scholarly journals Exploring the diversity of double-detonation explosions for Type Ia supernovae: effects of the post-explosion helium shell composition

2021 ◽  
Vol 502 (3) ◽  
pp. 3533-3553
Author(s):  
M R Magee ◽  
K Maguire ◽  
R Kotak ◽  
S A Sim
Keyword(s):  
Light Curve ◽  
Type Ia Supernovae ◽  
Iron Group ◽  
Maximum Light ◽  
Wide Range ◽  
Type Ia ◽  
Explosion Mechanism ◽  
Ia Supernovae ◽  
Almost All ◽  
Good Agreement

ABSTRACT The detonation of a helium shell on top of a carbon–oxygen white dwarf has been argued as a potential explosion mechanism for Type Ia supernovae (SNe Ia). The ash produced during helium shell burning can lead to light curves and spectra that are inconsistent with normal SNe Ia, but may be viable for some objects showing a light-curve bump within the days following explosion. We present a series of radiative transfer models designed to mimic predictions from double-detonation explosion models. We consider a range of core and shell masses, and systematically explore multiple post-explosion compositions for the helium shell. We find that a variety of luminosities and time-scales for early light-curve bumps result from those models with shells containing 56Ni, 52Fe, or 48Cr. Comparing our models to SNe Ia with light-curve bumps, we find that these models can reproduce the shapes of almost all of the bumps observed, but only those objects with red colours around maximum light (B − V ≳ 1) are well matched throughout their evolution. Consistent with previous works, we also show that those models in which the shell does not contain iron-group elements provide good agreement with normal SNe Ia of different luminosities from shortly after explosion up to maximum light. While our models do not amount to positive evidence in favour of the double-detonation scenario, we show that provided the helium shell ash does not contain iron-group elements, it may be viable for a wide range of normal SNe Ia.

scholarly journals Determining the 56Ni distribution of type Ia supernovae from observations within days of explosion

2020 ◽  
Vol 634 ◽  
pp. A37 ◽  
Author(s):  
M. R. Magee ◽  
K. Maguire ◽  
R. Kotak ◽  
S. A. Sim ◽  
J. H. Gillanders ◽  
...  
Keyword(s):  
Light Curve ◽  
Current Model ◽  
Light Curves ◽  
Radioactive Isotopes ◽  
Type Ia Supernovae ◽  
Maximum Light ◽  
Thermonuclear Supernovae ◽  
Type Ia ◽  
Model Set ◽  
Ia Supernovae

Recent studies have shown how the distribution of 56Ni within the ejected material of type Ia supernovae can have profound consequences on the observed light curves. Observations at early times can therefore provide important details on the explosion physics in thermonuclear supernovae, which are poorly constrained. To this end, we present a series of radiative transfer calculations that explore variations in the 56Ni distribution. Our models also show the importance of the density profile in shaping the light curve, which is often neglected in the literature. Using our model set, we investigate the observations that are necessary to determine the 56Ni distribution as robustly as possible within the current model set. We find that this includes observations beginning at least ∼14 days before B-band maximum, extending to approximately maximum light with a relatively high (≲3 day) cadence, and in at least one blue and one red band (such as B and R, or g and r) are required. We compare a number of well-observed type Ia supernovae that meet these criteria to our models and find that the light curves of ∼70–80% of objects in our sample are consistent with being produced solely by variations in the 56Ni distributions. The remaining supernovae show an excess of flux at early times, indicating missing physics that is not accounted for within our model set, such as an interaction or the presence of short-lived radioactive isotopes. Comparing our model light curves and spectra to observations and delayed detonation models demonstrates that while a somewhat extended 56Ni distribution is necessary to reproduce the observed light curve shape, this does not negatively affect the spectra at maximum light. Investigating current explosion models shows that observations typically require a shallower decrease in the 56Ni mass towards the outer ejecta than is produced for models of a given 56Ni mass. Future models that test differences in the explosion physics and detonation criteria should be explored to determine the conditions necessary to reproduce the 56Ni distributions found here.

scholarly journals A rate study of Type Ia supernovae with Subaru/XMM-Newton Deep Survey

2009 ◽  
Vol 5 (S262) ◽  
pp. 358-361
Author(s):  
Yutaka Ihara ◽  
Mamoru Doi ◽  
Tomoki Morokuma ◽  
Raynald Pain ◽  
Naohiro Takanashi ◽  
...  
Keyword(s):  
Star Formation ◽  
Light Curve ◽  
Delay Time ◽  
Detection Efficiency ◽  
Light Curves ◽  
Star Formation History ◽  
Type Ia Supernovae ◽  
Wide Range ◽  
Type Ia ◽  
Ia Supernovae

AbstractWe present a measurement of the rate of high-z Type Ia supernovae (SNe Ia) using multi-epoch observations of Subaru/XMM-Newton Deep Field (SXDF) with Suprime-Cam on the Subaru Telescope. Although SNe Ia are regarded as a standard candle, progenitor systems of SNe Ia have not been resolved yet. One of the key parameters to show the progenitor systems by observations is the delay time distribution between the binary system formation and subsequent SN explosion. Recently, a wide range of delay time is studied by SN Ia rates compared with an assumed cosmic star formation history. If SNe Ia with short delay time are dominant, the cosmic SN Ia rate evolution should closely trace that of the cosmic star formation. In order to detect a lot of high-z SNe Ia and measure SN Ia rates, we repeatedly carried out wide and deep imaging observations in the í-band with Suprime-Cam in 2002 (FoV~1 deg2, mi < 25.5 mag). We obtained detailed light curves of the variable objects, and 50 objects are classified as SNe Ia using the light curve fitting method at the redshift range of 0.2 < z < 1.3. In order to check the completeness and contamination of the light curve classification method, we performed Monte Carlo simulations and generated ~100,000 light curves of SNe Ia and II from templates. The control time and detection efficiency of the SN survey are also calculated using the artificial light curves. We derived an increasing trend of rates at around z ~ 1.2. Our results are almost consistent with other SN Ia rate results from low-z to high-z. Our results are the first results of high-z SN Ia rates with large statistics using light curves obtained by ground based telescopes, and give us visions of the SN rate studies for the future.

scholarly journals Constraints on the density distribution of type Ia supernovae ejecta inferred from late-time light-curve flattening

2020 ◽  
Vol 493 (4) ◽  
pp. 5617-5624
Author(s):  
Doron Kushnir ◽  
Eli Waxman
Keyword(s):  
Light Curve ◽  
Weighted Average ◽  
Far Infrared ◽  
Average Density ◽  
Light Curves ◽  
Type Ia Supernovae ◽  
Late Time ◽  
Simple Method ◽  
Type Ia ◽  
Ia Supernovae

ABSTRACT The finite time, τdep, over which positrons from β+ decays of 56Co deposit energy in type Ia supernovae ejecta lead, in case the positrons are trapped, to a slower decay of the bolometric luminosity compared to an exponential decline. Significant light-curve flattening is obtained when the ejecta density drops below the value for which τdep equals the 56Co lifetime. We provide a simple method to accurately describe this ‘delayed deposition’ effect, which is straightforward to use for analysis of observed light curves. We find that the ejecta heating is dominated by delayed deposition typically from 600 to 1200 d, and only later by longer lived isotopes 57Co and 55Fe decay (assuming solar abundance). For the relatively narrow 56Ni velocity distributions of commonly studied explosion models, the modification of the light curve depends mainly on the 56Ni mass-weighted average density, 〈ρ〉t3. Accurate late-time bolometric light curves, which may be obtained with JWST far-infrared (far-IR) measurements, will thus enable to discriminate between explosion models by determining 〈ρ〉t3 (and the 57Co and 55Fe abundances). The flattening of light curves inferred from recent observations, which is uncertain due to the lack of far-IR data, is readily explained by delayed deposition in models with $\langle \rho \rangle t^{3} \approx 0.2\, \mathrm{M}_{\odot }\, (10^{4}\, \textrm{km}\, \textrm{s}^{-1})^{-3}$, and does not imply supersolar 57Co and 55Fe abundances.

scholarly journals Observations of Type Ia Supernovae and Challenges for Cosmology

2005 ◽  
Vol 192 ◽  
pp. 525-533
Author(s):  
Weidong Li ◽  
Alexei V. Filippenko
Keyword(s):  
Dark Energy ◽  
Light Curve ◽  
Rise Time ◽  
Accelerating Universe ◽  
Type Ia Supernovae ◽  
Hubble Diagram ◽  
High Quality ◽  
Type Ia ◽  
Secondary Parameter ◽  
Ia Supernovae

SummaryObservations of Type Ia supernovae (SNe Ia) reveal correlations between their luminosities and light-curve shapes, and between their spectral sequence and photometric sequence. Assuming SNe Ia do not evolve at different redshifts, the Hubble diagram of SNe Ia may indicate an accelerating Universe, the signature of a cosmological constant or other forms of dark energy. Several studies raise concerns about the evolution of SNe Ia (e.g., the peculiarity rate, the rise time, and the color of SNe Ia at different redshifts), but all these studies suffer from the difficulties of obtaining high-quality spectroscopy and photometry for SNe Ia at high redshifts. There are also some troubling cases of SNe Ia that provide counter examples to the observed correlations, suggesting that a secondary parameter is necessary to describe the whole SN Ia family. Understanding SNe Ia both observationally and theoretically will be the key to boosting confidence in the SN Ia cosmological results.

scholarly journals A Common Explosion Mechanism for Type Ia Supernovae

Science ◽  
2007 ◽  
Vol 315 (5813) ◽  
pp. 825-828 ◽  
Author(s):  
P. A. Mazzali ◽  
F. K. Ropke ◽  
S. Benetti ◽  
W. Hillebrandt
Keyword(s):  
Type Ia Supernovae ◽  
Type Ia ◽  
Explosion Mechanism ◽  
Ia Supernovae

scholarly journals A closer look at non-interacting He stars as a channel for producing the old population of type Ia supernovae

2020 ◽  
Vol 641 ◽  
pp. A20
Author(s):  
Zhengwei Liu ◽  
Richard J. Stancliffe
Keyword(s):  
Binary Systems ◽  
Type Ia Supernovae ◽  
Population Synthesis ◽  
Thermonuclear Explosion ◽  
Delay Times ◽  
Type Ia ◽  
Binary Evolution ◽  
Chandrasekhar Limit ◽  
Ia Supernovae ◽  
Almost All

The nature of the progenitors of type Ia supernovae (SNe Ia) remains a mystery. Binary systems consisting of a white dwarf (WD) and a main-sequence (MS) donor are potential progenitors of SNe Ia, in which a thermonuclear explosion of the WD may occur when its mass reaches the Chandrasekhar limit during accretion of material from a companion star. In the present work, we address theoretical rates and delay times of a specific MS donor channel to SNe Ia, in which a helium (He) star + MS binary produced from a common envelope event subsequently forms a WD + MS system without the He star undergoing mass transfer by Roche lobe overflow. By combining the results of self-consistent binary evolution calculations with population synthesis models, we find that the contribution of SNe Ia in this channel is around 2.0 × 10−4 yr−1. In addition, we find that delay times of SNe Ia in this channel cover a range of about 1.0–2.6 Gyr, and almost all SNe Ia produced in this way (about 97%) have a delay time of ≳1 Gyr. While the rate of SN Ia in this work is about 10% of the overall SN Ia rate, the channel represents a possible contribution to the old population (1–3 Gyr) of observed SNe Ia.

scholarly journals The dependence of Type Ia Supernovae salt2 light-curve parameters on host galaxy morphology

2020 ◽  
Vol 499 (4) ◽  
pp. 5121-5135
Author(s):  
M V Pruzhinskaya ◽  
A K Novinskaya ◽  
N Pauna ◽  
P Rosnet
Keyword(s):  
Light Curve ◽  
Host Galaxy ◽  
Type Ia Supernovae ◽  
Distance Modulus ◽  
Early Type ◽  
Late Type ◽  
Hubble Diagram ◽  
Type Ia ◽  
Ia Supernovae ◽  
Galaxy Morphology

ABSTRACT Type Ia Supernovae (SNe Ia) are widely used to measure distances in the Universe. Despite the recent progress achieved in SN Ia standardization, the Hubble diagram still shows some remaining intrinsic dispersion. The remaining scatter in supernova luminosity could be due to the environmental effects that are accounted for as mass step correction in the current cosmological analyses. In this work, we compare the local and global colour (U − V), the local star formation rate, and the host stellar mass to the host galaxy morphology. The observed trends suggest that the host galaxy morphology is a relevant parameter to characterize the SN Ia environment. Therefore, we study the influence of host galaxy morphology on light-curve parameters of SNe Ia from the pantheon cosmological supernova sample. We determine the Hubble morphological type of host galaxies for a subsample of 330 SNe Ia. We confirm that the salt2 stretch parameter x1 depends on the host morphology with the p-value ∼10−14. The supernovae with lower stretch value are hosted mainly by elliptical and lenticular galaxies. No correlation for the salt2 colour parameter c is found. We also examine Hubble diagram residuals for supernovae hosted by ‘early-type’ and ‘late-type’ morphological groups of galaxies. The analysis reveals that the mean distance modulus residual in early-type galaxies is smaller than the one in late-type galaxies, which means that early-type galaxies contain brighter supernovae after stretch and colour corrections. However, we do not observe any difference in the residual dispersion for these two morphological groups. The obtained results are in the line with other analyses showing environmental dependence of SN Ia light-curve parameters and luminosity. We confirm the importance of including a host galaxy parameter into the standardization procedure of SNe Ia for further cosmological studies.

scholarly journals Testing the isotropy of the Universe with Type Ia supernovae in a model-independent way

2017 ◽  
Vol 474 (3) ◽  
pp. 3516-3522 ◽  
Author(s):  
Yu-Yang Wang ◽  
F Y Wang
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Light Curve ◽  
Type Ia Supernovae ◽  
Anisotropic Universe ◽  
Preferred Direction ◽  
Type Ia ◽  
Model Independent ◽  
Ia Supernovae ◽  
The Universe

Abstract In this paper, we study an anisotropic universe model with Bianchi-I metric using Joint light-curve analysis (JLA) sample of Type Ia supernovae (SNe Ia). Because light-curve parameters of SNe Ia vary with different cosmological models and SNe Ia samples, we fit the SNe Ia light-curve parameters and cosmological parameters simultaneously employing Markov chain Monte Carlo method. Therefore, the results on the amount of deviation from isotropy of the dark energy equation of state (δ), and the level of anisotropy of the large-scale geometry (Σ0) at present, are totally model-independent. The constraints on the skewness and cosmic shear are −0.101 &lt; δ &lt; 0.071 and −0.007 &lt; Σ0 &lt; 0.008. This result is consistent with a standard isotropic universe (δ = Σ0 = 0). However, a moderate level of anisotropy in the geometry of the Universe and the equation of state of dark energy, is allowed. Besides, there is no obvious evidence for a preferred direction of anisotropic axis in this model.

How Similar are Type Ia Supernovae?

1994 ◽  
Vol 11 (1) ◽  
pp. 65-67 ◽  
Author(s):  
Raylee A. Stathakis ◽  
Elaine M. Sadler
Keyword(s):  
Wavelength Region ◽  
Spectral Lines ◽  
Type Ia Supernovae ◽  
Expansion Velocity ◽  
Evolutionary Trend ◽  
Maximum Light ◽  
Galaxy Type ◽  
Type Ia ◽  
Ia Supernovae ◽  
Parent Galaxy

AbstractWe have compared the spectra of six Type Ia supernovae, at ages between 4 and 404 days after maximum light, to see whether all show similar evolutionary behaviour. We find that the spectral lines between 6800 Å and 8000 Å follow a smooth evolutionary trend, but that lines redward of 8000 Å show significant differences. SN 1987I and SN 19880 show extra emission over a broader wavelength region, possibly due to OI 8446 Å emission which would indicate higher envelope densities for these objects. Our results are consistent with the trend of expansion velocity with parent galaxy type reported by Branch and van den Bergh (1993). Variations within the class of Ia SNe may affect their use as standard candles.

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