Search results
Results from the WOW.Com Content Network
The Dark Energy Survey (DES) is an astronomical survey designed to constrain the properties of dark energy.It uses images taken in the near-ultraviolet, visible, and near-infrared to measure the expansion of the universe using Type Ia supernovae, baryon acoustic oscillations, the number of galaxy clusters, and weak gravitational lensing. [1]
Galaxy-galaxy lensing is a specific type of weak (and occasionally strong) gravitational lensing, in which the foreground object responsible for distorting the shapes of background galaxies is itself an individual field galaxy (as opposed to a galaxy cluster or the large-scale structure of the cosmos). Of the three typical mass regimes in weak ...
In strong and weak lensing, the mass of the lens is large enough (mass of a galaxy or galaxy cluster) that the displacement of light by the lens can be resolved with a high resolution telescope such as the Hubble Space Telescope. With microlensing, the lens mass is too low (mass of a planet or a star) for the displacement of light to be ...
Radio-faint galaxies like M 31 and M33, the Milky Way's neighbors, have weaker fields (about 5 μG), while gas-rich galaxies with high star-formation rates, like M 51, M 83 and NGC 6946, have 15 μG on average. In prominent spiral arms, the field strength can be up to 25 μG, in regions where cold gas and dust are also concentrated.
Galaxies can consist of millions to trillions of stars. The galaxy we live in is called the Milky Way, and astronomers estimate it has between 200-400 billion stars.
By measuring the distortion geometry, the mass of the intervening cluster can be obtained. In the weak regime, lensing does not distort background galaxies into arcs, causing minute distortions instead. By examining the apparent shear deformation of the adjacent background galaxies, the mean distribution of dark matter can be characterized.
A field galaxy is a galaxy that does not belong to a larger galaxy group or cluster and hence is gravitationally alone. Roughly 80% of all galaxies located within 5 Mpc (16 Mly) of the Milky Way are in groups or clusters of galaxies. [1] Most low-surface-brightness galaxies are field galaxies. [2]
Hubble eXtreme Deep Field: 2012: 2.3′x3′ Hubble Ultra-Deep Field (UV/VIS/NIR) 2014: Hubble Frontier Fields MACS J0416.1-2403 [10] 2015: Hubble Frontier Fields Abell 2744 [11] 2015: Hubble Frontier Fields MACS J0717.5+3745: 2015: Hubble Frontier Fields MACS J1149.5+2223 [12] 2015: Hubble Frontier Fields Abell S1063 [13] 2016: Hubble Frontier ...