REVIEW 11 cited by
Hidden Little Monsters: Spectroscopic Identification of Low-Mass, Broad-Line AGN at $z>5$ with CEERS
Not yet reviewed by Pith; the record is open.
This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.
SPECIMEN: schema-true, not a live event
T0 review · schema-true
One-sentence machine reading of the paper's core claim.
pith:XXXXXXXX · record.json · timestamp
abstract
We report on the discovery of two low-luminosity, broad-line AGN at $z>5$ identified using JWST NIRSpec spectroscopy from the CEERS Survey. We detect broad H$\alpha$ emission from both sources, with FWHM of $2038\pm286$ and $1807\pm207$ km s$^{-1}$, resulting in black hole (BH) masses that are 1-2 dex below that of existing samples of luminous quasars at $z>5$. The first source, CEERS 1670 at $z=5.242$, is 2-3 dex fainter than known quasars at similar redshifts and was previously identified as a candidate low-luminosity AGN based on its rest-frame optical SED. We measure a BH mass of $M_{\rm BH}=1.3\pm0.4\times 10^{7}~M_{\odot}$, confirming that this AGN is powered by the least-massive BH known in the universe at the end of cosmic reionization. The second source, CEERS 3210 at $z=5.624$, is inferred to be a heavily obscured, broad-line AGN caught in a transition phase between a dust-obscured starburst and an unobscured quasar. We estimate its BH mass to be $M_{\rm BH}\simeq 0.9-4.7 \times 10^{7}~M_{\odot}$, depending on the level of dust obscuration assumed. We derive host stellar masses, $M_\star$, allowing us to place constraints on the BH-galaxy mass relationship in the lowest mass range yet probed in the early universe. The $M_{\rm BH}/M_\star$ ratio for CEERS 1670, in particular, is consistent with or higher than the empirical relationship seen in massive galaxies at $z=0$. We examine the emission-line ratios of both sources and find that their location on the BPT and OHNO diagrams is consistent with model predictions for low-metallicity AGN with $Z/Z_\odot \simeq 0.2-0.4$. The spectroscopic identification of low-luminosity, broad-line AGN at $z>5$ with $M_{\rm BH}\simeq 10^{7}~M_{\odot}$ demonstrates the capability of JWST to push BH masses closer to the range predicted for the BH seed population and provides a unique opportunity to study the early stages of BH-galaxy assembly.
Forward citations
Cited by 11 Pith papers
-
Two Peas in a Pod: The First Confirmed Dual Active Galactic Nucleus within a Green Pea Galaxy System
A compact Green Pea galaxy system hosts two resolved, simultaneously accreting supermassive black holes — the first confirmed dual AGN in such a galaxy.
-
ATLAS. II. Extremely High Incidence of Balmer Line Absorption with Predominant Blueshifts in LRDs: Statistical Insights through Comparison with Type 1 AGNs
Balmer-line absorption occurs in ~35% (14/40) of JWST little-red-dot AGNs, roughly 850x the rate in SDSS type-1 AGNs, with mostly slow blueshifted absorber velocities.
-
Outflows in super-Eddington quasars drive clumpy circumgalactic medium and extended H$\alpha$ nebulae at $z \gtrsim 6$
In z≈6 quasar simulations, super-Eddington black-hole growth clears escape channels, ejects cold clumps that raise neutral-hydrogen covering, and powers extended Hα nebulae that shrink when the quasar is obscured.
-
An (in)complete NIRSpec census of Balmer absorption in Type 1 AGN -- radiation-driven outflows in little red dots, quasars and variable stars
About 44% of little red dots have hydrogen-alpha absorption from outflowing gas, implying radiatively driven outflows rather than static atmospheres.
-
Bright Galaxies at Cosmic Dawn: A Cloud-Scale Star Formation Model Unifying Variable SFE, IMFs, and Stochasticity
A cloud-based semi-analytic model shows that a top-heavy stellar initial mass function and a cloud-property-dependent star-formation efficiency, rather than cloud mass or density, most strongly shape the UV luminosity...
-
Ultrahigh-energy cosmogenic neutrino emissions in the high-redshift universe
If Little Red Dots accelerate protons to ~10 EeV, their interactions with the high-redshift CMB produce a ~50 PeV cosmogenic neutrino bump consistent with IceCube.
-
The Two Orbital, Interacting Hatano-Nelson Model
Phase diagrams for a purely real spectrum are obtained in the two-particle sector of a two-chain interacting Hatano–Nelson–Hubbard model, with winding-number and Lindblad checks of boundary and open-system behavior.
-
Discovery of Multiply Ionized Iron Emission Powered by an Active Galactic Nucleus in a z~7 Little Red Dot
The z=6.68 Little Red Dot THRILS 46403 shows a 4.5 sigma [FeVII] line, the first robust coronal-line detection among z>5 LRDs, plus narrow Balmer absorption, supporting an AGN with direct sightlines to gas at or beyon...
-
Magellan Spectroscopy of AGNs in Low-mass Galaxies: Scaling Relations and a Triple-Peaked AGN
New Magellan spectra of six low-mass AGN host galaxies yield black hole masses consistent with known scaling relations, and reveal a galaxy with triple-peaked emission lines likely produced by a central AGN outflow pl...
-
Not-quite-primordial black holes seeded by cosmic string loops
Cosmic string loops moving through the early universe can seed halos that collapse into 10^5 solar mass black holes, potentially explaining JWST's little red dots.
-
Little Red Dots from Small-Scale Primordial Black Hole Clustering
Densely clustered 30-solar-mass primordial black holes can sequentially merge into ~10^6 solar-mass seeds by redshift 6, possibly explaining JWST little red dots, with high spin from tidal torques and a two-peak gravi...
Discussion (0). Sign in to comment.