- ID:
- ivo://CDS.VizieR/J/A+A/655/A90
- Title:
- SN 2020cxd multi-photometry
- Short Name:
- J/A+A/655/A90
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We present observations and analysis of SN 2020cxd, a low-luminosity (LL), long-lived Type IIP supernova (SN). This object was a clear outlier in the magnitude-limited SN sample recently presented by the Zwicky Transient Facility (ZTF) Bright Transient Survey. We demonstrate that SN 2020cxd is an additional member of the group of LL SNe, and discuss the rarity of LL SNe in the context of the ZTF survey, and how further studies of these faintest members of the core-collapse (CC) SN family might help understand the underlying initial mass function for stars that explode. We present optical light curves (LCs) from the ZTF in the $gri$ bands and several epochs of ultra-violet data from the Neil Gehrels Swift Observatory as well as a sequence of optical spectra. We construct colour curves, a bolometric LC, compare ejecta-velocity and black-body temperature evolutions for LL SNe, as well as for typical Type II SNe. Furthermore, we adopt a Monte Carlo code that fits semi-analytic models to the LC of SN 2020cxd, which allows the estimation of physical parameters. Using our late-time nebular spectra, we also compare against SN II spectral synthesis models from the literature to constrain the progenitor properties of SN 2020cxd. The LCs of SN 2020cxd show great similarity with those of LL SNe IIP, in luminosity, timescale and colours. Also the spectral evolution of SN 2020cxd is that of a Type IIP SN. The spectra show prominent and narrow P-Cygni lines, indicating low expansion velocities. This is one of the faintest LL SNe observed, with an absolute plateau magnitude of M_r_=-14.5mag, and also one with the longest plateau lengths, with a duration of 118 days. Finally, the velocities measured from the nebular emission lines are among the lowest ever seen in a SN, with intrinsic Full Width at Half Maximum of 478km/s. The underluminous late-time exponential LC tail indicates that the mass of ^56^Ni ejected during the explosion is much smaller than the average of normal SNe IIP, we estimate M_^56^Ni_=0.003M+{sun+_. The Monte Carlo fitting of the bolometric LC suggests that the progenitor of SN 2020cxd had a radius of R_0_=1.3x10^13^cm, kinetic energy of E_kin_=4.3x10^50^erg, and ejecta mass M_ej_=9.5M_{sun}_. From the bolometric LC, we estimate the total radiated energy E_rad_=1.52x10^48^erg. Using our late-time nebular spectra, we compare against SN II spectral synthesis models to constrain the progenitor Zero-age Main-sequence mass and found it likely to be <~15M_{sun}+. SN 2020cxd is a LL Type IIP SN. The inferred progenitor parameters and the features observed in the nebular spectrum favour a low-energy, Ni-poor, iron CC SN from a low mass ~12M_{sun}_ red supergiant.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/562/A17
- Title:
- SN 2011dh - The first 100 days
- Short Name:
- J/A+A/562/A17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical and near-infrared (NIR) photometry and spectroscopy of the Type IIb supernova (SN) 2011dh for the first 100 days. We complement our extensive dataset with Swift ultra-violet (UV) and Spitzer mid-infrared (MIR) data to build a UV to MIR bolometric lightcurve using both photometric and spectroscopic data. Hydrodynamical modelling of the SN based on this bolometric lightcurve have been presented in Bersten et al. (2012ApJ...757...31B).
- ID:
- ivo://CDS.VizieR/J/A+A/580/A142
- Title:
- SN 2011dh. The first two years
- Short Name:
- J/A+A/580/A142
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical and near-infrared (NIR) photometry and spectroscopy as well as modelling of the lightcurves of the Type IIb supernova (SN) 2011dh. Our extensive dataset, for which we present the observations obtained after day 100, spans two years, and complemented with Spitzer mid-infrared (MIR) data, we use it to build an optical-to-MIR bolometric lightcurve between days 3 and 732.
- ID:
- ivo://CDS.VizieR/J/other/PZ/28.8
- Title:
- SN 2004dj UBVRI light curves
- Short Name:
- J/other/PZ/28.8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD UBVRI photometry is presented for type II SN 2004dj for about 1200 days, starting on day 2 past discovery. The photometric behaviour is typical of SNe II-P, although some minor peculiarities are noticed. We compare the photometric data for the host cluster S96 before and after the SN 2004dj outburst and do not find any significant changes.
- ID:
- ivo://CDS.VizieR/J/ApJS/219/13
- Title:
- SNe Ia light curves for the LSQ-CSP sample
- Short Name:
- J/ApJS/219/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The La Silla/QUEST Variability Survey (LSQ) and the Carnegie Supernova Project (CSP II) are collaborating to discover and obtain photometric light curves for a large sample of low-redshift (z<0.1) Type Ia supernovae (SNe Ia). The supernovae are discovered in the LSQ survey using the 1m ESO Schmidt telescope at the La Silla Observatory with the 10 square degree QUEST camera. The follow-up photometric observations are carried out using the 1m Swope telescope and the 2.5m du Pont telescopes at the Las Campanas Observatory. This paper describes the survey, discusses the methods of analyzing the data, and presents the light curves for the first 31 SNe Ia obtained in the survey. The SALT 2.4 supernova light-curve fitter was used to analyze the photometric data, and the Hubble diagram for this first sample is presented. The measurement errors for these supernovae averaged 4%, and their intrinsic spread was 14%.
3336. SNe Ia spectra from SNLS
- 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.
- 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/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/461/2003
- Title:
- SN 2013ej light curves 1 to 450d after explosion
- Short Name:
- J/MNRAS/461/2003
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical and near-infrared photometric and spectroscopic observations of SN 2013ej, in galaxy M74, from 1 to 450 d after the explosion. SN 2013ej is a hydrogen-rich supernova, classified as a Type IIL due to its relatively fast decline following the initial peak. It has a relatively high peak luminosity (absolute magnitude M_V_=-17.6) but a small ^56^Ni production of ~0.023M_{sun}_. Its photospheric evolution is similar to other Type II SNe, with shallow absorption in the H_{alpha}_ profile typical for a Type IIL. During transition to the radioactive decay tail at ~100d, we find the SN to grow bluer in B-V colour, in contrast to some other Type II supernovae. At late times, the bolometric light curve declined faster than expected from ^56^Co decay and we observed unusually broad and asymmetric nebular emission lines. Based on comparison of nebular emission lines most sensitive to the progenitor core mass, we find our observations are best matched to synthesized spectral models with a M_ZAMS_=12-15 M_{sun}_ progenitor. The derived mass range is similar to but not higher than the mass estimated for Type IIP progenitors. This is against the idea that Type IIL are from more massive stars. Observations are consistent with the SN having a progenitor with a relatively low-mass envelope.
- ID:
- ivo://CDS.VizieR/J/A+A/646/A22
- Title:
- SN 2020faa multiphotometry and spectra
- Short Name:
- J/A+A/646/A22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations of SN 2020faa. This Type II supernova displays a luminous lightcurve that started to rebrighten from an initial decline. We investigate this in relation to the famous supernova iPTF14hls, which received a great deal of attention and multiple interpretations in the literature, but whose nature and source of energy still remain unknown. We demonstrate the great similarity between SN 2020faa and iPTF14hls during the first 6 months, and use this comparison to forecast the evolution of SN 2020faa and to reflect on the less well observed early evolution of iPTF14hls. We present and analyse our observational data, consisting mainly of optical lightcurves from the Zwicky Transient Facility in the gri bands and of a sequence of optical spectra. We construct colour curves and a bolometric lightcurve, and we compare ejecta-velocity and black-body radius evolutions for the two supernovae and for more typical Type II supernovae. The lightcurves show a great similarity with those of iPTF14hls over the first 6 months in luminosity, timescale, and colour. In addition, the spectral evolution of SN 2020faa is that of a Type II supernova, although it probes earlier epochs than those available for iPTF14hls. The similar lightcurve behaviour is suggestive of SN 2020faa being a new iPTF14hls. We present these observations now to advocate follow-up observations, since most of the more striking evolution of supernova iPTF14hls came later, with lightcurve undulations and a spectacular longevity. On the other hand, for SN 2020faa we have better constraints on the explosion epoch than we had for iPTF14hls, and we have been able to spectroscopically monitor it from earlier phases than was done for the more famous sibling.
