The above image is a computer simulation of the distribution of mass in a Dark Matter dominated Universe. ... Structure (\eg density enhancements) clearly forms at the intersection of these filaments. ... What is Dark Matter? ... Testing for the presence of dark matter in the solar neighborhood now becomes an accounting problem The possible sources of this mass in the solar neighborhood are 1) luminous stars, 2) interstellar gas, 3) stellar remnants (mostly white dwarfs) and 4) dark matter: . ...

We compare atomic gas, molecular gas, and the recent star formation rate (SFR) inferred from HЮБ in the Small Magellanic Cloud (SMC). ... This allows us to disentangle conversion factor effects from the impact of metallicity on the formation and star formation efficiency of molecular gas. ... At a fixed total gas surface density the SMC has a 5-10 times lower molecular gas fraction (and star formation rate) than large spiral galaxies. ...

Chiaki Kobayashi, Ralph Sutherland How galaxies did form and evolution? - to answer this unsolved problem, we are simulating the formation and evolutionary history of galaxies in the Universe, including star formation, supernovae feedback, and chemical enrichment. Comparing the spacial distribution of elements within galaxies with observations, we will examine fundamental physical processes that drive galaxy formation. ... COALA : Universe Galaxy AGN Star Planet ...

The Stats of Couples From Pairing Algorithms to Binary Mass-Ratio Distributions Yutong Shan Binary Formation: Theory vs. Observation How do we think most Binaries form? ... 2009) Mass-Ratio Distribution: жpik's Law Observed binary mass-ratio distribution is often `fitted' with a power law: жpik's Law: f(q) ~ q q = Msecondary/Mpri mary жpik's Exponent, Equal-mass favoured Unequal-mass favoured Primary Mass (Mprim) Flat Often stated as a function of Primary Mass q = Msec / Mprim (Raghavan et al. ...

... The sample of the Local Volume galaxies (distance smaller than 10 Mpc) gives a unique opportunity to study the properties of galaxies including the weakest objects: the absolute magnitude M B -10 and the virial mass M vir 10 9 M x263C;. ... Luminosity function of the Local Volume galaxies. ... The luminosity functions for galaxies are presented: red dashed line - from the 2dFGRS survey (Norberg et al. 2002); blue dash-dotted line - from the SDSS survey (Blanton et al. ...

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. ...

... The Fornax Cluster galaxy FCC 35 shows an unusual multiply peaked integrated HI profile. We have now observed FCC 35 with the Australia Telescope Compact Array and have found a compact HI source with M_HI = 2.2 x 10^8 Msun; and a spatially overlapping complex of HI gas with the same mass. By combining optical observations with the HI data, we are able to identify FCC 35 as a young compact source of star formation with a nearby intergalactic HI cloud that is devoid of stars. ...

Proposal Identification No.: A2004 Date Received: 2004 -Sep-30 12:45:57 Technical Page Proposal Type: General Category: Sub-Category: Observation Category: Total Time Requested: Prop osal Title: ABSTRACT: Commensal Astronomy Spectroscopy Galactic 28 Hours An Initial HI Survey of the Taurus Region We propose to carry out a high spectral resolution survey of a 60 square degree region of the Taurus Molecular Cloud. ... X Part of the observing run. ...

My main field of interest is modelling dust extinction and emission in the disk of spiral galaxies. Radiative transfer simulations are compared to optical, FIR and sub-mm observations to assess the dust mass, distribution relative to star and optical/emission properties. ... I'm also interested in the formation, evolution and survival of dust grains in high-redshift objects, and in comparing the extinction / emission properties of dust with observations of distant sources. ...

... The sky distribution of the BCGs from the HSS sample is shown in Fig. 6 together with BCGs from the SBS and Case surveys (Izotov et al. [ 1993b ]; Pustilnik et al. ... First, we compare the apparent magnitude distributions of the three samples. ... The similar behaviour of the faint end of the apparent magnitude distributions infers that the Northern BCG sample may have a similar completeness down to this limiting magnitude. ...

... First, we computed the mean errors of orbit parameters on the assumption of the linear connection of them with observation errors and then we compared obtained estimates with those resulting from the assumption of the nonlinearity of this connection. Secondly, we correlate orbital parameters and their errors obtained by the method of the least modulus with those obtained by the least-squares method. ...

XMM­Newton CCF Release Note XMM­CCF­REL­135 EPIC MOS Spectral Response Distribution R. D. Saxton, S. Sembay 10 Dec 2002 1 CCF components Name of CCF VALDATE EVALDATE List of Blocks changed CAL VERSION XSCS flag EMOS1 REDIST 0020.CCF 1999­12­10 2000­07­15 CCD REDISTRIBUTION ­n 3.152 NO EMOS1 REDIST 0021.CCF 2000­07­15 2000­11­09 CCD REDISTRIBUTION ­n 3.152 NO EMOS1 REDIST 0022.CCF 2000­11­09 2001 ­04­18 ... Mos­1, epoch 1 (rev 62) imaging mode response, all patterns. ...

... The dayside auroral precipitation consist of magnetosheath related boundary layer precipitation, and plasma sheet related BPS/CPS precipitation (extensions of the nightside precipitation regions). ... For example, the much lower fluxes from the LLBL region when compared to the cusp are compensated by the bidirectional electron beams found in the LLBL: the precipitating energy fluxes in the LLBL and the cusp are not that different. ... directly through the cusp and plasma mantle . ...

A comparative study of type I and type II supernovae . ... Sternberg State Astronomical Institute, Moscow, U.S.S.R. (Received 26 November, 1985) . ... No significant difference between SNe I and SNe II has been found in their radial distribution and frequency of outbursts in spiral galaxies. ... The radial distribution of type Ia SNe in spiral galaxies is only slightly steeper than the one for SNe II, while SNe Ib/c are more concentrated towards the central regions. ...

... One of the objectives of this work is to derive radial distribution of supernova remnant surface densities in spiral galaxies. ... Other objectives include the comparison of the SNR radial distribution with the radial distribution of HII regions to look for any association between Type II progenitors and the SNRs and comparison of the SNR distribution to the spiral arm patterns. ... Knowing the positions of the SNRs, we can compare their distributions relative to HII regions and spiral arms. ...

... 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. ...

... Ciel Espace, le magazine qui vous guide toujours plus loin . ... des pages consacr†йes †а la publication de vos photos Mais c'est aussi une vraie communaut†й avec laquelle partager votre passion et nourrir votre curiosit†й. Accueil Mati†иre noire : une observation d†йfie les astronomes . ... A la une . ... En effet, selon les mod†иles th†йoriques, les concentrations de mati†иre noire sont les lieux o†µ naissent les galaxies. ... Une mati†иre noire au comportement ordinaire ? ... Etat du ciel . ...

... Galaxies rotate and move in clusters as if a tremendous amount of unseen matter is present. But does dark matter exist in the greater universe too -- and if so, where? ... In the above frame from a computer simulation of our universe , a 300 million light-year slice shows dark matter in gray and galaxies as colored circles. ... Publications with keywords: universe - dark matter - 2dF survey - simulation . Publications with words: universe - dark matter - 2dF survey - simulation . ...

... 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. ...

What follows is a brief list of benchmarks and discoveries that shaped our ideas on atoms and nuclei. ... Discovery of electrons . ... Comparing this to Faraday's results, one could get " Avogadro's number ", the number of (say) hydrogen atoms in one gram of hydrogen--an enormously large number. ... Similarly, energized atoms are only allowed to exist in one of a number of energy levels. ... By the way, Avogadro's number is 602,000,000,000,000,000,000,000 (6.02 10 23 ) molecules in 1 gr hydrogen. ...