- ID:
- ivo://CDS.VizieR/J/A+A/614/A134
- Title:
- SNe Ia spectra from SNLS
- Short Name:
- J/A+A/614/A134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim to present 70 spectra of 68 new high-redshift type Ia supernovae (SNe Ia) measured at ESO's VLT during the final two years of operation (2006-2008) of the Supernova Legacy Survey (SNLS). This new sample complements the VLT three year spectral set. Altogether, these two data sets form the five year sample of SNLS SN Ia spectra measured at the VLT on which the final SNLS cosmological analysis will partly be based. In the redshift range considered, this sample is unique in terms of homogeneity and number of spectra. We use it to investigate the possibility of a spectral evolution of SNe Ia populations with redshift as well as SNe Ia spectral properties as a function of lightcurve fit parameters and the mass of the host-galaxy. Reduction and extraction are based on both IRAF standard tasks and our own reduction pipeline. Redshifts are estimated from host-galaxy lines whenever possible or alternatively from supernova features. We used the spectro-photometric SN Ia model SALT2 combined with a set of galaxy templates that model the host-galaxy contamination to assess the type Ia nature of the candidates. We identify 68 new SNe Ia with redshift ranging from z=0.207 to z=0.98 for an average redshift of z=0.62. Each spectrum is presented individually along with its best-fit SALT2 model. Adding this new sample to the three year VLT sample of SNLS, the final dataset contains 209 spectra corresponding to 192 SNe Ia identified at the VLT. We also publish the redshifts of other candidates (host galaxies or other transients) whose spectra were obtained at the same time as the spectra of live SNe Ia. This list provides a new redshift catalog useful for upcoming galaxy surveys. Using the full VLT SNe Ia sample, we build composite spectra around maximum light with cuts in color, the lightcurve shape parameter ("stretch"), host-galaxy mass and redshift. We find that high-z SNe Ia are bluer, brighter and have weaker intermediate mass element absorption lines than their low-z counterparts at a level consistent with what is expected from selection effects. We also find a flux excess in the range [3000-3400]{AA} for SNe Ia in low mass host-galaxies (M<10^10^M_{sun}_) or with locally blue U-V colors, and suggest that the UV flux (or local color) may be used in future cosmological studies as a third standardization parameter in addition to stretch and color.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/651/A81
- Title:
- SNe Ic from (i)PTF light curves
- Short Name:
- J/A+A/651/A81
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Type Ic supernovae represent the explosions of the most stripped massive stars, but their progenitors and explosion mechanisms remain unclear. Larger samples of observed supernovae can help characterize the population of these transients. We present an analysis of 44 spectroscopically normal Type Ic supernovae, with focus on the light curves. The photometric data were obtained over 7 years with the Palomar Transient Factory (PTF) and its continuation, the intermediate Palomar TransientFactory (iPTF). This is the first homogeneous and large sample of SNe Ic from an untargeted survey, and we aim to estimate explosion parameters for the sample.
- ID:
- ivo://CDS.VizieR/J/ApJS/233/6
- Title:
- SNe II light curves & spectra from the CfA
- Short Name:
- J/ApJS/233/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multiband photometry of 60 spectroscopically confirmed supernovae (SNe): 39 SNe II/IIP, 19 IIn, 1 IIb, and 1 that was originally classified as a IIn but later as a Ibn. Of these, 46 have only optical photometry, 6 have only near-infrared (NIR) photometry, and 8 have both optical and NIR. The median redshift of the sample is 0.016. We also present 195 optical spectra for 48 of the 60 SN. There are 26 optical and 2 NIR light curves of SNe II/IIP with redshifts z>0.01, some of which may give rise to useful distances for cosmological applications. All photometry was obtained between 2000 and 2011 at the Fred Lawrence Whipple Observatory (FLWO), via the 1.2m and 1.3m PAIRITEL telescopes for the optical and NIR, respectively. Each SN was observed in a subset of the u'UBVRIr'i'JHK_s_ bands. There are a total of 2932 optical and 816 NIR light curve points. Optical spectra were obtained using the FLWO 1.5m Tillinghast telescope with the FAST spectrograph and the MMT Telescope with the Blue Channel Spectrograph. Our photometry is in reasonable agreement with select samples from the literature: two-thirds of our star sequences have average V offsets within +/-0.02mag and roughly three-quarters of our light curves have average differences within +/-0.04mag. The data from this work and the literature will provide insight into SN II explosions, help with developing methods for photometric SN classification, and contribute to their use as cosmological distance indicators.
- ID:
- ivo://CDS.VizieR/J/ApJ/789/104
- Title:
- SNe IIn observations and properties
- Short Name:
- J/ApJ/789/104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- There is a growing number of Type IIn supernovae (SNe) which present an outburst prior to their presumably final explosion. These precursors may affect the SN display, and are likely related to poorly charted phenomena in the final stages of stellar evolution. By coadding Palomar Transient Factory (PTF) images taken prior to the explosion, here we present a search for precursors in a sample of 16 Type IIn SNe. We find five SNe IIn that likely have at least one possible precursor event (PTF 10bjb, SN 2010mc, PTF 10weh, SN 2011ht, and PTF 12cxj), three of which are reported here for the first time. For each SN we calculate the control time. We find that precursor events among SNe IIn are common: at the one-sided 99% confidence level, >50% of SNe IIn have at least one pre-explosion outburst that is brighter than 3x10^7^ L_{sun}_ taking place up to 1/3 yr prior to the SN explosion. The average rate of such precursor events during the year prior to the SN explosion is likely >~ 1/yr, and fainter precursors are possibly even more common. Ignoring the two weakest precursors in our sample, the precursors rate we find is still on the order of one per year. We also find possible correlations between the integrated luminosity of the precursor and the SN total radiated energy, peak luminosity, and rise time. These correlations are expected if the precursors are mass-ejection events, and the early-time light curve of these SNe is powered by interaction of the SN shock and ejecta with optically thick circumstellar material.
- ID:
- ivo://CDS.VizieR/J/ApJ/886/27
- Title:
- SNe IIP progenitors. I. LMC giant comparison sample
- Short Name:
- J/ApJ/886/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the evolution of massive star progenitors of supernovae of type IIP. We take the example of the nearby and well-studied SN2013ej. We explore how convective overshoot affects the stellar structure, surface abundances, and effective temperature of massive stars, using the Modules for Experiments in Stellar Astrophysics. In particular, models with moderate overshoot (f=0.02-0.031) show the presence of blue loops in the Hertzsprung-Russell diagram with a red to blue excursion (log_10_[Teff/K] from <3.6 to >4.0) and transition back to red, during the core helium-burning phase. Models with overshoot outside this range of f values kept the star in the red supergiant state throughout the post-helium-ignition phases. The surface CNO abundance shows enrichment post-main-sequence and again around the time when helium is exhausted in the core. These evolutionary changes in surface CNO abundance are indistinguishable in the currently available observations due to large observational uncertainties. However, these observations may distinguish between the ratio of surface nitrogen to oxygen at different evolutionary stages of the star. We also compare the effects of convective overshoot on various parameters related to likelihood of explosion of a star as opposed to collapse to a black hole. These parameters are the compactness parameter, M_4_, and {mu}_4_. The combination {mu}_4_xM_4_, and {mu}_4_ have similar variations with f and both peak at f=0.032. We find that all of our 13M_{sun}_ models are likely to explode.
- ID:
- ivo://CDS.VizieR/J/MNRAS/412/1441
- Title:
- SNe luminosity functions
- Short Name:
- J/MNRAS/412/1441
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the second paper of a series in which we present new measurements of the observed rates of supernovae (SNe) in the local Universe, determined from the Lick Observatory Supernova Search (LOSS). In this paper, a complete SN sample is constructed, and the observed (uncorrected for host-galaxy extinction) luminosity functions (LFs) of SNe are derived. These LFs solve two issues that have plagued previous rate calculations for nearby SNe: the luminosity distribution of SNe and the host-galaxy extinction. We select a volume-limited sample of 175 SNe, collect photometry for every object and fit a family of light curves to constrain the peak magnitudes and light-curve shapes. The volume-limited LFs show that they are not well represented by a Gaussian distribution.
- ID:
- ivo://CDS.VizieR/J/ApJ/791/105
- Title:
- SNe progenitor masses probability distribution
- Short Name:
- J/ApJ/791/105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using resolved stellar photometry measured from archival Hubble Space Telescope imaging, we generate color-magnitude diagrams of the stars within 50 pc of the locations of historic core-collapse supernovae (SNe) that took place in galaxies within 8 Mpc. We fit these color-magnitude distributions with stellar evolution models to determine the best-fit age distribution of the young population. We then translate these age distributions into probability distributions for the progenitor mass of each SN. The measurements are anchored by the main-sequence stars surrounding the event, making them less sensitive to assumptions about binarity, post-main-sequence evolution, or circumstellar dust. We demonstrate that, in cases where the literature contains masses that have been measured from direct imaging, our measurements are consistent with (but less precise than) these measurements. Using this technique, we constrain the progenitor masses of 17 historic SNe, 11 of which have no previous estimates from direct imaging. Our measurements still allow the possibility that all SN progenitor masses are <20 M_{sun}_. However, the large uncertainties for the highest-mass progenitors also allow the possibility of no upper-mass cutoff.
- ID:
- ivo://CDS.VizieR/J/A+A/623/A173
- Title:
- SNe/SNRs in starburst galaxy Arp 220
- Short Name:
- J/A+A/623/A173
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nearby ultra-luminous infrared galaxy (ULIRG) Arp 220 is an excellent laboratory for studies of extreme astrophysical environments. For 20 years, Very Long Baseline Interferometry (VLBI) has been used to monitor a population of compact sources thought to be supernovae (SNe), supernova remnants (SNRs) and possibly active galactic nuclei (AGNs). SNe and SNRs are thought to be the sites of relativistic particle acceleration powering the star formation induced radio emission, and are hence important for studies of e.g. the origin of the FIR-radio correlation. In this work we aim for a self-consistent analysis of a large collection of Arp 220 continuum VLBI data sets. With more data and improved consistency in calibration and imaging, we aim to detect more sources and improve source classifications with respect to previous studies. Furthermore, we aim to increase the number of sources with robust size estimates, to analyse the compact source luminosity function (LF), and to search for a luminosity-diameter (LD) relation within Arp 220. Using new and archival VLBI data spanning 20 years, we obtain 23 high-resolution radio images of Arp 220 at wavelengths from 18cm to 2cm. From model-fitting to the images we obtain estimates of flux densities and sizes of all detected sources. The sources are classified in groups according to their observed lightcurves, spectra and sizes. We fit a multi-frequency supernova lightcurve model to the object brightest at 6cm to estimate explosion properties for this object.
- ID:
- ivo://CDS.VizieR/J/ApJ/835/166
- Title:
- SNe type II from CSP-I, SDSS-II, and SNLS
- Short Name:
- J/ApJ/835/166
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The coming era of large photometric wide-field surveys will increase the detection rate of supernovae by orders of magnitude. Such numbers will restrict spectroscopic follow-up in the vast majority of cases, and hence new methods based solely on photometric data must be developed. Here, we construct a complete Hubble diagram of Type II supernovae (SNe II) combining data from three different samples: the Carnegie Supernova Project-I, the Sloan Digital Sky Survey II SN, and the Supernova Legacy Survey. Applying the Photometric Color Method (PCM) to 73 SNe II with a redshift range of 0.01-0.5 and with no spectral information, we derive an intrinsic dispersion of 0.35mag. A comparison with the Standard Candle Method (SCM) using 61 SNe II is also performed and an intrinsic dispersion in the Hubble diagram of 0.27mag, i.e., 13% in distance uncertainties, is derived. Due to the lack of good statistics at higher redshifts for both methods, only weak constraints on the cosmological parameters are obtained. However, assuming a flat universe and using the PCM, we derive the universe's matter density: {Omega}_m_=0.32_-0.21_^+0.30^ providing a new independent evidence for dark energy at the level of two sigma.
- ID:
- ivo://CDS.VizieR/J/ApJ/791/57
- Title:
- SN host galaxies basic information
- Short Name:
- J/ApJ/791/57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compare the host galaxies of 902 supernovae (SNe), including SNe Ia, SNe II, and SNe Ibc, which are selected by cross-matching the Asiago Supernova Catalog (Barbon et al., cat II/227) with the Sloan Digital Sky Survey (SDSS) Data Release 7 (Strauss et al., 2002AJ....124.1810S). We selected an additional 213 galaxies by requiring the light fraction of spectral observations to be >15%, which could represent well the global properties of the galaxies. Among these 213 galaxies, 135 appear on the Baldwin-Phillips-Terlevich diagram, which allows us to compare the hosts in terms of whether they are star-forming (SF) galaxies, active galactic nuclei (AGNs; including composites, LINERs, and Seyfert 2s) or absorption-line galaxies (Absorps; i.e., their related emission lines are weak or non-existent). The diagrams related to the parameters D_n_(4000), H{delta}_A_, stellar masses, star formation rates (SFRs), and specific SFRs for the SNe hosts show that almost all SNe II and most of the SNe Ibc occur in SF galaxies, which have a wide range of stellar masses and low D_n_(4000). The SNe Ia hosts as SF galaxies following similar trends. A significant fraction of SNe Ia occurs in AGNs and absorption-line galaxies, which are massive and have high D_n_(4000). The stellar population analysis from spectral synthesis fitting shows that the hosts of SNe II have a younger stellar population than hosts of SNe Ia. These results are compared with those of the 689 comparison galaxies where the SDSS fiber captures less than 15% of the total light. These comparison galaxies appear biased toward higher 12+log(O/H) (~0.1 dex) at a given stellar mass. Therefore, we believe the aperture effect should be kept in mind when the properties of the hosts for different types of SNe are discussed.
