Galaxy formation and evolution

Abstract:

We present a sample of 2081 sources selected at a photometric redshift zphot > 8 across the JADES DR5 data release in GOODS-S and GOODS-N over a total area of 469 arcmin2. These sources range from MUV = −22 to MUV = −16, with 19 objects at zphot > 14. We estimate the UV slopes for the full sample from fits to the photometry and find evidence for a steepening of the relationship between the UV continuum slope and MUV to higher redshifts, a result that differs from prior analyses of brighter samples in the literature. We provide evidence that over one-quarter of our sources have evidence for being morphologically extended, with many galaxies showing multiple bright knots or clumps even out to z ∼ 13–14, an indication of how galaxies at cosmic dawn are growing and evolving. We discuss JADES-GN+189.15982+62.28899, a GOODS-N F200W dropout galaxy at zphot ∼ 15–18, which has been observed spectroscopically with JWST/NIRSpec in prism mode, resulting in a very low signal-to-noise spectrum that is consistent with the photometry and rules out a number of low-redshift solutions for the source. Finally, we use a subsample of 123 objects in our sample with spectroscopic redshifts to explore the usage of alternate fitting templates and a prescription for Lyα damping wing absorption, finding that both produce significant improvements to the estimated photometric redshifts.

Abstract:

The Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) is a wide-field, integral-field spectroscopic survey designed to map the large-scale distribution of Lyα-emitting galaxies (LAEs) at 1.88 < z < 3.52 and constrain dark energy at cosmic noon. Using the 10 m Hobby–Eberly Telescope and the Visible Integral-Field Replicable Unit (IFU) Spectrograph, HETDEX obtains >35,000 spectra per exposure over 3500–5500 Å at R ∼ 800 with ∼1.″8 image quality, enabling an untargeted census of emission-line galaxies across 540 deg2. We present HETDEX Public Data Release 1 (PDR1), comprising 431,713 IFU observations covering 86.67 deg2 of noncontiguous sky in the Spring (13h, +51°) and Fall (1 .h 5, 0°) fields, along with legacy regions (Cosmic Evolution Survey, Great Observations Origins Deep Survey North, North Ecliptic Pole, SA22). PDR1 includes the HETDEX Public Source Catalog 2 (HPSC2), an expanded and reprocessed version of E. Mentuch Cooper et al. (2023) incorporating four additional years of data, improved quality control, and new machine learning classifiers. HPSC2 contains 426,654 LAEs, 491,411 [O II] emitters, 19,457 low-z galaxies, 18,303 active galactic nuclei, and 150,608 stars, providing coordinates, redshifts or stellar velocities, and 1D spectra for each source. Because the data cubes use local sky subtraction optimized for faint emission-line detection, they are not suited for absolute surface-brightness measurements or very extended nearby galaxies. Appendix materials include the full detection catalog, the 1.6 million–candidate LAE sample, and raw detection databases. All products are publicly accessible through the HETDEX data portal (https://hetdex.org/data-results/), including access to a public JupyterLab. HPSC2 is also publicly available via Zenodo (doi:10.5281/zenodo.19581262).

Abstract:

We present the Parallel Application of Slitless Spectroscopy to Analyze Galaxy Evolution (PASSAGE) spectroscopic redshift catalog in the COSMOS field. PASSAGE is a JWST Cycle 1 Near Infrared Imager and Slitless Spectrograph (or NIRISS) wide-field slitless spectroscopy pure-parallel survey, obtaining near-infrared spectra of thousands of extragalactic sources. Fifteen out of 63 PASSAGE fields fall within the Hubble Space Telescope COSMOS footprint, of which 11 overlap with COSMOS-Web, a JWST treasury survey providing additional space-based photometry. We present our custom line-finding algorithm and visual inspection effort used to identify emission lines and derive the spectroscopic redshifts for line-emitting sources in PASSAGE. The line-finding algorithm identifies between ∼200 and 950 line-emitting candidates per field, of which typically 47% were identified as true emission lines post visual inspection. We identify 2183 emission-line sources at 0.08 ≲ z ≲ 4.7, 1896 of which have available COSMOS photometric redshifts. We find excellent redshift agreement between the COSMOS photometric redshifts and the PASSAGE spectroscopic redshifts for strong (signal-to-noise ratio > 5), multi-line-emitting sources. This agreement weakens for PASSAGE single-line emitters with ambiguous identities. These single-line emitters are likely misidentified around 18% of the time based on comparisons to photometric redshifts. We derive stellar masses using PASSAGE photometry and spectroscopic redshifts, in broad agreement with existing COSMOS-Web stellar masses, but with some discrepancy driven by redshift disagreements. We publicly release this spectroscopic redshift catalog, which will enable community-led science in prime extragalactic fields and serve as a crucial dataset for validating Euclid and Roman spectroscopy.

Abstract:

Dark matter dominates the matter content of the Universe, and its properties can be constrained through large-scale structure probes such as the cross-correlation between the unresolved gamma-ray background (UGRB) and weak gravitational lensing. We analysed 15 years of Fermi–LAT data, constructing UGRB intensity maps in ten energy bins (0.5–1000 GeV), and cross-correlated them with KiDS-Legacy shear in six tomographic bins. The measurements were performed using angular power spectra estimated with the pseudo- C ℓ method. No significant cross-correlation was found. Based on this non-detection, we present 95% upper bounds on the weakly interacting massive particle decay rate Γ dec and velocity-averaged annihilation cross-section ⟨ σ ann v ⟩ as functions of mass. We compared our results with bounds from other cosmological tracers and from local probes, and we found them to be complementary, particularly at low masses (GeV/TeV). In addition, using a Euclid -like lensing survey cross-correlated with Fermi–LAT, we forecast approximately two to four times tighter limits, highlighting the potential of forthcoming data to strengthen constraints on dark matter annihilation and decay.