- ID:
- ivo://CDS.VizieR/J/ApJ/738/162
- Title:
- SN Ia candidates from the SDSS-II SN Survey
- Short Name:
- J/ApJ/738/162
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze the three-year Sloan Digital Sky Survey II (SDSS-II) Supernova (SN) Survey data and identify a sample of 1070 photometric Type Ia supernova (SN Ia) candidates based on their multiband light curve data. This sample consists of SN candidates with no spectroscopic confirmation, with a subset of 210 candidates having spectroscopic redshifts of their host galaxies measured while the remaining 860 candidates are purely photometric in their identification. We describe a method for estimating the efficiency and purity of photometric SN Ia classification when spectroscopic confirmation of only a limited sample is available, and demonstrate that SN Ia candidates from SDSS-II can be identified photometrically with ~91% efficiency and with a contamination of ~6%. Although this is the largest uniform sample of SN candidates to date for studying photometric identification, we find that a larger spectroscopic sample of contaminating sources is required to obtain a better characterization of the background events. A Hubble diagram using SN candidates with no spectroscopic confirmation, but with host galaxy spectroscopic redshifts, yields a distance modulus dispersion that is only ~20%-40% larger than that of the spectroscopically confirmed SN Ia sample alone with no significant bias. A Hubble diagram with purely photometric classification and redshift-distance measurements, however, exhibits biases that require further investigation for precision cosmology.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/740/92
- Title:
- SN.Ia host galaxies properties
- Short Name:
- J/ApJ/740/92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We improve estimates of the stellar mass and mass-weighted average age of Type Ia supernova (SN Ia) host galaxies by combining UV and near-IR photometry with optical photometry in our analysis. Using 206 SNe Ia drawn from the full three-year Sloan Digital Sky Survey (SDSS-II) Supernova Survey and multi-wavelength host-galaxy photometry from SDSS, the Galaxy Evolution Explorer, and the United Kingdom Infrared Telescope Infrared Deep Sky Survey, we present evidence of a correlation (1.9{sigma} confidence level) between the residuals of SNe Ia about the best-fit Hubble relation and the mass-weighted average age of their host galaxies. The trend is such that older galaxies host SNe Ia that are brighter than average after standard light-curve corrections are made. We also confirm, at the 3.0{sigma} level, the trend seen by previous studies that more massive galaxies often host brighter SNe Ia after light-curve correction.
- ID:
- ivo://CDS.VizieR/J/ApJ/755/61
- Title:
- SN Ia host galaxies SFR from SDSS-II
- Short Name:
- J/ApJ/755/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using data from the Sloan Digital Sky Supernova Survey-II (SDSS-II SN Survey, Frieman et al., 2008AJ....135..338F), we measure the rate of Type Ia supernovae (SNe Ia) as a function of galaxy properties at intermediate redshift. A sample of 342 SNe Ia with 0.05<z<0.25 is constructed. Using broadband photometry and redshifts, we use the P\'EGASE.2 spectral energy distributions to estimate host galaxy stellar masses and recent star formation rates (SFRs).
- ID:
- ivo://CDS.VizieR/J/MNRAS/457/3470
- Title:
- SN Ia host-galaxy/cosmological parameters
- Short Name:
- J/MNRAS/457/3470
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a systematic study of the relationship between Type Ia Supernova (SN Ia) properties, and the characteristics of their host galaxies, using a sample of 581 SNe Ia from the full Sloan Digital Sky Survey II (SDSS-II) SN Survey. We also investigate the effects of this on the cosmological constraints derived from SNe Ia. Compared to previous studies, our sample is larger by a factor of >4, and covers a substantially larger redshift range (up to z~0.5), which is directly applicable to the volume of cosmological interest. We measure a significant correlation (>5{sigma}) between the host-galaxy stellar-mass and the SN Ia Hubble Residuals (HR). We find a weak correlation (1.4{sigma}) between the host-galaxy metallicity as measured from emission lines in the spectra, and the SN Ia HR. We also find evidence that the slope of the correlation between host-galaxy mass and HR is -0.11mag/log(M_host_/M_{sun}_) steeper in lower metallicity galaxies. We test the effects on a cosmological analysis using both the derived best-fitting correlations between host parameters and HR, and by allowing an additional free parameter in the fit to account for host properties which we then marginalize over when determining cosmological parameters. We see a shift towards more negative values of the equation-of-state parameter w, along with a shift to lower values of {Omega}_m_ after applying mass or metallicity corrections. The shift in cosmological parameters with host-galaxy stellar-mass correction is consistent with previous studies. We find a best-fitting cosmology of {OMEGA}_m+=0.266+/-0.016, {OMEGA}_{LAMBDA}_=0.740+/-0.018 and w=-1.151^+0.123^_-0.121_ (statistical errors only).
- ID:
- ivo://CDS.VizieR/J/MNRAS/435/1680
- Title:
- SN Ia host galaxy properties
- Short Name:
- J/MNRAS/435/1680
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the stellar populations of Type Ia supernova (SN Ia) host galaxies using Sloan Digital Sky Survey (SDSS)-II spectroscopy. The main focus is on the relationships of SN Ia properties with stellar velocity dispersion and the stellar population parameters age, metallicity and element abundance ratios. We concentrate on a sub-sample of 84 SNe Ia from the SDSS-II Supernova Survey and find that SALT2 stretch factor values show the strongest dependence on stellar population age. Hence, more luminous SNe Ia appear in younger stellar progenitor systems. No statistically significant trends in the Hubble residual with any of the stellar population parameters studied are found. Moreover, the method of photometric stellar mass derivation affects the Hubble residual-mass relationship. For an extended sample (247 objects), including SNe Ia with SDSS host galaxy photometry only, the Hubble residual-mass relationship behaves as a sloped step function. In the high-mass regime, probed by our host spectroscopy sample, this relationship is flat. Below a stellar mass of ~2x10^10^M_{sun}_, i.e. close to the evolutionary transition mass of low-redshift galaxies, the trend changes dramatically such that lower mass galaxies possess lower luminosity SNe Ia after light-curve corrections. The sloped step function of the Hubble residual-mass relationship should be accounted for when using stellar mass as a further parameter for minimizing the Hubble residuals.
- ID:
- ivo://CDS.VizieR/J/MNRAS/434/1443
- Title:
- SN Ia inside rich galaxy clusters
- Short Name:
- J/MNRAS/434/1443
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used the Gaussian Mixture Brightest Cluster Galaxy catalogue and Sloan Digital Sky Survey-II supernovae data with redshifts measured by the Baryon Oscillation Spectroscopic Survey to identify 48 Type Ia supernovae (SNe Ia) residing in rich galaxy clusters and compare their properties with 1015 SNe Ia in the field. Their light curves were parametrized by the SALT2 model and the significance of the observed differences was assessed by a resampling technique. To test our samples and methods, we first looked for known differences between SNe Ia residing in active and passive galaxies. We confirm that passive galaxies host SNe Ia with smaller stretch, weaker colour-luminosity relation [{beta} of 2.54(22) against 3.35(14)], and that are ~ 0.1mag more luminous after stretch and colour corrections. We show that only 0.02 percent of random samples drawn from our set of SNe Ia in active galaxies can reach these values. Reported differences in the Hubble residuals scatter could not be detected, possibly due to the exclusion of outliers. We then show that, while most field and cluster SNe Ia properties are compatible at the current level, their stretch distributions are different (~3{sigma}): besides having a higher concentration of passive galaxies than the field, the cluster's passive galaxies host SNe Ia with an average stretch even smaller than those in field passive galaxies (at 95 percent confidence). We argue that the older age of passive galaxies in clusters is responsible for this effect since, as we show, old passive galaxies host SNe Ia with smaller stretch than young passive galaxies (~4{sigma}).
- ID:
- ivo://CDS.VizieR/J/ApJ/713/1026
- Title:
- SN Ia rate at redshift <~0.3 from SDSS-II
- Short Name:
- J/ApJ/713/1026
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a measurement of the volumetric Type Ia supernova (SN Ia) rate based on data from the Sloan Digital Sky Survey II (SDSS-II) Supernova Survey. The adopted sample of supernovae (SNe) includes 516 SNe Ia at redshift z<~0.3, of which 270(52%) are spectroscopically identified as SNe Ia. The remaining 246 SNe Ia were identified through their light curves; 113 of these objects have spectroscopic redshifts from spectra of their host galaxy, and 133 have photometric redshifts estimated from the SN light curves. Based on consideration of 87 spectroscopically confirmed non-Ia SNe discovered by the SDSS-II SN Survey, we estimate that 2.04^+1.61^_-0.95_% of the photometric SNe Ia may be misidentified. The sample of SNe Ia used in this measurement represents an order of magnitude increase in the statistics for SN Ia rate measurements in the redshift range covered by the SDSS-II Supernova Survey.
- ID:
- ivo://CDS.VizieR/J/ApJ/748/L29
- Title:
- SN Ia supernovae observed by Swift/XRT
- Short Name:
- J/ApJ/748/L29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have considered 53 Type Ia supernovae (SNe Ia) observed by the Swift X-Ray Telescope. None of the SNe Ia are individually detected at any time or in stacked images. Using these data and assuming that the SNe Ia are a homogeneous class of objects, we have calculated upper limits to the X-ray luminosity (0.2-10 keV) and mass-loss rate of L_0.2-10_<1.7x10^38^erg/s and \dot{M}<1.1x10^-6^M_{sun}_/yr x (v_w_)/(10km/s), respectively. The results exclude massive or evolved stars as the companion objects in SN Ia progenitor systems, but allow the possibility of main sequence or small stars, along with double degenerate systems consisting of two white dwarfs, consistent with results obtained at other wavelengths (e.g., UV, radio) in other studies.
- ID:
- ivo://CDS.VizieR/J/A+A/589/A110
- Title:
- SN II in host HII regions
- Short Name:
- J/A+A/589/A110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectral modelling of typeII supernova atmospheres indicates a clear dependence of metal line strengths on progenitor metallicity. This dependence motivates further work to evaluate the accuracy with which these supernovae can be used as environment metallicity indicators. To assess this accuracy we present a sample of type II supernova host HII-region spectroscopy, from which environment oxygen abundances have been derived. These environment abundances are compared to the observed strength of metal lines in supernova spectra. Combining our sample with measurements from the literature, we present oxygen abundances of 119 host HII regions by extracting emission line fluxes and using abundance diagnostics. These abundances are then compared to equivalent widths of FeII 5018{AA} at various time and colour epochs. Our distribution of inferred type II supernova host HII-region abundances has a range of ~0.6dex. We confirm the dearth of type II supernovae exploding at metallicities lower than those found (on average) in the Large Magellanic Cloud. The equivalent width of FeII 5018{AA} at 50 days post-explosion shows a statistically significant correlation with host HII-region oxygen abundance. The strength of this correlation increases if one excludes abundance measurements derived far from supernova explosion sites. The correlation significance also increases if we only analyse a "gold" IIP sample, and if a colour epoch is used in place of time. In addition, no evidence is found of a correlation between progenitor metallicity and supernova light-curve or spectral properties - except for that stated above with respect to FeII 5018{AA} equivalent widths - suggesting progenitor metallicity is not a driving factor in producing the diversity that is observed in our sample. This study provides observational evidence of the usefulness of typeII supernovae as metallicity indicators. We finish with a discussion of the methodology needed to use supernova spectra as independent metallicity diagnostics throughout the Universe.
- ID:
- ivo://CDS.VizieR/J/ApJ/807/169
- Title:
- SN IIn catalog with Fermi LAT
- Short Name:
- J/ApJ/807/169
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Supernovae (SNe) exploding in a dense circumstellar medium (CSM) are hypothesized to accelerate cosmic rays in collisionless shocks and emit GeV {gamma}-rays and TeV neutrinos on a timescale of several months. We perform the first systematic search for {gamma}-ray emission in Fermi Large Area Telescope data in the energy range from 100MeV to 300GeV from the ensemble of 147 SNe Type IIn exploding in a dense CSM. We search for a {gamma}-ray excess at each SNe location in a one-year time window. In order to enhance a possible weak signal, we simultaneously study the closest and optically brightest sources of our sample in a joint-likelihood analysis in three different time windows (1 year, 6 months, and 3 months). For the most promising source of the sample, SN 2010jl (PTF 10aaxf), we repeat the analysis with an extended time window lasting 4.5 years. We do not find a significant excess in {gamma}-rays for any individual source nor for the combined sources and provide model-independent flux upper limits for both cases. In addition, we derive limits on the {gamma}-ray luminosity and the ratio of {gamma}-ray-to-optical luminosity ratio as a function of the index of the proton injection spectrum assuming a generic {gamma}-ray production model. Furthermore, we present detailed flux predictions based on multi-wavelength observations and the corresponding flux upper limit at a 95% confidence level (CL) for the source SN 2010jl (PTF 10aaxf).
