相关论文: Light Echoes of Historic Transients
Astronomical light echoes, the time-dependent light scattered by dust in the vicinity of varying objects, have been recognized for over a century. Initially, their utility was thought to be confined to mapping out the three-dimensional…
For over a century, light echoes have been observed around variable stars and transients. The discovery of centuries-old light echoes from supernovae in the Large Magellanic Cloud has allowed the spectroscopic characterization of these…
In principle, the light from historical supernovae could still be visible as scattered-light echoes even centuries later. However, while echoes have been discovered around some nearby extragalactic supernovae well after the explosion,…
Scattered light echoes from variable and cataclysmic stars offer one of the most effective means to probe the structure and composition of circumtellar and interstellar media. I build a simple model of light-echo surface brightness by…
Light echoes occur when light from a luminous transient is scattered by dust back into our line of sight with a time delay due to the extra propagation distance. We introduce a novel approach to estimating the distance to a source by…
The light echo systems of historical supernovae in the Milky Way and local group galaxies provide an unprecedented opportunity to reveal the effects of asymmetry on observables, particularly optical spectra. Scattering dust at different…
Light echoes give us a unique perspective on the nature of supernovae and non-terminal stellar explosions. Spectroscopy of light echoes can reveal details on the kinematics of the ejecta, probe asymmetry, and reveal details on its…
Light echoes are a promising tool to probe the environment where SNe Ia explode and an independent source of information on the progenitor's nature. After giving a brief introduction to the phenomenon we review the two known cases, i.e. SNe…
A light echo around SN 1993J was observed 8.2 years after explosion by a HST WFPC2 observation, adding to the small family of supernovae with light echoes. The light echo was formed by supernova light scattered from a dust sheet, which lies…
We report the discovery of an extensive system of scattered light echo arclets associated with the recent supernovae in the local neighbourhood of the Milky Way: Tycho (SN 1572) and Cassiopeia A. Existing work suggests that the Tycho SN was…
In general, Light Echoes (LE) are beautiful, rather academical and therefore unavoidably useless phenomena. In some cases, however, they can give interesting information about the environment surrounding the exploding star. After giving a…
Supernova (SN) light echoes could be a powerful tool for determining distances to galaxies geometrically, Sparks 1994. In this paper we present CCD photometry of the environments of 64 historical supernovae, the first results of a program…
We identify a light echo candidate from Hubble Space Telescope (HST) imaging of NGC 2441, the host galaxy of the Type Ia supernova 1995E. From the echo's angular size and the estimated distance to the host galaxy, we find a distance of 207…
When a flash of light from a star overtakes a straight linear filament of gas or dust and is seen later by an observer, a pattern of perceived illumination occurs that encodes information about the distance to the flash, the distance to…
Light Echoes (LEs) are the reflections of astrophysical transients off of interstellar dust. They are fascinating astronomical phenomena that enable studies of the scattering dust as well as of the original transients. LEs, however, are…
The spectra of type IIn supernovae indicate the presence of apre-existing slow, dense circumstellar wind (CSW). If the CSW extends sufficiently far from the progenitor star, then dust formation should occur in the wind. The light from the…
We present follow-up optical imaging and spectroscopy of one of the light echoes of $\eta$ Carinae's 19th-century Great Eruption discovered by Rest et al. (2012). By obtaining images and spectra at the same light echo position between 2011…
In this paper we present and discuss the effects of scattered light echoes (LE) on the luminosity and spectral appearance of Type Ia Supernovae (SNe). After introducing the basic concepts of LE spectral synthesis, by means of LE models and…
Light echoes are interesting because of the wealth of information they offer about their progenitors and the reflecting dust. Due to their faint surface brightnesses, difference imaging is necessary to separate most light echoes from the…
The UV radiation from a quasar leaves a characteristic pattern in the distribution of ionized hydrogen throughout the surrounding space. This pattern or light echo propagates through the intergalactic medium at the speed of light, and can…