scholarly journals The influence of line opacity treatment in stella on supernova light curves

2020 ◽  
Vol 499 (3) ◽  
pp. 4312-4324
Author(s):  
Alexandra Kozyreva ◽  
Luke Shingles ◽  
Alexey Mironov ◽  
Petr Baklanov ◽  
Sergey Blinnikov
Keyword(s):  
Radiative Transfer ◽  
Spectral Synthesis ◽  
Broad Band ◽  
Light Curves ◽  
Radiation Hydrodynamics ◽  
Type Ii ◽  
Type Ia ◽  
The Impact ◽  
Supernovae Type Ia

ABSTRACT We systematically explore the effect of the treatment of line opacity on supernova light curves. We find that it is important to consider line opacity for both scattering and absorption (i.e. thermalization, which mimics the effect of fluorescence). We explore the impact of the degree of thermalization on three major types of supernovae: Type Ia, Type II-peculiar, and Type II-plateau. For this we use the radiative transfer code stella and analyse broad-band light curves in the context of simulations done with the spectral synthesis code artis and in the context of a few examples of observed supernovae of each type. We found that the plausible range for the ratio between absorption and scattering in the radiation hydrodynamics code stella is (0.8–1):(0.2–0), i.e. the recommended thermalization parameter is 0.9.

scholarly journals Detecting the First Supernovae in the Universe with JWST

2011 ◽  
Vol 7 (S279) ◽  
pp. 269-273
Author(s):  
Daniel J. Whalen
Keyword(s):  
Numerical Simulations ◽  
Light Curves ◽  
Radiation Hydrodynamics ◽  
Wide Field ◽  
Type Ii ◽  
James Webb Space Telescope ◽  
Type Ia ◽  
Population Iii Stars ◽  
The Universe ◽  
Infrared Survey

AbstractMassive Population III stars die as pair-instability supernovae (PI SNe), the most energetic thermonuclear explosions in the universe with energies up to 100 times those of Type Ia or Type II SNe. Their extreme luminosities may allow them to be observed from the earliest epochs, revealing the nature of Pop III stars and the primitive galaxies in which they reside. We present numerical simulations of Pop III PI SNe done with the radiation hydrodynamics code RAGE and calculations of their light curves and spectra performed with the SPECTRUM code. We find that 150 - 250 M⊙ PI SNe will be visible to the James Webb Space Telescope (JWST) out to z ~ 30 and to z ~ 15 - 20 in all-sky NIR surveys by the Wide Field Infrared Survey Telescope (WFIRST).

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 Impact of Realistic Red Supergiant Mass Loss on Stellar Evolution

2021 ◽  
Vol 922 (1) ◽  
pp. 55
Author(s):  
Emma R. Beasor ◽  
Ben Davies ◽  
Nathan Smith
Keyword(s):  
Mass Loss ◽  
Stellar Evolution ◽  
Massive Stars ◽  
Light Curves ◽  
Core Collapse ◽  
Strong Impact ◽  
Type Ii ◽  
Evolutionary Models ◽  
Cool Star ◽  
The Impact

Abstract Accurate mass-loss rates are essential for meaningful stellar evolutionary models. For massive single stars with initial masses between 8 and 30M ⊙the implementation of cool supergiant mass loss in stellar models strongly affects the resulting evolution, and the most commonly used prescription for these cool-star phases is that of de Jager. Recently, we published a new M ̇ prescription calibrated to RSGs with initial masses between 10 and 25 M ⊙, which unlike previous prescriptions does not overestimate M ̇ for the most massive stars. Here, we carry out a comparative study to the MESA-MIST models, in which we test the effect of altering mass loss by recomputing the evolution of stars with masses 12–27 M ⊙ with the new M ̇ -prescription implemented. We show that while the evolutionary tracks in the HR diagram of the stars do not change appreciably, the mass of the H-rich envelope at core collapse is drastically increased compared to models using the de Jager prescription. This increased envelope mass would have a strong impact on the Type II-P SN lightcurve, and would not allow stars under 30 M ⊙ to evolve back to the blue and explode as H-poor SN. We also predict that the amount of H-envelope around single stars at explosion should be correlated with initial mass, and we discuss the prospects of using this as a method of determining progenitor masses from supernova light curves.

scholarly journals Hydrodynamic Models of Low-Mass Pulsating Supergiants with Radiative Transfer

1989 ◽  
Vol 111 ◽  
pp. 264-264
Author(s):  
A.B. Foken
Keyword(s):  
Radiative Transfer ◽  
Variable Star ◽  
Stable Limit Cycle ◽  
Light Curves ◽  
Transfer Model ◽  
Stable Limit ◽  
Type Ii ◽  
Hydrodynamic Models ◽  
Stellar Pulsations ◽  
Low Mass

AbstractA method of calculating nonlinear stellar pulsations including nonstationary radiative transfer in a grey spherical atmosphere is described. With the help of this method eleven type II supergiant radiative models were constructed with masses of 0.6M⊙, luminosities ranging from 128L⊙ to 3123L⊙ and periods in the range from 1.123 to 46 days. A stable limit cycle was found to be accessible only by models with an effective temperature between 5700K and 6165K. The model with Te = 6165K is stable, whereas the models cooler than 5700K show nonregular behavior. Transition from strictly periodic to nonregular pulsation arises when M/R ≲ 0.018, due to high amplitudes, δr/r ≈ 1, and strong shocks in the atmosphere. The radiative transfer effects lead to some decay in the radial amplitude, as well as to a more significant decrease, about 0.6 magnitudes, in the light variation. A photometric comparison between the light curves of the models calculated with and without transfer and the observed light curve of the variable star No. 154 in M3 shows that the results predicted by the transfer model are in much better agreement with obervational data.

scholarly journals Light Curve Models for SN 2009dc

2011 ◽  
Vol 7 (S281) ◽  
pp. 314-315
Author(s):  
Yasuomi Kamiya
Keyword(s):  
Light Curve ◽  
White Dwarfs ◽  
Light Curves ◽  
Host Galaxy ◽  
Type Ia Supernovae ◽  
Radiation Hydrodynamics ◽  
One Dimensional ◽  
Type Ia ◽  
Ia Supernovae

AbstractSimplified explosion models of super-Chandrasekhar-mass C-O white dwarfs (WDs) are constructed with parameters such as WD mass and 56Ni mass. Their light curves are obtained by solving one-dimensional equations of radiation hydrodynamics, and compared with the observations of SN 2009dc, one of the overluminous Type Ia supernovae, to estimate its properties. As a result, the progenitor of SN 2009dc is suggested to be a 2.2–2.4-M⊙ C-O WD with 1.2–1.4 M⊙ of 56Ni, if the extinction by its host galaxy is negligible.

scholarly journals Foreground mitigation strategy for measuring the 21 cm-LAE cross-correlation

2017 ◽  
Vol 12 (S333) ◽  
pp. 292-295
Author(s):  
Shintaro Yoshiura ◽  
Jack L. B. Line ◽  
Kenji Kubota ◽  
Kenji Hasegawa ◽  
Keitaro Takahashi
Keyword(s):  
Radiative Transfer ◽  
Power Spectrum ◽  
Cross Correlation ◽  
Radio Galaxies ◽  
Mitigation Strategy ◽  
Radiation Hydrodynamics ◽  
Murchison Widefield Array ◽  
The Impact ◽  
Foreground Removal ◽  
Cross Power Spectrum

AbstractThe cross power spectrum of the 21 cm signal and Lyman-α emitters (LAEs) is a probe of the Epoch of Reionization. Astrophysical foregrounds do not correlate with the LAE distribution, though the foregrounds contribute to the error. To study the impact of foregrounds on the measurement, we assume realistic observation by the Murchison Widefield Array using a catalogue of radio galaxies, a LAE survey by the Subaru Hyper Supreme-Cam and the redshift of LAEs is determined by the Prime Focus Spectrograph. The HI distribution is estimated from a radiative transfer simulation with models based on results of radiation hydrodynamics simulation. Using these models, we found that the error of cross power spectrum is dominated by foreground terms. Furthermore, we estimate the effects of foreground removal, and find 99% of the foreground removal is required to detect the 21 cm-LAE signal at k ∼ 0.4 h Mpc−1.

Decelerating to accelerating scenario for Bianchi type-II string Universe in f(R,T)-gravity theory

2020 ◽  
Vol 17 (07) ◽  
pp. 2050108
Author(s):  
Priyanka Garg ◽  
Anirudh Pradhan ◽  
Rashid Zia ◽  
Mohd. Zeyauddin
Keyword(s):  
Cosmological Model ◽  
Bianchi Type ◽  
Cosmological Parameters ◽  
Momentum Tensor ◽  
Diagnostic Tools ◽  
Type Ii ◽  
Field Equations ◽  
Type Ia ◽  
The Stability ◽  
Supernovae Type Ia

In this paper, we have discussed string cosmological model within the framework of [Formula: see text] theory of gravity in homogeneous but anisotropic Bianchi Type-II space-time. We have considered cosmic string as a source of energy–momentum tensor. We get the solution of the corresponding field equations by assuming deceleration parameter [Formula: see text], which is time-dependent (here, [Formula: see text] and [Formula: see text] are arbitrary constants). This particular form of scale factor enables us to explain the two scenarios, (i) By using recent constraints ([Formula: see text], [Formula: see text]) from supernovae type Ia union data (Cunha, Kinematic constraints to the transition redshift from supernovae type Ia union data, Phys. Rev. D 79 (2009) 047301), we find the values of arbitrary constants [Formula: see text] and [Formula: see text] for which we have derived a cosmological model showing accelerating expansion universe ([Formula: see text]) only throughout the evolution and (ii) By using the recent constraints ([Formula: see text], and [Formula: see text]) from SNIa data in combination with BAO and CMB observations (Giostri et al. From cosmic deceleration to acceleration: new constraints from SN Ia and BAO/CMB, J. Cosmol. Astrophys. 3 (2012) 27), we find the values of arbitrary constants for which we have derived a cosmological model with phase transition from early decelerating ([Formula: see text]) to the present accelerating ([Formula: see text]) universe. Also, for the model, we have evaluated and discussed the various physical and kinematic parameters. We have also shown the variation of these cosmological parameters graphically for specific values of the constants. The stability and physical viability are also discussed for the derived models using some recently developed diagnostic tools.

scholarly journals The Environments of Type Ib/c Supernovae

1996 ◽  
Vol 165 ◽  
pp. 135-140
Author(s):  
S. D. Van Dyk ◽  
A. J. Barth ◽  
A. V. Filippenko
Keyword(s):  
Radio Emission ◽  
Spectral Feature ◽  
Optical Spectra ◽  
Light Curves ◽  
Infrared Light ◽  
Classical Type ◽  
Type I ◽  
Type Ii ◽  
Entire Class ◽  
Type Ia

Up to about 1985, supernovae (SNe) generally were placed into the two Minkowski classes, type I and type II, defined by the absence or presence, respectively, of hydrogen in their optical spectra. Around that time it was acknowledged that several type I SNe were systematically peculiar, both spectroscopically and photometrically (Elias et al. 1985; Wheeler & Levreault 1985; Uomoto & Kirshner 1985; Branch 1986; Filippenko 1986), by missing the characteristic Si II spectral feature near 6150 å, having distinct infrared light curves, being optically redder and subluminous, and showing radio emission (Sramek et al. 1984). These SNe were designated as type Ib (Elias et al. 1985; Branch 1986) to distinguish them from the classical type Ia. Harkness et al. (1987) identified He I lines in spectra of the SN Ib 1984L, but some subsequent examples showed no He in their spectra and were further subclassified as Type Ic (Wheeler & Harkness 1990). The two subtypes, however, are nearly indistinguishable at late times. In this Symposium the entire class has been referred to as type Ib/c SNe. A recent bright example is SN 1994I in M51 (Filippenko et al. 1994).

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