| 1. |
- Abdalla, E., et al.
(författare)
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Cosmology intertwined : A review of the particle physics, astrophysics, and cosmology associated with the cosmological tensions and anomalies
- 2022
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Ingår i: Journal of High Energy Astrophysics. - : Elsevier BV. - 2214-4048 .- 2214-4056. ; 34, s. 49-211
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 2. |
- Bradač, M., et al.
(författare)
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ALMA [C II] 158 μm Detection of a Redshift 7 Lensed Galaxy behind RX J1347.1-1145
- 2017
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Ingår i: Astrophysical Journal Letters. - : Institute of Physics Publishing (IOPP). - 2041-8205 .- 2041-8213. ; 836:1
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Tidskriftsartikel (refereegranskat)abstract
- We present the results of ALMA spectroscopic follow-up of a z =6.766 Lyα emitting galaxy behind the cluster RX J1347.1-1145. We report the detection of [C ii] 158 μm line fully consistent with the Lyα redshift and with the peak of the optical emission. Given the magnification of μ =5.0 ±0.3, the intrinsic (corrected for lensing) luminosity of the [C ii] line is L [C ii] = 1.4+0.2-0.3 × 107 L⊙, roughly ∼5 times fainter than other detections of z ∼ 7 galaxies. The result indicates that low L [C ii] in z ∼ 7 galaxies compared to the local counterparts might be caused by their low metallicities and/or feedback. The small velocity offset (δv = 20+140-40 Km s-1) between the Lyα and [C ii] line is unusual, and may be indicative of ionizing photons escaping.
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| 3. |
- Pierel, J. D. R., et al.
(författare)
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LensWatch. I. Resolved HST Observations and Constraints on the Strongly Lensed Type Ia Supernova 2022qmx (SN Zwicky)
- 2023
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 948:2
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Tidskriftsartikel (refereegranskat)abstract
- Supernovae (SNe) that have been multiply imaged by gravitational lensing are rare and powerful probes for cosmology. Each detection is an opportunity to develop the critical tools and methodologies needed as the sample of lensed SNe increases by orders of magnitude with the upcoming Vera C. Rubin Observatory and Nancy Grace Roman Space Telescope. The latest such discovery is of the quadruply imaged Type Ia SN 2022qmx (aka, SN Zwicky) at z = 0.3544. SN Zwicky was discovered by the Zwicky Transient Facility in spatially unresolved data. Here we present follow-up Hubble Space Telescope observations of SN Zwicky, the first from the multicycle LensWatch (www.lenswatch.org) program. We measure photometry for each of the four images of SN Zwicky, which are resolved in three WFC3/UVIS filters (F475W, F625W, and F814W) but unresolved with WFC3/IR F160W, and present an analysis of the lensing system using a variety of independent lens modeling methods. We find consistency between lens-model-predicted time delays (less than or similar to 1 day), and delays estimated with the single epoch of Hubble Space Telescope colors (less than or similar to 3.5 days), including the uncertainty from chromatic microlensing (similar to 1-1.5 days). Our lens models converge to an Einstein radius of theta(E) = 0.168 (+0.009)(-0.005) the smallest yet seen in a lensed SN system. The standard candle nature of SN Zwicky provides magnification estimates independent of the lens modeling that are brighter than predicted by similar to 1.7 (-0.6) (+0.8) mag and similar to 0.9 (-0.6) (+0.8) mag for two of the four images, suggesting significant microlensing and/or additional substructure beyond the flexibility of our image-position mass models.
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| 4. |
- Kelly, P. L., et al.
(författare)
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SN REFSDAL : CLASSIFICATION AS A LUMINOUS AND BLUE SN 1987A-LIKE TYPE II SUPERNOVA
- 2016
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 831:2
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Tidskriftsartikel (refereegranskat)abstract
- We have acquired Hubble Space Telescope (HST) and Very Large Telescope near-infrared spectra and images of supernova (SN) Refsdal after its discovery as an Einstein cross in fall 2014. The HST light curve of SN Refsdal has a shape consistent with the distinctive, slowly rising light curves of SN. 1987A-like SNe, and we find strong evidence for a broad H alpha P-Cygni profile and Na I D absorption in the HST grism spectrum at the redshift (z = 1.49) of the spiral host galaxy. SNe. IIn, largely powered by circumstellar interaction, could provide a good match to the light curve of SN Refsdal, but the spectrum of a SN IIn would not show broad and strong H alpha and Na I D absorption. From the grism spectrum, we measure an H alpha expansion velocity consistent with those of SN. 1987A-like SNe at a similar phase. The luminosity, evolution, and Gaussian profile of the H alpha emission of the WFC3 and X-shooter spectra, separated by similar to 2.5 months in the rest frame, provide additional evidence that supports the SN. 1987A-like classification. In comparison with other examples of SN. 1987A-like SNe, photometry of SN Refsdal favors bluer B - V and V - R colors and one of the largest luminosities for the assumed range of potential magnifications. The evolution of the light curve at late times will provide additional evidence about the potential existence of any substantial circumstellar material. Using MOSFIRE and X-shooter spectra, we estimate a subsolar host-galaxy metallicity (8.3 +/- 0.1 dex and <8.4 dex, respectively) near the explosion site.
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