4 research outputs found
A Highly Magnified Gravitationally Lensed Red QSO at z = 2.5 with a Significant Flux Ratio Anomaly
We present the discovery of a gravitationally lensed dust-reddened QSO at z = 2.517, identified in a survey for QSOs by infrared selection. Hubble Space Telescope imaging reveals a quadruply lensed system in a cusp configuration, with a maximum image separation of ∼1.″8. We find that, compared to the central image of the cusp, the neighboring brightest image is anomalous by a factor of ∼7-10, which is the largest flux anomaly measured to date in a lensed QSO. Incorporating high-resolution Very Large Array radio imaging and submillimeter imaging with the Atacama Large Millimeter/submillimeter Array, we conclude that a low-mass perturber is the most likely explanation for the anomaly. The optical through near-infrared spectrum reveals that the QSO is moderately reddened with E(B − V) ≃ 0.7-0.9. We see an upturn in the ultraviolet spectrum due to ∼1% of the intrinsic emission being leaked back into the line of sight, which suggests that the reddening is intrinsic and not due to the lens. The QSO may have an Eddington ratio as high as L/L Edd ≈ 0.2. Consistent with previous red QSO samples, this source exhibits outflows in its spectrum, as well as morphological properties suggestive of it being in a merger-driven transitional phase. We find a host galaxy stellar mass of log M ⋆ / M ⊙ = 11.4 , which is higher than the local M BH versus M ⋆ relation but consistent with other high-redshift QSOs. When demagnified, this QSO is at the knee of the luminosity function, allowing for the detailed study of a more typical moderate-luminosity infrared-selected QSO at high redshift.</p
Coalbed methane resources and reservoir characteristics of NO. II1 coal seam in the Jiaozuo coalfield, China
Jiaozuo coalfield is located in the northwest of Henan province, China, and Close to the Southern Qinshui coal basin. (lie most successfully commercial CBM resource developed area in China. The No. II1 coal seam is the main economic coal seam in Jiaozuo coalfield and its average thickness exceeds 5.36m. The maximum reflectance of vitrinite (R-0.max) No. II1 coal across the Jiaozuo is between 3.16% and 4.78%. The coalbody structure of the No. II1 coal seam changes greatly in different part and can be generally divided into 1 similar to 3 sub-layers. The micropores ill the No.II1 coal seam is the major pores, secondly are transitional pores, and then less macropores and mesopores. The No. II1 coal seam has stronger adsorption, and the reservoir natural permeability has all evident heterogeneity vary from 0.0001 to 83.71mD. High permeability region is often near fault structure or the boundary of fault block. The CBM genetic type is homologous thermal cracking gas of humic coal with high matunity. Gas content with the burial depth of 163 similar to 1070m varies very greatly from 4.65 to 45.75m(3)/t, with all average value of 18.3m(3)/t, and gradually increases from northeast to southwest. According to the latest evaluation for CBM resource in Jiaozuo coalfield, the existing total in-place CBM resources in the No. In coal seam with the depth of shallower than 2000 m are close to 1.2 x 10(12)m(3), most of them mainly distribute in the depth of 1000 similar to 1500 m. The existing total in-place CBM resources is dominated by the inferred CBM resource reserves (more than 70%), which distribute the undrilled places with few coal geological knowledge and deeper than 1000m. The resource concentration of the No. II1 coal,earn in Jiaozuo coalfield is in the range of (0.513-3.478)x10(8) m(3)/km(2), with an average value of 1.805x10(8) m(3)/km(2). Based on the CBM resource investigation and reservoir evaluation, the most prospective target zones for CBM production in Jiaozuo coalfield include Guhanshan coal mine, Jiulishan coal mine and the west part of Qiangnan coal district
H0LiCOW-XIII. A 2.4 per cent measurement of H0from lensed quasars: 5.3σ tension between early-and late-Universe probes
We present a measurement of the Hubble constant (H0) and other cosmological parameters from a joint analysis of six gravitationally lensed quasars with measured time delays. All lenses except the first are analysed blindly with respect to the cosmological parameters. In a flat Λ cold dark matter (ΛCDM) cosmology, we find a precision measurement, in agreement with local measurements of H0 from type Ia supernovae calibrated by the distance ladder, but in 3.1σ tension with Planck observations of the cosmic microwave background (CMB). This method is completely independent of both the supernovae and CMB analyses. A combination of time-delay cosmography and the distance ladder results is in 5.3σ tension with Planck CMB determinations of H0 in flat ΛCDM. We compute Bayes factors to verify that all lenses give statistically consistent results, showing that we are not underestimating our uncertainties and are able to control our systematics. We explore extensions to flat ΛCDM using constraints from time-delay cosmography alone, as well as combinations with other cosmological probes, including CMB observations from Planck, baryon acoustic oscillations, and type Ia supernovae. Time-delay cosmography improves the precision of the other probes, demonstrating the strong complementarity. Allowing for spatial curvature does not resolve the tension with Planck. Using the distance constraints from time-delay cosmography to anchor the type Ia supernova distance scale, we reduce the sensitivity of our H0 inference to cosmological model assumptions. For six different cosmological models, our combined inference on H0 ranges from ∼73 to 78 km s-1 Mpc-1, which is consistent with the local distance ladder constraints
Cosmology intertwined: A review of the particle physics, astrophysics, and cosmology associated with the cosmological tensions and anomalies
The standard Λ Cold Dark Matter (ΛCDM) cosmological model provides a good description of a wide range of astrophysical and cosmological data. However, there are a few big open questions that make the standard model look like an approximation to a more realistic scenario yet to be found. In this paper, we list a few important goals that need to be addressed in the next decade, taking into account the current discordances between the different cosmological probes, such as the disagreement in the value of the Hubble constant H0, the σ8–S8 tension, and other less statistically significant anomalies. While these discordances can still be in part the result of systematic errors, their persistence after several years of accurate analysis strongly hints at cracks in the standard cosmological scenario and the necessity for new physics or generalisations beyond the standard model. In this paper, we focus on the 5.0σ tension between the Planck CMB estimate of the Hubble constant H0 and the SH0ES collaboration measurements. After showing the H0 evaluations made from different teams using different methods and geometric calibrations, we list a few interesting new physics models that could alleviate this tension and discuss how the next decade's experiments will be crucial. Moreover, we focus on the tension of the Planck CMB data with weak lensing measurements and redshift surveys, about the value of the matter energy density Ωm, and the amplitude or rate of the growth of structure (σ8,fσ8). We list a few interesting models proposed for alleviating this tension, and we discuss the importance of trying to fit a full array of data with a single model and not just one parameter at a time. Additionally, we present a wide range of other less discussed anomalies at a statistical significance level lower than the H0–S8 tensions which may also constitute hints towards new physics, and we discuss possible generic theoretical approaches that can collectively explain the non-standard nature of these signals. Finally, we give an overview of upgraded experiments and next-generation space missions and facilities on Earth that will be of crucial importance to address all these open questions