相关论文: Circumstellar Emission from Type Ib and Ic Superno…
Core-collapse supernova remnants are structures of the interstellar medium (ISM) left behind the explosive death of most massive stars (smaller or equal to 40 Mo). Since they result in the expansion of the supernova shock wave into the…
We present X-ray, UV/optical, and radio observations of the stripped-envelope, core-collapse supernova (SN) 2011ei, one of the least luminous SNe IIb or Ib observed to date. Our observations begin with a discovery within 1 day of explosion…
We present a simple analysis of X-ray emission and absorption for hot-star winds, designed to explore the natural scalings of the observed X-ray luminosity with wind and sstellar properties. We show that an exospheric approximation, in…
Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. To clarify the systematics of the observed X-ray properties, we have analyzed a large series of Chandra and XMM observations,…
The striking broad emission line spectroscopic appearance of Wolf-Rayet (WR) stars has long defied analysis, due to the extreme physical conditions within their line and continuum forming regions. Recently, model atmosphere studies have…
(Abridged) We consider the interaction of a relativistically-moving shell, composed of thermal photons, a reversing magnetic field and a small admixture of charged particles, with a dense Wolf-Rayet wind. A thin outer layer of Wolf-Rayet…
Knowledge of the progenitors of core-collapse supernovae is a fundamental component in understanding the explosions. The recent progress in finding such stars is reviewed. The minimum initial mass that can produce a supernova has converged…
Recent observations of gamma-ray bursts (GRBs) have provided growing evidence for collimated outflows and emission, and strengthened the connection between GRBs and supernovae. If massive stars are the progenitors of GRBs, the hard photon…
The association of a supernova with a gamma-ray burst (GRB 030329) implies a massive star progenitor, which is expected to have an environment formed by pre-burst stellar winds. Although some sources are consistent with the expected wind…
We present a stacking analysis of 2.61 Msec of archival Chandra observations of stellar wind bow shocks. We place an upper limit on the X-ray luminosity of IR-detected bow shocks of $<2\times10^{29}$ erg s$^{-1}$, a more stringent…
We examine a systematic comparison of jet-knots, hotspots and radio lobes recently observed with Chandra and ASCA. This report will discuss the origin of their X-ray emissions and investigate the dynamics of the jets. The data was compiled…
We suggest that the luminous extreme ultraviolet (EUV) emission which has been detected recently from clusters of galaxies is Inverse Compton (IC) scattering of Cosmic Microwave Background (CMB) radiation by low energy cosmic ray electrons…
The discovery of the GRB-supernova association poses the question on the nature of the inner engine as the outcome of Type Ib/c supernovae. These events are believed to represent core-collapse of massive stars, probably in low-period…
We present a numerical investigation of the contribution of the presupernova ejecta of Wolf-Rayet stars to the environment surrounding gamma-ray bursts (GRBs), and describe how this external matter can affect the observable afterglow…
Most types of massive stars display X-ray emission that is affected by the properties of their stellar winds. Single non-magnetic OB stars have an X-ray luminosity that scales with their bolometric luminosity and their emission is thought…
This paper estimates the relative frequency of different types of core-collapse supernovae, in terms of the ratio f between the number of type Ib--Ic and of type II supernovae. We estimate f independently for all normal and Seyfert galaxies…
When the ejecta of supernovae interact with the progenitor star's circumstellar environment, a strong shock is driven back into the ejecta, causing the material to become bright optically and in X-rays. Most notably, as the shock traverses…
This paper discusses our ongoing efforts to characterize dust-enshrouded Wolf-Rayet (WR) stars in the radio and infrared. We have used the Very Large Array to measure the broadband radio spectrum of WR stars in suspected binary systems and…
A subset (~ 10%) of massive stars present strong, globally ordered (mostly dipolar) magnetic fields. The trapping and channeling of their stellar winds in closed magnetic loops leads to magnetically confined wind shocks (MCWS), with…
We investigate the effects of winds on the observational properties of Type Ib and Ic supernova (SN Ib/Ic) progenitors using spectral models constructed with the non-LTE stellar atmospheric code CMFGEN. We consider SN Ib/Ic progenitor…