Next: Implementation Up: Compensation for Read-Out Noise Previous: Compensation for Read-Out Noise . Various methods are being used to compensate for the resolution loss that is present in image data acquired by the Hubble Space Telescope. ... There are a variety of noise sources present in HST image data acquired with a CCD camera. ... We use the term background counts for the cumulative effect of these extraneous electrons. Background counts are Poisson distributed. ...

... Let be a random deviate which follows a Poissonian probability distribution about the expectation value . Although the Poisson distribution itself is only defined for integer , one can find the following continuous `envelope function' to the Poisson values: . ... where is the gamma function . ... The expectation value of is . ... Equation 5 is used both in the present program and in boxdetect to estimate the null-hypothesis probability distribution of the weighted sum of Poissonian images. ...

... Next: Cheating Poisson: A Up: Statistical Analysis Previous: Spatial Models and . ... The spatial distribution of stars in the Local Group dwarf irregular galaxy NGC 6822 has been studied, using recent positions and deep photometry for about 15,000 stars in the galaxy. Based on photometrical data, OB stars and red stars could be studied separately. Spatial statistical tools have been applied to the analysis of the spatial structure. ... Figure: Model selection by the aid of CAIC . ...

... Using sl_array . Array information . ... Inline::SLang . Doug's Home Page . ... Since the support for arrays in S-Lang and Perl do not match, the conversion of array values between the two languages is not entirely seemless, as shown in the examples below. ... The third option is to use a Perl Array_Type object to store the data; the Array_Type class is part of Inline::SLang and is as inefficient as using an array reference but does retain knowledge about the array size and type. ...

... The Boolean object is an object wrapper for a boolean value. ... JavaScript 1.3: added toSource method . ... If value is omitted or is 0, -0, null, false, NaN , undefined, or the empty string ( "" ), the object has an initial value of false. All other values, including any object or the string "false" , create an object with an initial value of true. ... For Boolean objects and values, the built-in toString method returns the string "true" or "false" depending on the value of the boolean object. ...

... The changebar (represented by two hyphens in the image) appears in the 10px space to the left of the paragraph. The illustration shows a vertical line that represents the left edge of the paragraph's containing block. ... The change bars (two red hyphens) appear to the left of the word "THIS", which begins the fourth line of text. The following PRE element simulates the example. Vertical bars represent the left containing block edge. ... to the left of the line containing | ...

Spectrophotometric resources (galaxies and stars) . HyperLeda home | ... LL_ELODIE "low-resolution" ELODIE archive . Resolution 0.055 nm (FWHM); W-range: 400 - 680 nm; 1388 stars; 1962 spectra . ... Resolution 0.013 nm (FWHM); W-range: 400 - 680 nm; 1388 stars; 1962 spectra . ... Resolution 0.4 nm; W-range: 580 - 1020 nm; 137 spectra; 126 stars . ... Resolution 1 nm; W-range: 480 to 770 nm; 18 spectra; 18 stars . ... Resolution 0.15 nm (FWHM); W-range: 395 - 475 nm; 78 spectra; 78 stars . ...

Next: Radial velocity of the Up: Optical spectrum of IRAS04296 Previous: Observations and spectra reduction . ... However, molecular emission features are only very rarely observed in the optical spectra of PPNe. ... On the other hand, it is well known that cometary nuclei spectra show prominent Swan band emission. In both spectra of IRAS04296 we have discovered strong emission in the (0;0) and (0;1) bands of the Swan system of the molecule. ... Now consider the case of IRAS04296. ...