相关论文: Spectroscopic observation of planetary nebulae
Spectral retrieval has long been a powerful tool for interpreting planetary remote sensing observations. Flexible, parameterised, agnostic models are coupled with inversion algorithms in order to infer atmospheric properties directly from…
A detailed examination of new high quality radio catalogues (e.g. Cornish) in combination with available mid-infrared (MIR) satellite imagery (e.g. Glimpse) has allowed us to find 70 new planetary nebula (PN) candidates based on existing…
The spectra of the planetary nebulae NGC3242 and NGC6369 are reanalysed using spectral measurements made in the mid-infrared with the Spitzer Space Telescope and the Infrared Space Observatory (ISO). The aim is to determine the chemical…
Beginning with a historical account of the spectral classification, its refinement through additional criteria is presented. The line strengths and ratios used in two dimensional classifications of each spectral class are described. A…
The characterization of exoplanetary atmospheres through transit spectra is becoming increasingly feasible, and technology for direct detection remains ongoing. The possibility of detecting spectral features could enable quantitative…
Using subspace methods, we study the distribution of physical components of galaxies in wavelength space. We find that it is valid to assume that the stellar and the gaseous components of galaxies span complementary subspaces. To first…
We utilized photometric data from the space telescope AKARI to identify potential planetary nebulae (PNe) and proto-planetary nebulae (PPNe) candidates. Using the colour-colour diagram, we found a region with a high concentration of…
The determination of chemical abundances from stellar spectra is considered a mature field of astrophysics. Digital spectra of stars are recorded and processed with standard techniques, much like samples in the biological sciences.…
This paper examines the variations, because of atmospheric extinction, of broad-band visible spectra, obtained from long-slit spectroscopy, in the vicinity of some stars, nebulae, and one faint galaxy.
To detect Earth-like planets in the visible with a coronagraphic telescope, two major noise sources have to be overcome: the photon noise of the diffracted star light, and the speckle noise due to the star light scattered by instrumental…
This paper considers environmental problems of natural and anthropogenic atmospheric aerosol pollution and its global and regional monitoring. Efficient aerosol investigations may be achieved by spectropolarimetric measurements.…
While symbiotic Miras and planetary nebulae are hard to distinguish by optical spectroscopy, their near infrared colors differ. We propose the near infrared two-color diagram to be an excellent tool to easily distinguish these two classes…
The notions of spectral measures and spectral classes, which are well known for graphs, are generalized and investigated for oriented hypergraphs.
Atmospheric spectroscopy provides a window into the properties of exoplanets. However, the physical interpretation of retrieved data and its implications for the internal properties of exoplanets remains nebulous. This letter addresses…
We are conducting a spectroscopic monitoring of O and WN -type stars in our Galaxy. In this work, we summarize some of our first results related to the search for radial-velocity variations indicative of orbital motion.
The study of eclipsing binaries is our primary source of measured properties of normal stars, achieved through analysis of light and radial velocity curves of eclipsing systems. The study of oscillations and pulsations is increasingly vital…
Upcoming large-scale spectroscopic surveys such as WEAVE and 4MOST will provide thousands of spectra of massive stars, which need to be analysed in an efficient and homogeneous way. Studies on massive stars are usually based on samples of a…
The spectral region between 1250 Angstroms - 3000 Angstroms contains important spectral lines to understand the morphological structures and evolution of planetary nebulae. This is the region sampled by UVIT through various filter bands…
We review recent advances in our understanding of massive stars through the analysis of their spectra. Improvements in model atmospheres and analysis methods are briefly discussed. Results obtained for stars in the Local Group are compared…
Planetary nebulae (PNe) have diverse morphological shapes, including point-symmetric and multipolar structures. Many PNe also have complicated internal structures such as torus, lobes, knots, and ansae. A complete accounting of all the…