Next: Selection and Multi-Source/Multi-Frequency Datasets Up: Visibility Data Concepts Previous: Selecting UV Data in . A Miriad visibility dataset can contain simultaneous observations at multiple spectral bands, or spectral windows. ... When there are multiple spectral windows, channels are still numbered from 1 to N , where channel 1 is the first channel of the first spectral window, and channel N is the last channel of the last spectral window. ... line=channel,1 . ...

... The x-ray spectral analysis consists of a comparison between the observed pulse height spectrum and a pulse height spectrum calculated using a given spectral model. ... To obtain the spectral parameters for an x-ray source, several steps need to be followed. For each source: . ... obtain the best fit parameters for a spectral model - repeated for each model of interest . obtain a 1-D or 2-D grid of values around the best fit values - this can be done for as many models as desired . ...

The following files list line and continuum emissivities from the Arcetri Spectral Code. ... Ne = 10^8 g-zipped file (phot cm^3 s^-1); Ne = 10^8 g-zipped file (erg cm^3 s-1) . ... File format (html): File format for the continuum files . ... File format (html): File format for binned line emission files The following files list transitions whose emissivities have values greater than a fixed amount (10^-19 phot s^-1 cm^+3 and 10^-30 erg s^-1 cm^+3 respectively): . ...

... Thomson's multiple window method of spectral estimationthomson provides a very good estimate of the power spectrum by measuring the energy contained within a collection of rectangular shaped frequency intervals. ... Often, much of the fine structure of a spectral estimate is due to noise. It should be stressed that while other methods of spectral estimation (such as the Welchoppenheim method) exist, the Thomson method is particularly noteworthy for its precisely defined rectangular frequency bins. ...

... Подставки под телевизоры и Hi-Fi . ... Теплая детская шапка-бини Reima Auva идеально подойдет для прогулок в прохладное время года. ... Современный дизайн и расцветка делают эту шапку модным и стильным предметом детского гардероба. ... Цвет: разноцветный . Коллекция: Весна-лето 2016 . ... Пол: Мужской . ... Цвет: мультиколор. ... Сезон: Весна-лето 2016. ... Цвет: черный . ... Цвет: белый . ... Пол: Женский . ... Цвет: синий . ... Barkan 34.C.B 4D кронштейн - Barkan - Barkan . ...

Next: Conclusions Up: Selection Effects Previous: Inconsistent (or Inconsistently Applied) . Another possible bias, present in this as well as all other surveys which use spectral indices based upon nonsimultaneous data in their selection process, is due to variability. ... In order to minimize the effect of non-simultaneous radio survey data upon our samples, we decided to expand the common definition of flat-spectrum radio sources to extend to (instead of 0.5). ...

Next: Methods for Structuring and Searching Very Large Catalogs . ... We have explored two automated classification methods: supervised classification using Artificial Neural Networks (ANN) and unsupervised classification using Self Organized Maps (SOM). These methods are used to classify IUE low-dispersion spectra of normal stars with spectral types ranging from O3 to G5. This paper describes the application of automated methods to the problem of the classification of stellar spectra. ...

... The Wide Field Spectral Imager ( WISPI ) seen here in the Roll Roof Facility provides visible and near-infrared spectra of the sky across 4 degree fields. ... A computer controlled mounting automates the acquisition of 2-D rastered spectral images. ... Light from the sky enters the large 400mm lens at top center, is imaged on the slit, collimated by the smaller 180 mm lens, and diffracted by the grating at the bottom toward the 200mm lens and CCD camera on the right. ... Camera - 200mm f/2 Nikor ED ...

... December 21, 1997 . ... Advantages are briefly discussed of gaining in spectral resolution, which is accompanied by losses in signal level, as compared with the attempts to improve the accuracy of measurement of line parameters by means of rising the S/N ratio alone with increasing the exposure time. To partially solve the problem of observations of faint objects at the BTA a new design echelle spectrometer is proposed. high resolution spectroscopy . ...