Next: Rotation Periods of PMS Stars Previous: Direct Monitoring of PMS Stars . Studies using direct detection of periods via rotational modulation have been carried out on stars in several young clusters which are near the zero--age main sequence (ZAMS), including the Hyades, the Pleiades and Persei (see Radick 1988, Schaller et al . ... Rotation in ZAMS clusters has a strong mass dependence. High--mass stars tend to rotate much more quickly than the low--mass stars. ...

... The Hydra Cluster of Galaxies . ... 16.04.2001 . ... Most of a cluster's mass , however, appears to be in a form too dark to see , as analyses of the distribution of X-ray light , gravitational lensing , and internal motions indicate. Abell 1060, as the above cluster is also known, appears to have an even higher fraction of dark matter than seen in a similar cluster, a situation astronomers cannot easily reconcile with both clusters forming solely from gravitational attraction. ... April 2001 . ...

... ESO, the European Southern Observatory . ... ESO's Governing Bodies . ... Green ESO . ... This artistтАЩs impression shows the Milky Way galaxy. The blue halo of material surrounding the galaxy indicates the expected distribution of the mysterious dark matter, which was first introduced by astronomers to explain the rotation properties of the galaxy and is now also an essential ingredient in current theories of the formation and evolution of galaxies. ... Dark Matter , Milky Way . ... Milky Way . ...

... 2004 January 20 . Unexpected Galaxy String in the Early Universe . ... Explanation: How could such a long string of galaxies form so early in the universe? Several new measurements of galaxies and clusters in the early universe are reporting structures involving galaxies and clusters that are larger than expected with the new standard "dark-energy" cosmology . The controversy centers on the inability of a dark-energy dominated universe to create such large structures. ... About APOD | ...

Tidal Triggering of Star Formation and the Butcher­Oemler Effect Mark J. Henriksen (University of Alabama and UCLA) Gene Byrd (University of Alabama) We have calculated the expected level of star formation which would be induced in a disk galaxy falling into the potential well of a cluster of galaxies due to: drag force from the ICM, the radial tidal force from the cluster potential, and the lateral tidal force from the cluster potential. ... Table 4 contains the downstream post­ shock critical mass. ...

. F igure . 7. Distributions of height above the Galactic plane for (a) thick-disk, (b) old-halo, and (c) young-halo clusters. The curves are exponential least-squares approximations of the corresponding distributions. discussion in the text | privious figure | next figure .

... The (very) slow rotation of magnetic Ap stars. ... Magnetic stars in young clusters and associations. ... Magnetic fields in low-mass stars from high-resolution infrared spectroscopy. ... Magnetic field measurements of late B-type starss. ... Measurement of magnetic field of FK Com. ... Magnetic field of white dwarfs. ... The magnetic star evolution project (teleconference). ... Conference-2014 . Program . ... Laboratory for the Stellar Magnetism Study of SAO of RAS . ...

... 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...

The radial distribution of metallicity of star-forming galaxies in a galaxy cluster can inform us about the mass assembly and enrichment history of the galaxy cluster. ... Both galaxy clusters are cool-core clusters at redshift z т?? ... The gas-phase metallicity of star- forming galaxies in MACS1115+01 exhibit anti-correlation with projected distance т??0.15 ТБ 0.08 dex/Mpc, whereas the radial metallicity distribution of RXJ1532+30 is statistically flat (т??0.09 ТБ 0.12 dex/Mpc). ...

... Kopylov, A.I., Kopylova, F.G. "Structure of galaxy groups and clusters and measurement of their masses", . ... Kopylova, F.G., Kopylov, A.I. "Peculiar motions of galaxy clusters and groups in the Hercules and Leo supercluster regions", . ... Kopylova, F.G., Kopylov, A.I. "Analysis of the properties of clusters of galaxies in the region of the Leo supercluster", . ... Kopylova, F.G., Kopylov, A.I. "Analysis of the properties of clusters of galaxies in the region of the Ursa Major supercluster", . ...

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