EMBER: A Little Red Dot Candidate at zspec=10.36 in the Seed Black Hole Era
Abstract
Little red dots (LRDs) are a newly discovered population that may trace rapidly growing black holes (BHs) and provide a link between seed BHs and luminous active galactic nuclei (AGNs). However, no LRD had previously been spectroscopically confirmed at z>10, leaving this earliest phase observationally unexplored. Using JWST/NIRSpec spectroscopy from the EMBER program, we measure a spectroscopic redshift of zspec=10.361+0.003−0.002 for \target, the highest-redshift LRD candidate known to date. The redshift is constrained by a prominent Lyα break and multiple tentative emission lines, including C\,{\sc iv}\,λλ1549,1551 and [O\,{\sc iii}]\,λ4363 detected at S/N=3.9 and $3.6$, respectively. Its extreme NIRCam-MIRI color of mF444W−mF770W=1.82±0.1, characteristic V-shaped continuum with a turnover near the Balmer limit, and continuum slopes of βUV=−2.26+0.11−0.11 and βopt=1.17+0.74−0.70 all support its LRD nature. A possible iron complex at λrest∼0.24--0.25 μm and a possibly high log([O III] λ4363/Hγ)=0.17+0.24−0.22 further support an AGN-like interpretation, as seen in previously known LRDs. Tentative detection of Lyα emission may indicate enhanced Lyα transmission at z∼10. Our findings extend the observational frontier of BH growth into the seed-BH formation era, and upcoming MIRI spectroscopy will further establish the physical nature of the source.
Related
- Formation of Heavy Seed Black Holes and Little Red Dots-like Compact Clusters in Metal-enriched Star-forming Regions
- More Numerous and Bluer: Companions of the Brightest Little Red Dots Differ from Control Galaxies at >3σ, Hinting at Synchronized Black Hole Seed Formation
- More Numerous and Bluer: Companions of the Brightest Little Red Dots Differ from Control Galaxies at > 3 σ , Hinting at Synchronized Black Hole Seed Formation
- Poisson Clustering and Seed Effect of PBHs: Implications for Microlensing, Gravitational Waves, Little Red Dots and Ultra-Faint Dwarf Galaxies
- Massive black holes seeded by dark matter: Implications for little red dots and gravitational wave signatures
BibTeX
@misc{tanaka2026ember,
title = {{EMBER: A Little Red Dot Candidate at $z_\rm spec=10.36$ in the Seed Black Hole Era}},
author = {Takumi S. Tanaka and Hollis B. Akins and John D. Silverman and Caitlin M. Casey and Ezequiel Treister and Manuel Aravena and Yuichi Harikane and Benny Trakhtenbrot and Kohei Inayoshi and Kazuhiro Shimasaku and Maximilien Franco and Seiji Fujimoto and Mingyu Li and Hiroya Umeda and Jan-Torge Schindler and Akio K. Inoue and Jean-Baptiste Billand and Darshan Kakkad and Xuheng Ding and Steven L. Finkelstein and Michaela Hirschmann and Z. Ghaffari and Andrew J. Battisti and Lauro Moscardini and Nicole E. Drakos and Rasha M. Samir and Jeyhan S. Kartaltepe and Qinyue Fei and Ming-Yang Zhuang and Olivier Ilbert and Wuji Wang and Rafael C. Arango-Toro and Hiddo S. B. Algera and Greta Toni and Junya Arita and Kei Ito and Ghassem Gozaliasl and Dale D. Kocevski and Yunjing Wu and Masafusa Onoue and Marc Huertas-Company and Yiyang Zhang and Jason Rhodes and Andreas L. Faisst and Zihao Li and Crystal L. Martin and Makoto Ando and Vasily Kokorev and Sophie L. Newman and Can Xu and Suin Matsui and Jialai Wang and Carter Flayhart and Hossein Hatamnia and Ali Ahmad Khostovan and Ronaldo Laishram and Felix Martinez III and David B. Sanders and Sune Toft and Francesco Valentino},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.00195},
eprint = {2611.00195},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.00195},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - EMBER: A Little Red Dot Candidate at z_spec=10.36 in the Seed Black Hole Era
AU - Takumi S. Tanaka
AU - Hollis B. Akins
AU - John D. Silverman
AU - Caitlin M. Casey
AU - Ezequiel Treister
AU - Manuel Aravena
AU - Yuichi Harikane
AU - Benny Trakhtenbrot
AU - Kohei Inayoshi
AU - Kazuhiro Shimasaku
AU - Maximilien Franco
AU - Seiji Fujimoto
AU - Mingyu Li
AU - Hiroya Umeda
AU - Jan-Torge Schindler
AU - Akio K. Inoue
AU - Jean-Baptiste Billand
AU - Darshan Kakkad
AU - Xuheng Ding
AU - Steven L. Finkelstein
AU - Michaela Hirschmann
AU - Z. Ghaffari
AU - Andrew J. Battisti
AU - Lauro Moscardini
AU - Nicole E. Drakos
AU - Rasha M. Samir
AU - Jeyhan S. Kartaltepe
AU - Qinyue Fei
AU - Ming-Yang Zhuang
AU - Olivier Ilbert
AU - Wuji Wang
AU - Rafael C. Arango-Toro
AU - Hiddo S. B. Algera
AU - Greta Toni
AU - Junya Arita
AU - Kei Ito
AU - Ghassem Gozaliasl
AU - Dale D. Kocevski
AU - Yunjing Wu
AU - Masafusa Onoue
AU - Marc Huertas-Company
AU - Yiyang Zhang
AU - Jason Rhodes
AU - Andreas L. Faisst
AU - Zihao Li
AU - Crystal L. Martin
AU - Makoto Ando
AU - Vasily Kokorev
AU - Sophie L. Newman
AU - Can Xu
AU - Suin Matsui
AU - Jialai Wang
AU - Carter Flayhart
AU - Hossein Hatamnia
AU - Ali Ahmad Khostovan
AU - Ronaldo Laishram
AU - Felix Martinez III
AU - David B. Sanders
AU - Sune Toft
AU - Francesco Valentino
PY - 2026
DA - 2026/11/01
PB - arXiv
DO - 10.48550/arxiv.2611.00195
UR - https://arxiv.org/abs/2611.00195
AB - Little red dots (LRDs) are a newly discovered population that may trace rapidly growing black holes (BHs) and provide a link between seed BHs and luminous active galactic nuclei (AGNs). However, no LRD had previously been spectroscopically confirmed at z>10, leaving this earliest phase observationally unexplored. Using JWST/NIRSpec spectroscopy from the EMBER program, we measure a spectroscopic redshift of z_spec=10.361^+0.003_−0.002 for \target, the highest-redshift LRD candidate known to date. The redshift is constrained by a prominent Lyα break and multiple tentative emission lines, including C\,{\sc iv}\,λλ1549,1551 and [O\,{\sc iii}]\,λ4363 detected at S/N=3.9 and $3.6$, respectively. Its extreme NIRCam-MIRI color of m_F444W−m_F770W=1.82±0.1, characteristic V-shaped continuum with a turnover near the Balmer limit, and continuum slopes of β_UV=−2.26^+0.11_−0.11 and β_opt=1.17^+0.74_−0.70 all support its LRD nature. A possible iron complex at λ_rest∼0.24--0.25 μm and a possibly high log([O III] λ4363/Hγ)=0.17^+0.24_−0.22 further support an AGN-like interpretation, as seen in previously known LRDs. Tentative detection of Lyα emission may indicate enhanced Lyα transmission at z∼10. Our findings extend the observational frontier of BH growth into the seed-BH formation era, and upcoming MIRI spectroscopy will further establish the physical nature of the source.
ER -