Type I supernovae. I - Analytic solutions for the early part of the light curve

1982 ◽  
Vol 253 ◽  
pp. 785 ◽  
Author(s):  
W. D. Arnett
Keyword(s):  
Light Curve ◽  
Analytic Solutions ◽  
Type I

Optical Light Curve of the Type I[CLC]a[/CLC] Supernova 1998[CLC]bu[/CLC] in M96 and the Supernova Calibration of the Hubble Constant

1999 ◽  
Vol 117 (3) ◽  
pp. 1175-1184 ◽  
Author(s):  
Nicholas B. Suntzeff ◽  
M. M. Phillips ◽  
R. Covarrubias ◽  
M. Navarrete ◽  
J. J. Pérez ◽  
...  
Keyword(s):  
Light Curve ◽  
Hubble Constant ◽  
Type I ◽  
Optical Light Curve

scholarly journals Urca nuclide production in Type-I X-ray bursts and implications for nuclear physics studies

2020 ◽  
Vol 500 (3) ◽  
pp. 2958-2968
Author(s):  
Grant Merz ◽  
Zach Meisel
Keyword(s):  
Light Curve ◽  
Nuclear Reaction ◽  
Nuclear Physics ◽  
Thermal Structure ◽  
Reaction Rates ◽  
High Mass ◽  
Type I ◽  
Model Calculations ◽  
X Ray ◽  
Lower Temperature

ABSTRACT The thermal structure of accreting neutron stars is affected by the presence of urca nuclei in the neutron star crust. Nuclear isobars harbouring urca nuclides can be produced in the ashes of Type I X-ray bursts, but the details of their production have not yet been explored. Using the code MESA, we investigate urca nuclide production in a one-dimensional model of Type I X-ray bursts using astrophysical conditions thought to resemble the source GS 1826-24. We find that high-mass (A ≥ 55) urca nuclei are primarily produced late in the X-ray burst, during hydrogen-burning freeze-out that corresponds to the tail of the burst light curve. The ∼0.4–0.6 GK temperature relevant for the nucleosynthesis of these urca nuclides is much lower than the ∼1 GK temperature most relevant for X-ray burst light curve impacts by nuclear reaction rates involving high-mass nuclides. The latter temperature is often assumed for nuclear physics studies. Therefore, our findings alter the excitation energy range of interest in compound nuclei for nuclear physics studies of urca nuclide production. We demonstrate that for some cases this will need to be considered in planning for nuclear physics experiments. Additionally, we show that the lower temperature range for urca nuclide production explains why variations of some nuclear reaction rates in model calculations impacts the burst light curve but not local features of the burst ashes.

scholarly journals The light curve of type I Supernovae

1980 ◽  
Author(s):  
S. A. Colgate ◽  
Albert G. Petschek ◽  
John T. Kriese
Keyword(s):  
Light Curve ◽  
Type I

Dynamics of anisotropic cosmic models with different matter sources in extended scalar-tensor theory

2019 ◽  
Vol 16 (12) ◽  
pp. 1950190
Author(s):  
Saira Waheed
Keyword(s):  
Scalar Potential ◽  
String Tension ◽  
Analytic Solutions ◽  
Particle Energy ◽  
Model Parameters ◽  
Physical Analysis ◽  
Type I ◽  
Scalar Tensor Theory ◽  
Ricci Dark Energy ◽  
Tensor Theory

In this work, we develop some interesting models of cosmos exhibiting anisotropic properties in the extended scalar-tensor theory. In the first place, we consider the LRS Bianchi type I (BI) geometry filled with matter contents as magnetized bulk viscous cloud of strings. We developed analytic solutions and explore the cosmological significance of some interesting physical measures like cosmic volume, directional Hubble parameter, deceleration parameter, viscosity factor, particle energy density, shear and expansion scalars, and string tension density. Moreover, modified holographic Ricci dark energy is introduced in anisotropic scenario to discuss the dynamics of anisotropic comic models. In order to construct the exact cosmic solutions, we take hybrid law of scale factor as well as some viable ansatz for scalar field and its scalar potential. The physical viability of model parameters is discussed through graphical analysis. Physical analysis of both models show that our results are in agreement with the current observations and hence are cosmologically viable and promising.

Probing the anisotropy effects on the CPL parametrizations from light-curve SNIa, BAO and OHD datasets

2019 ◽  
Vol 16 (11) ◽  
pp. 1950177 ◽  
Author(s):  
H. Hossienkhani ◽  
N. Azimi ◽  
Z. Zarei
Keyword(s):  
Light Curve ◽  
Observational Data ◽  
Cosmological Parameters ◽  
Estimation Method ◽  
Likelihood Estimation ◽  
Anisotropic Universe ◽  
Type I ◽  
Acoustic Oscillations ◽  
Type Ia ◽  
Best Fit

Recent observers have shown that an anisotropy cosmic expansion may exist. In this work, we study the effects of low anisotropy with Bianchi type I model using the current observational data, which includes the supernova Legacy Survey (SNLS) sample of 238 SN events ([Formula: see text]) and 1048 Pantheon sample confirmed type Ia supernova (SNIa) covering the redshift range [Formula: see text]. Assuming an anisotropic universe, we use the two parametrizations of the dark energy equation-of-state, such as the [Formula: see text] (PA) and [Formula: see text] (PB), and then we fit the SNIa light-curve parameters and free cosmological parameters, simultaneously employing maximum likelihood estimation method. When combining the Baryon Acoustic Oscillations (BAO) and the observational Hubble data (OHD) measurements with the SNLS SN sample, we find [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] for the PA model and [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] for the PB model. When combining also Pantheon data, we obtain [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] for the PA model and [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] for the PB model. The analysis shows that by considering the anisotropy effects, it leads to more best-fit parameters in [Formula: see text]CDM model with the current observational data.

scholarly journals THE BIANCHI TYPE I MODEL WITH TWO INTERACTING SCALAR FIELDS

2007 ◽  
Vol 16 (11) ◽  
pp. 1845-1852 ◽  
Author(s):  
VLADIMIR FOLOMEEV
Keyword(s):  
Potential Energy ◽  
Early Universe ◽  
Special Form ◽  
Bianchi Type ◽  
Scalar Fields ◽  
Analytic Solutions ◽  
Type I ◽  
Anisotropic Model ◽  
Friedmann Model ◽  
Matter Fields

The flat anisotropic model of the early Universe is considered. Two interacting scalar fields with a special form of potential energy are a source of matter fields. Analytic solutions for stages of inflation and preheating are found. It is shown that the solutions tend asymptotically to an isotropic Friedmann model.

scholarly journals A New Binary Star System of EW Type in Draco: GSC 03905-01870

2018 ◽  
Author(s):  
Salvador Barquin
Keyword(s):  
Light Curve ◽  
Binary Stars ◽  
Variable Star ◽  
Binary Star ◽  
Type I ◽  
Star System ◽  
Primary Minimum ◽  
Eclipsing Binary ◽  
Eclipsing Binary Stars ◽  
Binary Star System

Discovery of a new binary star system (GSC 03905-01870 = USNO-B1.0 1431-0327922 = UCAC4 716-059522) in the Draco constellation is presented. It was discovered during a search for previously unreported eclipsing binary stars through the ASAS-SN database. The shape of the light curve and its characteristics (period of 0.428988±0.000001 d, amplitude of 0.34±0.02 V Mag, primary minimum epoch HJD 2457994.2756±0.0002) indicates that the new variable star is an eclipsing binary of W Ursae Majoris type. I registered this variable star in The International Variable Star Index (VSX), its AAVSO UID is 000-BMP-891.

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