REVIEW 13 cited by
Reionization after JWST: a photon budget crisis?
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
New James Webb Space Telescope (JWST) observations are revealing the first galaxies to be prolific producers of ionizing photons, which we argue gives rise to a tension between different probes of reionization. Over the last two decades a consensus has emerged where star-forming galaxies are able to generate enough photons to drive reionization, given reasonable values for their number densities, ionizing efficiencies $\xi_{\rm ion}$ (per unit UV luminosity), and escape fractions $f_{\rm esc}$. However, some new JWST observations infer high values of $\xi_{\rm ion}$ during reionization and an enhanced abundance of earlier ($z\gtrsim 9$) galaxies, dramatically increasing the number of ionizing photons produced at high $z$. Simultaneously, recent low-$z$ studies predict significant escape fractions for faint reionization-era galaxies. Put together, we show that the galaxies we have directly observed ($M_{\rm UV} < -15$) not only can drive reionization, but would end it too early. That is, our current galaxy observations, taken at face value, imply an excess of ionizing photons and thus a process of reionization in tension with the cosmic microwave background (CMB) and Lyman-$\alpha$ forest. Considering galaxies down to $M_{\rm UV}\approx -11$, below current observational limits, only worsens this tension. We discuss possible avenues to resolve this photon budget crisis, including systematics in either theory or observations.
Forward citations
Cited by 13 Pith papers
-
A self-consistent analytical model for both the photoionization rate and reionization history
A new analytical formalism self-consistently predicts both the ionized fraction x_i(z) and photoionization rate Gamma_HI(z), achieving percent-level accuracy in x_i and 20-30% accuracy in Gamma_HI versus radiative tra...
-
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...
-
JWST Constraints on Primordial Magnetic Fields
JWST UV luminosity function calibration of reionization history bounds primordial magnetic fields to √<B²> < 0.27 nG (n_B=-2) and < 0.18 nG (n_B=2) at 95% CL by ruling out double reionization at z≈24.
-
A GLIMPSE of the 99%: a census of the faintest galaxies during the epoch reionization and its implications for galaxy formation models
The UV luminosity function at z~7 rises steeply with slope alpha=-1.98 to M_UV=-12.3 with no turnover, indicating faint galaxies dominate the ionizing photon budget during reionization.
-
Cosmic $\tau$ensions Indirectly Correlate with Reionization Optical Depth
The correlations between tau_reio and the parameters behind cosmic tensions are not intrinsic, but arise indirectly through networks of other cosmological parameters.
-
A New Boundary Condition on Reionization
A zero-lag Pearson correlation between 21-cm and line-intensity maps is predicted to drop sharply at ionized fractions of 1-10%, providing a novel marker for the onset of reionization.
-
Probing the ionizing photon output of galaxies near cosmic dawn with the patchy kSZ effect
In calibrated reionization simulations, the patchy kSZ power at ell~3000 correlates strongly with the start of reionization once the end is fixed by Lyman-alpha forest data, yielding model-dependent limits on early io...
-
Tilting at the Turnover: Modeling the Faint-End of the UV Luminosity Function Behind Abell s1063 with JWST
Using lensed JWST data behind Abell S1063, the UVLF at z~6-11 is fit with gradual quadratic turnover, yielding no evidence for turnover to M_UV=-13.5 at z=6, exclusion limits on turnover models, and lower bounds showi...
-
Constraints on Neutrino Physics from DESI DR2 BAO and DR1 Full Shape
DESI DR2 BAO and full-shape data plus CMB yield ∑m_ν < 0.0642 eV (95% CL) under ΛCDM, in 3σ tension with oscillation lower limits, relaxed to <0.163 eV in w0waCDM.
-
Gamma-ray bursts reveal the history and faint contributors of cosmic reionization
Long gamma-ray bursts imply a higher cosmic star formation rate density at z>6 than galaxy surveys detect, sufficient to drive reionization with moderate ionizing efficiency and escape fraction, implying a large popul...
-
Raising the reionization optical depth with inflationary CMB features
Marginalizing over generalized slow-roll inflationary templates for the CMB low-power feature raises the 95% upper limit on τ to 0.075 (Planck) or 0.082 (all CMB+BAO), resolving incompatibility with lower bounds.
-
Early- and Late-Time Modifications to $\Lambda$CDM: Implications for the Hubble Tension
An extended model with decaying dark matter around equality and w0 dark energy yields H0 ≈ 70 km/s/Mpc from Planck+ACT+DESI data, reducing Hubble tension to ~2.2σ while producing Bayesian evidence comparable to ΛCDM.
-
Ionizing Radiation Escape from Low-Redshift Galaxies and Its Connection to Cosmic Reionization
Low-redshift LyC emitters show that high escape fractions require low neutral gas and dust absorption, high ionization, and compact star formation, with radiative feedback dominating in the youngest starbursts.
Discussion (0). Sign in to comment.