Hubble Diagram Research Articles

The Foundation Supernova Survey: Photospheric Velocity Correlations in Type Ia Supernovae

Abstract The ejecta velocities of Type Ia supernovae (SNe Ia), as measured by the Si ii λ6355 line, have been shown to correlate with other supernova properties, including color and standardized luminosity. We investigate these results using the Foundation Supernova Survey, with a spectroscopic data release presented here, and photometry analyzed with the SALT2 light-curve fitter. We find that the Foundation data do not show significant evidence for an offset in color between SNe Ia with high and normal photospheric velocities, with Δc = 0.004 ± 0.015. Our SALT2 analysis does show evidence for redder high-velocity SNe Ia in other samples, including objects from the Carnegie Supernova Project, with a combined sample yielding Δc = 0.018 ± 0.008. When split on velocity, the Foundation SNe Ia also do not show a significant difference in Hubble diagram residual, ΔHR = 0.015 ± 0.049 mag. Intriguingly, we find that SN Ia ejecta velocity information may be gleaned from photometry, particularly in redder optical bands. For high-redshift SNe Ia, these rest-frame red wavelengths will be observed by the Nancy Grace Roman Space Telescope. Our results are in line with previous work that suggests SN Ia host-galaxy stellar mass is correlated with ejecta velocity: high-velocity SNe Ia are found nearly exclusively in high-stellar-mass hosts. However, host-galaxy properties alone do not explain velocity-dependent differences in supernova colors and luminosities across samples. Measuring and understanding the connection between intrinsic explosion properties and supernova environments, across cosmic time, will be important for precision cosmology with SNe Ia.

Cosmographic approach to Running Vacuum dark energy models: New constraints using BAOs and Hubble diagrams at higher redshifts

Abstract In this work we study different types of dark energy (DE) models in the framework of the cosmographic approach, with emphasis on the Running Vacuum models (RVMs). We assess their viability using different information criteria and compare them with the so-called Ghost DE models (GDEs) as well as with the concordance ΛCDM model. We use the Hubble diagrams for Pantheon SnIa, quasars (QSOs), gamma-ray bursts (GRBs) as well as the data on baryonic acoustic oscillations (BAOs) in four different combinations. Upon minimizing the χ2 function of the distance modulus in the context of the Markov Chain Monte Carlo method (MCMC), we put constraints on the current values of the standard cosmographic parameters in a model-independent way. It turns out that, in the absence of BAOs data, the various DE models generally exhibit cosmographic tensions with the observations at the highest redshifts (namely with the QSOs and GRBs data). However, if we include the robust observations from BAOs to our cosmographic sample, the ΛCDM and RVMs are clearly favored against the GDEs. Finally, judging from the perspective of the deviance information criterion (DIC), which enables us to compare models making use of the Markov chains of the MCMC method, we conclude that the RVMs are the preferred kind of DE models. We find it remarkable that these models, which had been previously shown to be capable of alleviating the σ8 and H0 tensions, appear now also as the most successful ones at the level of the cosmographic analysis.

Reconstructing the Hubble diagram of gamma-ray bursts using deep learning

ABSTRACT We calibrate the distance and reconstruct the Hubble diagram of gamma-ray bursts (GRBs) using deep learning. We construct an artificial neural network, which combines the recurrent neural network and Bayesian neural network, and train the network using the Pantheon compilation of Type-Ia supernovae. The trained network is used to calibrate the distance of 174 GRBs based on the Combo-relation. We verify that there is no evident redshift evolution of Combo-relation, and obtain the slope and intercept parameters, $\gamma =0.856^{+0.083}_{-0.078}$ and $\log A=49.661^{+0.199}_{-0.217}$, with an intrinsic scatter $\sigma _{\rm int}=0.228^{+0.041}_{-0.040}$. Our calibrating method is independent of cosmological model, thus the calibrated GRBs can be directly used to constrain cosmological parameters. It is shown that GRBs alone can tightly constrain the ΛCDM model, with $\Omega _{\rm M}=0.280^{+0.049}_{-0.057}$. However, the constraint on the ωCDM model is relatively looser, with $\Omega _{\rm M}=0.345^{+0.059}_{-0.060}$ and ω < −1.414. The combination of GRBs and Pantheon can tightly constrain the ωCDM model, with $\Omega _{\rm M}=0.336^{+0.055}_{-0.050}$ and $\omega =-1.141^{+0.156}_{-0.135}$.

Using our newest VLT-KMOS HII galaxies and other cosmic tracers to test the Lambda cold dark matter tension

ABSTRACT We place novel constraints on the cosmokinetic parameters by using a joint analysis of the newest Very Large Telescope (VLT)-K-band Multi Object Spectrograph (KMOS) HII galaxies (HIIG) with the Type Ia Supernovae (SNIa) Pantheon sample. We combine the latter data sets in order to reconstruct, in a model-independent way, the Hubble diagram to as high redshifts as possible. Using a Gaussian process, we derive the basic cosmokinetic parameters and compare them with those of Lambda cold dark matter (ΛCDM). In the case of SNIa, we find that the extracted values of the cosmokinetic parameters are in agreement with the predictions of ΛCDM model. Combining SNIa with high-redshift tracers of the Hubble relation, namely HIIG data, we obtain consistent results with those based on ΛCDM as far as the present values of the cosmokinetic parameters are concerned, but find significant deviations in the evolution of the cosmokinetic parameters with respect to the expectations of the concordance ΛCDM model.

Testing the consistency of dust laws in SN Ia host galaxies: A BayeSN Examination of Foundation DR1

Abstract We apply BayeSN, our new hierarchical Bayesian model for the SEDs of Type Ia supernovae (SNe Ia), to analyse the griz light curves of 157 nearby SNe Ia (0.015 < z < 0.08) from the public Foundation DR1 dataset. We train a new version of BayeSN, continuous from 0.35–0.95 μm, which we use to model the properties of SNe Ia in the rest-frame z-band, study the properties of dust in their host galaxies, and construct a Hubble diagram of SN Ia distances determined from full griz light curves. Our griz Hubble diagram has a low total RMS of 0.13 mag using BayeSN, compared to 0.16 mag using SALT2. Additionally, we test the consistency of the dust law RV between low- and high-mass host galaxies by using our model to fit the full time- and wavelength-dependent SEDs of SNe Ia up to moderate reddening (peak apparent B − V ≲ 0.3). Splitting the population at the median host mass, we find RV = 2.84 ± 0.31 in low-mass hosts, and RV = 2.58 ± 0.23 in high-mass hosts, both consistent with the global value of RV = 2.61 ± 0.21 that we estimate for the full sample. For all choices of mass split we consider, RV is consistent across the step within ≲ 1.2σ. Modelling population distributions of dust laws in low- and high-mass hosts, we find that both subsamples are highly consistent with the full sample’s population mean μ(RV) = 2.70 ± 0.25 with a 95 per cent upper bound on the population σ(RV) < 0.61. The RV population means are consistent within ≲ 1.2σ. We find that simultaneous fitting of host-mass-dependent dust properties within our hierarchical model does not account for the conventional mass step.

The Influence of the Peculiar Velocities of SNe Ia in Clusters of Galaxies on the Redshift Measurements

The most intriguing question of modern astronomy is the question of our Universe formation. The Hubble diagram analysis with Type Ia Supernovae (SNe Ia) is widely used to estimate the cosmological parameters with high accuracy. The cosmological measurements allow us to better understand the early stages of the Universe evolution. Nevertheless, the redshift on the SN Ia Hubble diagram includes the contribution from the unknown peculiar velocities that decreases the accuracy of such measurements. We consider the contamination of peculiar velocities of the host galaxies for those SNe that exploded in galaxy clusters. For this purpose, we use the Pantheon cosmological sample and offer the procedure to minimise the influence of such uncertainties.

Revisiting the cosmic distance duality relation with machine learning reconstruction methods: the combination of HII galaxies and ultra-compact radio quasars

In this paper, we carry out an assessment of cosmic distance duality relation (CDDR) based on the latest observations of HII galaxies acting as standard candles and ultra-compact structure in radio quasars acting as standard rulers. Particularly, two machine learning reconstruction methods [Gaussian Process (GP) and Artificial Neural Network (ANN)] are applied to reconstruct the Hubble diagrams from observational data. We show that both approaches are capable of reconstructing the current constraints on possible deviations from the CDDR in the redshift range zsim 2.3. Considering four different parametric methods of CDDR, which quantify deviations from the CDDR and the standard cosmological model, we compare the results of the two different machine learning approaches. It is observed that the validity of CDDR is in well agreement with the current observational data within 1sigma based on the reconstructed distances through GP in the overlapping redshift domain. Moreover, we find that ultra-compact radio quasars could provide 10^{-3}-level constraints on the violation parameter at high redshifts, when combined with the observations of HII galaxies. In the framework of ANN, one could derive robust constraints on the violation parameter at a precision of 10^{-2}, with the validity of such distance duality relation within 2sigma confidence level.

Cosmic variance of H0 in light of forthcoming high-redshift surveys

Forthcoming surveys will extend the understanding of cosmological large scale structures up to unprecedented redshift. According to this perspective, we present a fully relativistic framework to evaluate the impact of stochastic inhomogeneities on the determination of the Hubble constant. To this aim, we work within linear perturbation theory and relate the fluctuations of the luminosity distance-redshift relation, in the Cosmic Concordance model, to the intrinsic uncertainty associated to the measurement of $H_0$ from high-redshift surveys ($0.15\le z\le3.85$). We first present the detailed derivation of the luminosity distance-redshift relation 2-point correlation function and then provide analytical results for all the involved relativistic effects, such as peculiar velocity, lensing, time delay and (integrated) Sachs-Wolfe, and their angular spectra. Hence, we apply our analytical results to the study of high-redshift Hubble diagram, according to what has been recently claimed in literature. Following the specific of Euclid Deep Survey and LSST, we conclude that the cosmic variance associated with the measurement of the Hubble constant is at most of 0.1 %. Our work extends the analysis already done in literature for closer sources, where only peculiar velocity has been taken into account. We then conclude that deep surveys will provide an estimation of the $H_0$ which will be more precise than the one obtained from local sources, at least in regard of the intrinsic uncertainty related to a stochastic distribution of inhomogeneities.

Noether symmetry in teleparalle extended gravity ‎

In this paper, we study the modified gravity theory, where and represent the scalar-torsion and trace of energy-momentum tensor, respectively. According to our cosmological study, we show that the gravity theory has a good agreement with observations. Function type for can be determined by several factors. The most important motivation for determining is that the Lagrangian of model follows the Noether continues symmetry; therefore, according to the Noether approach, we try to determine the function of . Moreover, the proposed model should behave in agreement with observations in terms of phenomenology. As a result, we compared the predictions of the model with observation constrains, for example, the cosmic microwave background and Hubble diagram can be mentioned. In this paper, we study the gravity in the FRW space-time. So, we achieved the effective Lagrangian with respect to independent variables, scale factor , scalar-torsion and trace of energy-momentum tensor . After imposing the Noether symmetry to Lagrangian, we can introduce the suitable form for the function. . Then, we calculated the Noether conservative quantity for the model.

Dynamical analysis and statefinder of Barrow holographic dark energy

Based on the holographic principle and the Barrow entropy, Barrow holographic dark energy had been proposed. In order to analyze the stability and the evolution of Barrow holographic dark energy, we, in this paper, apply the dynamical analysis and statefinder methods to Barrow holographic dark energy with different IR cutoff and interacting terms. In the case of using Hubble horizon as IR cutoff with the interacting term Q=frac{lambda }{H}rho _{m}rho _{D}, we find this model is stable and can be used to describe the whole evolution of the universe when the energy transfers from the pressureless matter to the Barrow holographic dark energy. When the dynamical analysis method is applied to this stable model, an attractor corresponding to an accelerated expansion epoch exists and this attractor can behave as the cosmological constant. Furthermore, the coincidence problem can be solved in this case. Then, after using the statefinder analysis method to this model, we find this model can be discriminated from the standard Lambda CDM model. Finally, we have discussed the turning point of Hubble diagram in Barrow holographic dark energy and find the turning point does not exist in this model.

Hubble diagram at higher redshifts: model independent calibration of quasars

ABSTRACT In this paper, we present a model-independent approach to calibrate the largest quasar sample. Calibrating quasar samples is essentially constraining the parameters of the linear relation between the log of the ultraviolet (UV) and X-ray luminosities. This calibration allows quasars to be used as standardized candles. There is a strong correlation between the parameters characterizing the quasar luminosity relation and the cosmological distances inferred from using quasars as standardized candles. We break this degeneracy by using Gaussian process regression to model-independently reconstruct the expansion history of the Universe from the latest type Ia supernova observations. Using the calibrated quasar data set, we further reconstruct the expansion history up to redshift of z ∼ 7.5. Finally, we test the consistency between the calibrated quasar sample and the standard Lambda cold dark matter ($\rm {\Lambda }CDM$) model based on the posterior probability distribution of the GP hyperparameters. Our results show that the quasar sample is in good agreement with the standard $\rm {\Lambda }CDM$ model in the redshift range of the supernova, despite the 2−3σ significant deviations taking place at higher redshifts. Fitting the standard $\rm {\Lambda }CDM$ model to the calibrated quasar sample, we obtain a high value of the matter density parameter $\Omega _m = 0.382^{+0.045}_{-0.042}$, which is marginally consistent with the constraints from other cosmological observations.

Measuring cosmological parameters with a luminosity–time correlation of gamma-ray bursts

ABSTRACT Gamma-ray bursts (GRBs), as a possible probe to extend the Hubble diagram to high redshifts, have attracted much attention recently. In this paper, we select two samples of GRBs that have a plateau phase in X-ray afterglow. One is short GRBs (SGRBs) with plateau phases dominated by magnetic dipole (MD) radiations. The other is long GRBs (LGRBs) with gravitational wave (GW) dominated plateau phases. These GRBs can be well standardized using the correlation between the plateau luminosity L0 and the end time of plateau tb. The so-called circularity problem is mitigated by using the observational Hubble parameter data and Gaussian process method. The calibrated L0 – tb correlations are also used to constrain Lambda cold dark matter (ΛCDM) and w(z) = w0 models. Combining the MD–LGRBs sample from Wang et al. (2021) and the MD–SGRBs sample, we find $\Omega _{\mathrm{ m}} = 0.33_{-0.09}^{+0.06}$ and ΩΛ = $1.06_{-0.34}^{+0.15}$ excluding systematic uncertainties in the non-flat ΛCDM model. Adding Type Ia supernovae from Pantheon sample, the best-fitting results are w0 = $-1.11_{-0.15}^{+0.11}$ and Ωm = $0.34_{-0.04}^{+0.05}$ in the w = w0 model. These results are in agreement with the ΛCDM model. Our result supports that selection of GRBs from the same physical mechanism is crucial for cosmological purposes.

A new comparison between holographic dark energy and standard varLambda -cosmology in the context of cosmography method

The cosmography method is a model-independent technique used to reconstruct the Hubble expansion of the Universe at low redshifts. In this method, using the Hubble diagrams from Type Ia Supernovae (SNIa) in Pantheon catalog, quasars and Gamma-Ray Bursts (GRB), we put observational constraints on the cosmographic parameters in holographic dark energy (HDE) and concordance varLambda CDM models by minimizing the error function chi ^2 based on the statistical Markov Chain Monte Carlo (MCMC) algorithm. Then, we compare the results of the models with the results of the model-independent cosmography method. Except for the Pantheon sample, we observe that there is a big tension between standard cosmology and Hubble diagram observations, while the HDE model remains consistent in all cases. Then we use different combinations of Hubble diagram data to reconstruct the Hubble parameter of the model and compare it with the observed Hubble data. We observe that the Hubble parameter reconstructed from the model-independent cosmography method has the smallest deviation from the Hubble data and the varLambda CDM (HDE) model has the largest (middle) deviation, especially when we keep the observational data point 226^{+8.0}_{-0.8} at redshift z=2.36 in the analysis. On the contrary, in the redshift z <1, we see that the compatibility of varLambda CDM cosmology and observation is even better than the model independent cosmography method.

The Carnegie Chicago Hubble Program X: Tip of the Red Giant Branch Distances to NGC 5643 and NGC 1404

Abstract The primary goal of the Carnegie Chicago Hubble Program (CCHP) is to calibrate the zero-point of the Type Ia supernova (SN Ia) Hubble Diagram through the use of Population II standard candles. So far, the CCHP has measured direct distances to 11 SNe Ia, and here we increase that number to 15 with two new Tip of the Red Giant Branch (TRGB) distances measured to NGC 5643 and NGC 1404. We present resolved, point-source photometry from new Hubble Space Telescope imaging of these two galaxies in the F814W and F606W bandpasses. From each galaxy’s stellar halo, we construct an F814W-band luminosity function in which we detect an unambiguous edge feature identified as the TRGB. For NGC 5643, we find μ 0 = 30.48 ± 0.03(stat) ± 0.07(sys) mag, and for NGC 1404 we find μ 0 = 31.36 ± 0.04(stat) ± 0.05(sys) mag. From a preliminary consideration of the SNe Ia in these galaxies, we find increased confidence in the results presented in Paper VIII. The high precision of our TRGB distances enables a significant measurement of the 3D displacement between the Fornax cluster galaxies NGC 1404 and NGC 1316 (Fornax A) equal to 1.50 − 0.39 + 0.25 Mpc, which we show is in agreement with independent constraints found in the literature.

Redshift evolution of the Amati relation: Calibrated results from the Hubble diagram of quasars at high redshifts

Gamma-ray bursts (GRBs) have long been proposed as a complementary probe to type Ia supernovae (SNe Ia) and the cosmic microwave background to explore the expansion history of the high-redshift universe, mainly because they are bright enough to be detected at greater distances. Although they lack definite physical explanations, many empirical correlations between GRB isotropic energy or luminosity and some directly detectable spectral or temporal properties have been proposed to make GRBs standard candles. Since the observed GRB rate falls off rapidly at low redshifts, this thus prevents a cosmology independent calibration of these correlations. In order to avoid the circularity problem, SN Ia data are usually used to calibrate the luminosity relations of GRBs in the low redshift region (limited by the redshift range for SN Ia sample), and then they are extrapolate the luminosity relations to the high redshift region. This approach is based on the assumption of no redshift evolution for GRB luminosity relations. In this work, we suggest the use of a complete quasar sample in the redshift range of 0.5 &lt; z &lt; 5.5 to test such an assumption. We divided the quasar sample into several subsamples with different redshift bins, and used each subsample to calibrate the isotropic γ-ray equivalent energy of GRBs in relevant redshift bins. By fitting the newly calibrated data, we find strong evidence that the most commonly used Amati relation between spectral peak energy and isotropic-equivalent radiated energy shows no, or marginal, evolution with redshift. Indeed, at different redshifts, the coefficients in the Amati relation could have a maximum variation of 0.93% at different redshifts, and there could be no coincidence in the range of 1σ.

Prospects of high redshift constraints on dark energy models with the Ep, i − Eiso correlation in long gamma ray bursts

ABSTRACT So far large and different data sets revealed the accelerated expansion rate of the Universe, which is usually explained in terms of dark energy. The nature of dark energy is not yet known, and several models have been introduced: a non-zero cosmological constant, a potential energy of some scalar field, effects related to the non-homogeneous distribution of matter, or effects due to alternative theories of gravity. Recently, a tension with the flat ΛCDM model has been discovered using a high-redshift Hubble diagram of supernovae, quasars, and gamma-ray bursts (GRB). Here we use the Union2 type Ia supernovae and GRB Hubble diagram, and a set of direct measurements of the Hubble parameter to explore different dark energy models. We use the Chevallier–Polarski–Linder parametrization of the dark energy equation of state, a minimally coupled quintessence scalar field, and, finally, we consider models with dark energy at early times. We perform a statistical analysis based on the Markov chain Monte Carlo method, and explore the probability distributions of the cosmological parameters for each of the competing models. We apply the Akaike Information Criterion to compare these models: our analysis indicates that an evolving dark energy, described by a scalar field with exponential potential seems to be favoured by observational data.

Reconciling low and high redshift GRB luminosity correlations

The correlation between the peak spectra energy (${E}_{p}$) and the equivalent isotropic energy (${E}_{\mathrm{iso}}$) of long gamma-ray bursts (GRBs), the so-called Amati relation, is often used to constrain the high-redshift Hubble diagram. Assuming Lambda cold dark matter cosmology, G.-J. Wang et al. [Astrophys. J. 836, 103 (2017)] found a $\ensuremath{\gtrsim}3\ensuremath{\sigma}$ tension in the data-calibrated Amati coefficients between low and high redshift GRB samples. To reduce the impact of fiducial cosmology, we use the parametrization based on cosmic age (PAge), an almost model-independent framework to trace the cosmological expansion history. We find that the low and high redshift tension in Amati coefficients stays almost the same for the broad class of models covered by PAge, indicating that the cosmological assumption is not the dominant driver of the redshift evolution of GRB luminosity correlation. Next, we analyze the selection effect due to flux limits in observations. We find Amati relation evolves much more significantly across energy scales of ${E}_{\mathrm{iso}}$. We debias the GRB data by selectively discarding samples to match low-$z$ and high-$z$ ${E}_{\mathrm{iso}}$ distributions. After debiasing, the Amati coefficients agree well between low-$z$ and high-$z$ data groups, whereas the evidence of ${E}_{\mathrm{iso}}$ dependence of Amati relation remains to be strong. Thus, the redshift evolution of GRB luminosity correlation can be fully interpreted as a selection bias and does not imply cosmological evolution of GRBs.

Inhomogeneous Hubble diagram from vector K-mouflage

In this letter we construct the Hubble diagram for a universe where dark matter is universally charged under a dark non-linear electromagnetic force which features a screening mechanism of the K-mouflage type for repulsive forces. By resorting to the Newtonian approximation, we explicitly show that the cosmological evolution generates an inhomogeneous Hubble diagram that corresponds to a curvature dominated expansion at short distances and converges to the cosmological one of ΛCDM. We discuss the potential impact of this inhomogeneous profile on the Hubble tension. For completeness, we explicitly show how the Newtonian approximation can be derived from an inhomogeneous relativistic Lemaître model.

On problems with cosmography in cosmic dark ages

Quasars show considerable promise as standard candles in a high-redshift window beyond Type Ia supernovae. Recently, Risaliti, Lusso & collaborators [1–3] have succeeded in producing a high redshift Hubble diagram (z≲7) that supports “a trend whereby the Hubble diagram of quasars is well reproduced by the standard flat ΛCDM model up to z∼1.5−2, but strong deviations emerge at higher redshifts”. This conclusion hinges upon a log polynomial expansion for the luminosity distance. In this note, we demonstrate that this expansion (or “improvements” thereof) typically can only be trusted up to z∼1.5−2. As a result, a breakdown in the validity of the expansion may be misinterpreted as a (phantom) deviation from flat ΛCDM. We further illustrate the problem through mock data examples.

Independent cosmological constraints from high-z H ii galaxies: new results from VLT-KMOS data

ABSTRACT We present independent determinations of cosmological parameters using the distance estimator based on the established correlation between the Balmer line luminosity, L(H β), and the velocity dispersion (σ) for H ii galaxies (HIIG). These results are based on new VLT-KMOS high spectral resolution observations of 41 high-z (1.3 ≤ z ≤2.6) HIIG combined with published data for 45 high-z and 107 z ≤0.15 HIIG, while the cosmological analysis is based on the MultiNest Markov Chain Monte Carlo (MCMC) procedure not considering systematic uncertainties. Using only HIIG to constrain the matter density parameter (Ωm), we find $\Omega _\mathrm{ m} = 0.244^{+0.040}_{-0.049}$ (stat), an improvement over our best previous cosmological parameter constraints, as indicated by a 37 per cent increase of the figure of merit. The marginalized best-fitting parameter values for the plane {Ωm; w0} = $\lbrace 0.249^{+0.11}_{-0.065}; -1.18^{+0.45}_{-0.41}\rbrace$ (stat) show an improvement of the cosmological parameters constraints by 40 per cent. Combining the HIIG Hubble diagram, the cosmic microwave background (CMB) and the baryon acoustic oscillation (BAO) probes yields Ωm = 0.298 ± 0.012 and w0 = −1.005 ± 0.051, which are certainly compatible – although less constraining – than the solution based on the joint analysis of Ia supernovae (SNIa), CMB and BAO measurements. An attempt to constrain the evolution of the dark energy with time (CPL model), using a joint analysis of the HIIG, CMB, and BAO measurements, shows a degenerate 1σ contour of the parameters in the {w0, wa} plane.