scholarly journals Comparison of the optical light curves of hydrogen-rich and hydrogen-poor type II supernovae

2019 ◽  
Vol 488 (3) ◽  
pp. 4239-4257 ◽  
Author(s):  
P J Pessi ◽  
G Folatelli ◽  
J P Anderson ◽  
M Bersten ◽  
C Burns ◽  
...  
Keyword(s):  
Light Curve ◽  
Light Curves ◽  
Radioactive Material ◽  
Type Ii ◽  
Optical Wavelength ◽  
V Band ◽  
Hydrogen Lines ◽  
Hydrogen Mass ◽  
Magnitude Difference ◽  
Wavelength Light

ABSTRACT Type II supernovae (SNe II) show strong hydrogen features in their spectra throughout their whole evolution, while type IIb supernovae (SNe IIb) spectra evolve from dominant hydrogen lines at early times to increasingly strong helium features later on. However, it is currently unclear whether the progenitors of these SN types form a continuum in pre-SN hydrogen mass or whether they are physically distinct. SN light-curve morphology directly relates to progenitor and explosion properties such as the amount of hydrogen in the envelope, the pre-SN radius, the explosion energy, and the synthesized mass of radioactive material. In this work, we study the morphology of the optical-wavelength light curves of hydrogen-rich SNe II and hydrogen-poor SNe IIb to test whether an observational continuum exists between the two. Using a sample of 95 SNe (73 SNe II and 22 SNe IIb), we define a range of key observational parameters and present a comparative analysis between both types. We find a lack of events that bridge the observed properties of SNe II and IIb. Light-curve parameters such as rise times and post-maximum decline rates and curvatures clearly separate both SN types and we therefore conclude that there is no continuum, with the two SN types forming two observationally distinct families. In the V band a rise time of 17 d (SNe II lower and SNe IIb higher), and a magnitude difference between 30 and 40 d post-explosion of 0.4 mag (SNe II lower and SNe IIb higher) serve as approximate thresholds to differentiate both types.

scholarly journals V-band light-curve morphologies of supernovae type II

2013 ◽  
Vol 9 (S296) ◽  
pp. 332-333
Author(s):  
Joseph P Anderson
Keyword(s):  
Light Curve ◽  
Light Curves ◽  
Type Ii ◽  
V Band ◽  
Absolute Magnitudes

AbstractWe present an analysis of V-band light-curves morphologies of type II supernovae (SNII). This investigation is achieved through photometry of more than 100 SNe including a first analysis of SNII data obtained by the Carnegie Supernova Project (CSP). We define the important observables and present correlations between SNe absolute magnitudes and light-curve decline rates: we find that brighter SNII tend to have faster declining light-curves at all epochs.

scholarly journals Princicpal Component Analysis of type II supernova V band light-curves

2014 ◽  
Vol 10 (S306) ◽  
pp. 330-332
Author(s):  
Lluís Galbany
Keyword(s):  
Principal Component Analysis ◽  
Light Curve ◽  
Principal Component ◽  
Component Analysis ◽  
Light Curves ◽  
Physical Parameters ◽  
Core Collapse ◽  
Type Ii ◽  
V Band ◽  
The Common

AbstractWe present a Principal Component Analysis (PCA) of the V band light-curves of a sample of more than 100 nearby Core collapse supernovae (CC SNe) from [Anderson et al. (2014)]. We used different reference epochs in order to extract the common properties of these light-curves and searched for correlations to some physical parameters such as the burning of 56Ni, and morphological light-curve parameters such as the length of the plateau, the stretch of the light-curve, and the decrements in brightness after maximum and after the plateau. We also used these similarities to create SNe II light-curve templates that will be used in the future for standardize these objects and determine cosmological distances.

scholarly journals Light-curve properties of SN 2017fgc and HV SNe Ia

2021 ◽  
Vol 502 (3) ◽  
pp. 4112-4124
Author(s):  
Umut Burgaz ◽  
Keiichi Maeda ◽  
Belinda Kalomeni ◽  
Miho Kawabata ◽  
Masayuki Yamanaka ◽  
...  
Keyword(s):  
Light Curve ◽  
Near Infrared ◽  
Light Curves ◽  
Normal Velocity ◽  
External Effects ◽  
Band Maximum ◽  
Bolometric Luminosity ◽  
V Band ◽  
Photometric And Spectroscopic Observations ◽  
Type Ia

ABSTRACT Photometric and spectroscopic observations of Type Ia supernova (SN) 2017fgc, which cover the period from −12 to + 137 d since the B-band maximum are presented. SN 2017fgc is a photometrically normal SN Ia with the luminosity decline rate, Δm15(B)true  = 1.10 ± 0.10 mag. Spectroscopically, it belongs to the high-velocity (HV) SNe Ia group, with the Si ii λ6355 velocity near the B-band maximum estimated to be 15 200 ± 480 km s−1. At the epochs around the near-infrared secondary peak, the R and I bands show an excess of ∼0.2-mag level compared to the light curves of the normal velocity (NV) SNe Ia. Further inspection of the samples of HV and NV SNe Ia indicates that the excess is a generic feature among HV SNe Ia, different from NV SNe Ia. There is also a hint that the excess is seen in the V band, both in SN 2017fgc and other HV SNe Ia, which behaves like a less prominent shoulder in the light curve. The excess is not obvious in the B band (and unknown in the U band), and the colour is consistent with the fiducial SN colour. This might indicate that the excess is attributed to the bolometric luminosity, not in the colour. This excess is less likely caused by external effects, like an echo or change in reddening but could be due to an ionization effect, which reflects an intrinsic, either distinct or continuous, difference in the ejecta properties between HV and NV SNe Ia.

scholarly journals SN 2017ivv: two years of evolution of a transitional Type II supernova

2020 ◽  
Vol 499 (1) ◽  
pp. 974-992
Author(s):  
C P Gutiérrez ◽  
A Pastorello ◽  
A Jerkstrand ◽  
L Galbany ◽  
M Sullivan ◽  
...  
Keyword(s):  
Light Curve ◽  
Main Sequence ◽  
Rapid Decline ◽  
Type Ii ◽  
Additional Energy ◽  
V Band ◽  
Weak Phase ◽  
Faint Galaxy ◽  
Transitional Type ◽  
Fast Rise

ABSTRACT We present the photometric and spectroscopic evolution of the Type II supernova (SN II) SN 2017ivv (also known as ASASSN-17qp). Located in an extremely faint galaxy (Mr = −10.3 mag), SN 2017ivv shows an unprecedented evolution during the 2 yr of observations. At early times, the light curve shows a fast rise (∼6−8 d) to a peak of ${\it M}^{\rm max}_{g}= -17.84$ mag, followed by a very rapid decline of 7.94 ± 0.48 mag per 100 d in the V band. The extensive photometric coverage at late phases shows that the radioactive tail has two slopes, one steeper than that expected from the decay of 56Co (between 100 and 350 d), and another slower (after 450 d), probably produced by an additional energy source. From the bolometric light curve, we estimated that the amount of ejected 56Ni is ∼0.059 ± 0.003 M⊙. The nebular spectra of SN 2017ivv show a remarkable transformation that allows the evolution to be split into three phases: (1) Hα strong phase (<200 d); (2) Hα weak phase (between 200 and 350 d); and (3) Hα broad phase (>500 d). We find that the nebular analysis favours a binary progenitor and an asymmetric explosion. Finally, comparing the nebular spectra of SN 2017ivv to models suggests a progenitor with a zero-age main-sequence mass of 15–17 M⊙.

scholarly journals Expected Changes of SNe with Redshift due to Evolution of Their Progenitors

2005 ◽  
Vol 192 ◽  
pp. 567-572
Author(s):  
Inma Domínguez ◽  
Peter Höflich ◽  
Oscar Straniero ◽  
Marco Limongi ◽  
Alessandro Chieffi
Keyword(s):  
Light Curve ◽  
Main Sequence ◽  
High Redshift ◽  
Stellar Populations ◽  
Light Curves ◽  
Type Ii ◽  
First Stars ◽  
Metal Free ◽  
Standard Candle ◽  
Type Ia

SummaryWe have analyzed the influence of the stellar populations, from which SN progenitors come, on the observational outcome, including the metal free Pop. III. We use our models to study the evolution of the progenitor, the subsequent explosion and the light curves. For Type Ia, the variation of the main sequence mass of the progenitor of the exploding WD produces an offset in the maximum-decline relation of 0.2 mag. This effect is critical for the use of high redshift Type Ia SNe as cosmological standard candles. In contrast, the metallicity does not change the above relation (at maximum, ΔMV ≤0.06 mag). For Type II, we find a dependence of the light curve properties with both main sequence mass and metallicity of the progenitor, and we identify a rather homogeneous subclass, “Extreme II-P,” that may be used as a quasi-standard candle. Note that, although not as good as Type Ia for distance determinations, Type II are expected to have occurred since the first stars were formed.

scholarly journals Influence of macroclumping on type II supernova light curves

2019 ◽  
Vol 629 ◽  
pp. A17
Author(s):  
Luc Dessart ◽  
Edouard Audit
Keyword(s):  
Light Curve ◽  
Early Time ◽  
Radiation Energy ◽  
Mean Free Path ◽  
Light Curves ◽  
Type Ii ◽  
Different Temperatures ◽  
Curve Modeling ◽  
2D And 3D ◽  
The Impact

Core-collapse supernova (SN) ejecta are probably structured on both small and large scales, with greater deviations from spherical symmetry nearer the explosion site. Here, we present 2D and 3D gray radiation hydrodynamics simulations of type II SN light curves from red and blue supergiant star explosions to investigate the impact of inhomogeneities in density or composition on SN observables, with a characteristic scale set to a few percent of the local radius. Clumping is found to hasten the release of stored radiation, boosting the early time luminosity and shortening the photospheric phase. Around the photosphere, radiation leaks between the clumps where the photon mean free path is greater. Since radiation is stored uniformly in volume, a greater clumping can increase this leakage by storing more and more mass into smaller and denser clumps containing less and less radiation energy. An inhomogeneous medium in which different regions recombine at different temperatures can also impact the light curve. Clumping can thus be a source of diversity in SN brightness. Clumping may lead to a systematic underestimate of ejecta masses from light curve modeling, although a significant offset seems to require a large density contrast of a few tens between clumps and interclump medium.

scholarly journals The Type II supernovae 2006V and 2006au: two SN 1987A-like events

2011 ◽  
Vol 7 (S279) ◽  
pp. 403-404
Author(s):  
Francesco Taddia
Keyword(s):  
Light Curve ◽  
Near Infrared ◽  
Light Curves ◽  
Type Ii ◽  
Host Galaxies ◽  
Remarkable Similarity ◽  
Sn 1987A ◽  
Nir Light ◽  
Initial Dip ◽  
Analytic Models

AbstractWe studied optical and near-infrared (NIR) light curves, and optical spectra of Supernovae (SNe) 2006V and 2006au, two objects monitored by the Carnegie Supernova Project (CSP) and displaying remarkable similarity to SN 1987A, although they were brighter, bluer and with higher expansion velocities. SN 2006au also shows an initial dip in the light curve, which we have interpreted as the cooling tail of the shock break-out. By fitting semi-analytic models to the UVOIR light curve of each object, we derive the physical properties of the progenitors and we conclude that SNe 2006V and 2006au were most likely Blue Supergiant (BSG) stars that exploded with larger energies as compared to that of SN 1987A. We are currently investigating the host galaxies of a few BSG SNe, in order to understand the role played by the metallicity in the production of these rare exploding BSG stars.

scholarly journals The Flavours of SN II Light Curves

2011 ◽  
Vol 7 (S279) ◽  
pp. 34-39 ◽  
Author(s):  
Iair Arcavi
Keyword(s):  
Light Curve ◽  
Rare Events ◽  
Light Curves ◽  
Host Galaxy ◽  
Core Collapse ◽  
Type Ii

AbstractWe present R-Band light curves of Type II supernovae (SNe) from the Caltech Core Collapse Program (CCCP). With the exception of interacting (Type IIn) SNe and rare events with long rise times, we find that most light curve shapes belong to one of three distinct classes: plateau, slowly declining and rapidly declining events. The latter class is composed solely of Type IIb SNe which present similar light curve shapes to those of SNe Ib, suggesting, perhaps, similar progenitor channels. We do not find any intermediate light curves, implying that these subclasses are unlikely to reflect variance of continuous parameters, but rather might result from physically distinct progenitor systems, strengthening the suggestion of a binary origin for at least some stripped SNe. We find a large plateau luminosity range for SNe IIP, while the plateau lengths seem rather uniform at approximately 100 days. We present also host galaxy trends from the Palomar Transien Factory (PTF) core collapse SN sample, which augment some of the photometric results.

scholarly journals An investigation of 56Ni shells as the source of early light curve bumps in type Ia supernovae

2020 ◽  
Vol 642 ◽  
pp. A189
Author(s):  
M. R. Magee ◽  
K. Maguire
Keyword(s):  
Light Curve ◽  
Light Curves ◽  
Radioactive Material ◽  
Type Ia Supernovae ◽  
Spectral Evolution ◽  
Strong Suppression ◽  
Shell Models ◽  
Type Ia ◽  
Optical Light Curve ◽  
Ia Supernovae

An excess of flux (i.e. a bump) in the early light curves of type Ia supernovae has been observed in a handful of cases. Multiple scenarios have been proposed to explain this excess flux. Recently, it has been shown that for at least one object (SN 2018oh) the excess emission observed could be the result of a large amount of 56Ni in the outer ejecta (∼0.03 M⊙). We present a series of model light curves and spectra for ejecta profiles containing 56Ni shells of varying masses (0.01, 0.02, 0.03, and 0.04 M⊙) and widths. We find that even for our lowest mass 56Ni shell, an increase of >2 magnitudes is produced in the bolometric light curve at one day after explosion relative to models without a 56Ni shell. We show that the colour evolution of models with a 56Ni shell differs significantly from those without and shows a colour inversion similar to some double-detonation explosion models. Furthermore, spectra of our 56Ni shell models show that strong suppression of flux between ∼3700–4000 Å close to maximum light appears to be a generic feature for this class of model. Comparing our models to observations of SNe 2017cbv and 2018oh, we show that a 56Ni shell of 0.02–0.04 M⊙ can match shapes of the early optical light curve bumps, but the colour and spectral evolution are in disagreement. Our models also predict a strong UV bump that is not observed. This would indicate that an alternative origin for the flux excess is necessary. In addition, based on existing explosion scenarios, producing such a 56Ni shell in the outer ejecta as required to match the light curve shape, without the presence of additional short-lived radioactive material, may prove challenging. Given that only a small amount of 56Ni in the outer ejecta is required to produce a bump in the light curve, such non-monotonically decreasing 56Ni distributions in the outer ejecta must be rare, if they were to occur at all.

scholarly journals The Berkeley sample of Type II supernovae: BVRI light curves and spectroscopy of 55 SNe II

2019 ◽  
Vol 490 (2) ◽  
pp. 2799-2821 ◽  
Author(s):  
T de Jaeger ◽  
W Zheng ◽  
B E Stahl ◽  
A V Filippenko ◽  
T G Brink ◽  
...  
Keyword(s):  
Theoretical Models ◽  
Spectral Lines ◽  
Light Curves ◽  
Expansion Velocity ◽  
Type Ii ◽  
V Band ◽  
Evolution Analysis ◽  
Absolute Magnitudes ◽  
Distance Indicators ◽  
Good Agreement

ABSTRACT In this work, BVRI light curves of 55 Type II supernovae (SNe II) from the Lick Observatory Supernova Search programme obtained with the Katzman Automatic Imaging Telescope and the 1 m Nickel telescope from 2006 to 2018 are presented. Additionally, more than 150 spectra gathered with the 3 m Shane telescope are published. We conduct an analyse of the peak absolute magnitudes, decline rates, and time durations of different phases of the light and colour curves. Typically, our light curves are sampled with a median cadence of 5.5 d for a total of 5093 photometric points. In average, V-band plateau declines with a rate of 1.29 mag (100 d)−1, which is consistent with previously published samples. For each band, the plateau slope correlates with the plateau length and the absolute peak magnitude: SNe II with steeper decline have shorter plateau duration and are brighter. A time-evolution analysis of spectral lines in term of velocities and pseudo-equivalent widths is also presented in this paper. Our spectroscopic sample ranges between 1 and 200 d post-explosion and has a median ejecta expansion velocity at 50 d post-explosion of 6500 km s−1 (H α line) and a standard dispersion of 2000 km s−1. Nebular spectra are in good agreement with theoretical models using a progenitor star having a mass <16M⊙. All the data are available to the community and will help to understand SN II diversity better, and therefore to improve their utility as cosmological distance indicators.

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