The Mass-Density of the Universe and the Distribution of Dark Matter Neta A. Bahcall Princeton University, USA One of the most fundamental questions of cosmology is: How much matter is there in the Universe and how is it distributed? Here we show that several independent measures - including those utilizing clusters of galaxies - all indicate that the mass-density of the Universe is low: only 20-30% of the critical density. ... The results reveal a low den- sity of 0.16+-0.05. ...

... About ATMoB . ... The Observing Committee is starting an Observing Awards Program to promote observing among the membership of the Amateur Telescope Makers of Boston. ... Participant must be a current member of the Amateur Telescope Makers of Boston . ... To qualify for your Observing Award Certificate, turn in your worksheet and drawings to an ATMoB Observing Committee member or observing@atmob.org . ... This Excel sheet has useful macros. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... All the galaxies are divided into 4 groups depending on the environment type; every subsample contains more than 10 galaxies. ... An effect of environments is seen both for the nuclei and for the bulges: if we consider the clusters (Virgo and Ursa Ma jor) and group centers as dense environments and the field and group periphery as sparse environments, then in the dense environments the stellar populations of S0s are in average older by 4­5 Gyr than in the sparse ones. ...

... Dept. for Physics of Stars&Galaxies . ... Using a database view Sloan Digital Sky Survey (SDSS), containing almost a million spectra created 15,000 sample galaxies with active star formation, which is used for various studies and physical state of evolution of galaxies. ... Star clusters of the Galaxy . The project MWSC (Milky Way Star Clusters) directory using 2MASS, which includes nearly 500 million vision to the limit Ks = 15.3, analyzed more than 4,000 cluster-like objects in the galaxy. ...

... Chubukova I. - Data Mining (2007) PDF Data Mining . Hand D. Mannila H. Smyth P. - Principles of data mining (2001) DJVU Data Mining . Mitra S. Acharya T. - Data mining (2003) (In Russian) DJVU Data Mining . Abbass H. Sarker R. Newton C. - Data Mining Heuristic Approach (2002) PDF Data Mining . Rao C. Wegman E. Solka J. - Handbook of Statistics Data Mining and Data Visualization (2004) PDF Data Mining . ... Whittet D. - Dust in galaxies (2003) PDF Межзвездная среда . ...

... Bad Astronomy . ... Bitesize Astronomy . ... The last step encompassed them all with galaxies , and how we discovered that the Milky Way was not the entire Universe. ... And just like those star clusters, there are different kinds of galaxy clusters. ... There are vast clusters of clusters, called superclusters, which contains hundreds of thousands or even millions of galaxies. ... Our own Galaxy has 400 billion stars in it, yet there are clusters out there with millions of galaxies like our own. ...

... The analysis of two-dimensional galaxy distribution in the Jagiellonian Field (JF) was carried out by the wavelet technique. The positions of galaxies were taken from the Revised Jagiellonian Field Catalogue (RJFC) based on digitized scans of the JF original photographic plates. We discuss briefly the procedure of star/galaxy separation applied by us to the RJFC, the algorithm and the first results of mapping of the selected parts of the RJFC. ...

... Session 1 - Stars, star formation, stellar populations and planets . 9.20 10.00 . ... HST Spectroscopy of the Hottest White Dwarfs . ... Coffee break . ... Lunch break . ... A (long) look at neutron stars with HST . ... Session 2 - Nearby galaxies, bulges, spheroids, galaxy formation . ... New HST/ACS Insights into the Evolution of Star-Forming Dwarf Galaxies with Extreme Properties of Cosmological Relevance . ... Deriving properties of Lyman-break galaxies at z~3-5 using HST/VLT/Spitzer data . ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... The number distribution is shown in the middle panel. The right panel illustrates the distribution of chirp mass due to different DWD types, normalized by the total number (2.76†Ч108) of DWDs in the Galaxy (bin size M = 0.001M ? ... The frequency spectra of DWD strain amplitude and number distribution are presented as a function of galactic component, DWD type, formation channel, and metallicity. тИТ4.5. ...

... We address a question if globular clusters (GC) in a protogalaxy could for some time evolve chemically as isolated systems, enriching themselves with heavy elements produced in first supernova events that follow initial star formation. We determine both the critical mass of a protoglobular cluster that is needed to retain the ejecta of the very first supernova, and the critical energy (i.e., number of supernovae) that is needed to expel the residual gas from a cluster of a given mass. ...

. Fractal Matter Distribution . Observed fractal galaxy distribution is discuused in: . F.Sylos Labini, M.Montuori L.Pietronero, "Scale invariance of galaxy clustering" astro-ph/9711073 . The home page of "The Debate on fractal Universe"

... Bisnovatyi-Kogan, Gennady S.; Merafina , Marco; Vaccarelli , Maria Rosaria; Spherically Symmetric Stellar Clusters with Anisotropy and Cutoff Energy in Momentum Distribution. ... We construct numerical models of spherically symmetric Newtonian stellar clusters with anisotropic distribution functions. ... Models of spherically symmetric relativistic stellar clusters with anisotropic distribution functions in relativistic regime are described by using Maxwellian distribution function with energy...

Working session on Standard Candles Chair: F. Haberl · Definition of standard candles Sources with constant X-ray flux: white dwarfs isolated neutron stars supernova remnants cluster of galaxies · Scientific drivers for accurate absolute fluxes neutron star radii cosmology (e.g. total mass of galaxy clusters, Sunyaev Zeldovic effect) · Calibration purposes absolute flux ...

... О Далекой Галактике . ... Теперь в Далекой Галактике вы всегда можете увидеть свежие фотографии Солнца. ... Форум . Форум "Далекой Галактики" - прекрасное место для общения всех астрономов. ... Новости из космоса . ... Подписаться на новости Далекой Галактики Вы можете здесь: . ... Новости из Далекой Галактики - популярно об Астрономии . ... Если вы хотите выразить свое мнение о сайте "Далекая Галактика", или просто почитать мнения других посетителей - пожалуйста, заходите в Гостевую книгу . ...

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J/AstL/vol/page SAI Open Clusters Catalog (Glushkova+, 2009) ================================================================================ Automated search for star clusters in large multiband surveys. ... Color excesses E(B-V), distance moduli and ages were determined for 141 new and 27 known, but poorly studied clusters. We present the Sternberg Astronomical Institute Open Clusters Catalog (SAI OCL Catalog) of coordinates, diameters and main physical parameters of these clusters. ...

Clusters of galaxies are the largest gravitationally bounded structures in the Universe dominated by dark matter. We review the observational appearance and physical models of plasma structures in clusters of galaxies. ... The knowledge of the complex dynamical and feedback processes is necessary to understand the energy and matter balance as well as to constrain the role of the non-thermal components of clusters. ...

Russian . ... Very Early Universe: inflation, generation of primordial perturbations, preheating . Very Early Universe: inflation, generation of initial perturbations, preheating . Cosmic Microwave Background Radiation: anisotropy and polarization . ... Dark Energy and Dark Matter models . High Energy Astrophysics: accretion discs, cosmic rays, gamma-ray bursts . ... Astrophysics of black holes and wormholes . ...

Central Bodies Masses of Selected Globular Clusters N.A.Shakht, A.A.Kiselev, Yu.N.Gnedin and E.A.Grosheva. The Main Astronomical (Pulkovo) Observatory RAS 47 Tuc ­NGC 104 RA 00 24 .1 Dec -72° 04 .9 Size = 30.9 mvis + 4. 0 m D from = 12,1 kpc, h m Cen - NGC 5139 NGC 6397 (Ara) RA 17 h40.m7 Dec -53o 40'.4 Size = 31',0 mvis + 5,3m D from =2.3 kpc RA 13h 26m .8 Dec -47° 28 6 Size = 36.3 m vis +3. 7 m D from =15.8 ±1.1 kpc, 12109 years, Age: 10109 years, (13.4 ± 0.8)109 years. ...

Общая Астрономическая Конференция > Практика > Астрономический наблюдательно-информационный портал > Звездные ассоциации - шаровые скопления (поиск и описание) .. Шаровые скопления Терзяна (Terzan globular clusters) .. ... Поиск . ... Terzan 5 подробнее о шаровом скоплении читайте здесь (# 861 ) . ... Звездные ассоциации - шаровые скопления (поиск и описание) .. ... Messier 13 Great Globular Cluster in Hercules (M13) - шаровое скопление NGC 6205 (Melotte 150) в созвездии Геркулес (Hercules) .. ...