Protogalaxies Encyclopedia of Astronomy & Astrophysics eaa.iop.org S G Djorgovski
... protracted time scale, comparable with the Hubble time, with most of the stars already formed in the merging units and some formed in merger-induced starbursts. It is likely that there was a full spectrum of galaxy assembly scenarios or formation histories at work. The interplay of mass assembly and ...
... protracted time scale, comparable with the Hubble time, with most of the stars already formed in the merging units and some formed in merger-induced starbursts. It is likely that there was a full spectrum of galaxy assembly scenarios or formation histories at work. The interplay of mass assembly and ...
The formation and evolution of galaxies
... • Sloan Digital Sky Survey: a great look at the local Universe • Will measure accurate photometry for 100 million objects • Redshifts (and star formation rates) for 1 million galaxies and 100,000 quasars. Out to z=0.2 About 1 Gpc, or 2.7 billion light years The age of the Universe is ~13.7 bil ...
... • Sloan Digital Sky Survey: a great look at the local Universe • Will measure accurate photometry for 100 million objects • Redshifts (and star formation rates) for 1 million galaxies and 100,000 quasars. Out to z=0.2 About 1 Gpc, or 2.7 billion light years The age of the Universe is ~13.7 bil ...
Walk Softly When Exploring the Dark Side of the Universe Karl Gebhardt
... dominates at the edges of galaxies. However, new technology is making this feasible. ...
... dominates at the edges of galaxies. However, new technology is making this feasible. ...
Paul Green - Chandra X-Ray Observatory (CXC)
... 2012 X-Ray Binaries Workshop Abstract In 1962, Scorpius X-1 became the first X-ray source discovered outside the Solar System. In the 50 years since, X-ray binaries have proven to be important for studies of fundamental physical processes such as mass accretion and jet formation. Contemporary X-ray ...
... 2012 X-Ray Binaries Workshop Abstract In 1962, Scorpius X-1 became the first X-ray source discovered outside the Solar System. In the 50 years since, X-ray binaries have proven to be important for studies of fundamental physical processes such as mass accretion and jet formation. Contemporary X-ray ...
Document
... ● detect giant planets directly ● detect giant planets indirectly from gravitational “gaps” in disks ● characterize planets from properties of disks (location, widths) ...
... ● detect giant planets directly ● detect giant planets indirectly from gravitational “gaps” in disks ● characterize planets from properties of disks (location, widths) ...
A new formula for the rotation velocity – and density distribution of a
... follow the Keplerian decrease in which the circular rotation velocity v decreases α R-1/2 where R is the distance to the center. According to the 3:rd law of Kepler the mass of a galaxy can be expressed as : M = v2 R / G and the rotation velocity as : v = ( G M / R )1/2 where G is the gravitation co ...
... follow the Keplerian decrease in which the circular rotation velocity v decreases α R-1/2 where R is the distance to the center. According to the 3:rd law of Kepler the mass of a galaxy can be expressed as : M = v2 R / G and the rotation velocity as : v = ( G M / R )1/2 where G is the gravitation co ...
Weak gravitational lensing
While the presence of any mass bends the path of light passing near it, this effect rarely produces the giant arcs and multiple images associated with strong gravitational lensing. Most lines of sight in the universe are thoroughly in the weak lensing regime, in which the deflection is impossible to detect in a single background source. However, even in these cases, the presence of the foreground mass can be detected, by way of a systematic alignment of background sources around the lensing mass. Weak gravitational lensing is thus an intrinsically statistical measurement, but it provides a way to measure the masses of astronomical objects without requiring assumptions about their composition or dynamical state.