相关论文: The spectrum of HD46223
This paper presents new investigations on coherent scattering in the forward direction (orders of magnitude; conservation of energy; dependence of scattered light on geometry and wavelength), and on how scattered light contamination in the…
The spectrum of five stars is analysed and explained by the superimposition of two components. One is the extinction of the direct starlight, with an extinction coefficient A which varies as the inverse of the wavelength across all the UV.…
This paper presents an analysis of the UV spectrum of some nebulae with clearly identified illuminating stars, all observed by the IUE satellite. The data show remarkable properties of the UV spectrum of the nebulae. Each spectrum is the…
When a star is observed behind an interstellar cloud of sufficient column density, we do not observe the direct light from the star, which is totally extinguished. Rather, we see only starlight scattered at small angles from the star. I use…
The comparison, undertaken in preceding papers, of the UV observations of nebulae and of reddened stars reveals contradictory aspects of interstellar extinction. The aim of this paper is to understand the implications hidden behind the…
This paper examines the relationship between spectra of stars of same spectral type with extremely low reddenings. According to the standard theory, the relationship between the spectrum of stars with same spectral type and small, but…
In this paper I review a series of observations which do not agree with the standard interpretation of the extinction curve. The consequence is that light we receive from a reddened star must be contaminated by starlight scattered at very…
The optical surface brightness of dark nebulae is mainly due to scattering of integrated starlight by classical dust grains. It contains information on the impinging interstellar radiation field, cloud structure, and grain scattering…
The interpretation of ultraviolet Galactic interstellar extinction curves is obscured today by accumulated assumptions, such as a purported link between the 2200 A bump and metallicity, that are not firmly supported by observations. In this…
The 2200 A bump is a major figure of interstellar extinction. Extinction curves with no bump however exist and are, with no exception, linear from the near-infrared down to 2500 A at least, often over all the visible-UV spectrum. The…
We have made an extensive study of the UV spectrum of Eta Carinae, and find that we do not directly observe the star and its wind in the UV. Because of dust along our line of sight, the UV light that we observe arises from bound-bound…
By radiation transfer models with a realistic power spectra of the projected density distributions, we show that the optical properties of grains are poorly constrained by observations of reflection nebulae. The ISM is known to be…
Optical spectropolarimetry of the luminous IRAS source FSC10214$+$4724 (z$=2.286$) reveals that the strong (\twid17\%) linear polarization detected by Lawrence \etal\/ is shared by both the narrow UV emission lines and the underlying…
Spectropolarimetry from the near IR to the far UV of light scattered by dust provides a valuable diagnostic of the dust composition, grain size distribution and spatial distribution. To facilitate the use of this diagnostic, we present…
We discuss the interstellar absorption from many atomic and molecular species seen in high-resolution $HST$/STIS UV and high-S/N optical spectra of the moderately reddened B3-5~V star HD~62542. This remarkable sight line exhibits both very…
The light variability of hot magnetic chemically peculiar stars is typically caused by the flux redistribution in spots with peculiar abundance. This raises the question why some stars with surface abundance spots show significant…
We analyze low resolution Spitzer infrared (IR) 5-14 micron spectra of the diffuse emission toward a carefully selected sample of stars. The sample is composed of sight lines toward stars that have well determined ultraviolet (UV)…
This article discusses the interstellar extinction curve in the visible and the value of Rv. It is concluded that the visible extinction curve is likely to be linear in the visible, and that indirect estimates of Rv from tentative…
We present the results of UV imaging polarimetry of the Seyfert 2 galaxy Mrk 477 taken by the Faint Object Camera onboard the Hubble Space Telescope (HST). From a previous HST UV image (lambda ~ 2180A), Mrk 477 has been known to have a…
The dust shell around the evolved star HD 179821 has been detected in scattered light in near-IR imaging polarimetry observations. Here, we subtract the contribution of the unpolarized stellar light to obtain an intrinsic linear…