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. ...

... 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. ...

Next: The Newton--Raphson Method. Up: Fitting of Data Previous: Fitting of Data . ... In a linear problem, if the errors on the observations have a gaussian distribution, the ``Maximum Likelihood Principle'' gives you the ``best estimate'' of the parameters as the solution of the so-called ``Least Squares Minimization'' that follows: . ... A certain number of numerical methods have been developed to solve the non--linear least squares problem, four have so far been implemented in MIDAS. ...

The problem of solar wind data correlation for the observations onboard several spacecraft is very important for three points of view: . ... This problem is studied now in detail by systematic determination of ion flux and ion velocity data correlations by INTERBALL-1 (IKI group), WIND and IMP 8 (both - MIT group). ... Solar wind plasma correlation lengths from IMP 8, WIND and INTERBALL-1. ... Correlation of solar wind observations onboard several spacecraft: INTERBALL-1, IMP 8 and WIND data. ...

... There are compelling reasons for the pulsar community to utilise a standard data storage format. For example, standardisation of file formats significantly decreases the amount of effort required to integrate new instruments into the analysis chain. ... Accordingly, we have defined PSRFITS as a standard FITS-based format for pulsar data files. ... For example, the first line of Processing History HDU contains information about the data acquisition program and the initial structure of the file. ...

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. ...

... 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 . ...

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. ...

... Bojan Nikolic web pages (r. 329) . ... Analysis of (radio) spectra . I describe an approach to fitting and comparison of radio spectra based on Bayesian analysis and realised using a new implementation of the nested sampling algorithm. ... I this paper I cover the theoretical background, the algorithms used and the implementation details of the computer code. I also briefly illustrate the method with some previously published data for three near-by galaxies. ... Paper I: Method . ...

Some peculiarities of orbits of observed comets. ... Icarus, 2005 Simulation and reality Distribution of anti-perihelia of short-period comets with e 0.9 ( ecliptic coordinates ) Distribution of anti-perihelia of short-period comets with e 0.9 ( ecliptic coordinates ) Distribution of anti-perihelia of long-period comets with 0.9 e 1 ( ecliptic coordinates ) ­ ...

The radial distribution of metallicity of star-forming galaxies in a galaxy cluster can inform us about the mass assembly and enrichment history of the galaxy cluster. ... Both galaxy clusters are cool-core clusters at redshift z т?? ... The gas-phase metallicity of star- forming galaxies in MACS1115+01 exhibit anti-correlation with projected distance т??0.15 ТБ 0.08 dex/Mpc, whereas the radial metallicity distribution of RXJ1532+30 is statistically flat (т??0.09 ТБ 0.12 dex/Mpc). ...

Next: RECEIVER CHOICE Up: Spectral-Line Observing at AO Previous: Spectral-Line Observing at AO . ... This involves deciding which receiver you wish to use, the observing procedure and parameters you wish to employ, what frequency range and set-up for the correlator boards you want, integration length, any equipment you may need to deal with RFI (filters, radar blankers, etc.), etc. ... These files are automatically saved into your project area on the ``observer'' computer. ...

Magnetic stars, 2004,225-229 Averaged magnetic phase curves. ... ANALYSIS OF THE CATALOG 227 4 3 N stars 2 1 -4000 -3000 -2000 -1000 0 1000 2000 B0 (G) Figure 3: Number distribution of stars vs. coeffcient B0 for those stars which exhibit a magnetic phase curve with a double wave. of a magnetic star can occur if the angle between the magnetic and rotational axes is small or even zero. ... The catalog lists phase curves for 139 stars, 134 of them are magnetic Ap stars. ...

... 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 with wavelength are shown in Fig. 16 for homogeneous spheroidal particles with PF orientation. ... The distinction between prolate and oblate spheroids is also clearly seen. ...

Next: Redshift Distribution Up: Sample Identification Previous: Previously Identified Sources . ... In Figure 3, we plot the redshift distribution of DXRBS FSRQs opposite that of the 1 Jy and S4 samples. In Figure 4, we plot the redshift distribution of DXRBS BL Lacs opposite the Slew and 1 Jy samples. ... The apparent deficit of objects at the very highest luminosities is a result of the smaller area of sky covered by DXRBS compared to, e.g., the Slew and 1 Jy samples. ...

NMW survey overview . Access image archive . ... The New Milky Way survey aims to detect bright (V<13.5) optical transients near the Galactic plane using an automated wide-field (8x6 deg.) system capable of surveying the whole Milky Way area visible from the observing site in one night. ... All images obtained during the transient search survey are available online (please use the image archive access form ). ... Images per field: . ... Images per night: . ... Milky Way imaging time: . ...

... AMPLE (Adaptable Minor Planet Ephemerides) is integrated software package to deal with a number of problems concerning minor planets with the aid of IBM-type personal computer. ... compiling a list of all numbered minor planets which can be seen at certain moment within specified sky region and visualization of their mutual positions; . ... As AMPLE is able to reproduce virtually any table of "the Ephemerides of Minor Planets" , it may be considered as computer version of the EMP. ...

... Abstract: We present Monte Carlo radiative transfer simulations for spiral galaxies modelled as a stellar disk and a two-phase clumpy dust distribution. ... As a general result, clumpy models are less opaque than the corresponding homogeneous models. ... 0.00 0.15 0.50 0.1 0.5 1.0 2.0 5.0 10.0 0.25 X . ... We have also produced several homogeneous models, to compare to the clumpy models. ... Homogeneous and clumpy models with the same tauV have the same dust mass. ...

THE PARAMETERS INVOLVED IN HAPKE'S MODEL FOR ESTIMATION OF THE COMPOSITION OF THE EJECTA LUNAR TERRAINS. ... In the previous papers we were estimated the surface roughness of the ejecta lunar terrains by means comparison of the local phase function and the average integrated lunar indicatrix. ... The Hapke's theoretical model of the lunar surface reflection. ... For THE PARAMETERS INVOLVED IN HAPKE'S MODEL: S.G. Pugacheva, V.V. Shevchenko a low-albedo lunar surface parameter Bo = 1. ...

Static Fourier spectrometers are often used for spectral measurements of the ionosphere emissions. There are two main advantages of Fourier spectrometers (FS) - large geometric factor and high spectral resolution; these parameters are two orders better than for grating spectral instruments. ... In scanning Fourier spectrometer optical and electric modulation of signal is used to avoid this problem, for static Fourier spectrometer there are no such ways. ...