086/172900

    work page doi:10.1086/172900 1993

  39. [40]

    A., Aftab, A., Whalen, D

    Latif, M. A., Aftab, A., Whalen, D. J., & Mezcua, M. 2025, A&A, 694, L14, doi: 10.1051/0004-6361/202453194

    work page doi:10.1051/0004-6361/202453194 2025

  40. [41]

    Leung, G. C. K., Finkelstein, S. L., P´ erez-Gonz´ alez, P. G., et al. 2025, ApJ, 992, 26, doi: 10.3847/1538-4357/adfcce

    work page doi:10.3847/1538-4357/adfcce 2025

  41. [42]

    Li, Z., Inayoshi, K., Chen, K., Ichikawa, K., & Ho, L. C. 2025, ApJ, 980, 36, doi: 10.3847/1538-4357/ada5fb

    work page doi:10.3847/1538-4357/ada5fb 2025

  42. [43]

    2024, ApJ, 974, 147, doi: 10.3847/1538-4357/ad6565

    Lin, X., Wang, F., Fan, X., et al. 2024, ApJ, 974, 147, doi: 10.3847/1538-4357/ad6565

    work page doi:10.3847/1538-4357/ad6565 2024

  43. [44]

    2026a, ApJ, 996, 93, doi: 10.3847/1538-4357/ae1b9b

    Lin, X., Fan, X., Wang, F., et al. 2026a, ApJ, 996, 93, doi: 10.3847/1538-4357/ae1b9b

    work page doi:10.3847/1538-4357/ae1b9b

  44. [45]

    2026b, ApJ, 997, 61, doi: 10.3847/1538-4357/ae1eef

    Lin, X., Fan, X., Sun, F., et al. 2026b, ApJ, 997, 61, doi: 10.3847/1538-4357/ae1eef

    work page doi:10.3847/1538-4357/ae1eef

  45. [46]

    2026c, ApJ, 997, 364, doi: 10.3847/1538-4357/ae2bdf

    Lin, X., Fan, X., Cai, Z., et al. 2026c, ApJ, 997, 364, doi: 10.3847/1538-4357/ae2bdf

    work page doi:10.3847/1538-4357/ae2bdf

  46. [47]

    How I Wonder What You Are -- JWST's Little Red Dots do not TWINKLE

    Liu, Z., Naidu, R. P., Secunda, A., et al. 2026, arXiv e-prints, arXiv:2604.13000, doi: 10.48550/arXiv.2604.13000

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.48550/arxiv.2604.13000 2026

  47. [48]

    E., Setton, D

    Ma, Y., Greene, J. E., Setton, D. J., et al. 2025, arXiv e-prints, arXiv:2504.08032, doi: 10.48550/arXiv.2504.08032

    work page doi:10.48550/arxiv.2504.08032 2025

  48. [49]

    2024, ApJL, 976, L24, doi: 10.3847/2041-8213/ad90e1

    Madau, P., & Haardt, F. 2024, ApJL, 976, L24, doi: 10.3847/2041-8213/ad90e1

    work page doi:10.3847/2041-8213/ad90e1 2024

  49. [50]

    2024, Astronomy and Astrophysics, 691, A145, doi: 10.1051/0004-6361/202347640

    Maiolino, R., Scholtz, J., Curtis-Lake, E., et al. 2024, A&A, 691, A145, doi: 10.1051/0004-6361/202347640

    work page doi:10.1051/0004-6361/202347640 2024

  50. [51]

    2025, MNRAS, 538, 1921, doi: 10.1093/mnras/staf359

    Maiolino, R., Risaliti, G., Signorini, M., et al. 2025, MNRAS, 538, 1921, doi: 10.1093/mnras/staf359

    work page doi:10.1093/mnras/staf359 2025

  51. [52]

    P., Brammer, G., et al

    Matthee, J., Naidu, R. P., Brammer, G., et al. 2024, ApJ, 963, 129, doi: 10.3847/1538-4357/ad2345

    work page doi:10.3847/1538-4357/ad2345 2024

  52. [53]

    2026, arXiv e-prints, arXiv:2603.17667, doi: 10.48550/arXiv.2603.17667

    Matthee, J., Torralba, A., Pezzulli, G., et al. 2026, arXiv e-prints, arXiv:2603.17667, doi: 10.48550/arXiv.2603.17667 28Pan et al

    work page doi:10.48550/arxiv.2603.17667 2026

  53. [54]

    2026, A&A, 706, A372, doi: 10.1051/0004-6361/202453317

    Mazzolari, G., Gilli, R., Maiolino, R., et al. 2026, A&A, 706, A372, doi: 10.1051/0004-6361/202453317

    work page doi:10.1051/0004-6361/202453317 2026

  54. [55]

    A "Black Hole Star" Reveals the Remarkable Gas-Enshrouded Hearts of the Little Red Dots

    Naidu, R. P., Matthee, J., Katz, H., et al. 2025, arXiv e-prints, arXiv:2503.16596, doi: 10.48550/arXiv.2503.16596

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.48550/arxiv.2503.16596 2025

  55. [56]

    2025, ApJL, 989, L19, doi: 10.3847/2041-8213/ade871

    Pacucci, F., & Loeb, A. 2025, ApJL, 989, L19, doi: 10.3847/2041-8213/ade871

    work page doi:10.3847/2041-8213/ade871 2025

  56. [57]

    The Structure and Evolution of LRDs: Insights from JWST NIRSpec Medium and High Resolution Spectroscopy at $z\sim4$

    Pang, Y., Wang, X., Cheng, C., et al. 2026, arXiv e-prints, arXiv:2602.12548, doi: 10.48550/arXiv.2602.12548 P´ erez-Gonz´ alez, P. G., Barro, G., Rieke, G. H., et al. 2024, ApJ, 968, 4, doi: 10.3847/1538-4357/ad38bb

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.48550/arxiv.2602.12548 2026

  57. [58]

    E., Greene, J

    Reines, A. E., Greene, J. E., & Geha, M. 2013, ApJ, 775, 116, doi: 10.1088/0004-637X/775/2/116

    work page internal anchor Pith review doi:10.1088/0004-637x/775/2/116 2013

  58. [59]

    The Way We Tally Becomes the Tale: the Impact of Selection Strategies on the Inferred Evolution of Little Red Dots Across Cosmic Time

    Rinaldi, P., Hainline, K., D’Eugenio, F., et al. 2026, arXiv e-prints, arXiv:2604.07138, doi: 10.48550/arXiv.2604.07138

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.48550/arxiv.2604.07138 2026

  59. [60]

    P., et al

    Rusakov, V., Watson, D., Nikopoulos, G. P., et al. 2026, Nature, 649, 574, doi: 10.1038/s41586-025-09900-4

    work page doi:10.1038/s41586-025-09900-4 2026

  60. [61]

    J., Greene, J

    Setton, D. J., Greene, J. E., Spilker, J. S., et al. 2025, ApJL, 991, L10, doi: 10.3847/2041-8213/ade78b

    work page doi:10.3847/2041-8213/ade78b 2025

  61. [62]

    F., Faucher-Gigu` ere, C.-A., et al

    Shen, X., Hopkins, P. F., Faucher-Gigu` ere, C.-A., et al. 2020, MNRAS, 495, 3252, doi: 10.1093/mnras/staa1381

    work page doi:10.1093/mnras/staa1381 2020

  62. [63]

    A., Oguri, M., et al

    Shen, Y., Strauss, M. A., Oguri, M., et al. 2007, AJ, 133, 2222, doi: 10.1086/513517

    work page doi:10.1086/513517 2007

  63. [64]

    T., Strauss, M

    Shen, Y., Richards, G. T., Strauss, M. A., et al. 2011, ApJS, 194, 45, doi: 10.1088/0067-0049/194/2/45

    work page doi:10.1088/0067-0049/194/2/45 2011

  64. [65]

    2024, arXiv e-prints, arXiv:2408.12713, doi: 10.48550/arXiv.2408.12713

    Shen, Y., Zhuang, M.-Y., Li, J., et al. 2024, arXiv e-prints, arXiv:2408.12713, doi: 10.48550/arXiv.2408.12713

    work page doi:10.48550/arxiv.2408.12713 2024

  65. [66]

    L., Ashby, M

    Song, M., Finkelstein, S. L., Ashby, M. L. N., et al. 2016, ApJ, 825, 5, doi: 10.3847/0004-637X/825/1/5

    work page doi:10.3847/0004-637x/825/1/5 2016

  66. [67]

    , keywords =

    Stern, J., & Laor, A. 2012, MNRAS, 423, 600, doi: 10.1111/j.1365-2966.2012.20901.x

    work page doi:10.1111/j.1365-2966.2012.20901.x 2012

  67. [68]

    2025, arXiv e-prints, arXiv:2509.19585, doi: 10.48550/arXiv.2509.19585

    Stone, Z., Shen, Y., Zhuang, M.-Y., et al. 2025, arXiv e-prints, arXiv:2509.19585, doi: 10.48550/arXiv.2509.19585

    work page doi:10.48550/arxiv.2509.19585 2025

  68. [69]

    Little Red Dot $-$ Host Galaxy $=$ Black Hole Star: A Gas-Enshrouded Heart at the Center of Every Little Red Dot

    Sun, W. Q., Naidu, R. P., Matthee, J., et al. 2026, arXiv e-prints, arXiv:2601.20929, doi: 10.48550/arXiv.2601.20929

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.48550/arxiv.2601.20929 2026

  69. [70]

    J., Barger, A

    Taylor, A. J., Barger, A. J., Cowie, L. L., et al. 2023, ApJS, 266, 24, doi: 10.3847/1538-4365/accd70

    work page doi:10.3847/1538-4365/accd70 2023

  70. [71]

    J., Finkelstein, S

    Taylor, A. J., Finkelstein, S. L., Kocevski, D. D., et al. 2025, ApJ, 986, 165, doi: 10.3847/1538-4357/add15b

    work page doi:10.3847/1538-4357/add15b 2025

  71. [72]

    L., Fan, X., Wang, F., & Yang, J

    Tee, W. L., Fan, X., Wang, F., & Yang, J. 2025, ApJL, 983, L26, doi: 10.3847/2041-8213/adc5e3

    work page doi:10.3847/2041-8213/adc5e3 2025

  72. [73]

    2026a, A&A, 707, A75, doi: 10.1051/0004-6361/202557537

    Torralba, A., Matthee, J., Pezzulli, G., et al. 2026, A&A, 707, A75, doi: 10.1051/0004-6361/202557537

    work page doi:10.1051/0004-6361/202557537 2026

  73. [74]

    2025, ApJL, 994, L6, doi: 10.3847/2041-8213/ae13a9

    Tripodi, R., Bradaˇ c, M., D’Eugenio, F., et al. 2025, ApJL, 994, L6, doi: 10.3847/2041-8213/ae13a9

    work page doi:10.3847/2041-8213/ae13a9 2025

  74. [75]

    2026, ApJ, 999, 183, doi: 10.3847/1538-4357/ae4101

    Umeda, H., Inayoshi, K., Harikane, Y., & Murase, K. 2026, ApJ, 999, 183, doi: 10.3847/1538-4357/ae4101

    work page doi:10.3847/1538-4357/ae4101 2026

  75. [76]

    Vestergaard, M., & Peterson, B. M. 2006, ApJ, 641, 689, doi: 10.1086/500572

    work page internal anchor Pith review doi:10.1086/500572 2006

  76. [77]

    E., et al

    Virtanen, P., Gommers, R., Oliphant, T. E., et al. 2020, Nature Methods, 17, 261, doi: 10.1038/s41592-019-0686-2

    work page doi:10.1038/s41592-019-0686-2 2020

  77. [78]

    2024, ApJL, 969, L13, doi: 10.3847/2041-8213/ad55f7

    Wang, B., Leja, J., de Graaff, A., et al. 2024, ApJL, 969, L13, doi: 10.3847/2041-8213/ad55f7

    work page doi:10.3847/2041-8213/ad55f7 2024

  78. [79]

    L., et al

    Wang, B., de Graaff, A., Davies, R. L., et al. 2025, ApJ, 984, 121, doi: 10.3847/1538-4357/adc1ca

    work page doi:10.3847/1538-4357/adc1ca 2025

  79. [80]

    2026, arXiv e-prints, arXiv:2602.06024, doi: 10.48550/arXiv.2602.06024

    Wang, B., Leja, J., Labbe, I., et al. 2026, arXiv e-prints, arXiv:2602.06024, doi: 10.48550/arXiv.2602.06024

    work page doi:10.48550/arxiv.2602.06024 2026

  80. [81]

    C., Alberts, S., Ji, Z., et al

    Williams, C. C., Alberts, S., Ji, Z., et al. 2024, ApJ, 968, 34, doi: 10.3847/1538-4357/ad3f17

    work page doi:10.3847/1538-4357/ad3f17 2024

Showing first 80 references.