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Abstract We measure the projected two-point correlation functions of emission-line galaxies (ELGs) from the Dark Energy Spectroscopic Instrument One-Percent Survey and model their dependence on stellar mass and [OII] luminosity. We select ∼180,000 ELGs with redshifts of 0.8 < z < 1.6, and define 27 samples according to cuts in redshift and both galaxy properties. Following a framework that describes the conditional [OII] luminosity–stellar mass distribution as a function of halo mass, we simultaneously model the clustering measurements of all samples at fixed redshift. Based on the modeling result, most ELGs in our samples are classified as central galaxies, residing in halos of a narrow mass range with a typical median of ∼10^12.2−12.4h⁻¹M_⊙. We observe a weak dependence of clustering amplitude on stellar mass, which is reflected in the model constraints and is likely a consequence of the 0.5 dex measurement uncertainty in the stellar mass estimates. The model shows a trend between galaxy bias and [OII] luminosity at high redshift (1.2 < z < 1.6) that is otherwise absent at lower redshifts. 

We present a study of the weak lensing inferred matter profiles ΔΣ(R) of 698 South Pole Telescope (SPT) thermal Sunyaev-Zel’dovich effect (tSZE) selected and MCMF optically confirmed galaxy clusters in the redshift range 0.25 <  z <  0.94 that have associated weak gravitational lensing shear profiles from the Dark Energy Survey (DES). Rescaling these profiles to account for the mass dependent size and the redshift dependent density produces average rescaled matter profiles ΔΣ(R/R_200c)/(ρ_critR_200c) with a lower dispersion than the unscaled ΔΣ(R) versions, indicating a significant degree of self-similarity. Galaxy clusters from hydrodynamical simulations also exhibit matter profiles that suggest a high degree of self-similarity, with RMS variation among the average rescaled matter profiles with redshift and mass falling by a factor of approximately six and 23, respectively, compared to the unscaled average matter profiles. We employed this regularity in a new Bayesian method for weak lensing mass calibration that employs the so-called cluster mass posteriorP(M₂₀₀|ζ̂, λ̂,z), which describes the individual cluster masses given their tSZE (ζ̂) and optical (λ̂,z) observables. This method enables simultaneous constraints on richnessλ-mass and tSZE detection significanceζ-mass relations using average rescaled cluster matter profiles. We validated the method using realistic mock datasets and present observable-mass relation constraints for the SPT×DES sample, where we constrained the amplitude, mass trend, redshift trend, and intrinsic scatter. Our observable-mass relation results are in agreement with the mass calibration derived from the recent cosmological analysis of the SPT×DES data based on a cluster-by-cluster lensing calibration. Our new mass calibration technique offers a higher efficiency when compared to the single cluster calibration technique. We present new validation tests of the observable-mass relation that indicate the underlying power-law form and scatter are adequate to describe the real cluster sample but that also suggest a redshift variation in the intrinsic scatter of theλ-mass relation may offer a better description. In addition, the average rescaled matter profiles offer high signal-to-noise ratio (S/N) constraints on the shape of real cluster matter profiles, which are in good agreement with available hydrodynamical ΛCDM simulations. This high S/N profile contains information about baryon feedback, the collisional nature of dark matter, and potential deviations from general relativity. 

We use galaxy cluster abundance measurements from the South Pole Telescope enhanced by multicomponent matched filter confirmation and complemented with mass information obtained using weak-lensing data from Dark Energy Survey Year 3 (DES Y3) and targeted Hubble Space Telescope observations for probing deviations from the cold dark matter paradigm. Concretely, we consider a class of dark sector models featuring interactions between dark matter (DM) and a dark radiation (DR) component within the framework of the effective theory of structure formation (ETHOS). We focus on scenarios that lead to power suppression over a wide range of scales, and thus can be tested with data sensitive to large scales, as realized, for example, for DM–DR interactions following from an unbroken non-Abelian $SU\left(N\right)$gauge theory (interaction rate with power-law index $n=0$within the ETHOS parametrization). Cluster abundance measurements are mostly sensitive to the amount of DR interacting with DM, parametrized by the ratio of DR temperature to the cosmic microwave background (CMB) temperature, ${\xi }_{\mathrm{DR}}=T_{\mathrm{DR}}/T_{\mathrm{CMB}}$. We find an upper limit ${\xi }_{\mathrm{DR}}<17\%$at 95% credibility. When the cluster data are combined with Planck 2018 CMB data along with baryon acoustic oscillation (BAO) measurements we find ${\xi }_{\mathrm{DR}}<10\%$, corresponding to a limit on the abundance of interacting DR that is around 3 times tighter than that from CMB + BAO data alone. We also discuss the complementarity of weak lensing informed cluster abundance studies with probes sensitive to smaller scales, explore the impact on our analysis of massive neutrinos, and comment on a slight preference for the presence of a nonzero interacting DR abundance, which enables a physical solution to the $S_8$tension. Published by the American Physical Society2025 

Abstract We measure the clustering of Lyman Alpha Emitting galaxies (LAEs) selected from the One-hundred-square-degree DECam Imaging in Narrowbands (ODIN) survey, with spectroscopic follow-up from Dark Energy Spectroscopic Instrument (DESI). We use DESI spectroscopy to optimize our selection and to constrain the interloper fraction and redshift distribution of our narrow-band selected sources. We select samples of 4000 LAEs atz= 2.45 and 3.1 in 9 sq.deg. centered on the COSMOS field with median Lyα fluxes of ≈ 10^-16erg s^-1cm^-2. Covariances and cosmological inferences are obtained from a series of mock catalogs built upon high-resolution N-body simulations that match the footprint, number density, redshift distribution and observed clustering of the sample. We find that both samples have a correlation length ofr₀= 3.0 ± 0.2 h^-1Mpc. Within our fiducial cosmology these correspond to 3D number densities of ≈ 10^-3h³Mpc^-3and, from our mock catalogs, biases of 1.7 and 2.0 atz= 2.45 and 3.1, respectively. We discuss the implications of these measurements for the use of LAEs as large-scale structure tracers for high-redshift cosmology. 

ABSTRACT Current and future Type Ia Supernova (SN Ia) surveys will need to adopt new approaches to classifying SNe and obtaining their redshifts without spectra if they wish to reach their full potential. We present here a novel approach that uses only photometry to identify SNe Ia in the 5-yr Dark Energy Survey (DES) data set using the SuperNNova classifier. Our approach, which does not rely on any information from the SN host-galaxy, recovers SNe Ia that might otherwise be lost due to a lack of an identifiable host. We select $$2{,}298$$ high-quality SNe Ia from the DES 5-yr data set an almost complete sample of detected SNe Ia. More than 700 of these have no spectroscopic host redshift and are potentially new SNIa compared to the DES-SN5YR cosmology analysis. To analyse these SNe Ia, we derive their redshifts and properties using only their light curves with a modified version of the SALT2 light-curve fitter. Compared to other DES SN Ia samples with spectroscopic redshifts, our new sample has in average higher redshift, bluer and broader light curves, and fainter host-galaxies. Future surveys such as LSST will also face an additional challenge, the scarcity of spectroscopic resources for follow-up. When applying our novel method to DES data, we reduce the need for follow-up by a factor of four and three for host-galaxy and live SN, respectively, compared to earlier approaches. Our novel method thus leads to better optimization of spectroscopic resources for follow-up. 

Late Cenozoic evolution of the Baja California (BC) peninsula governs its species diversity, with changes to terrestrial habitats and shorelines driven by volcanic and tectonic processes. New geologic mapping and geochronology in central BC help assess if recent landscape evolution created a barrier to gene flow. The NW-trending topographic divide of the BC peninsula near San Ignacio-Santa Rosalia (27.4N) is a low (400500 m asl), broad (2030 km-wide) pass. At the pass, ~2022-Ma volcaniclastic strata, mafic lavas, fluvial conglomerate, cross-bedded eolian sandstone, and a felsic tuff dip ~515 SW. Similar lithology and chronology suggest these strata correlate to the lower Comondu Group (CG). They are overlain by middle Miocene (~1114 Ma) mafic lavas with similar SW dips that overlap in age with the upper CG. NW of the pass, upper Miocene (~9.511 Ma) post-CG volcaniclastic strata and mafic lava flows are exposed in the Sierra San Francisco and dip ~10 SE on its SE flank, inclined differently than older SW-dipping CG at the pass. The basalt of Esperanza (~10 Ma) unconformably overlies the CG at and west of the pass. Its ~1 regional dip suggests that ~515 of SW tilting occurred prior to ~10 Ma in the footwall of the NW-striking Campamento fault, located at the base of the ~150 m-high rift escarpment. The N-striking Arroyo Yaqui fault, ~10 km E of the Campamento fault in a low-relief region capped by Quaternary marine strata, exposes crystalline basement in its footwall and may be a major rift margin structure. Thus the location, orientation, and age of the divide may be controlled by rift-related faulting and tilting plus beveling and lateral retreat of the escarpment. Pliocene tidal sediments occur up to ~200 m asl ~20 km west of the low pass similar to Pliocene marine strata east of the pass at ~300 m asl, indicating late Miocene to Pliocene subsidence was followed by >200 m of post-4 Ma uplift. Uplift was likely driven by transtensional faulting and possibly magmatic inflation by ~7090 km-wavelength domes. Further mapping will constrain the timing of vertical crustal motions and test whether the tidal embayment crossed the peninsula through this low pass, isolated species, and prevented terrestrial gene flow. Integration of geologic and genetic data will determine how volcano- tectonic processes shaped genetic diversity. 

Central Baja California (BC) experienced tectonism and volcanism that shaped the landscape from the Miocene to Recent. One important feature is the San Ignacio trough (SIT) that hosted a marine seaway or embayment and acted as a physical barrier to animal and plant migration. This barrier may be responsible for a well-known break in the DNA, N and S of this region. Central BC has also hosted contemporary voluminous and chemically diverse volcanism. Radiometric ages provide important constraints on the origins and longevity of critical topographic features. The Baja GeoGenomics research group is investigating the nature and timing of Pliocene marine and tidal deposits in the NE-oriented, low-lying SIT, located W of the peninsular divide. These new data reveal that the Sierra San Francisco, a highland volcanic area immediately N of the SIT, is a series of volcanoes constructed of dacitic and andesitic Peleean domes with voluminous lahar and pyroclastic flow deposits. These calcalkaline rocks were previously thought to be subduction-related magmatism and part of the early to middle Miocene (~2412 Ma) Comondu Group. However, zircon U-Pb and 40Ar/39Ar dates yield ages of 11-9 Ma. These data indicate the Sierra San Francisco erupted post-subduction and is not part of the lithologically similar but older Comondu Group. Within the SIT, 12km NE of San Ignacio at 200 m asl, newly mapped marine tidal deposits, informally called the San Regis beds, indicate that the SIT has been significantly uplifted. Mafic scoria interbedded in tidal deposits yield a groundmass 40Ar/39Ar age of about 4.2 0.1 Ma. San Regis tidal beds are unconformably overlain by a rhyolite ash-flow tuff from the Quaternary La Reforma caldera situated to the E, on the Gulf of California coast. The highly mobile ash cloud flowed W into the SIT at least as far as the San Regis beds locality NE of San Ignacio. The tuff yielded a preliminary U-Pb zircon age of 1.09 0.04 Ma and an 40Ar/39Ar anorthoclase age of 1.11± 0.01 Ma. These dates indicate that the ash-flow was one of the latest erupted from the caldera and its distribution was in part controlled by the SIT. In BC genetic diversity along the peninsula appears to change at the latitude of the SIT. Tidal and volcanic deposits suggest this topographic low persisted for over 4Ma and remains a distinctive feature in the topography today.