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1. A GLIMPSE into the very faint end of the H β +[O III] λλ 4960,5008 luminosity function at z ∼ 7 – 9 behind Abell S1063

   https://doi.org/10.1051/0004-6361/202556868  

   Korber, Damien; Chemerynska, Iryna; Furtak, Lukas J; Atek, Hakim; Endsley, Ryan; Schaerer, Daniel; Chisholm, John; Kokorev, Vasily; Saldana-Lopez, Alberto; Adamo, Angela; et al (April 2026, Astronomy & Astrophysics)

   We used the ultra-deep GLIMPSE JWST/NIRCam survey to constrain the faint end of the [O III]+Hβluminosity function (LF) down to 10³⁹erg s⁻¹atz ∼ 7 − 9 behind the lensed Hubble Frontier Field galaxy cluster Abell S1063. We applied a spectral energy distribution fitting on a Lyman-break galaxy selected sample of 164 lensed galaxies and measured their combined Hβ+[O III]λλ4960, 5008 flux to build the emission line LF. We found a [O III]+HβLF with a faint-end slope (α= −1.78^+0.06_−0.06forz = 7 − 8 andα= −1.55^+0.11_−0.11forz = 8 − 9), which is flatter than the UV LF at similar redshifts (α ≤ −2) and suggests a lower number density of weak [O III]+Hβemitting galaxies at fixedM_UV. We analysed several possible explanations: (i) a decrease in the [O III]+Hβ-to-UV ratio due to bursty star formation histories (SFHs), (ii) the effect of metallicity on the [O III]-to-Hβratio, or (iii) signs of a faint-end turnover in the UV LF. Under the assumption of an evolving [O III]-to-Hβratio, we separated the contribution of [O III]λ5008 and Hβand obtained a flatter [O III]λ5008 LF (α= −1.66^+0.05_−0.05forz = 7 − 8 andα= −1.45^+0.09_−0.10forz = 8 − 9) but steeper HβLF ($$ \alpha=-1.95_{-0.08}^{+0.08} $$ forz = 7 − 8 andα= −1.68^+0.13_−0.14forz = 8 − 9). The combination of a decreasing metallicity and bursty SFH can reconcile the observed differences between the UV and [O III]+HβLF. By converting this LF into the ionising photon-production rateṄ_ion, we show that galaxies withL_Hα ≥ 10³⁹erg s⁻¹, that is, with a star formation rate (SFR) (Hα)  ≥  5 × 10⁻³M_⊙yr⁻¹) cause 31%−90% and 46%−156% of the ionising photon budget (at 7 < z < 8 and 8 < z < 9), when we assume a constant escape fraction of Lyman-continuum photon (f_esc = 0.14). The shape of the LF further shows the negligible contribution of faint galaxies to theṄ_ion. Additionally, we derived the cosmic star formation rate density (SFRD), finding results consistent with previous estimates. However, the sensitivity of GLIMPSE to lower SFRs reinforces the conclusion that very faint galaxies contribute very little toṄ_ionand the SFRD. Our results suggests that GLIMPSE has detected the bulk of the total [O III]+Hβemission from star-forming galaxies, and that galaxies below our detection limits are likely minor contributors to cosmic re-ionisation. 

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2. A CEERS Discovery of an Accreting Supermassive Black Hole 570 Myr after the Big Bang: Identifying a Progenitor of Massive z > 6 Quasars

   https://doi.org/10.3847/2041-8213/ace619  

   Larson, Rebecca L; Finkelstein, Steven L; Kocevski, Dale D; Hutchison, Taylor A; Trump, Jonathan R; Arrabal_Haro, Pablo; Bromm, Volker; Cleri, Nikko J; Dickinson, Mark; Fujimoto, Seiji; et al (August 2023, The Astrophysical Journal Letters)

   Abstract We report the discovery of an accreting supermassive black hole atz= 8.679. This galaxy, denoted here as CEERS_1019, was previously discovered as a Lyα-break galaxy by Hubble with a Lyαredshift from Keck. As part of the Cosmic Evolution Early Release Science (CEERS) survey, we have observed this source with JWST/NIRSpec, MIRI, NIRCam, and NIRCam/WFSS and uncovered a plethora of emission lines. The Hβline is best fit by a narrow plus a broad component, where the latter is measured at 2.5σwith an FWHM ∼1200 km s⁻¹. We conclude this originates in the broadline region of an active galactic nucleus (AGN). This is supported by the presence of weak high-ionization lines (N V, N IV], and C III]), as well as a spatial point-source component. The implied mass of the black hole (BH) is log (M_BH/M_⊙) = 6.95 ± 0.37, and we estimate that it is accreting at 1.2 ± 0.5 times the Eddington limit. The 1–8μm photometric spectral energy distribution shows a continuum dominated by starlight and constrains the host galaxy to be massive (log M/M_⊙∼9.5) and highly star-forming (star formation rate, or SFR ∼ 30 M_⊙yr⁻¹; log sSFR ∼ − 7.9 yr⁻¹). The line ratios show that the gas is metal-poor (Z/Z_⊙∼ 0.1), dense (n_e∼ 10³cm⁻³), and highly ionized (logU∼ − 2.1). We use this present highest-redshift AGN discovery to place constraints on BH seeding models and find that a combination of either super-Eddington accretion from stellar seeds or Eddington accretion from very massive BH seeds is required to form this object. 

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3. Lyα Emission Line Profiles of Extreme [O iii]- emitting Galaxies at z ≳ 2: Implications for Lyα Visibility in the Reionization Era

   https://doi.org/10.3847/1538-4357/ad5ae0  

   Tang, Mengtao; Stark, Daniel P; Ellis, Richard S; Topping, Michael W; Mason, Charlotte; Li, Zhihui; Plat, Adèle (August 2024, The Astrophysical Journal)

   Abstract JWST observations have recently begun delivering the first samples of Lyαvelocity profile measurements atz> 6, opening a new window into the reionization process. Interpretation ofz≳ 6 line profiles is currently stunted by limitations in our knowledge of the intrinsic Lyαprofile (before encountering the intergalactic medium (IGM)) of the galaxies that are common atz≳ 6. To overcome this shortcoming, we have obtained resolved (R∼ 3900) Lyαspectroscopy of 42 galaxies atz= 2.1–3.4 with similar properties as are seen atz> 6. We quantify a variety of Lyαprofile statistics as a function of [Oiii]+Hβequivalent width (EW). Our spectra reveal a new population ofz≃ 2–3 galaxies with large [Oiii]+HβEWs (>1200 Å) and a large fraction of Lyαflux emerging near the systemic redshift (peak velocity ≃0 km s⁻¹). These spectra indicate that low-density neutral hydrogen channels are able to form in a subset of low-mass galaxies (≲1 × 10⁸M_⊙) that experience a burst of star formation (sSFR > 100 Gyr⁻¹). Other extreme [Oiii] emitters show weaker Lyαthat is shifted to higher velocities (≃240 km s⁻¹) with little emission near the line center. We investigate the impact the IGM is likely to have on these intrinsic line profiles in the reionization era, finding that the centrally peaked Lyαemitters should be strongly attenuated atz≳ 5. We show that these line profiles are particularly sensitive to the impact of resonant scattering from infalling IGM and can be strongly attenuated even when the IGM is highly ionized atz≃ 5. We compare these expectations against a new database ofz≳ 6.5 galaxies with robust velocity profiles measured with JWST/NIRSpec. 

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4. A Dataset of Plausible Proton Transfer Steps for Arrow-Pushing Mechanisms

   https://doi.org/10.1038/s41597-025-06490-8  

   Dashuta, Alexander E; Miller, Ryan J; Baldi, Pierre; Sander, Thomas; Van_Vranken, David L (December 2026, Scientific Data)

   Abstract Proton transfers are fundamental steps in polar reaction mechanisms. We generated a large dataset of over 51 million kinetically plausible proton transfer steps between heteroatoms from about 8,000 acids and conjugate bases with experimental aqueous pK_as, spanning pK_avalues from −15 to +37. Rate factors were estimated at 25 °C using a simplified Eigen equation with pK_as but without statistical factors. Steps with estimated rate constants ≥ 10³M⁻¹s⁻¹were included in the final dataset. Additionally, 5,043 proton transfer steps from carbon acids to heteroatom bases were estimated using the Eigen-Bernasconi equation based on reported intrinsic rate constants and Brønsted β values. Carbon proton transfers with rate constants ≥ 10³ M⁻¹s⁻¹were added to the final dataset. Each entry was encoded in SMIRKS format with electron-flow specification for machine learning compatibility. Diversity of structure was prioritized over diversity of conditions; calculated rate constants are expected to be accurate in aqueous environments. This approach and dataset should prove valuable for training models to predict stepwise mechanistic pathways. 

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5. The Critical Role of LIGO-India in the Era of Next-generation Observatories

   https://doi.org/10.3847/2041-8213/add15f  

   Pandey, Shiksha; Gupta, Ish; Chandra, Koustav; Sathyaprakash, Bangalore S (May 2025, The Astrophysical Journal Letters)

   Abstract We examine the role of LIGO-India in facilitating multimessenger astronomy in the era of next-generation observatories. A network with two L-shaped Cosmic Explorer (CE) detectors and one triangular Einstein Telescope (ET) would precisely localize nearly the entire annual binary neutron star (NS) merger population up to a redshift of 0.5—over 10,000 events would be localized within 10 deg², including approximately 150 events within 0.1 deg². Luminosity distance would be measured to within 10% for over 9000 events and within 1% for ∼100 events. Surprisingly, replacing the 20 km CE detector with LIGO-India operating at A^♯sensitivity (I^♯) yields a nearly identical performance. The factor-of-5 shorter arms are offset by a fourfold increase in baseline relative to a second CE in the US, preserving localization accuracy, with over 9000 events within 10 deg²and ∼90 events within 0.1 deg². This configuration detects ∼6000 events with luminosity distance uncertainties under 10%, including ∼50 with under 1%. Both networks provide $\mathcal{O}\left(100\right)$ early-warning detections up to 10 minutes before merger, with localization areas ≤10 deg². WhileI^♯enables excellent localization and early warnings, its shorter arms and narrower sensitivity band would limit its reach for other science goals, such as detecting Population III binary black hole mergers atz≳ 10, NS mergers atz∼ 2, or constraining cosmological parameters. 

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