Related papers: Including All the Lines
In recent years, significant advances have been made in exoplanet and brown dwarf observations. By using state-of-the-art models, astronomers can determine properties of their atmospheres, such as temperatures, the presence of clouds, or…
Stellar emission and absorption lines are routinely observed in galaxies at redshifts up to 5 with spectrographs on 8-10m class telescopes. While the overall spectra are well understood and have been successfully modeled using empirical and…
Line Chart Data Extraction is a natural extension of Optical Character Recognition where the objective is to recover the underlying numerical information a chart image represents. Some recent works such as ChartOCR approach this problem…
I present the Automated Line Fitting Algorithm, ALFA, a new code which can fit emission line spectra of arbitrary wavelength coverage and resolution, fully automatically. In contrast to traditional emission line fitting methods which…
Aims: We generate theoretical ultraviolet and extreme-ultraviolet emission line ratios for O IV and show their strong versatility as electron temperature and density diagnostics for astrophysical plasmas. Methods: Recent fully relativistic…
Archetypal analysis represents each individual member of a set of data vectors as a mixture (a constrained linear combination) of the pure types or archetypes of the data set. The archetypes are themselves required to be mixtures of the…
Modeling emission lines from the millimeter to the UV and producing synthetic spectra is crucial for a good understanding of observations, yet it is an art filled with hazards. This is the proceedings of "Walking the Line", a 3-day…
The well-known age-metallicity-attenuation degeneracy does not permit unique and good estimates of basic parameters of stars and stellar populations. The effects of dust can be avoided using spectral line indices, but current methods have…
The determination of chemical abundances constitutes a fundamental requirement for obtaining a complete picture of a star. Particularly in massive stars, CNO abundances are of prime interest, due to the nuclear CNO-cycle and various mixing…
In order to measure automatically the equivalent width of the Balmer lines in a database of 40,000 atmosphere models, we have developed a program that mimics the work of an astronomer in terms of identifying and eliminating secondary…
We present an algorithm to express Wilson lines that are defined on piecewise linear paths in function of their individual segments, reducing the number of diagrams needed to be calculated. The important step lies in the observation that…
Context. Stellar spectral synthesis is essential for various applications, ranging from determining stellar parameters to comprehensive stellar variability calculations. New observational resources as well as advanced stellar atmosphere…
I have carried out spectrum synthesis of R = 120,000 spectra of several A and B stars having v sin i less than about 6 km/s. The following conclusions emerge: (1) As T_e descends from 12,000 to 8,000 K, microturbulent velocity xi deduced…
We present a comprehensive framework for evaluating line chart smoothing methods under a variety of visual analytics tasks. Line charts are commonly used to visualize a series of data samples. When the number of samples is large, or the…
Line-intensity mapping (LIM) is an emerging technique to probe the large-scale structure of the Universe. By targeting the integrated intensity of specific spectral lines, it captures the emission from all sources and is sensitive to the…
Each complex network (or class of networks) presents specific topological features which characterize its connectivity and highly influence the dynamics of processes executed on the network. The analysis, discrimination, and synthesis of…
Context. The homogenization of the stellar parameters is an important goal for large observational spectroscopic surveys, but it is very difficult to achieve it because of the diversity of the spectroscopic analysis methods used within a…
We present details regarding the construction of a composite spectrum of quasar (QSO) absorption line systems. In this composite spectrum we identify more than 70 absorption lines, and observe oxygen and hydrogen emission features at a…
Let $S$ be a finite set of points in the plane and let $\mathcal{T}(S)$ be the set of intersection points between pairs of lines passing through any two points in $S$. We characterize all configurations of points $S$ such that iteration of…
The advent of 8--10 meter class telescopes enables direct measurement of the chemical properties in the ionized gas of cosmologically--distant galaxies with the same nebular analysis techniques used in local H II regions. We show that…