... To determine the parameters we want (stellar magnitudes and colors) from the observations we have, we fit the data to a model. The model should represent the circumstances of the observations as realistically as possible; otherwise, effects present in the data but not in the model will be distributed among the available adjustable parameters, such as stellar magnitudes, extinction coefficients, and transformation parameters. ... The bias problem . ...

... The technology needed to implement a Distributed Astronomical Data Archive (DADA) is available today (e.g., Fullton 1993). Query interface standards are needed, however, before the DADA information will be discoverable. ... These parameters would be used to index each dataset in each catalog. ... The technology is available today to perform cross-catalog queries, to fetch the data at the click of a mouse, quickly to add new observation catalogs, and to distribute the load across multiple machines. ...

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. ...

Magellanic Clouds in interaction evolutionary search for good models Adam Rzicka1, Jan Palous1, Christian Theis2 1Astronomical Institute, Prague; 2Institut fЭr Astronomie, Wien Idea investigate the LMC-SMC-Milky Way (MW) interaction by modeling the distribution of HI related to the Magellanic System (BrЭns et al. ... How much does the HI distribution tell about the LMC/SMC motion? ... It's all about proper motion... select a high-quality model (FF 0.5) and look around Tidal models don't work.. ...

As in the last years, the Ephemerides of Minor Planets for 2015 are prepared by the IAA RAS only in the electronic form. ... Orbital elements of all numbered planets have been determined in IAA all over again on the ground of available observations in the catalog of the Minor Planet Center. ... More detailed information on orbital elements used in the present volume of EMP and their accuracy is given in section "Information on new orbital elements". ... a) information on new orbital elements; . ...

... 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 . ...

Weaving together Astronomy+Statistics+Computer Science+Engineering+Intrumentation, far beyond the growing borders . ... 2002, ApJ, 571, 545) , here is a formal expression for the Likelihood Ratio Test Statistic, . ... Tags: EotW , Equation , Equation of the Week , F-test , likelihood , likelihood ratio test , LRT , Protassov , Rostislav Protassov . ... Likelihood-ratio type tests are actually the basis of many common tests; for example, the one-sided Z test is equivalent to a likelihood ratio test. ...

Next: Program use Up: Description of program searchdup Previous: Description of program searchdup . Parameter input is done with a graphic user interface. ... Input file: Name of the input catalog file. It has to be formatted, one record per source/observation, according to the format used in the Arcetri observations and source archives. ... Minimum number of observations per source Source with less than this number of independent observations are not included in the output file . ...

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. ...