Next: Star Formation Rate and Up: No Title Previous: Calculation of Evolutionary Tracks . To start calculations, we choose the distributions of the initial binary parameters: the mass of the primary ZAMS component, , binary mass ratio, , orbital separation a . ... whereas the mass ratio distribution is not. ... The zero assumption often made is that the mass ratio distribution has a flat shape, that is binaries with a high mass ratio occur as frequently as those with equal masses. ...

Target Acquisition Reference Information . ... In almost all cases where an onboard acquisition will not work (because the object is in a crowded field, or is variable, or is a moving target), it is sufficient to use an early acquisition to get a WFPC2 or FOC image a few weeks in advance of the GHRS observation. ... Explicit BRIGHT and FAINT limits may be specified if you desire, although there is an increased risk of a failed acquisition unless you are confident of those fluxes. ... MAPs . ...

... User Guide ] Task: uvsfit Purpose: Fit point sources to a given vis file. ... You can reduce the data volume by averaging in frequency using the line parameter (apply bandpass first) or selecting a subset of the data. If you want to produce model or residual visibilities at full resolution for all the data, you can run UVSFIT again with all source parameters specified and fixed. ... Key: sspar This gives initial estimates of source spectral parameters. ... 1 The spectral term alpha1 is fixed. ...

... 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. ...

... The planning and reduction programs are distributed with array sizes set large enough to let most observers work without difficulty. However, you might need to reduce a very large data set, or to deal with a very large number of passbands (9 is the nominal limit). ... The main problem is holding the matrix of normal equations during the iterations; on the other hand, star catalogs can be made quite large without paying much of a price in terms of performance. ...

... astro-ph . ... Whitespace-separated words are treated as AND ed. Show 10 50 100 articles per page in Full Compact mode . ... Quasar Variability in the Framework of Poissonian Models . ... It is shown that in this very general framework the well established anti-correlation between variability amplitude and wavelength can only be understood as an effect of an underlying spectral component which remains stable on long time-scales, and is redder than the variable component. ...

Kholtygin A.F., Shneiwais A.B. Stochastic Data in Astronomy: Fourier Analasis of Strongly Unevaen Time Series . Astrophysics, 48 , 87-100 ( 2005 ) . A detail analysis of the CLEAN algorithm for strongly uneven time series is given. ... The results of our analysis are used for searАhing the harmonic components in line