scholarly journals STUDY OF ENERGETIC TRANSIENTS USING TOOLS LIKE MESA & SNEC, MOSFIT AND SNCOSMO

2021 ◽  
Vol 53 ◽  
pp. 215-224
Author(s):  
A. Aryan ◽  
S. B. Pandey ◽  
A. Kumar ◽  
R. Gupta ◽  
A. J. Castro-Tirado ◽  
...  
Keyword(s):  
Light Curve ◽  
Main Sequence ◽  
Red Shift ◽  
Physical Parameters ◽  
Core Collapse ◽  
Bolometric Luminosity ◽  
Stretch Factor ◽  
Analysis Tools ◽  
Template Fitting

We explore the study of energetic transients including core-collapse supernovae using various publicly available analysis tools like MESA & SNEC, MOSFiT and SNCOSMO. We used MESA to evolve a star having zero age main sequence mass (Mzams) of 24 M⊙ until the onset of core-collapse. Then we exploded this model using openly available explosion codes, STELLA & SNEC and obatined various observable parameters such as bolometric luminosity and photospheric velocities etc. We also used MOSFiT to model the light curve of a type Ic supernova, SN1999ex and obtained various physical parameters. SNCOSMO is used for template fitting of various supernovae by varying various parameters such as red shift, dust map, stretch factor of light curve, explosion epoch of supernova etc.

scholarly journals Progenitor for Type Ic Supernova 2007bi

2011 ◽  
Vol 7 (S279) ◽  
pp. 427-428
Author(s):  
Takashi Yoshida ◽  
Hideyuki Umeda
Keyword(s):  
Light Curve ◽  
Mass Loss ◽  
Loss Rate ◽  
Main Sequence ◽  
Massive Stars ◽  
Mass Loss Rate ◽  
Mass Range ◽  
Stellar Mass ◽  
Core Collapse ◽  
Core Collapse Supernova

AbstractWe investigate the evolution of very massive stars with Z = 0.2 Z⊙ to constrain the progenitor of the extremely luminous Type Ic SN 2007bi. In order to reproduce the 56Ni amount produced in SN 2007bi, the range of the stellar mass at the zero-age main-sequence is expected to be 515 - 575M⊙ for pair-instability supernova and 110 - 280M⊙ for core-collapse supernova. Uncertainty in the mass loss rate affects the mass range appropriate for the explosion of SN 2007bi. A core-collapse supernova of a WO star evolved from a 110 M⊙ star produces sufficient radioactive 56Ni to reproduce the light curve of SN 2007bi.

scholarly journals Signatures of circumstellar interaction in the unusual transient AT 2018cow

2019 ◽  
Vol 488 (3) ◽  
pp. 3772-3782 ◽  
Author(s):  
Ori D Fox ◽  
Nathan Smith
Keyword(s):  
Light Curve ◽  
Spectroscopic Properties ◽  
Core Collapse ◽  
Blue Colour ◽  
X Ray ◽  
Bolometric Luminosity ◽  
Balmer Lines ◽  
H Ii Region ◽  
Fast Light

ABSTRACT AT 2018cow is a unique transient that stands out due to its relatively fast light curve, high peak bolometric luminosity, and blue colour. These properties distinguish it from typical radioactively powered core-collapse supernovae (SNe). Instead, the characteristics are more similar to a growing sample of Fast Blue Optical Transients (FBOTs). Mostly discovered at hundreds of Mpc, FBOT follow-up is usually limited to several photometry points and low signal-to-noise spectra. At only ∼60 Mpc, AT 2018cow offers an opportunity for detailed follow-up. Studies of this object published to date propose a number of interpretations for AT 2018cow, but none of these specifically consider the interacting Type Ibn SN subclass. We point out that while narrow lines do not dominate the spectrum of AT 2018cow, as narrow Balmer lines typically do in SNe IIn, the narrow lines in AT 2018cow may nevertheless include emission from pre-shock CSM. In particular, the He i lines in AT 2018cow are broader than H ii region lines in the same spectrum, and they closely resemble He i lines in some examples of SNe Ibn or transitional SNe Ibn/IIn objects. We compare AT 2018cow to interacting SNe Ibn and IIn and find a number of noteworthy similarities, including light-curve rise and fall times, peak magnitude, X-ray light curves, and spectroscopic properties. We therefore explore the hypothesis that CSM interaction in a relatively H-poor system might help explain some observed properties of AT 2018cow, and we go on to consider progenitor implications for AT 2018cow, FBOTs, and SNe Ibn.

scholarly journals PTF11rka: an interacting supernova at the crossroads of stripped-envelope and H-poor superluminous stellar core collapses

2020 ◽  
Vol 497 (3) ◽  
pp. 3542-3556
Author(s):  
E Pian ◽  
P A Mazzali ◽  
T J Moriya ◽  
A Rubin ◽  
A Gal-Yam ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Light Curve ◽  
Lower Energy ◽  
Rest Frame ◽  
Main Sequence ◽  
Gamma Ray ◽  
Core Collapse ◽  
Curve Shape ◽  
Maximum Brightness ◽  
The Core

ABSTRACT The hydrogen-poor supernova (SN) PTF11rka (z = 0.0744), reported by the Palomar Transient Factory, was observed with various telescopes starting a few days after the estimated explosion time of 2011 December 5 UT and up to 432 rest-frame days thereafter. The rising part of the light curve was monitored only in the RPTF filter band, and maximum in this band was reached ∼30 rest-frame days after the estimated explosion time. The light curve and spectra of PTF11rka are consistent with the core-collapse explosion of a ∼10 M⊙ carbon–oxygen core evolved from a progenitor of main-sequence mass 25–40 M⊙, that liberated a kinetic energy Ek≈4 × 1051 erg, expelled ∼8 M⊙ of ejecta, and synthesized ∼0.5 M⊙ of 56Ni. The photospheric spectra of PTF11rka are characterized by narrow absorption lines that point to suppression of the highest ejecta velocities (≳ 15 000 km s−1). This would be expected if the ejecta impacted a dense, clumpy circumstellar medium. This in turn caused them to lose a fraction of their energy (∼5 × 1050 erg), less than 2 per cent of which was converted into radiation that sustained the light curve before maximum brightness. This is reminiscent of the superluminous SN 2007bi, the light-curve shape and spectra of which are very similar to those of PTF11rka, although the latter is a factor of 10 less luminous and evolves faster in time. PTF11rka is in fact more similar to gamma-ray burst SNe in luminosity, although it has a lower energy and a lower Ek/Mej ratio.

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.

SN2017ein: bolometric light curve and physical parameters

2017 ◽  
Vol 4 (1) ◽  
pp. 15-19
Author(s):  
P.S. Tadjimuratov ◽  
◽  
D. Mirzakulov ◽  
Keyword(s):  
Light Curve ◽  
Physical Parameters

scholarly journals An extensive photometric study of the Blazhko RR Lyrae star RZ Lyr*

2012 ◽  
Vol 423 (2) ◽  
pp. 993-1005 ◽  
Author(s):  
J. Jurcsik ◽  
Á. Sódor ◽  
G. Hajdu ◽  
B. Szeidl ◽  
Á. Dózsa ◽  
...  
Keyword(s):  
Light Curve ◽  
Light Curves ◽  
Stellar Structure ◽  
Time Base ◽  
Photometric Method ◽  
Physical Parameters ◽  
Component Solution ◽  
Rr Lyrae ◽  
Curve Variation ◽  
Type Variable

Abstract The analysis of recent, extended multicolour CCD and archive photoelectric, photographic and visual observations has revealed several important properties of RZ Lyr, an RRab-type variable exhibiting large-amplitude Blazhko modulation. On the time base of ∼110 yr, a strict anticorrelation between the pulsation- and modulation-period changes is established. The light curve of RZ Lyr shows a remarkable bump on the descending branch in the small-amplitude phase of the modulation, similarly to the light curves of bump Cepheids. We speculate that the stellar structure temporally suits a 4:1 resonance between the periods of the fundamental and one of the higher order radial modes in this modulation phase. The light-curve variation of RZ Lyr can be correctly fitted with a two-modulation-component solution; the 121-d period of the main modulation is nearly but not exactly four times longer than the period of the secondary modulation component. Using the inverse photometric method, the variations in the pulsation-averaged values of the physical parameters in different phases of both modulation components are determined.

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 New Data on the Eclipsing Binary V1848 Ori and Improved Orbital and Light Curve Solutions

2020 ◽  
Vol 29 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Fatemeh Davoudi ◽  
Atila Poro ◽  
Fahri Alicavus ◽  
Afshin Halavati ◽  
Saeed Doostmohammadi ◽  
...  
Keyword(s):  
Binary System ◽  
Light Curve ◽  
Mass Function ◽  
Light Curves ◽  
Complete Analysis ◽  
Physical Parameters ◽  
Mass Ratio ◽  
Third Body ◽  
Eclipsing Binary

AbstractNew observations of the eclipsing binary system V1848 Ori were carried out using the V filter resulting in a determination of new times of minima and new ephemeris were obtained. We presented the first complete analysis of the system’s orbital period behavior and analysis of O-C diagram done by the GA and MCMC approaches in OCFit code. The O-C diagram demonstrates a sinusoidal trend in the data; this trend suggests a cyclic change caused by the LITE effect with a period of 10.57 years and an amplitude of 7.182 minutes. It appears that there is a third body with mass function of f (m3) = 0.0058 M⊙ in this binary system. The light curves were analyzed using the Wilson-Devinney code to determine some geometrical and physical parameters of the system. These results show that V1848 Ori is a contact W UMa binary system with the mass ratio of q = 0.76 and a weak fillout factor of 5.8%. The O’Connell effect was not seen in the light curve and there is no need to add spot.

scholarly journals Variability of young stellar objects in the star-forming region Pelican Nebula

2019 ◽  
Vol 627 ◽  
pp. A135 ◽  
Author(s):  
A. Bhardwaj ◽  
N. Panwar ◽  
G. J. Herczeg ◽  
W. P. Chen ◽  
H. P. Singh
Keyword(s):  
Main Sequence ◽  
T Tauri Stars ◽  
Young Stellar Objects ◽  
Spectral Energy ◽  
Physical Parameters ◽  
Main Sequence Stars ◽  
Stellar Objects ◽  
Star Forming ◽  
T Tauri ◽  
Optical Wavelengths

Context. Pre-main-sequence variability characteristics can be used to probe the physical processes leading to the formation and initial evolution of both stars and planets. Aims. The photometric variability of pre-main-sequence stars is studied at optical wavelengths to explore star–disk interactions, accretion, spots, and other physical mechanisms associated with young stellar objects. Methods. We observed a field of 16′ × 16′ in the star-forming region Pelican Nebula (IC 5070) at BVRI wavelengths for 90 nights spread over one year in 2012−2013. More than 250 epochs in the VRI bands are used to identify and classify variables up to V ∼ 21 mag. Their physical association with the cluster IC 5070 is established based on the parallaxes and proper motions from the Gaia second data release (DR2). Multiwavelength photometric data are used to estimate physical parameters based on the isochrone fitting and spectral energy distributions. Results. We present a catalog of optical time-series photometry with periods, mean magnitudes, and classifications for 95 variable stars including 67 pre-main-sequence variables towards star-forming region IC 5070. The pre-main-sequence variables are further classified as candidate classical T Tauri and weak-line T Tauri stars based on their light curve variations and the locations on the color-color and color-magnitude diagrams using optical and infrared data together with Gaia DR2 astrometry. Classical T Tauri stars display variability amplitudes up to three times the maximum fluctuation in disk-free weak-line T Tauri stars, which show strong periodic variations. Short-term variability is missed in our photometry within single nights. Several classical T Tauri stars display long-lasting (≥10 days) single or multiple fading and brightening events of up to two magnitudes at optical wavelengths. The typical mass and age of the pre-main-sequence variables from the isochrone fitting and spectral energy distributions are estimated to be ≤1 M⊙ and ∼2 Myr, respectively. We do not find any correlation between the optical amplitudes or periods with the physical parameters (mass and age) of pre-main-sequence stars. Conclusions. The low-mass pre-main-sequence stars in the Pelican Nebula region display distinct variability and color trends and nearly 30% of the variables exhibit strong periodic signatures attributed to cold spot modulations. In the case of accretion bursts and extinction events, the average amplitudes are larger than one magnitude at optical wavelengths. These optical magnitude fluctuations are stable on a timescale of one year.

scholarly journals Maximum Entropy for Gravitational Wave Data Analysis: Inferring the Physical Parameters of Core‐Collapse Supernovae

2008 ◽  
Vol 678 (2) ◽  
pp. 1142-1157 ◽  
Author(s):  
T. Z. Summerscales ◽  
Adam Burrows ◽  
Lee Samuel Finn ◽  
Christian D. Ott
Keyword(s):  
Data Analysis ◽  
Gravitational Wave ◽  
Maximum Entropy ◽  
Physical Parameters ◽  
Core Collapse ◽  
Wave Data
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