ULMS: An Accelerator for the Applications by Shifting Writing Log from Local Disk to Clouds

2010 ◽  
Author(s):  
Li Zhou ◽  
Yong Zhang ◽  
Chunxiao Xing
Keyword(s):  
Local Disk

scholarly journals The Luminosity Function of White Dwarfs in the Local Disk and Halo

1989 ◽  
Vol 114 ◽  
pp. 15-23 ◽  
Author(s):  
James Liebert ◽  
Conard C. Dahn ◽  
David G. Monet
Keyword(s):  
White Dwarfs ◽  
Luminosity Function ◽  
Solar Neighborhood ◽  
Star Formation History ◽  
Empirical Estimates ◽  
Formation History ◽  
History Of ◽  
Cool White Dwarfs ◽  
Local Disk

The luminosity function (LF) and total space density of white dwarfs in the solar neighborhood contain important information about the star formation history of the stellar population, and provide an independent method of measuring its age. The first empirical estimates of the LF for degenerate stars were those of Weidemann (1967), Kovetz and Shaviv (1976) and Sion and Liebert (1977). The follow-up investigations made possible by the huge Luyten Palomar proper motion surveys, however, added many more faint white dwarfs to the known sample. While the number of known cool white dwarfs grew to nearly one hundred, these did not include any that were much fainter intrinsically than the coolest degenerates found from the early Luyten, van Biesbroeck and Eggen-Greenstein lists.

scholarly journals How Unusual are Stars with Planets?

2004 ◽  
Vol 213 ◽  
pp. 51-54
Author(s):  
I. Neill Reid
Keyword(s):  
Comparative Analysis ◽  
Planetary Systems ◽  
Solar Abundance ◽  
Strong Trend ◽  
Planetary Mass ◽  
Local Disk

Comparative analysis of the parent stars of extrasolar planetary systems and the local disk population shows a strong trend for increasing frequency with increasing abundance. Approximately 4.5% of solar-abundance (−0.15 < [m/H] ≤ +0.15) stars have detectable planetary-mass companions.

scholarly journals Minor mergers: fundamental but unexplored drivers of galaxy evolution

2015 ◽  
Vol 11 (S319) ◽  
pp. 130-136
Author(s):  
Sugata Kaviraj
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Morphological Type ◽  
Disk Galaxies ◽  
Early Type ◽  
Gas Reservoirs ◽  
Star Formation Activity ◽  
Merger Process ◽  
Minor Mergers ◽  
Local Disk

AbstractWe use the SDSS Stripe 82 to study the stellar-mass growth that is triggered by minor mergers in local disk galaxies. Since major mergers destroy disks and create spheroids, morphologically disturbed spirals are likely remnants of minor mergers (since the disk remains intact). Disturbed spirals exhibit enhanced specific star formation rates (SSFRs), with the enhancement increasing in galaxies with ‘later’ morphological type (that have larger gas reservoirs and smaller bulges). By combining the SSFR enhancements with the fraction of time spirals in various morphological classes spend in this ‘enhanced’ mode, we estimate that ~40% of the star formation activity in local spirals is directly triggered by minor mergers. Combining our results with the star formation in local early-type galaxies – which is almost completely driven by minor mergers – suggests that around half the star formation activity at the present day is likely to be triggered by the minor-merger process.

scholarly journals Kinematic analysis of spiral structures in the local disk

2002 ◽  
Vol 389 (1) ◽  
pp. 143-148 ◽  
Author(s):  
T. Yano ◽  
M. Chiba ◽  
N. Gouda
Keyword(s):  
Kinematic Analysis ◽  
Spiral Structures ◽  
Local Disk

scholarly journals Another Source of Local Missing Mass

1995 ◽  
Vol 164 ◽  
pp. 383-383
Author(s):  
O.Yu. Malkov
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Galactic Plane ◽  
Missing Mass ◽  
Correct Method ◽  
Local Disk

It is well-known that the velocities and distributions of stars perpendicular to the Galactic plane indicate the presence of unseen or missing mass in the local disk of the Milky Way. In spite of an abundance of papers on this subject, no consensus seems to have been reached on not only the amount of dark matter, but even on a “correct” method of analysis.

scholarly journals The Existence of Moving Groups and the Disk Heating Problem

1996 ◽  
Vol 169 ◽  
pp. 513-514
Author(s):  
B. Chen ◽  
F. Figueras ◽  
J. Torra ◽  
R. Asiain ◽  
C. Jordi
Keyword(s):  
Main Sequence ◽  
Velocity Dispersion ◽  
A Priori ◽  
The Sun ◽  
Main Sequence Stars ◽  
Large Sample ◽  
Objective Evidence ◽  
Moving Groups ◽  
Input Catalogue ◽  
Local Disk

A powerful moving group-finding algorithm has been developed and applied to a large sample of B, A and F main sequence stars from the Hipparcos Input Catalogue. Four moving groups near the Sun (Pleiades, Sirius, IC2391 and Hyades) have been identified without assuming any a priori knowledge of the properties of moving groups. This is the most convincing objective evidence for their existence. After the members of the moving groups are removed from the sample, we investigate the disk heating problem. The results show that the velocity dispersion of the local disk stars increases with age, roughly as ≃ ∞ τ1/5.

scholarly journals Chemical evolution of D in the Local Disk

2009 ◽  
Vol 5 (S268) ◽  
pp. 499-500
Author(s):  
Takuji Tsujimoto ◽  
Joss Bland-Hawthorn
Keyword(s):  
Star Formation ◽  
Chemical Evolution ◽  
Large Scale ◽  
Gradual Increase ◽  
Galactic Disk ◽  
Solar Abundance ◽  
Gas System ◽  
Low Metallicity ◽  
Recent Tendency ◽  
Local Disk

AbstractChemical features of the local disk have firmly established the picture for the formation of the Galactic disk that the star formation has proceeded under the continuous accretion of low-metallicity gas from the halo. It sets two determinant processes for the evolution of deuterium (D), that is, the destruction of D in the interior of stars and the supply of new (nearly) primordial D associated with the gas infall. Conventional Galactic chemical evolution (GCE) models predict that this scheme leads to a monotonic decrease in D/H with time and ends up in the present-day D/H abundance (D/H)0 which is severely lower than the recently observed estimates. These predicted features are the natural results of a construction of the metal-rich (~solar abundance) local star+gas system. Here we propose that the new GCE models, that incorporate large-scale winds form the Galactic bulge which entrain heavy elements and drop them on the disk with the recent tendency of star formation in tune with the observed implications, make the system rich in both metals and D. In addition, our finding of a gradual increase in D/H with time during the last several Gyr is observationally supported by the D/H abundance for the protosolar cloud lower than (D/H)0.

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