We present 1-D non-Local-Thermodynamic-Equilibrium time-dependent radiative-transfer simulations for a large grid of supernovae (SNe) IIb/Ib/Ic that result from the terminal explosion of the mass donor in a close-binary system. Our sample covers ejecta masses $M_{\rm e}$ of 1.7$-$5.2M$_\odot$, kinetic energies $E_{\rm kin}$ of 0.6$-$5.0$\times$10$^{51}$erg, and $^{56}$Ni masses of 0.05$-$0.30M$_\odot$. We find a strong correlation between the $^{56}$Ni mass and the photometric properties at maximum, and between the rise time to bolometric maximum and the post-maximum decline rate. We confirm the small scatter in ($V-R$) at 10d past $R$-band maximum. The quantity $V_{\rm m} \equiv \sqrt{2E_{\rm kin}/M_{\rm e}}$ is comparable to the Doppler velocity measured from HeI 5875Å at maximum in SNe IIb/Ib, although some scatter arises from the uncertain level of chemical mixing. The OI7772Å line may be used for SNe Ic, but the correspondence deteriorates with higher ejecta mass/energy. We identify a temporal reversal of the Doppler velocity at maximum absorption in the $\sim$1.05$μ$m feature in all models. The reversal is due to HeI alone and could serve as a test for the presence of helium in SNe Ic. Because of variations in composition and ionisation, the ejecta opacity shows substantial variations with both velocity and time. This is in part the origin of the offset between our model light curves and the predictions from the Arnett model.
The shape of the light curve peak of radioactive--powered core--collapse "stripped--envelope" supernovae constrains the ejecta mass, nickel mass, and kinetic energy by the brightness and diffusion time for a given opacity and observed expansion velocity. Late--time light curves give constraints on the ejecta mass and energy, given the gamma--ray opacity. Previous work has shown that the principal light curve peaks for SN~IIb with small amounts of hydrogen and for hydrogen/helium--deficient SN~Ib/c are often rather similar near maximum light, suggesting similar ejecta masses and kinetic energie…
We present 1-D non-Local-Thermodynamic-Equilibrium time-dependent radiative-transfer simulations for supernovae (SNe) of type IIb, Ib, and Ic that result from the terminal explosion of the mass donor in a close-binary system. Here, we select three ejecta with a total kinetic energy of ~1.2e51erg, but characterised by different ejecta masses (2-5Msun), composition, and chemical mixing. The type IIb/Ib models correspond to the progenitors that have retained their He-rich shell at the time of explosion. The type Ic model arises from a progenitor that has lost its helium shell, but retains 0.32Msu…
We present non-LTE time-dependent radiative-transfer simulations of supernova (SN) IIb/Ib/Ic spectra and light curves, based on ~1B-energy piston-driven ejecta, with and without 56Ni, produced from single and binary Wolf-Rayet (W-R) stars evolved at solar and sub-solar metallicities. Our bolometric light curves show a 10-day long post-breakout plateau with a luminosity of 1-5x10^7Lsun. In our 56Ni-rich models, with ~3Msun ejecta masses, this plateau precedes a 20-30-day long re-brightening phase initiated by the outward-diffusing heat wave powered by radioactive decay at depth. In low ejecta-m…
SN 2018ivc is an unusual type II supernova (SN II). It is a variant of SNe IIL, which might represent a transitional case between SNe IIP with a massive H-rich envelope, and IIb with only a small amount of the H-rich envelope. However, SN 2018ivc shows an optical light curve evolution more complicated than canonical SNe IIL. In this paper, we present the results of prompt follow-up observations of SN 2018ivc with the Atacama Large Millimeter/submillimeter Array (ALMA). Its synchrotron emission is similar to that of SN IIb 1993J, suggesting that it is intrinsically an SN IIb-like explosion of a…
Optical observations of the type IIb SN 2013df from a few days to about 250 days after explosion are presented. These observations are complemented with UV photometry taken by \textit{SWIFT} up to 60 days post-explosion. The double-peak optical light curve is similar to those of SNe 1993J and 2011fu although with different decline and rise rates. From the modelling of the bolometric light curve, we have estimated that the total mass of synthesised $^{56}$Ni in the explosion is $\sim0.1$ M$_{\odot}$, while the ejecta mass is $0.8-1.4$ M$_{\odot}$ and the explosion energy $0.4-1.2 \times 10^{51}…
SN 2024iss: A Multi-Wavelength Exposé of a Type IIb Supernova with an Early-Time Ultraviolet Spectrum and Shock Breakout Constraints
University of North Carolina at Chapel Hill（北卡罗来纳大学教堂山分校）；California Institute of Technology（加州理工学院）；University of Illinois at Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）；Institut d’Astrophysique de Paris, CNRS-Sorbonne Université（巴黎天体物理研究所，CNRS-索邦大学）
We investigate line formation processes in Type IIb supernovae (SNe) from 100 to 500 days post-explosion using spectral synthesis calculations. The modeling identifies the nuclear burning layers and physical mechanisms that produce the major emission lines, and the diagnostic potential of these. We compare the model calculations with data on the three best observed Type IIb SNe to-date - SN 1993J, SN 2008ax, and SN 2011dh. Oxygen nucleosynthesis depends sensitively on the main-sequence mass of the star and modeling of the [O I] 6300, 6364 lines constrains the progenitors of these three SNe to …
We present advances in modeling Type IIP supernovae using MESA for evolution to shock breakout coupled with STELLA for generating light and radial velocity curves. Explosion models and synthetic light curves can be used to translate observable properties of supernovae (such as the luminosity at day 50 and the duration of the plateau, as well as the observable quantity $ET$, defined as the time-weighted integrated luminosity that would have been generated if there was no ${\rm ^{56}Ni}$ in the ejecta) into families of explosions which produce the same light curve and velocities on the plateau. …
We use the new NLTE lightcurve and spectral synthesis code JEKYLL to evolve a macroscopically mixed ejecta model of a type IIb Supernova (SN) originating from a star with an initial mass of 12 solar masses through the photospheric and nebular phase. We compare to SN 2011dh, and find that both the spectra and the lightcurves are well reproduced. Our work further strengthens the evidence that this SN originated from a star with an initial mass of about 12 solar masses that had lost all but tiny (<0.1 solar masses) fraction of its hydrogen envelope. We also investigate the effects of the macrosco…
Core--collapsed supernovae (CCSNe) have been considered to be one of sources of dust in the universe. What kind and how much mass of dust are formed in the ejecta and are injected into the interstellar medium (ISM) depend on the type of CCSNe, through the difference in the thickness (mass) of outer envelope. In this review, after summarizing the existing results of observations on dust formation in CCSNe, we investigate formation of dust in the ejecta and its evolution in the supernova remnants (SNRs) of Type II--P and Type IIb SNe. Then, the time evolution of thermal emission from dust in the…
Circumstellar interaction of supernova (SN) ejecta is an essential process in its evolution and observations of SNe have found the signature of circumstellar interaction both in the early and late evolutionary phase of SNe. In this Letter, we show that if the SN forward shock plunges into tenuous stellar wind from dense circumstellar medium (CSM) in the vicinity of the progenitor (i.e., confined CSM), the subsequent time evolutions of the SN-CSM interaction system deviates from the prediction of self-similar solution. In this case, after all of the confined CSM is swept up by the SN forward sh…
SN 2013df is a nearby Type IIb supernova that seems to be the spectroscopic twin of the well-known SN 1993J. Previous studies revealed many, but not all interesting properties of this event. Our goal was to add new understanding of both the early and late-time phases of SN 2013df. Our spectral analysis is based on 6 optical spectra obtained with the 9.2m Hobby-Eberly Telescope during the first month after explosion, complemented by a near-infrared spectrum. We applied the SYNAPPS spectral synthesis code to constrain the chemical composition and physical properties of the ejecta. A principal re…
We present results of a supernova light-curve population synthesis, predicting the range of possible supernova lightcurves arising from a population of progenitor stars that include interacting binary systems. We show that the known diversity of supernova lightcurves can be interpreted as arising from binary interactions. Given detailed models of the progenitor stars, we are able to the determine what parameters within these stars determine the shape of their supernova lightcurve. The primary factors are the mass of supernova ejecta and the mass of hydrogen in the final progenitor. We find tha…
SN 2022ngb: A faint, slowly evolving Type IIb supernova with a low-mass envelope
Yunnan Key Laboratory of Survey Science, Yunnan University（云南省测绘科学重点实验室，云南大学）；INAF - Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；Yunnan Observatories, Chinese Academy of Sciences (CAS)（中国科学院云南天文台）；International Centre of Supernovae, Yunnan Key Laboratory（超新星国际研究中心，云南省重点实验室）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所（ICE，CSIC））；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）
SN 2022ngb是一颗低光度IIb型超新星，其前身星为中等质量、相对紧凑的剥离包层恒星，爆炸参数包括喷流质量、能量和放射性物质分布。
We report the late-time evolution of Type IIb Supernova (SN IIb) 2013df. SN 2013df showed a dramatic change in its spectral features at ~1 year after the explosion. Early on it showed typical characteristics shared by SNe IIb/Ib/Ic dominated by metal emission lines, while later on it was dominated by broad and flat-topped Halpha and He I emissions. The late-time spectra are strikingly similar to SN IIb 1993J, which is the only previous example clearly showing the same transition. This late-time evolution is fully explained by a change in the energy input from the $^{56}$Co decay to the interac…
Models for the spectra and the light curve, in the photospheric as well as in the late nebular phase, are used to infer the properties of the very radio-bright, broad-lined type IIb Supernova 2003bg. Consistent fits to the light curve and the spectral evolution are obtained with an explosion that ejected ~ 4 M_sun of material with a kinetic energy of ~ 5 10^51 erg. A thin layer of hydrogen, comprising ~ 0.05 M_sun, is inferred to be present in the ejecta at the highest velocities (v >~ 9000 km/s), while a thicker helium layer, comprising ~ 1.25 M_sun, was ejected at velocities between 6500 and…
In this work, photometric and spectroscopic analyses of a very low-luminosity Type IIb supernova (SN) 2016iyc have been performed. SN 2016iyc lies near the faint end among the distribution of similar supernovae (SNe). Given lower ejecta mass ($M_{\rm ej}$) and low nickel mass ($M_{\rm Ni}$) from the literature, combined with SN 2016iyc lying near the faint end, one-dimensional stellar evolution models of 9 - 14 M$_{\odot}$ zero-age main-sequence (ZAMS) stars as the possible progenitors of SN 2016iyc have been performed using the publicly available code MESA. Moreover, synthetic explosions of t…
Here we present previously unpublished optical spectra of supernova (SN) 2001ig, a Type IIb SN, from about a week after explosion until nearly one year later. The earliest spectrum consists of only a few broad absorption features, but soon more common Type II SN features including hydrogen P-Cygni profiles and helium absorption become apparent. At later times, as the H features fade and the He I absorption becomes more prominent, we observe the SN to transition from a Type II to a Type Ib. Finally, observations after 250 days past explosion show a nebular-phase SN spectrum with one of the larg…
Type IIb Supernova (SN) 2011dh, with conclusive detection of an unprecedented Yellow Supergiant (YSG) progenitor, provides an excellent opportunity to deepen our understanding on the massive star evolution in the final centuries toward the SN explosion. In this paper, we report on detection and analyses of thermal X-ray emission from SN IIb 2011dh at ~500 days after the explosion on Chandra archival data, providing a solidly derived mass loss rate of an YSG progenitor for the first time. We find that the circumstellar media (CSM) should be dense, more than that expected from a Wolf-Rayet (WR) …
We present optical and near infrared observations of the type IIb supernova (SN) 2011fu from a few days to $\sim300$ d after explosion. The SN presents a double-peaked light curve (LC) similar to that of SN 1993J, although more luminous and with a longer cooling phase after the primary peak. The spectral evolution is also similar to SN 1993J's, with hydrogen dominating the spectra to $\sim40$ d, then helium gaining strength, and nebular emission lines appearing from $\sim60$ d post-explosion. The velocities derived from the P-Cygni absorptions are overall similar to those of other type IIb SNe…
Much controversy surrounds the inferred progenitor masses of Type II-Plateau (II-P) supernovae (SNe). The debate is nourished by the discrepant results from radiation-hydrodynamics simulations, from pre-explosion imaging, and from studies of host stellar populations. Here, we present a controlled experiment using four solar metallicity models with zero-age main-sequence masses of 12, 15, 20, and 25Msun. Because of the effects of core burning and surface mass loss, these models reach core collapse as red-supergiant (RSG) stars with a similar H-rich envelope mass of 8 to 9Msun but with final mas…
Aims: We study the chemistry of the Type IIb supernova ejecta that led to the Cas A supernova remnant to assess the chemical type and quantity of dust that forms and evolves in the remnant phase. We later model a dense oxygen-rich ejecta knot that is crossed by the reverse shock in Cas A to study the evolution of the clump gas phase and the possibility to reform dust clusters in the post-reverse shock gas. Methods: A chemical network including all processes efficient at high gas temperatures and densities is considered. The formation of key bimolecular species (CO, SiO) and dust clusters is de…
Extensive optical and near-infrared (NIR) observations of the type IIb supernova 2008ax are presented, covering the first year after the explosion. The light curve is mostly similar in shape to that of the prototypical type IIb SN 1993J, but shows a slightly faster decline rate at late phases and lacks the prominent narrow early-time peak of SN 1993J. From the bolometric light curve and ejecta expansion velocities, we estimate that about 0.07-0.15 solar masses of 56Ni were produced during the explosion and that the total ejecta mass was between 2 and 5 solar masses, with a kinetic energy of at…
We study the optical emission from heavy element ejecta in the oxygen-rich young supernova remnant (SNR) 1E 0102.2-7219 (1E 0102) in the Small Magellanic Cloud. We have used the Multi-Unit Spectroscopic Explorer (MUSE) optical integral field spectrograph at the Very Large Telescope (VLT) on Cerro Paranal and the wide field spectrograph (WiFeS) at the ANU 2.3 m telescope at Siding Spring Observatory to obtain deep observations of 1E 0102. Our observations cover the entire extent of the remnant from below 3500Å to 9350Å. Our observations unambiguously reveal the presence of fast-moving ejecta em…
A set of hydrodynamical models based on stellar evolutionary progenitors is used to study the nature of SN 2011dh. Our modeling suggests that a large progenitor star ---with R ~200 Rsun---, is needed to reproduce the early light curve of SN 2011dh. This is consistent with the suggestion that the yellow super-giant star detected at the location of the SN in deep pre-explosion images is the progenitor star. From the main peak of the bolometric light curve and expansion velocities we constrain the mass of the ejecta to be ~2 Msun, the explosion energy to be E= 6-10 x 10^50 erg, and the 56Ni mass …
We investigate the formation of dust grains in the ejecta of a SN IIb and their evolution in the shocked gas in the SNR by considering the uniform and power-law density structures for the CSM. Based on these calculations, we also simulate the time evolution of thermal emission from the shock-heated dust in the SNR and compare the results with the observations of Cas A SNR. We find that the total mass of dust formed in the SN IIb is as large as 0.167 M_sun but the average radius of dust is smaller than 0.01 mum and is significantly different from those in SNe II-P with the massive H-envelope. I…
Probing the low-mass end of core-collapse supernovae using a sample of strongly-stripped Calcium-rich Type IIb Supernovae from the Zwicky Transient Facility
H and He features in photospheric spectra have seldom been used to infer quantitatively the properties of Type IIb, Ib and Ic supernovae (SNe IIb, Ib and Ic) and their progenitor stars. Most radiative transfer models ignored NLTE effects, which are extremely strong especially in the He-dominated zones. In this paper, a comprehensive set of model atmospheres for low-mass SNe IIb/Ib/Ic is presented. Long-standing questions such as how much He can be contained in SNe Ic, where He lines are not seen, can thus be addressed. The state of H and He is computed in full NLTE, including the effect of hea…
We present results of the photometric (from 3 to 509 days past explosion) and spectroscopic (up to 230 days past explosion) monitoring campaign of the He-rich Type IIb supernova (SN) 2015as. The {\it (B-V)} colour evolution of SN 2015as closely resemble those of SN 2008ax, suggesting that SN 2015as belongs to the SN IIb subgroup that does not show the early, short-duration photometric peak. The light curve of SN 2015as reaches the $B$-band maximum about 22 days after the explosion, at an absolute magnitude of -16.82 $\pm$ 0.18 mag. At $\sim$ 75 days after the explosion, its spectrum transition…
We study properties of early radio emission from stripped-envelope supernovae (those of type IIb/Ib/Ic). We suggest there is a sub-class of stripped-envelope supernovae in their radio properties, including optically well-studied type Ic supernovae (SNe Ic) 2002ap and 2007gr, showing a rapid rise to a radio peak within ~ 10 days reaching to a low luminosity (at least an order of magnitude fainter than a majority of SNe IIb/Ib/Ic). They show a decline after the peak shallower than others while the spectral index is similar. We show that all these properties are naturally explained if the circums…
Literature data are collated for 38 stripped-envelope core-collapse supernovae (SE SNe; i.e. SNe IIb, Ib, Ic and Ic-BL) that have good light curve coverage in more than one optical band. Using bolometric corrections derived in previous work, the bolometric light curve of each SN is recovered and template bolometric light curves provided. Peak light distributions and decay rates are investigated; SNe subtypes are not cleanly distinguished in this parameter space, although some grouping of types does occur and there is a suggestion of a Phillips-like relation for most SNe Ic-BL. The bolometric l…
1E 0102.2--7219 (hereafter E0102) is a young supernova remnant (SNR) in the Small Magellanic Cloud (SMC). It contains oxygen-rich SN ejecta, a possible neutron star (NS), and a small amount of fast-moving H-rich ejecta material. These properties are also seen in Cas A, it has thus been suggested that E0102 is also a Type IIb SNR, whose SN progenitor's hydrogen envelope was stripped off possibly via interactions with a companion star. To search for a surviving companion of E0102's SN progenitor, we have used archival Hubble Space Telescope (HST) continuum images to make photometric measurements…
We present an analysis of 507 spectra of 173 stripped-envelope (SE) supernovae (SNe) discovered by the untargeted Palomar Transient Factory (PTF) and intermediate PTF (iPTF) surveys. Our sample contains 55 Type IIb SNe (SNe IIb), 45 Type Ib SNe (SNe Ib), 56 Type Ic SNe (SNe Ic), and 17 Type Ib/c SNe (SNe Ib/c). We compare the SE SN subtypes via measurements of the pseudo-equivalent widths (pEWs) and velocities of the He I $λ\lambda5876, 7065$ and O I $\lambda7774$ absorption lines. Consistent with previous work, we find that SNe Ic show higher pEWs and velocities in O I $\lambda7774$ compared …
In previous papers we discussed results from fully time-dependent radiative transfer models for core-collapse supernova (SN) ejecta, including the Type II-peculiar SN 1987A, the more "generic" SN II-Plateau, and more recently Type IIb/Ib/Ic SNe. Here we describe the modifications to our radiative modeling code, CMFGEN, which allowed those studies to be undertaken. The changes allow for time-dependent radiative transfer of SN ejecta in homologous expansion. In the modeling we treat the entire SN ejecta, from the innermost layer that does not fall back on the compact remnant out to the progenito…
The death of massive stars is believed to involve aspheric explosions initiated by the collapse of an iron core. The specifics of how these catastrophic explosions proceed remain uncertain due, in part, to limited observational constraints on various processes that can introduce asymmetries deep inside the star. Here we present near-infrared observations of the young Milky Way supernova remnant Cassiopeia A, descendant of a type IIb core-collapse explosion, and a three-dimensional map of its interior, unshocked ejecta. The remnant's interior has a bubble-like morphology that smoothly connects …
SN 2025aico: Early observations of a faint Type IIb supernova with a low-mass envelope
South-Western Institute for Astronomy Research, Yunnan University（云南大学西南天文研究所）；Yunnan Key Laboratory of Survey Science, Yunnan University（云南大学云南省测绘科学重点实验室）；INAF - Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；Yunnan Observatories, Chinese Academy of Sciences（中国科学院云南天文台）；International Centre of Supernovae, Yunnan Key Laboratory（云南省超新星国际研究中心）；Indian Institute of Astrophysics（印度天体物理研究所）；Pondicherry University（本地治里大学）；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；Tsung-Dao Lee Institute, Shanghai Jiao Tong University（上海交通大学李政道研究所）
SN 2024iss: A Double-peaked Type IIb Supernova with Evidence of Circumstellar Interaction
National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文学与空间科学学院）；Las Cumbres Observatory（拉斯坎布拉观测站）；University of California, Santa Barbara（加州大学圣塔芭芭拉分校）；Università degli Studi di Padova（帕多瓦大学）；INAF - Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布里埃拉天文台）；Department of Astronomy, University of California, Berkeley（加州大学伯克利分校天文学系）；Yunnan Observatories, Chinese Academy of Sciences（中国科学院云南天文台）；International Centre of Supernovae, Yunnan Key Laboratory（国际超新星研究中心（云南省重点实验室））；Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences（中国科学院天体结构与演化重点实验室）；Department of Physics, Tsinghua University（清华大学物理系）
We present a three-dimensional kinematic reconstruction of the optically-emitting, oxygen-rich ejecta of supernova remnant N132D in the Large Magellanic Cloud. Data were obtained with the 6.5 m Magellan telescope in combination with the IMACS+GISMO instrument and survey [O III] $λλ$4959,5007 line emission in a ${\sim}$3$^{\prime}~\times$ 3$^{\prime}$ region centered on N132D. The spatial and spectral resolution of our data enable detailed examination of the optical ejecta structure. The majority of N132D's optically bright oxygen ejecta are arranged in a torus-like geometry tilted approximatel…
Type Ibn Supernovae (SNe Ibn) show signatures of strong interaction between the SN ejecta and hydrogen-poor circumstellar matter (CSM). Deriving the ejecta and CSM properties of SNe Ibn provides a great opportunity to study the final evolution of massive stars. In the present work, we present a light curve (LC) model for the ejecta-CSM interaction, taking into account the processes in which the high-energy photons originally created at the forward and reverse shocks are converted to the observed emission in the optical. The model is applied to a sample of SNe Ibn and `SN Ibn' rapidly evolving …
The nature of the first massive stars may be inferred by investigating the origin of the extremely metal-poor (EMP) stars, likely formed from the ejecta of one or a few previous massive stars. We investigate the rotational properties of early massive stars by comparing the abundance patterns of EMP stars with rotating massive stellar models. Low metallicity 20 $M_{\odot}$ stellar models with initial rotation rates between 0 and $70~\%$ of the critical velocity are computed. Explosions with strong fallback are assumed. The ejected material is considered to fit individually the abundance pattern…
Using non-LTE time-dependent radiative-transfer calculations, we study the impact of mixing and non-thermal processes associated with radioactive decay on SN IIb/Ib/Ic light curves (LCs) and spectra. Starting with short-period binary models of \leq5Msun He-rich stars (18-25Msun on the main-sequence), we produce 1.2B ejecta which we artificially mix to alter the chemical stratification. While the total 56Ni mass influences the LC peak, the spatial distribution of 56Ni, controlled by mixing processes, impacts both the multi-band LCs and spectra. With enhanced mixing, our synthetic LCs start thei…
Spectral observations of the type-IIb supernova (SN) 2016gkg at 300-800 days are reported. The spectra show nebular characteristics, revealing emission from the progenitor star's metal-rich core and providing clues to the kinematics and physical conditions of the explosion. The nebular spectra are dominated by emission lines of [O I] $λ\lambda6300, 6364$ and [Ca II] $λ\lambda7292, 7324$. Other notable, albeit weaker, emission lines include Mg I] $\lambda4571$, [Fe II] $\lambda7155$, O I $\lambda7774$, Ca II triplet, and a broad, boxy feature at the location of H$α$. Unlike in other stripped-en…
Simplified analytic methods are frequently used to model the light curves of supernovae and other energetic transients and to extract physical quantities, such as the ejecta mass and amount of radioactive heating. The applicability and quantitative accuracy of these models, however, have not been clearly delineated. Here we carry out a systematic study comparing certain analytic models to numerical radiation transport calculations. We show that the neglect of time-dependent diffusion limits the accuracy of common Arnett-like analytic models, and that the widely-applied Arnett's rule for inferr…
Many core-collapse supernova progenitors are presumed to be in binary systems. If a star explodes in a binary system, the early supernova light curve can be brightened by the collision of the supernova ejecta with the companion star. The early brightening can be observed when the observer is in the direction of the hole created by the collision. Based on a population synthesis model, we estimate the fractions of core-collapse supernovae in which the light-curve brightening by the collision can be observed. We find that 0.19% of core-collapse supernova light curves can be observed with the coll…
Stripped-envelope (SE) supernovae (SNe) include H-poor (Type IIb), H-free (Type Ib) and He-free (Type Ic) events thought to be associated with the deaths of massive stars. The exact nature of their progenitors is a matter of debate. Here we present the analysis of the light curves of 34 SE SNe published by the Carnegie Supernova Project (CSP-I), which are unparalleled in terms of photometric accuracy and wavelength range. Light-curve parameters are estimated through the fits of an analytical function and trends are searched for among the resulting fit parameters. We found a tentative correlati…
We report the first maximum-light far-Ultraviolet to near-infrared spectra (1000A - 1.62um, rest) of a H-poor superluminous supernova, Gaia16apd. At z=0.1018, it is one of the closest and the UV brightest such events, with 17.4 (AB) magnitude in Swift UV band (1928A) at -11days pre-maximum. Assuming an exponential form, we derived the rise time of 33days and the peak bolometric luminosity of 3x10^{44}ergs^-1. At maximum light, the estimated photospheric temperature and velocity are 17,000K and 14,000kms^-1 respectively. The inferred radiative and kinetic energy are roughly 1x10^{51} and 2x10^{…
Type Ic supernovae (SNe Ic) arise from the core-collapse of H (and He) poor stars, which could be either single WR stars or lower-mass stars stripped of their envelope by a companion. Their light curves are radioactively powered and usually show a fast rise to peak ($\sim$10-15 d), without any early (first few days) emission bumps (with the exception of broad-lined SNe Ic) as sometimes seen for other types of stripped-envelope SNe (e.g., Type IIb SN 1993J and Type Ib SN 2008D). We have studied iPTF15dtg, a spectroscopically normal SN Ic with an early excess in the optical light curves followed…
Near-Infrared and Optical Observations of SN 2024rbc: The First Early Detection of CO and Dust in a Type Ib Supernova
University of California, Berkeley（加州大学伯克利分校）；SETI Institute（SETI研究所）；Seoul National University（首尔国立大学）；Argelander-Institut für Astronomie, Universität Bonn（波恩大学阿尔兰德天文学研究所）；Max Planck Institute for Astrophysics（马克斯·普朗克天体物理研究所）；Gemini Observatory/NSF’s National Optical-Infrared Astronomy Research Laboratory（吉米天文台/美国国家光学红外天文研究实验室）；University of California, Santa Cruz（加州大学圣克鲁兹分校）
Only a handful of supernovae (SNe) have been studied in multi-wavelength from radio to X-rays, starting a few days after explosion. The early detection and classification of the nearby type IIb SN2011dh/PTF11eon in M51 provides a unique opportunity to conduct such observations. We present detailed data obtained at the youngest phase ever of a core-collapse supernova (days 3 to 12 after explosion) in the radio, millimeter and X-rays; when combined with optical data, this allows us to explore the early evolution of the SN blast wave and its surroundings. Our analysis shows that the expanding sup…
