Scale-heights of the Galactic disk subsytems with different ages and metallicities . V.Marsakov & Yu. ... It is based on the fact, that all stars cross the disk plane several times during their Galactic orbital period. ... We have used our representative sample of nearby disk F2-G2 stars Marsakov & Shevelev (1995) in which fundamental stellar parameters was determined on the basis of published date on uvby-photometry, proper motion and radial velocities. ... Marsakov V.A., Shevelev Yu.G. Bull. ...

... Briefly, the count rate at the detector from a source at a redshift z is . ... Another possible way that could lead to arising diverse peculiarities in the - distribution induced by the sources evolution is connected with a possible non-monotonic character of the star formation rate in galaxies. ... The most prominent feature of the obtained theoretical - is a notable sharp increase at low count rates due to evolutionary effects. ...

... We demonstrate through numerical simulations that model parameters estimated with our technique are essentially bias-free, even when the average number of counts per bin is 1. ... The IW technique avoids such biases by estimating through successive iterations, where for each iteration, j, , and the best-fit parameters are determined by minimization of . ... In our sample, we find that the minimum values and best-fit parameters converge after about 6 iterations. ...

... In brief: the frequency-dependent radiative transfer equation is solved for a dust under assumption of spherically-symmetric geometry for its distribution taking into account particle size distribution and quantum heating effects for the very small dust particles. ... Table: Model parameters for IRAS04296+3429. ... parameter . ... hot dust shell) . ... The best fit to the spectral energy distribution of IRAS04296 is shown by heavy solid line (see Table2 for details concerning parameters of the model...

... A number of different statistical methods are used for estimating parameters from a data set. The most commonly used one is the least squares method which estimates a parameter by minimizing the function : . where y is the dependent and x the independent variables while f is a given function. ... The most important assumptions are that the errors in the dependent variable are normal distributed, the variance is homogeneous, and the independent variables have no errors and are uncorrelated. ...

Next: Simulations Up: Maximum Likelihood Estimation of Previous: Introduction . The properties of an ensemble of faint galaxies can be defined by the distribution of the parameters of the models that best fit each individual object. ... The model also includes instrumental parameters, such as the sky background (estimated locally) and amplitude of the noise. ... The probability of the observed value is then computed for each pixel using the adopted error distribution. ...

http ://hea-www.harvard.edu/ AstroStat /slog/2008/eotw-chisq- distribution / Weaving together Astronomy+Statistics+Computer Science+Engineering+Intrumentation, far beyond the growing borders Fri, 01 Jun 2012 18:47:52 +0000 hourly 1 http ://wordpress.org/?v=3.4 http ://hea-www.harvard.edu/ AstroStat /slog/2008/eotw-chisq- distribution /comment-page-1/#comment-308 Alex Sun, 27 Jul 2008 01:52:08 +0000 http ://hea-www.harvard.edu/ ... Thanks, Aneta, very useful comment. ...

To construct two-dimension distribution of minor planets user should specify elements/ parameters/ function that will be plotted as abscissas and ordinates. In three-dimension case one should add to them the element plotted on Z axis. ... Though you may choose elements plotted along different axes at will, often there is good reason to plot such elements as a, n, or n" along X axis (two-dimension distributions) and to plot them along Y axis in three-dimension case. ...

... A list of spectrum files from a set of observations, referring to one RGS instrument and one spectral order. These spectra files must be produced using the attstyle=user and associated parameters from a call to rgsproc . ... A list of accompanying event list files, in the same order as the spectra files. ... If this parameter is set to yes, the spectra files of the input lists will be combined to produced a combined spectrum file each for both spectra and background spectra files. filermf . ...

... Fitting the observed dependence includes calculations of the polarization cross-sections averaged over particles orientation and size distribution, their normalization and the comparison of obtained dependencies with Serkowski's curve representing observational data for a chosen star. ... Variations of the polarization factors wit