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# NGC 1599

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 Supernovae 2005ao, 2005ap, 2005aqIAUC 8492 available at Central Bureau for Astronomical Telegrams. HYPERLEDA. II. The homogenized HI dataAfter a compilation of HI data from 611 references and new observationsmade in Nançay, we produce a catalog of homogenized HI data for16781 galaxies. The homogenization is made using the EPIDEMIC methodfrom which all data are progressively converted into the adoptedstandard. The result is a catalog giving: 1) the logarithm of twice themaximum rotation velocity, log 2V_Msin i, converted to thesystem of Mathewson et al. (\cite{Mathewson1996}). This quantity isgiven without correction for inclination; 2) the HI magnitude,m21, (area of the 21-cm line width expressed in magnitude)converted to the flux system of Theureau et al. (\cite{Theureau1998});3) the HI velocity, V_HI, expressed with the optical definition (i.e.,using wavelengths instead frequencies). The typical uncertainties are:0.04 for log 2V_Msin i, 0.25 mag for m21 and 9 kms-1 for V_HI.Full Tables \ref{epidemicw}, \ref{epidemicw2}, \ref{epidemicf},\ref{epidemicf2} and Fig. \ref{profiles} are available in electronicform at http://www.edpsciences.org. Full Tables \ref{references},\ref{cataf}, \ref{newdata} and \ref{notes} are available in electronicform at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5)or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/412/57 Nearby Optical Galaxies: Selection of the Sample and Identification of GroupsIn this paper we describe the Nearby Optical Galaxy (NOG) sample, whichis a complete, distance-limited (cz<=6000 km s-1) andmagnitude-limited (B<=14) sample of ~7000 optical galaxies. Thesample covers 2/3 (8.27 sr) of the sky (|b|>20deg) andappears to have a good completeness in redshift (97%). We select thesample on the basis of homogenized corrected total blue magnitudes inorder to minimize systematic effects in galaxy sampling. We identify thegroups in this sample by means of both the hierarchical and thepercolation friends-of-friends'' methods. The resulting catalogs ofloose groups appear to be similar and are among the largest catalogs ofgroups currently available. Most of the NOG galaxies (~60%) are found tobe members of galaxy pairs (~580 pairs for a total of ~15% of objects)or groups with at least three members (~500 groups for a total of ~45%of objects). About 40% of galaxies are left ungrouped (field galaxies).We illustrate the main features of the NOG galaxy distribution. Comparedto previous optical and IRAS galaxy samples, the NOG provides a densersampling of the galaxy distribution in the nearby universe. Given itslarge sky coverage, the identification of groups, and its high-densitysampling, the NOG is suited to the analysis of the galaxy density fieldof the nearby universe, especially on small scales. Total magnitude, radius, colour indices, colour gradients and photometric type of galaxiesWe present a catalogue of aperture photometry of galaxies, in UBVRI,assembled from three different origins: (i) an update of the catalogueof Buta et al. (1995) (ii) published photometric profiles and (iii)aperture photometry performed on CCD images. We explored different setsof growth curves to fit these data: (i) The Sersic law, (ii) The net ofgrowth curves used for the preparation of the RC3 and (iii) A linearinterpolation between the de Vaucouleurs (r(1/4) ) and exponential laws.Finally we adopted the latter solution. Fitting these growth curves, wederive (1) the total magnitude, (2) the effective radius, (3) the colourindices and (4) gradients and (5) the photometric type of 5169 galaxies.The photometric type is defined to statistically match the revisedmorphologic type and parametrizes the shape of the growth curve. It iscoded from -9, for very concentrated galaxies, to +10, for diffusegalaxies. Based in part on observations collected at the Haute-ProvenceObservatory. An image database. II. Catalogue between δ=-30deg and δ=70deg.A preliminary list of 68.040 galaxies was built from extraction of35.841 digitized images of the Palomar Sky Survey (Paper I). For eachgalaxy, the basic parameters are obtained: coordinates, diameter, axisratio, total magnitude, position angle. On this preliminary list, weapply severe selection rules to get a catalog of 28.000 galaxies, wellidentified and well documented. For each parameter, a comparison is madewith standard measurements. The accuracy of the raw photometricparameters is quite good despite of the simplicity of the method.Without any local correction, the standard error on the total magnitudeis about 0.5 magnitude up to a total magnitude of B_T_=17. Significantsecondary effects are detected concerning the magnitudes: distance toplate center effect and air-mass effect. The morphological catalogue of galaxies equatorial surveyWe present 865 redshifts of galaxies located in the equatorial stripdelta between -17.5 deg and -2.5 deg in the right ascension rangebetween 20 h and 5 h. Redshifts have been obtained for the completesample of all 833 galaxies in the Morphological Catalog of Galaxies withmagnitudes brighter than m = 14.5 (corresponding approximately tom(Zwicky) = 15.0). This sample also includes three galaxies from othersources with more reliable magnitudes, satisfying this limit, and 29fainter galaxies, usually companions of the galaxies in the magnitudelimited sample. Our maps of a very large volume of nearby spacedemonstrate a variety of coherent large scale structures which includelarge voids, 20-50/h Mpc in diameter and large walls at least 70/h Mpcacross. Identification of infrared sources in the IRAS circularsFrom IRAS (Infrared Astronomical Satellite) Circulars Nos. 4 to 15, 110infrared sources have been identified. Out of these 110 identifiedsources 99 are galaxies, nine are nebulae, one is a dark object, and oneis a non-stellar object. Thirty-five of these galaxies, have alreadybeen studied, mostly are spiral type. The characteristics of sixty-fourremaining galaxies, for which the type is not known or uncertain, arestudied by comparing their colors and luminosities with known galaxies.The galaxies observed by IRAS are mostly active galaxies.
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# Math Help - Poisson Problem

1. ## Poisson Problem

If the number of accidents occuring in an industrial plant during aa day is given by a Poisson random variable with parameter 3.
Find
i) probability that no accident occurs on a day
ii)the expected number of accidents per day.

2. Originally Posted by zorro
If the number of accidents occuring in an industrial plant during aa day is given by a Poisson random variable with parameter 3.
Find
i) probability that no accident occurs on a day
ii)the expected number of accidents per day.
These questions are totally trivial and suggest a complete lack of effort on your part in trying to understand this material. Go to your class notes and/or textbook and read the section on the Poisson distribution.

3. ## Then is this right

probability of an accident happening in a day is
$
p(x;\lambda) \ = \ \frac{\lambda^x \ e^{- \lambda}}{x!} \ = \ \frac{3^x \ e^{-3}}{x!} = \frac{3^x \ 0.050}{x!}
$

probability of accident happening is
$
\left ( 1 - \frac{3^x \ 0.050}{x!} \right)
$

Expected no. of accidents per day is
$
E(X) = \sum x . p(x;\lambda) = \sum x \ . \ \frac{3^x \ . \ 0.050}{x!}
$

4. Originally Posted by zorro
probability of an accident happening in a day is
$
p(x;\lambda) \ = \ \frac{\lambda^x \ e^{- \lambda}}{x!} \ = \ \frac{3^x \ e^{-3}}{x!} = \frac{3^x \ 0.050}{x!}
$

probability of accident happening is
$
\left ( 1 - \frac{3^x \ 0.050}{x!} \right)
$

Expected no. of accidents per day is
$
E(X) = \sum x . p(x;\lambda) = \sum x \ . \ \frac{3^x \ . \ 0.050}{x!}
$
$\Pr(\text{accident}) = 1 - \Pr(\text{no accident}) = 1 - \Pr(X = 0) = 1 - e^{-3} = \, ....$

$E(X) = \lambda = 3$.

You need to thoroughly review this topic - the questions, especially the second question, are extremely straightforward.

5. ## hw did u get E[x]

Originally Posted by mr fantastic
$\Pr(\text{accident}) = 1 - \Pr(\text{no accident}) = 1 - \Pr(X = 0) = 1 - e^{-3} = \, ....$

$E(X) = \lambda = 3$.

You need to thoroughly review this topic - the questions, especially the second question, are extremely straightforward.

Isnt

$E[x] \ =\ \sum x .\ [1-p(x;\lambda)]= \ 0 \ . \ [1-p(x;\lambda) ]=0$

6. Originally Posted by zorro
Isnt

$E[x] \ =\ \sum x .\ [1-p(x;\lambda)]= \ 0 \ . \ [1-p(x;\lambda) ]=0$
No.

$E[X] = \sum x \cdot p(x; \, \lambda)$.

And the result of this calculation (which can be used without proof I would have thought unless the calculation is specifically asked for: http://www.mathhelpforum.com/math-he...tributiom.html) is $E[X] = \lambda$.