Cosmology

Abstract:

This paper accompanies Data Release 4 of the James Webb Space Telescope (JWST) Advanced Deep Extragalactic Survey, which presents the full NIRSpec spectroscopy of the survey. We provide spectra of 5190 targets across Great Observatories Origins Deep Survey (GOODS)-North and GOODS-South (including the Hubble Ultra Deep Field), observed with the low-dispersion (–300) prism and three medium-resolution () gratings spanning m; 2654 were also observed with the higher resolution () G395H grating. The tiered survey design obtained h exposures for galaxies in the Deep and Ultra Deep tiers, and shallower observations (–3 h per setting) of galaxies in the Medium tiers. Targets were selected from photometric redshifts or colours, with priority given to rest-UV-selected galaxies at and F444W-selected galaxies at . We describe the full target selection and present spectroscopic redshifts and success rates. In total, we obtain robust redshifts for 3297 galaxies, including 396 at and 2545 at . To facilitate uniform analyses, we define ‘gold’ subsamples based on UV- and F444W-selection. Using the parent samples and redshift success rates, we construct rest-UV luminosity functions at from the Medium- and Deep-JWST tiers. Our number densities agree well with previous determinations from both photometric and spectroscopic samples, with modest interloper fractions confirming the reliability of photometric UV-bright galaxy selections at these redshifts.

Abstract:

We study the gravitational dynamics of quasi-hierarchical triple systems, where the outer orbital period is significantly longer than the inner one, but the outer orbit is extremely eccentric, rendering the time at pericentre comparable to the inner period. Such systems are not amenable to the standard techniques of perturbation theory and orbit-averaging. Modelling the evolution of these triples as a sequence of impulses at the outer pericentre, we show, by comparing with direct three-body integrations, that such triples lend themselves to a description as an analytical map between subsequent outer pericentre passages. This map exhibits secular oscillations, going beyond the von Zeipel–Lidov–Kozai mechanism. We show that the time to coalescence due to gravitational waves in such systems is modified. We then study the long-term evolution under this map, which lead to a random-walk-like behaviour of the inner eccentricity. While this behaviour is probably absent from isolated triples, it could exist in triples where the outer orbit is weakly coupled to a system with which it can exchange angular momentum, and we describe some properties of this random walk.

Abstract:

We present the fourth data release of the JWST Advanced Deep Extragalactic Survey (JADES), providing deep spectroscopic observations in the two GOODS fields. A companion paper presents the target selection, spectroscopic redshifts and success rates, and in this paper, we discuss the data reduction and present emission-line flux measurements. The spectroscopy in this work consists of medium-depth, deep, and ultradeep NIRSpec/MSA spectra of 5190 targets, covering the spectral range m and observed with both the low-dispersion prism () and all three medium-resolution gratings (). We describe the data reduction, analysis and description of the data products included in this data release. In total, we measured 3297 robust redshifts out of 5190 targets, spanning a redshift range from up to , including 974 at . This data release includes 1D and 2D fully reduced spectra with 3- and 5-pixel extractions, with slit-loss corrections and background subtraction optimized for point sources. Furthermore, we provide redshifts and SNR > 5 emission-line flux catalogues for the prism and grating spectra, as well as new guidelines to use these data products. Lastly, we are launching a new JADES online data base, designed to enable quick selection and browsing of this data release. Altogether, these data provide the largest statistical sample to date including both PRISM and medium grating spectra across full NIRSpec wavelength range to characterize the properties of galaxy populations across cosmic time.

Abstract:

Pair-instability should prevent the direct formation of black holes above about 50M⊙ creating a “pair-instability” mass gap. Yet gravitational-wave obser vations have detected black holes in this mass range. These systems can be explained with uncertainties in massive-star evolution, or hierarchical mergers in stellar clusters, which are expected to produce large spins with isotropic orien tations. Here we present evidence for the pair-instability mass gap in the LIGO–Virgo–KAGRA fourth transient catalog, with a lower edge at 44.3 +5.9 −3.5 M⊙. We also obtain a measurement of the 12C(α, γ) 35 16O reaction rate, yielding an Sfactor of 268+195 −116 keV b, a parameter critical for modeling helium burning and stellar evolution. The data reveal two populations: a low-spin group with no black holes above the gap, and a high-spin, isotropic group that extends across the full mass range and occupies the gap, consistent with hierarchical mergers. These findings are consistent with pair-instability playing a role in shaping the black hole mass spectrum, point to a connection between gravitational wave astronomy and nuclear astrophysics, and highlight dense stellar clusters as key environments in the growth of black holes.