LRD Watch DR1 · catalog object

LRDW J100042.20+022243.4

catalogTENTATIVEBH* channelCOSMOS (PRIMER COSMOS-2)

RA 10:00:42.201 150.1758366°

Dec +02:22:43.42 2.3787272°

SIMBAD within 2″ · ESASky

Images

F090W image, 3.2 arcsec across, north up — F090W0.03″ px

F115W image, 3.2 arcsec across, north up — F115W0.03″ px

F150W image, 3.2 arcsec across, north up — F150W0.03″ px

F200W image, 3.2 arcsec across, north up — F200W0.03″ px

F277W image, 3.2 arcsec across, north up — F277W0.06″ px

F356W image, 3.2 arcsec across, north up — F356W0.06″ px

F410M image, 3.2 arcsec across, north up — F410M0.06″ px

F444W image, 3.2 arcsec across, north up — F444W0.06″ px

Colour composite: F444W red, F356W green, F277W blue, 3.2 arcsec across, north up — compositebar 1″

3.2″ across, north up, east left, resampled from the deepest mosaic covering the object in each band; ticks mark the catalogue position. Each band is stretched on its own noise; the composite shares one flux scale, so its colour is real.

Spectral energy distribution

NIRCam wide
NIRCam medium
MIRI
2σ upper limit (S/N < 2)

Aperture fluxes in a 0.16″-radius circle, not corrected to total; the values are in the photometry table below. The gold line marks the Balmer limit (3646 Å rest) at z = 4.384.

At a glance

Tier: TENTATIVE
Found by: BH* channel
Redshift: 4.384 DJA grade 3, PRISM
Spectral shape: inconclusive de Graaff+25 criteria
F444W: 26.46 AB S/N 43, 0.16″ aperture
F277W − F444W: not in the colour lane
BH* share: 0.71 cliff_degraaff25; Δχ² galaxy 17.6, dwarf 52.2
Compactness: growth ratio 1.741 stars 2.248
Balmer break: 2.89 ± 0.40 F277W/F150W, red:Hb+OIII+blue:far-uv
Image vetting: half-stack pass; no flags raised
Literature: 3 catalogue(s), 0 AGN paper(s) within 0.016″

Vetting

Image vettingnot applicable
Half-stack testpass
Artifact risknone
Neighbournone
Extendedno

BH* channelBH* share 0.72 below 0.8 (composite)

Redshifts

Each redshift keeps its own column. Photometric redshifts of little red dots are unreliable: against spectra, about a third of AGN-template redshifts (z_agn; 31 of 95 in the last purity run) and about half of galaxy-template redshifts at z > 3 were catastrophic outliers (methods Section 8).

Column	What it is	z	Source
`z_spec`	Spectroscopic, DJA grade 3	4.3837	capers-cos16-v4_prism-clear_6368_18263.spec.fits
`z_vet`	Adopted by vetting	4.3837	zspec:dja_specz_grade3.csv:18263
`z_phot`	Photometric (P(z) peak)	—	not fitted
`z_bhs`	BH* channel fit	4.286	cliff_degraaff25
`z_agn`	Colour-lane fit	—	—

Spectral checks

V-shape (spectrum): inconclusive
Star (spectrum): no
V-shape (photometry): not measurable β_UV not measured, β_opt not measured at z_agn
Line in F410M: none 1 line-free optical band(s)
Line-ambiguous: no
Settling verdict: not evaluated

Literature

Published objects within 1″ of this position. A match is a positional recovery, not an adopted classification.

Barro et al. (2025)
Barro et al. (2026)
Kokorev et al. (2024)

Photometry

Circular aperture of radius 0.16″ at each band's native resolution, background from a 0.40–0.65″ annulus, programmes combined by inverse variance. For a point source multiply by the field's aperture correction (r = 0.16″ → 0.70″). Grey rows are below S/N 2.

Band	Instrument	Pivot (µm)	f (nJy)	σ (nJy)	AB mag	S/N	Ap. corr.
F090W	NIRCam wide	0.902	28.92	5.22	27.75	5.5	1.15
F115W	NIRCam wide	1.154	35.48	4.96	27.52	7.2	1.13
F150W	NIRCam wide	1.501	29.91	4.12	27.71	7.2	1.11
F200W	NIRCam wide	1.989	38.04	3.40	27.45	11.2	1.10
F277W	NIRCam wide	2.762	86.37	1.96	26.56	44.0	1.21
F300M	NIRCam medium	2.990	55.58	3.35	27.04	16.6	1.23
F356W	NIRCam wide	3.568	106.95	1.86	26.33	57.6	1.23
F410M	NIRCam medium	4.082	94.12	3.32	26.47	28.4	1.27
F444W	NIRCam wide	4.404	94.97	2.20	26.46	43.1	1.28
F770W	MIRI	7.636	57.35	13.12	27.00	4.4	1.83
F1280W	MIRI	12.809	29.94	55.09	27.71	0.5	—
F1500W	MIRI	15.048	70.35	67.37	26.78	1.0	—
F1800W	MIRI	17.970	212.75	112.91	25.58	1.9	—

Provenance

Field: COSMOS (PRIMER COSMOS-2) (primercosmos2)
Programmes: 01837, 02321, 07814 behind every mosaic the field measured
Pipeline rows merged: 1 all at one position
Detection pass: original
Release build: 33af9933d1cc 2026-10-17T14:29:44Z

Image sources

Band	Mosaic	Native pixel	Coverage
F090W	`jw01837-o004_t004_nircam_clear-f090w_i2d.fits`	0.031″	1.00
F115W	`jw01837-o004_t004_nircam_clear-f115w_i2d.fits`	0.031″	1.00
F150W	`jw01837-o004_t004_nircam_clear-f150w_i2d.fits`	0.031″	1.00
F200W	`jw01837-o004_t004_nircam_clear-f200w_i2d.fits`	0.031″	1.00
F277W	`jw01837-o004_t004_nircam_clear-f277w_i2d.fits`	0.063″	1.00
F356W	`jw01837-o004_t004_nircam_clear-f356w_i2d.fits`	0.063″	1.00
F410M	`jw01837-o004_t004_nircam_clear-f410m_i2d.fits`	0.063″	1.00
F444W	`jw01837-o004_t004_nircam_clear-f444w_i2d.fits`	0.063″	1.00

Cite

Anderson, Jordan (2026). LRD Watch DR1: little red dot candidates from an independent search of public JWST imaging (Version DR1) [Data set]. Cerin Amroth Research. Zenodo. https://doi.org/10.5281/zenodo.23062632 Object LRDW J100042.20+022243.4.

CC BY 4.0. Please also acknowledge the JWST programmes that took the data. LRD Watch DR1 is a vetted candidate catalogue, not a complete census: it has no selection function and cannot on its own give number densities. About the release.