Ia Host Research Articles

Luminosity Functions of the Host Galaxies of Supernova

We present the luminosity functions and stellar mass functions of supernova (SN) host galaxies and test if they differ from the functions of normal field galaxies. We utilize homogeneous samples consisting of 273 SNe Ia (z ≤ 0.3) and 44 core-collapse (CC) SNe (z ≤ 0.1) from the Sloan Digital Sky Survey II Supernova Survey and the high-signal-to-noise-ratio photometry of galaxies from the Hyper Suprime-Cam Subaru Strategic Program. SN hosts are classified into star-forming and passive galaxy groups based on the spectral energy distribution fitting. We find that the SN host luminosity functions and stellar mass functions deviate from those of normal field galaxies. Star-forming galaxies dominate the low-mass end of the SN Ia host mass function, while passive galaxies dominate the high-mass end. CC SNe are predominantly hosted by star-forming galaxies. In addition, intermediate-mass hosts produce CC SNe with the highest efficiency, while the efficiency of producing SNe Ia monotonically increases as the hosts become more massive. Furthermore, we derive the pseudo mass normalized SN rates (pSNuM) based on the mass functions. We find that the star-forming component of pSNuM Ia is less sensitive to the changes in stellar mass, in comparison with the total rate. The behavior of pSNuM CC suggests that the CC rate is proportional to the star-forming rate.

Using Rest-Frame Optical and NIR Data from the RAISIN Survey to Explore the Redshift Evolution of Dust Laws in SN Ia Host Galaxies

Abstract We use rest-frame optical and near-infrared (NIR) observations of 42 Type Ia supernovae (SNe Ia) from the Carnegie Supernova Project at low-z and 37 from the RAISIN Survey at high-z to investigate correlations between SN Ia host galaxy dust, host mass, and redshift. This is the first time the SN Ia host galaxy dust extinction law at high-z has been estimated using combined optical and rest-frame NIR data (YJ-band). We use the BayeSN hierarchical model to leverage the data’s wide rest-frame wavelength range (extending to ∼1.0–1.2 μm for the RAISIN sample at 0.2 ≲ z ≲ 0.6). By contrasting the RAISIN and CSP data, we constrain the population distributions of the host dust RV parameter for both redshift ranges. We place a limit on the difference in population mean RV between RAISIN and CSP of −1.16 < Δμ(RV) < 1.38 with 95% posterior probability. For RAISIN we estimate μ(RV) = 2.58 ± 0.57, and constrain the population standard deviation to σ(RV) < 0.90 [2.42] at the 68 [95]% level. Given that we are only able to constrain the size of the low- to high-z shift in μ(RV) to ≲ 1.4 – which could still propagate to a substantial bias in the equation of state parameter w – these and other recent results motivate continued effort to obtain rest-frame NIR data at low and high redshifts (e.g. using the Roman Space Telescope).

Reconnaissance with JWST of the J-region Asymptotic Giant Branch in Distance Ladder Galaxies: From Irregular Luminosity Functions to Approximation of the Hubble Constant

We study stars in the J-regions of the asymptotic giant branch (JAGB) of near-infrared color–magnitude diagrams in the maser host NGC 4258 and four hosts of six Type Ia supernovae (SNe Ia): NGC 1448, NGC 1559, NGC 5584, and NGC 5643. These clumps of stars are readily apparent near 1.0 < F150W − F277W < 1.5 and m F150W = 22–25 mag with James Webb Space Telescope NIRCam photometry. Various methods have been proposed to assign an apparent reference magnitude to this recently proposed standard candle, including the mode, median, sigma-clipped mean, or a modeled luminosity function parameter. We test the consistency of these by measuring intrahost variations, finding differences of up to ∼0.2 mag that significantly exceed statistical uncertainties. Brightness differences appear intrinsic, and are further amplified by the nonuniform shape of the JAGB luminosity function, also apparent in the LMC and SMC. We follow a “many methods” approach to measure consistently JAGB magnitudes and distance moduli to the SN Ia host sample calibrated by NGC 4258. We find broad agreement with distance moduli measured from Cepheids, tip of the red giant branch, and Miras. However, the SN host mean distance modulus estimated via the JAGB method necessary to estimate H 0 differs by ∼0.19 mag among the above definitions, the result of different levels of luminosity function asymmetry. The methods yield a full range of 71−78 km s−1 Mpc−1, i.e., a fiducial result of H 0 = 74.7 ± 2.1(stat) ± 2.3(sys, ±3.1 if combined in quadrature) km s−1 Mpc−1, with systematic errors limited by the differences in methods. Future work may seek to standardize and refine this promising tool further, making it more competitive with established distance indicators.

The Mira Distance to M101 and a 4% Measurement of H 0

The giant spiral galaxy M101 is host to the nearest recent Type Ia supernova (SN 2011fe) and thus has been extensively monitored in the near-infrared to study the late-time light curve of the SN. Leveraging this existing baseline of observations, we derive the first Mira-based distance to M101 by discovering and classifying a sample of 211 Miras with periods ranging from 240–400 days in the SN field. Combined with new Hubble Space Telescope (HST) WFC3/IR channel observations, our data set totals 11 epochs of F110W (HST YJ) and 13 epochs of F160W (HST H) data spanning ∼2900 days. We adopt absolute calibrations of the Mira period–luminosity relation based on geometric distances to the Large Magellanic Cloud and the water megamaser host galaxy NGC 4258, and find μ M101 = 29.10 ± 0.06 mag. This distance is in 1σ agreement with most other recent Cepheid and tip of the red giant branch distance measurements to M101. Including the previous Mira SN Ia host, NGC 1559, and SN 2005df, we determine the fiducial SN Ia peak luminosity, MB0=−19.27±0.09 mag. With the Hubble diagram of supernovae Ia, we derive H 0 = 72.37 ± 2.97 km s−1 Mpc−1, a 4.1% measurement of H 0 using Miras. We find excellent agreement with recent Cepheid distance ladder measurements of H 0 and confirm previous indications that the local universe value of H 0 is higher than the early universe value at ∼95% confidence. Currently, the Mira-based H 0 measurement is still dominated by the statistical uncertainty in the SN Ia peak magnitude.

WiFeS observations of nearby southern Type Ia supernova host galaxies

Abstract We present high-resolution observations of nearby ( $z\lesssim0.1$ ) galaxies that have hosted Type Ia supernovae to measure systemic spectroscopic redshifts using the wide field spectrograph (WiFeS) instrument on the Australian National University 2.3 m telescope at Siding Spring Observatory. While most of the galaxies targeted have previous spectroscopic redshifts, we provide demonstrably more accurate and precise redshifts with competitive uncertainties, motivated by potential systematic errors that could bias estimates of the Hubble constant ( $H_0$ ). The WiFeS instrument is remarkably stable; after calibration, the wavelength solution varies by $\lesssim$ 0.5 Å in red and blue with no evidence of a trend over the course of several years. By virtue of the $25\times 38$ arcsec field of view, we are always able to measure the redshift of the galactic core, or the entire galaxy in the cases where its angular extent is smaller than the field of view, reducing any errors due to galaxy rotation. We observed 185 southern SN Ia host galaxies and measured the redshift of each via at least one spatial region of (a) the core and (b) the average over the full-field/entire galaxy. Overall, we find stochastic differences between historical redshifts and our measured redshifts on the order of $\lesssim10^{-3}$ with a mean offset of 4.3 ${\times 10^{-5}}$ and normalised median absolute deviation of 1.2 ${\times 10^{-4}}$ . We show that a systematic redshift offset at this level is not enough to bias cosmology, as $H_0$ shifts by $+0.1$ km s $^{-1}$ Mpc $^{-1}$ when we replace Pantheon+ redshifts with our own, but the occasional large differences are interesting to note.

First JWST Observations of JAGB Stars in the SN Ia Host Galaxies: NGC 7250, NGC 4536, NGC 3972

The J-region Asymptotic Giant Branch (JAGB) method is a standard candle that leverages the constant luminosities of color-selected, carbon-rich AGB stars, measured in the near-infrared at 1.2 μm. The Chicago-Carnegie Hubble Program has obtained JWST imaging of the SN Ia host galaxies NGC 7250, NGC 4536, and NGC 3972. With these observations, the JAGB method can be studied for the first time using JWST. Lee et al. demonstrated the JAGB magnitude is optimally measured in the outer disks of galaxies, because in the inner regions the JAGB magnitude can vary significantly due to a confluence of reddening, blending, and crowding effects. However, determining where the “outer disk” lies can be subjective. Therefore, we introduce a novel method for systematically selecting the outer disk. In a given galaxy, the JAGB magnitude is first separately measured in concentric regions, and the “outer disk” is then defined as the first radial bin where the JAGB magnitude stabilizes to a few hundredths of a magnitude. After successfully employing this method in our JWST galaxy sample, we find the JAGB stars are well segregated from other stellar populations in color–magnitude space, and have observed dispersions about their individual F115W modes of σ N7250 = 0.32 mag, σ N4536 = 0.34 mag, and σ N3972 = 0.35 mag. These measured dispersions are similar to the scatter measured for the JAGB stars in the LMC using 2MASS data (σ = 0.33 mag). In conclusion, the JAGB stars as observed with JWST clearly demonstrate their considerable power both as high-precision extragalactic distance indicators and as SN Ia supernova calibrators.

A sample of dust attenuation laws for Dark Energy Survey supernova host galaxies

Context. Type Ia supernovae (SNe Ia) are useful distance indicators in cosmology, provided their luminosity is standardized by applying empirical corrections based on light-curve properties. One factor behind these corrections is dust extinction, which is accounted for in the color–luminosity relation of the standardization. This relation is usually assumed to be universal, which can potentially introduce systematics into the standardization. The “mass step” observed for SN Ia Hubble residuals has been suggested as one such systematic. Aims. We seek to obtain a more complete view of dust attenuation properties for a sample of 162 SN Ia host galaxies and to probe their link to the mass step. Methods. We inferred attenuation laws toward hosts from both global and local (4 kpc) Dark Energy Survey photometry and composite stellar population model fits. Results. We recovered a relation between the optical depth and the attenuation slope, best explained by differing star-to-dust geometry for different galaxy orientations, which is significantly different from the optical depth and extinction slope relation observed directly for SNe. We obtain a large variation of attenuation slopes and confirm these change with host properties, such as the stellar mass and age, meaning a universal SN Ia correction should ideally not be assumed. Analyzing the cosmological standardization, we find evidence for a mass step and a two-dimensional “dust step”, both more pronounced for red SNe. Although comparable, the two steps are not found to be completely analogous. Conclusions. We conclude that host galaxy dust data cannot fully account for the mass step, using either an alternative SN standardization with extinction proxied by host attenuation or a dust-step approach.

Standardized Luminosity of the Tip of the Red Giant Branch Utilizing Multiple Fields in NGC 4258 and the CATs Algorithm

The tip of the red giant branch provides a luminous standard candle for calibrating distance ladders that reach Type Ia supernova (SN Ia) hosts. However, recent work reveals that tip measurements vary at the ∼0.1 mag level for different stellar populations and locations within a host, which may lead to inconsistencies along the distance ladder. We pursue a calibration of the tip using 11 Hubble Space Telescope fields around the maser host, NGC 4258, that is consistent with SN Ia hosts by standardizing tip measurements via their contrast ratios. We find F814W-band tips that exhibit a full 0.3 mag range and 0.1 mag dispersion. We do not find any correlation between H i column density and the apparent tip to 0.04 ± 0.03 mag/cm−2. We search for a tip–contrast relation (TCR) and measure the TCR within the fields of NGC 4258 of −0.015 ± 0.008 mag/R, where R is the contrast ratio. This value is consistent with the TCR originally discovered in the GHOSTS sample of −0.023 ± 0.005 mag/R. Combining these measurements, we find a global TCR of −0.021 ± 0.004 mag/R and a calibration of mag. We also use stellar models to simulate single age and metallicity stellar populations with [Fe/H] from −2.0 to −0.7 and ages from 3 to 12 Gyr and reconstruct the global TCR found here to a factor of ∼2. This work is combined in a companion analysis with tip measurements of nearby SN Ia hosts to measure H 0.

Crowded No More: The Accuracy of the Hubble Constant Tested with High-resolution Observations of Cepheids by JWST

High-resolution James Webb Space Telescope (JWST) observations can test confusion-limited Hubble Space Telescope (HST) observations for a photometric bias that could affect extragalactic Cepheids and the determination of the Hubble constant. We present JWST NIRCAM observations in two epochs and three filters of >320 Cepheids in NGC 4258 (which has a 1.5% maser-based geometric distance) and in NGC 5584 (host of SN Ia 2007af), near the median distance of the SH0ES HST SN Ia host sample and with the best leverage among them to detect such a bias. JWST provides far superior source separation from line-of-sight companions than HST in the near-infrared to largely negate confusion or crowding noise at these wavelengths, where extinction is minimal. The result is a remarkable >2.5× reduction in the dispersion of the Cepheid period–luminosity relations, from 0.45 to 0.17 mag, improving individual Cepheid precision from 20% to 7%. Two-epoch photometry confirmed identifications, tested JWST photometric stability, and constrained Cepheid phases. The P–L relation intercepts are in very good agreement, with differences (JWST−HST) of 0.00 ± 0.03 and 0.02 ± 0.03 mag for NGC 4258 and NGC 5584, respectively. The difference in the determination of H0 between HST and JWST from these intercepts is 0.02 ± 0.04 mag, insensitive to JWST zero-points or count rate nonlinearity thanks to error cancellation between rungs. We explore a broad range of analysis variants (including passband combinations, phase corrections, measured detector offsets, and crowding levels) indicating robust baseline results. These observations provide the strongest evidence yet that systematic errors in HST Cepheid photometry do not play a significant role in the present Hubble Tension. Upcoming JWST observations of >12 SN Ia hosts should further refine the local measurement of the Hubble constant.

Connecting Infrared Surface Brightness Fluctuation Distances to Type Ia Supernova Hosts: Testing the Top Rung of the Distance Ladder

We compare infrared surface brightness fluctuation (IR SBF) distances measured in galaxies that have hosted type Ia supernovae (SNe Ia) to distances estimated from SNe Ia light-curve fits. We show that the properties of the SNe Ia found in IR SBF hosts are very different from those exploding in Cepheid calibrators, therefore this is a direct test of systematic uncertainties on the estimation of the Hubble constant (H 0) using SNe. The IR SBF results from Jensen et al. provide a large and uniformly measured sample of IR SBF distances which we directly compare with the distances to 25 SN Ia host galaxies. We divide the Hubble flow SNe Ia into subsamples that best match the divergent SN properties seen in the IR SBF hosts and Cepheid hosts. We further divide the SNe Ia into a sample with light-curve widths and host masses that are congruent to those found in the SBF-calibrated hosts. We refit the light-curve stretch and color correlations with luminosity, and use these revised parameters to calibrate a sample of “Hubble flow” SNe Ia with IR SBF calibrators. Relative to the Hubble flow sample, the average calibrator distance moduli vary by 0.03 mag depending on the SN Ia subsample examined and this adds a 1.8% systematic uncertainty to our Hubble constant estimate. Based on the IRSBF calibrators, H 0 = 74.6 ± 0.9(stat) ± 2.7(syst) km s−1 Mpc−1, which is consistent with the Hubble constant derived from SNe Ia calibrated from Cepheid variables. We conclude that IR SBFs provide reliable calibration of SNe Ia with a precision comparable to Cepheid calibrators, and with a significant saving in telescope time.

Examining the Properties of Low-luminosity Hosts of Type Ia Supernovae from ASAS-SN

We present a spectroscopic analysis of 44 low-luminosity host galaxies of Type Ia supernovae (SNe Ia) detected by the All-Sky Automated Survey for Supernovae (ASAS-SN), using hydrogen, oxygen, and sulfur emission lines to measure metallicities and star formation rates. We find no statistically significant evidence that the star formation activity and metallicities of the galaxies in our sample are inconsistent with galaxies of similar luminosities and masses. We identify two 3σ outlier galaxies that have high metallicities for their stellar masses, but find that their other properties are consistent with general galaxies. The overall consistency between our sample and general galaxy samples further strengthens the evidence from more luminous SN Ia host galaxy samples that SN Ia host galaxies are typical.

The period–luminosity relation for Mira variables in the Milky Way using Gaia DR3: a further distance anchor for H0

ABSTRACT Gaia DR3 parallaxes are used to calibrate preliminary period–luminosity relations of O-rich Mira variables in the 2MASS J, H, and Ks bands using a probabilistic model accounting for variations in the parallax zero-point and underestimation of the parallax uncertainties. The derived relations are compared to those measured for the Large and Small Magellanic Clouds, the Sagittarius dwarf spheroidal galaxy, globular cluster members, and the subset of Milky Way Mira variables with VLBI parallaxes. The Milky Way linear JHKs relations are slightly steeper and thus fainter at short period than the corresponding LMC relations, suggesting population effects in the near-infrared are perhaps larger than previous observational works have claimed. Models of the Gaia astrometry for the Mira variables suggest that, despite the intrinsic photocentre wobble and use of mean photometry in the astrometric solution of the current data reduction, the recovered parallaxes should be on average unbiased but with underestimated uncertainties for the nearest stars. The recommended Gaia EDR3 parallax zero-point corrections evaluated at $\nu _\mathrm{eff}=1.25\, \mu \mathrm{m}^{-1}$ require minimal ($\lesssim 5\, \mu \mathrm{as}$) corrections for redder five-parameter sources, but overcorrect the parallaxes for redder six-parameter sources, and the parallax uncertainties are underestimated at most by a factor ∼1.6 at $G\approx 12.5\, \mathrm{mag}$. The derived period–luminosity relations are used as anchors for the Mira variables in the Type Ia host galaxy NGC 1559 to find $H_0=(73.7\pm 4.4)\, \mathrm{km\, s}^{-1}\, \mathrm{Mpc}^{-1}$.

Further evidence that galaxy age drives observed Type Ia supernova luminosity differences

ABSTRACT Type Ia supernovae (SNe Ia) are explosions of white dwarf stars that facilitate exquisite measurements of cosmological expansion history, but improvements in accuracy and precision are hindered by observational biases. Of particular concern is the apparent difference in the corrected brightnesses of SNe Ia in different host galaxy environments. SNe Ia in more massive, passive, older environments appear brighter after having been standardized by their light-curve properties. The luminosity difference commonly takes the form of a step function. Recent works imply that environmental characteristics that trace the age of the stellar population in the vicinity of SNe show the largest steps. Here, we use simulations of SN Ia populations to test the impact of using different tracers and investigate promising new models of the step. We test models with a total-to-selective dust extinction ratio RV that changes between young and old SN Ia host galaxies, as well as an intrinsic luminosity difference between SNe from young and old progenitors. The data are well replicated by a model driven by a galaxy-age varying RV and no intrinsic SN luminosity difference, and we find that specific star formation rate measured locally to the SN is a relatively pure tracer of this galaxy-age difference. We cannot rule out an intrinsic difference causing part of the observed step and show that if luminosity differences are caused by multiple drivers then no single environmental measurement is able to accurately trace them. We encourage the use of multiple tracers in luminosity corrections to negate this issue.

Using Host Galaxy Photometric Redshifts to Improve Cosmological Constraints with Type Ia Supernovae in the LSST Era

We perform a rigorous cosmology analysis on simulated Type Ia supernovae (SNe Ia) and evaluate the improvement from including photometric host galaxy redshifts compared to using only the “z spec” subset with spectroscopic redshifts from the host or SN. We use the Deep Drilling Fields (∼50 deg2) from the Photometric LSST Astronomical Time-Series Classification Challenge (PLAsTiCC) in combination with a low-z sample based on Data Challenge2. The analysis includes light-curve fitting to standardize the SN brightness, a high-statistics simulation to obtain a bias-corrected Hubble diagram, a statistical+systematics covariance matrix including calibration and photo-z uncertainties, and cosmology fitting with a prior from the cosmic microwave background. Compared to using the z spec subset, including events with SN+host photo-z results in (i) more precise distances for z > 0.5, (ii) a Hubble diagram that extends 0.3 further in redshift, and (iii) a 50% increase in the Dark Energy Task Force figure of merit (FoM) based on the w 0 w a CDM model. Analyzing 25 simulated data samples, the average bias on w 0 and w a is consistent with zero. The host photo-z systematic of 0.01 reduces FoM by only 2% because (i) most z < 0.5 events are in the z spec subset, (ii) the combined SN+host photo-z has ×2 smaller bias, and (iii) the anticorrelation between fitted redshift and color self-corrects distance errors. To prepare for analyzing real data, the next SN Ia cosmology analysis with photo-zs should include non–SN Ia contamination and host galaxy misassociations.

Concerning colour: The effect of environment on type Ia supernova colour in the dark energy survey

ABSTRACT Recent analyses have found intriguing correlations between the colour (c) of type Ia supernovae (SNe Ia) and the size of their ‘mass-step’, the relationship between SN Ia host galaxy stellar mass (Mstellar) and SN Ia Hubble residual, and suggest that the cause of this relationship is dust. Using 675 photometrically classified SNe Ia from the Dark Energy Survey 5-yr sample, we study the differences in Hubble residual for a variety of global host galaxy and local environmental properties for SN Ia subsamples split by their colour. We find a 3σ difference in the mass-step when comparing blue (c &amp;lt; 0) and red (c &amp;gt; 0) SNe. We observe the lowest r.m.s. scatter (∼0.14 mag) in the Hubble residual for blue SNe in low mass/blue environments, suggesting that this is the most homogeneous sample for cosmological analyses. By fitting for c-dependent relationships between Hubble residuals and Mstellar, approximating existing dust models, we remove the mass-step from the data and find tentative ∼2σ residual steps in rest-frame galaxy U − R colour. This indicates that dust modelling based on Mstellar may not fully explain the remaining dispersion in SN Ia luminosity. Instead, accounting for a c-dependent relationship between Hubble residuals and global U − R, results in ≤1σ residual steps in Mstellar and local U − R, suggesting that U − R provides different information about the environment of SNe Ia compared to Mstellar, and motivating the inclusion of galaxy U − R colour in SN Ia distance bias correction.

The Local Value of H0

AbstractWe review the local determination of the Hubble constant, H0, focusing on recent measurements of a distance ladder constructed from geometry, Cepheid variables and Type Ia supernovae (SNe Ia). We explain in some detail the components of the ladder: (1) geometry from Milky Way parallaxes, masers in NGC 4258 and detached eclipsing binaries in the Large Magellanic Cloud; (2) measurements of Cepheids with the Hubble Space Telescope (HST) in these anchors and in the hosts of 42 SNe Ia; and (3) SNe Ia in the Hubble flow. Great attention to negating systematic uncertainties through the use of differential measurements is reviewed. A wide array of tests are discussed. The measurements provide a strong indication of a discrepancy between the local measure of H0 and its value predicted by Λ Cold Dark Matter theory, calibrated by the cosmic microwave background (Planck), a decade-long challenge known as the ‘Hubble Tension’. We present new measurements with the James Webb Space Telescope of &gt;320 Cepheids on both rungs of the distance ladder, in a SN Ia host and the geometric calibrator NGC 4258, showing good agreement with the same as measured with HST. This provides strong evidence that systematic errors in HST Cepheid photometry do not play a significant role in the present Hubble Tension. Future measurements are expected to refine the local determination of the Hubble constant.

Constraining the SN Ia host galaxy dust law distribution and mass step: hierarchical BayeSN analysis of optical and near-infrared light curves

ABSTRACT We use the BayeSN hierarchical probabilistic SED model to analyse the optical–NIR (BVriYJH) light curves of 86 Type Ia supernovae (SNe Ia) from the Carnegie Supernova Project to investigate the SN Ia host galaxy dust law distribution and correlations between SN Ia Hubble residuals and host mass. Our Bayesian analysis simultaneously constrains the mass step and dust RV population distribution by leveraging optical–NIR colour information. We demonstrate how a simplistic analysis where individual RV values are first estimated for each SN separately, and then the sample variance of these point estimates is computed, overestimates the RV population variance $\sigma _R^2$. This bias is exacerbated when neglecting residual intrinsic colour variation beyond that due to light curve shape. Instead, Bayesian shrinkage estimates of σR are more accurate, with fully hierarchical analysis of the light curves being ideal. For the 75 SNe with low-to-moderate reddening (peak apparent B − V ≤ 0.3), we estimate an RV distribution with population mean μR = 2.59 ± 0.14, and standard deviation σR = 0.62 ± 0.16. Splitting this subsample at the median host galaxy mass (1010.57 M⊙) yields consistent estimated RV distributions between low- and high-mass galaxies, with μR = 2.79 ± 0.18, σR = 0.42 ± 0.24, and μR = 2.35 ± 0.27, σR = 0.74 ± 0.36, respectively. When estimating distances from the full optical–NIR light curves while marginalizing over various forms of the dust RV distribution, a mass step of ≳0.06 mag persists in the Hubble residuals at the median host mass.

Stellar Populations in type Ia supernova host galaxies at intermediate-high redshift: Star formation and metallicity enrichment histories

ABSTRACT We present a summary of our project that studies galaxies hosting type Ia supernova (SN Ia) at different redshifts. We present Gran Telescopio de Canarias (GTC) optical spectroscopy of six SN Ia host galaxies at redshift z ∼ 0.4–0.5. They are joined to a set of SN Ia host galaxies at intermediate-high redshift, which include galaxies from surveys SDSS and COSMOS. The final sample, after a selection of galaxy spectra in terms of signal-to-noise and other characteristics, consists of 680 galaxies with redshift in the range 0.04 &amp;lt; z &amp;lt; 1. We perform an inverse stellar population synthesis with the code fado to estimate the star formation and enrichment histories of this set of galaxies, simultaneously obtaining their mean stellar age and metallicity and stellar mass. After analysing the correlations among these characteristics, we look for possible dependencies of the Hubble diagram residuals and supernova features (luminosity, colour and strength parameter) on these stellar parameters. We find that the Hubble residuals show a clear dependence on the stellar metallicity weighted by mass with a slope of −0.061 mag dex−1, when represented in logarithmic scale, log 〈ZM/Z⊙〉. This result supports our previous findings obtained from gas oxygen abundances for local and SDSS-survey galaxies. Comparing with other works from the literature that also use the stellar metallicity, we find a similar value, but with more precision and a better significance (2.08 versus ∼ 1.1), due to the higher number of objects and wider range of redshift of our sample.

Climbing out of the shadows: Building the distance ladder with black hole images

In the era of precision cosmology it has became crucial to find new and competitive probes to estimate cosmological parameters, in an effort of finding answers to the current cosmological tensions/discrepancies. In this work, we show the possibility of using observations of Super Massive Black Hole (SMBH) shadows as an anchor for the distance ladder, substituting the sources usually exploited for such purpose, such as Cepheid variable stars. Compared to the standard approaches, the use of SMBH has the advantage of not needing to be anchored with distance calibrators outside the Hubble flow since the shadows physical size can be estimated knowing the mass of the SMBH. Furthermore, SMBH are supposed to inhabit the center of all galaxies which, in principle, means that we can measure the size of the shadows in any Supernova type Ia host galaxy. Under the assumption that the mass of the SMBH can be accurately and reliably estimated, we find that the Hubble constant can be constrained with a $\approx10\%$ precision even considering current experimental design of ground-based interferometers. By constructing a SMBH catalogue based on a specific choice of the SMBH Mass Function (BHMF), we forecast the constraints on the Hubble constant, finding that a precision of $\approx4\%$ may be within reach of future interferometers.

A Comprehensive Measurement of the Local Value of the Hubble Constant with 1 km s−1 Mpc−1 Uncertainty from the Hubble Space Telescope and the SH0ES Team

We report observations from the Hubble Space Telescope (HST) of Cepheid variables in the host galaxies of 42 Type Ia supernovae (SNe Ia) used to calibrate the Hubble constant (H 0). These include the complete sample of all suitable SNe Ia discovered in the last four decades at redshift z ≤ 0.01, collected and calibrated from ≥1000 HST orbits, more than doubling the sample whose size limits the precision of the direct determination of H 0. The Cepheids are calibrated geometrically from Gaia EDR3 parallaxes, masers in NGC 4258 (here tripling that sample of Cepheids), and detached eclipsing binaries in the Large Magellanic Cloud. All Cepheids in these anchors and SN Ia hosts were measured with the same instrument (WFC3) and filters (F555W, F814W, F160W) to negate zero-point errors. We present multiple verifications of Cepheid photometry and six tests of background determinations that show Cepheid measurements are accurate in the presence of crowded backgrounds. The SNe Ia in these hosts calibrate the magnitude–redshift relation from the revised Pantheon+ compilation, accounting here for covariance between all SN data and with host properties and SN surveys matched throughout to negate systematics. We decrease the uncertainty in the local determination of H 0 to 1 km s−1 Mpc−1 including systematics. We present results for a comprehensive set of nearly 70 analysis variants to explore the sensitivity of H 0 to selections of anchors, SN surveys, redshift ranges, the treatment of Cepheid dust, metallicity, form of the period–luminosity relation, SN color, peculiar-velocity corrections, sample bifurcations, and simultaneous measurement of the expansion history. Our baseline result from the Cepheid–SN Ia sample is H 0 = 73.04 ± 1.04 km s−1 Mpc−1, which includes systematic uncertainties and lies near the median of all analysis variants. We demonstrate consistency with measures from HST of the TRGB between SN Ia hosts and NGC 4258, and include them simultaneously to yield 72.53 ± 0.99 km s−1 Mpc−1. The inclusion of high-redshift SNe Ia yields H 0 = 73.30 ± 1.04 km s−1 Mpc−1 and q 0 = −0.51 ± 0.024. We find a 5σ difference with the prediction of H 0 from Planck cosmic microwave background observations under ΛCDM, with no indication that the discrepancy arises from measurement uncertainties or analysis variations considered to date. The source of this now long-standing discrepancy between direct and cosmological routes to determining H 0 remains unknown.