![Quasars: Back to the Infant Universe](http://s1.studyres.com/store/data/015324091_1-225a876e60cd4c76ec3882961bcbb241-300x300.png)
Lecture1-1
... The colors of model SEDs (blue dots) and observed galaxies (black dots). Left panels shows the colors without emission line correction and right panels with emission line correction ...
... The colors of model SEDs (blue dots) and observed galaxies (black dots). Left panels shows the colors without emission line correction and right panels with emission line correction ...
Cold galaxies at low and high z
... Over 100 Type Ia supernova have been found at redshifts 0.5-1.5 Comparing these to nearby supernova, we find that in cosmological models with matter only, the distant supernovae are fainter than expected for their redshift (Perlmutter 2002). ‘Dark energy’ is pushing the galaxies apart. Sept 27th 200 ...
... Over 100 Type Ia supernova have been found at redshifts 0.5-1.5 Comparing these to nearby supernova, we find that in cosmological models with matter only, the distant supernovae are fainter than expected for their redshift (Perlmutter 2002). ‘Dark energy’ is pushing the galaxies apart. Sept 27th 200 ...
The Evolution of Galaxy - Tufts Institute of Cosmology
... of discovery in the study of clusters has accelerated over the past 40 years. Astronomers now know of some 10,000 of them. American astronomer George Abell compiled the first large list in the early 1950s, based on photographs of the entire northern sky taken at Palomar Observatory in California. By ...
... of discovery in the study of clusters has accelerated over the past 40 years. Astronomers now know of some 10,000 of them. American astronomer George Abell compiled the first large list in the early 1950s, based on photographs of the entire northern sky taken at Palomar Observatory in California. By ...
Living Things - Fairfield-Suisun Unified School District
... a narrow disk with a bulge in the middle. The galaxy’s spiral structure is visible only from above or below. ...
... a narrow disk with a bulge in the middle. The galaxy’s spiral structure is visible only from above or below. ...
Friday03
... • So: does BO effect really point to cluster-specific physics, or just the evolving field and infall rate (Ellingson et al. 2001)? Steidel et al. (1999) ...
... • So: does BO effect really point to cluster-specific physics, or just the evolving field and infall rate (Ellingson et al. 2001)? Steidel et al. (1999) ...
What is energy? - Worth County Schools
... • Anything that can fall has stored energy called gravitational potential energy. • Gravitational potential energy (GPE) is energy stored by objects due to their position above Earth’s surface. ...
... • Anything that can fall has stored energy called gravitational potential energy. • Gravitational potential energy (GPE) is energy stored by objects due to their position above Earth’s surface. ...
WHITE DWARFS AS A SOURCE OF CONSTRAINTS ON EXOTIC …
... Modern astrophysics is a great success of standard physical theories in understanding stellar structure and evolution Stars serves as a source of constraints on non standard ideas Some of these constraints turn out to be more stringent than laboratory ones First idea: weakly interacting partic ...
... Modern astrophysics is a great success of standard physical theories in understanding stellar structure and evolution Stars serves as a source of constraints on non standard ideas Some of these constraints turn out to be more stringent than laboratory ones First idea: weakly interacting partic ...
Homework #9 (Ch. 21)
... Why does the core of a massive star collapse? 5. Chaisson Review and Discussion 21.6 What occurs in a massive star to cause it to explode? 6. Chaisson Review and Discussion 21.7 What are the observational differences between Type I and Type II supernovae? 7. Chaisson Review and Discussion 21.8 What ...
... Why does the core of a massive star collapse? 5. Chaisson Review and Discussion 21.6 What occurs in a massive star to cause it to explode? 6. Chaisson Review and Discussion 21.7 What are the observational differences between Type I and Type II supernovae? 7. Chaisson Review and Discussion 21.8 What ...
Energy - Blountstown Middle School
... box. The colored bars show the work that the girl does (W) and the box’s potential energy (PE). ...
... box. The colored bars show the work that the girl does (W) and the box’s potential energy (PE). ...
Chapter 7 Powerpoint - Ms. Griffin
... box. The colored bars show the work that the girl does (W) and the box’s potential energy (PE). ...
... box. The colored bars show the work that the girl does (W) and the box’s potential energy (PE). ...
Study of the X-ray Source Population and the Dark Matter
... spatial and time resolution, the Wide Field Imager of the Athena Xray Observatory will make it possible to study X-ray sources down to very low flux limits. In Draco dSph, e.g., we will be able to observe X-ray sources with luminosities down to 1031 erg/s with 1000 to 2000 counts in 10 ksec, allowin ...
... spatial and time resolution, the Wide Field Imager of the Athena Xray Observatory will make it possible to study X-ray sources down to very low flux limits. In Draco dSph, e.g., we will be able to observe X-ray sources with luminosities down to 1031 erg/s with 1000 to 2000 counts in 10 ksec, allowin ...
Energy
... An object’s PEg depends on its mass (in kg), its height (in m), and the acceleration due to gravity (9.8 m/s2 near Earth’s surface). PEg=mgh Gravitational potential energy is measured relative to some reference level. ...
... An object’s PEg depends on its mass (in kg), its height (in m), and the acceleration due to gravity (9.8 m/s2 near Earth’s surface). PEg=mgh Gravitational potential energy is measured relative to some reference level. ...
Understanding the Astrophysics of Galaxy Evolution: the role of
... Over the past decade and a half, our observational understanding of galaxy evolution has grown enormously. Steidel and collaborators demonstrated that colour selection techniques allow so-called Lyman Break galaxies (LBGs) to be isolated efficiently at redshifts ∼ 3, thus breaking the z = 1 redshift ...
... Over the past decade and a half, our observational understanding of galaxy evolution has grown enormously. Steidel and collaborators demonstrated that colour selection techniques allow so-called Lyman Break galaxies (LBGs) to be isolated efficiently at redshifts ∼ 3, thus breaking the z = 1 redshift ...
Chapter 15, Galaxies
... We rely heavily on the standard candles for the measurement of the cosmological distance. How do we make sure that these standard candles are truly standard? ...
... We rely heavily on the standard candles for the measurement of the cosmological distance. How do we make sure that these standard candles are truly standard? ...
Document
... from an extremely dense and hot state, the Big Bang, 13.7 Gyr ago, expanding and cooling ever since. In the beginning, it consisted of an almost homogeneous plasma without heavy chemical elements and with only very tiny fluctuations in the density profile. It was very different from today’s structur ...
... from an extremely dense and hot state, the Big Bang, 13.7 Gyr ago, expanding and cooling ever since. In the beginning, it consisted of an almost homogeneous plasma without heavy chemical elements and with only very tiny fluctuations in the density profile. It was very different from today’s structur ...
Galaxies - Stockton University
... – Black-holes are also efficient although less so than neutron stars • This is because black-holes have no surface so much of the energy is never released but is swallowed up by the black-hole directly and also orbits are unstable within three times the Schwarschild radius and little energy is retur ...
... – Black-holes are also efficient although less so than neutron stars • This is because black-holes have no surface so much of the energy is never released but is swallowed up by the black-hole directly and also orbits are unstable within three times the Schwarschild radius and little energy is retur ...
1. The "Q" word and its meaning
... b. What are the timescale(s) for quenching? Pablo , Jarle c. Is quenching due to starvation or gas expulsion? Romeel 2. What do we learn from the MS on the "Q" word ? a. Is the apparent sSFR dichotomy real, and is it a fair statement that galaxies are either star-forming or quenched ? b. Is quenchin ...
... b. What are the timescale(s) for quenching? Pablo , Jarle c. Is quenching due to starvation or gas expulsion? Romeel 2. What do we learn from the MS on the "Q" word ? a. Is the apparent sSFR dichotomy real, and is it a fair statement that galaxies are either star-forming or quenched ? b. Is quenchin ...
Dark energy
![](https://commons.wikimedia.org/wiki/Special:FilePath/Dark_Energy.jpg?width=300)
In physical cosmology and astronomy, dark energy is an unknown form of energy which is hypothesized to permeate all of space, tending to accelerate the expansion of the universe. Dark energy is the most accepted hypothesis to explain the observations since the 1990s indicating that the universe is expanding at an accelerating rate. Assuming that the standard model of cosmology is correct, the best current measurements indicate that dark energy contributes 68.3% of the total energy in the present-day observable universe. The mass–energy of dark matter and ordinary matter contribute 26.8% and 4.9%, respectively, and other components such as neutrinos and photons contribute a very small amount. Again on a mass–energy equivalence basis, the density of dark energy (6.91 × 10−27 kg/m3) is very low, much less than the density of ordinary matter or dark matter within galaxies. However, it comes to dominate the mass–energy of the universe because it is uniform across space.Two proposed forms for dark energy are the cosmological constant, a constant energy density filling space homogeneously, and scalar fields such as quintessence or moduli, dynamic quantities whose energy density can vary in time and space. Contributions from scalar fields that are constant in space are usually also included in the cosmological constant. The cosmological constant can be formulated to be equivalent to vacuum energy. Scalar fields that do change in space can be difficult to distinguish from a cosmological constant because the change may be extremely slow.High-precision measurements of the expansion of the universe are required to understand how the expansion rate changes over time and space. In general relativity, the evolution of the expansion rate is parameterized by the cosmological equation of state (the relationship between temperature, pressure, and combined matter, energy, and vacuum energy density for any region of space). Measuring the equation of state for dark energy is one of the biggest efforts in observational cosmology today.Adding the cosmological constant to cosmology's standard FLRW metric leads to the Lambda-CDM model, which has been referred to as the ""standard model of cosmology"" because of its precise agreement with observations. Dark energy has been used as a crucial ingredient in a recent attempt to formulate a cyclic model for the universe.