One possible way for spiral galaxies to internally evolve would be for gas to flow to the center and form stars in a central disk (pseudo-bulge). ... In this paper we present radial profiles of stellar and 8 ЮМm emission from polycyclic aromatic hydrocarbons (PAHs) for 11 spiral galaxies to investigate whether the interstellar medium in these galaxies contains a central concentration above that expected from the exponential disk. ...

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. ...

Figure 1: The ux density distribution of confusing sources in the IDV sample for 1.4 GHz. ... N corresponds to the number of confusing sources detected in 101 images of the IDV sample target sources (no beam shape correction applied). 1 (a) 2.4 GHz (b) 4.8 GHz Figure 2: The number distribution of modulation indices,  of the total ux den- sity calculated over the duration of each observing run: May 1994 and August 1994. The distributions of  are shown for (a) 2.4 GHz and (b) 4.8 GHz. ...

... The distribution of redshifts among the DXRBS FSRQs identified so far (Figure 3) is quite similar to that of the 1 Jy and S4 samples. ... A more thorough comparison will have to await completion of our survey and the convolution of the redshift distribution with the WGACAT sky coverage. As has already been mentioned by Hook et al. (1996), selecting flat-spectrum sources is an efficient way of finding high-redshift, radio-loud quasars. ...

... Class . ... FRAMES NO FRAMES All Classes . ... FIELD | CONSTR | METHOD . DETAIL: FIELD | ... java.lang.Object ij.plugin.Distribution . ... public class Distribution . ... This plugin implements the Analyze/Distribution command. ... This method is called when the plugin is loaded. void . ... Constructor Detail public Distribution () . ... This method is called when the plugin is loaded. 'arg', which may be blank, is the argument specified for this plugin in IJ_Props.txt. ...

Model Selection Astro193, March 9 Steps in Hypothesis Testing 1/ Set up 2 possible exclusive hypotheses - two models : M0 ­ null hypothesis ­ formulated to be rejected M1 ­ an alternative hypothesis, research hypothesis 2/ Specify a priori the significance level 3/ Choose a test which: - has the required power - approximates the conditions - finds what is needed to obtain the sampling The model with the largest value provides the best description of the data. ...

... Using the central limit theorem, the total noise can be approximated by a Gaussian or normal distribution which has the frequency function : . ... where is the mean intensity of the source. ... In the statistical analysis of the probability distribution of data several estimators based on moments are used. ... For a normal distribution, these moments are and while for a Poisson distribution are and . Besides these moments other estimators are used to describe a distribution e.g. median and mode . ...

... According to the most popular cosmological paradigm, the greater part of the galaxy mass is accumulated in the dark matter halo. ... The polar ring galaxies (PRGs) reveal external rings or disks of gas, dust and stars rotating in a plane roughly perpendicular to the disk of the central galaxy. ... The shape of the dark halo in the model was chosen so as to achieve the best fit to the observed rotation of both galaxies themselves and their polar rings. ... The SPRC-7 galaxy. ...

. Pulkovo Observatory of Russian Academy of Sciences is situated . near Saint-Petersburg. It was founded in 1839. 196140, Saint-Petersburg, Pulkovskoye chaussee 65/1 . English version . Russian version . This page has been accessed times since May 1, 1999.

... 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...

... In the case of a single pixel of a single image, is the Poisson distribution about the expectation value of the counts due to background, . As described in section 3.2 , we say there is a source present in this pixel if is larger than a cutoff value . ... This value of , minus the expectation due to background , is defined here as the detection sensitivity. Note that this does not mean that a source with an expectation value of counts which is greater than will always be detected. ...