Niraj D. Welikala Thesis - D-Scholarship@Pitt
... and on these scales the density fluctuations are small in size (rms fluctuations of the order ∼ 0.1 at 1 Gpc). However, on scales of the order of 10 Mpc, the density fluctuations are large (∼ 1). The most apparent overdensities are therefore on small scales, less than 10 Mpc which are the typical sc ...
... and on these scales the density fluctuations are small in size (rms fluctuations of the order ∼ 0.1 at 1 Gpc). However, on scales of the order of 10 Mpc, the density fluctuations are large (∼ 1). The most apparent overdensities are therefore on small scales, less than 10 Mpc which are the typical sc ...
The VIMOS Ultra-Deep Survey (VUDS): Fast Increase in the Fraction
... Deharveng et al. 2008; Hayes et al. 2014). As a result of their nature, Lyα photons are found to be scattered at much larger scales than UV photons (Steidel et al. 2011; Momose et al. 2014). Predicting the escape fraction of the Lyα photons as a function of the galaxy properties involves including a ...
... Deharveng et al. 2008; Hayes et al. 2014). As a result of their nature, Lyα photons are found to be scattered at much larger scales than UV photons (Steidel et al. 2011; Momose et al. 2014). Predicting the escape fraction of the Lyα photons as a function of the galaxy properties involves including a ...
The empirical grounds of SN
... • GRB 990123 has been detected by the robotic telescope ROTSE, 22s and 47s after the g-ray trigger at V~11.7 and 8.9, respectively. At z=1.6, the isotropic energy release implies MV ~-35 and a global energetic budget comparable to >Mc2 • All GRBs could be collimated events, with opening angles q ~ ...
... • GRB 990123 has been detected by the robotic telescope ROTSE, 22s and 47s after the g-ray trigger at V~11.7 and 8.9, respectively. At z=1.6, the isotropic energy release implies MV ~-35 and a global energetic budget comparable to >Mc2 • All GRBs could be collimated events, with opening angles q ~ ...
THE STAR FORMATION AND NUCLEAR ACCRETION HISTORIES OF NORMAL GALAXIES
... Given their similar evolution, spectral shapes (e.g., Ptak et al. 1999), and potentially similar luminosities, it may be difficult to disentangle the X-ray emission from AGNs and star formation at z < ∼ 1. Probing the X-ray evolution of normal galaxies between z ' 0.1 and z ' 1 is also difficult bec ...
... Given their similar evolution, spectral shapes (e.g., Ptak et al. 1999), and potentially similar luminosities, it may be difficult to disentangle the X-ray emission from AGNs and star formation at z < ∼ 1. Probing the X-ray evolution of normal galaxies between z ' 0.1 and z ' 1 is also difficult bec ...
Elliptical Galaxies
... relatively bright in the center but fading rapidly with increasing radius. Elliptical galaxies are found mostly in the denser regions of the universe, from rich clusters to small groups; truely isolated ellipticals being relatively rare. Figure 1 shows the central region of the Coma cluster which is ...
... relatively bright in the center but fading rapidly with increasing radius. Elliptical galaxies are found mostly in the denser regions of the universe, from rich clusters to small groups; truely isolated ellipticals being relatively rare. Figure 1 shows the central region of the Coma cluster which is ...
Physical Manifestations of Zero-Point Energy
... had to do with the "dynamical Casimir effect" [35, 36]. After his death, I concluded he was wrong [37, 38]. But, probably the most interesting result of this work was a simple finite calculation of the regulated and renormalized van der Waals energy of a dielectric sphere. A year later Brevik, Marac ...
... had to do with the "dynamical Casimir effect" [35, 36]. After his death, I concluded he was wrong [37, 38]. But, probably the most interesting result of this work was a simple finite calculation of the regulated and renormalized van der Waals energy of a dielectric sphere. A year later Brevik, Marac ...
Lecture 2
... Hale 5m telescope • They targeted QSO fields in order to study known peaks in the matter distribution at high redshift Current Topics: Lyman Break Galaxies - Lecture 2 ...
... Hale 5m telescope • They targeted QSO fields in order to study known peaks in the matter distribution at high redshift Current Topics: Lyman Break Galaxies - Lecture 2 ...
SEARCHING for a QCD MIXED PHASE at the NUCLOTRON
... We need to identify the challenges and the discovery potential of such machines like NICA, creating the densest forms of matter in terrestrial laboratories. It requires concerted efforts to understand the stuff which constitutes the interiors of neutron stars and governs fantastic astrophysical phen ...
... We need to identify the challenges and the discovery potential of such machines like NICA, creating the densest forms of matter in terrestrial laboratories. It requires concerted efforts to understand the stuff which constitutes the interiors of neutron stars and governs fantastic astrophysical phen ...
Radiation Damage In Scientific Charge
... as the detection device in satellite Star Trackers, which provide attitude information to the satellite orientation system. However, one major drawback is their extreme vulnerability to radiation, which is readily abundant in space. Needless to say that it is very important to investigate this, befo ...
... as the detection device in satellite Star Trackers, which provide attitude information to the satellite orientation system. However, one major drawback is their extreme vulnerability to radiation, which is readily abundant in space. Needless to say that it is very important to investigate this, befo ...
Galaxies - hwchemistry
... • To hold stars in such small, short-period orbits, the centers of galaxies must contain masses of a million to a few billion solar masses. • Yet, no object is visible. – The evidence seems to require that the nuclei of galaxies contain supermassive black holes. – You have learned that Milky Way con ...
... • To hold stars in such small, short-period orbits, the centers of galaxies must contain masses of a million to a few billion solar masses. • Yet, no object is visible. – The evidence seems to require that the nuclei of galaxies contain supermassive black holes. – You have learned that Milky Way con ...
2. The X-ray-Radio correlation for bulgeless galaxies
... Correlations between the X-ray and Radio emissions are observed for both galaxies with Active Galactic Nuclei (AGN) and in Star Forming galaxies. For the first case, the Xray/Radio correlation seems to present different slopes for Radio-loud and Radio-quiet AGN and may be used to estimate the mass o ...
... Correlations between the X-ray and Radio emissions are observed for both galaxies with Active Galactic Nuclei (AGN) and in Star Forming galaxies. For the first case, the Xray/Radio correlation seems to present different slopes for Radio-loud and Radio-quiet AGN and may be used to estimate the mass o ...
Local Group Encyclopedia of Astronomy & Astrophysics eaa.iop.org Mario L Mateo
... Galaxy. Various indirect indicators suggest that our Galaxy can be classified as an Sbc galaxy, intermediate between the properties described for M31 and M33. Some recent studies at radio, infrared and optical wavelengths also suggest that our Galaxy contains an elongated central bar composed of old ...
... Galaxy. Various indirect indicators suggest that our Galaxy can be classified as an Sbc galaxy, intermediate between the properties described for M31 and M33. Some recent studies at radio, infrared and optical wavelengths also suggest that our Galaxy contains an elongated central bar composed of old ...
Prof.P. Ravindran, Lattice Dynamics-1
... • Mechanical waves are waves which propagate through a material medium at a wave speed which depends on the elastic and inertial properties of that medium. • There are two basic types of wave motion for mechanical waves: longitudinal waves and transverse waves. ...
... • Mechanical waves are waves which propagate through a material medium at a wave speed which depends on the elastic and inertial properties of that medium. • There are two basic types of wave motion for mechanical waves: longitudinal waves and transverse waves. ...
Evolution of galaxy morphology - Lecture 1 - NCRA-TIFR
... gravitationally bound agglomerations of stars, dust, gas, dark matter. Mass ratio Gas:Stars:Dark Matter - 1:10:100 they are the basic building blocks of the Universe on large scales they show a broad range in their physical properties Understanding of galaxy formation and evolution is one of the mai ...
... gravitationally bound agglomerations of stars, dust, gas, dark matter. Mass ratio Gas:Stars:Dark Matter - 1:10:100 they are the basic building blocks of the Universe on large scales they show a broad range in their physical properties Understanding of galaxy formation and evolution is one of the mai ...
Galaxies
... underlying dark matter. We have started to understand how baryonic gas within the dark matter halos cools and collapses to form stars, and how the energy from star formation can feed back into the surrounding gas and regulate subsequent star formation. However, at a fundamental level we still lack a ...
... underlying dark matter. We have started to understand how baryonic gas within the dark matter halos cools and collapses to form stars, and how the energy from star formation can feed back into the surrounding gas and regulate subsequent star formation. However, at a fundamental level we still lack a ...
T3-Cosmic Star Formation History
... Over the past two decades, an avalanche of new data from multiwavelength imaging and spectroscopic surveys has revolutionized our view of galaxy formation and evolution. Here we review the range of complementary techniques and theoretical tools that allow astronomers to map the cosmic history of sta ...
... Over the past two decades, an avalanche of new data from multiwavelength imaging and spectroscopic surveys has revolutionized our view of galaxy formation and evolution. Here we review the range of complementary techniques and theoretical tools that allow astronomers to map the cosmic history of sta ...
Dark energy
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.