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 ...
The physico-chemical history of Falling Evaporating Bodies around
... Dust is thus considered as inert matter, which does not react in any way and whose thermodynamic properties are taken from the literature. The FEB is assumed to orbit the star on a circular orbit at a few AU, so that it always receives the same radiation flux from the star. As long as this assumptio ...
... Dust is thus considered as inert matter, which does not react in any way and whose thermodynamic properties are taken from the literature. The FEB is assumed to orbit the star on a circular orbit at a few AU, so that it always receives the same radiation flux from the star. As long as this assumptio ...
Spinar Paradigm
... (1998) pointed out, the centrifugal barrier could explain the long (from several seconds to several hours) duration of the process of energy release in the central engines of gamma-ray bursts. It is remarkable that as it loses angular momentum a spinar (unlike, e.g., a radio pulsar) does not spind d ...
... (1998) pointed out, the centrifugal barrier could explain the long (from several seconds to several hours) duration of the process of energy release in the central engines of gamma-ray bursts. It is remarkable that as it loses angular momentum a spinar (unlike, e.g., a radio pulsar) does not spind d ...
Chapter 15 THE MILKY WAY IN RELATION TO OTHER GALAXIES
... detailed knowledge. However, we now know that it is not negligible at all (see the data of Lewis above) and is most likely equal to −1/h. Using this and usual values for the local Oort constants leads with Plaut’s (1965) data for old disk variables to h = 4.3–5.8 kpc. From this discussion I conclude ...
... detailed knowledge. However, we now know that it is not negligible at all (see the data of Lewis above) and is most likely equal to −1/h. Using this and usual values for the local Oort constants leads with Plaut’s (1965) data for old disk variables to h = 4.3–5.8 kpc. From this discussion I conclude ...
Lecture 17 - Yale University
... But....if the presence of a hot medium requires SN overlap, and for SN to overlap requires a hot medium, we have ourselves a classical chicken & egg problem... The solution to this problem requires additional feedback mechanisms. These include photo-ionization, proto-stellar jets, stellar winds (sho ...
... But....if the presence of a hot medium requires SN overlap, and for SN to overlap requires a hot medium, we have ourselves a classical chicken & egg problem... The solution to this problem requires additional feedback mechanisms. These include photo-ionization, proto-stellar jets, stellar winds (sho ...
Stages of star formation (the classical view)
... The formation of high-mass stars Shu's standard model CANNOT form stars of more than ~10 Msol Accretion characteristic time (free-fall time) tff = (3π / 32Gρ)1/2 only depends on density. For a dense core, n=104 cm-3, tff=4x105 yr Characteristic time for the protostellar core contraction (Kelvin-Hel ...
... The formation of high-mass stars Shu's standard model CANNOT form stars of more than ~10 Msol Accretion characteristic time (free-fall time) tff = (3π / 32Gρ)1/2 only depends on density. For a dense core, n=104 cm-3, tff=4x105 yr Characteristic time for the protostellar core contraction (Kelvin-Hel ...
Detection of the Stochastic Background of nHz Gravitational Radiation from Massive Black
... dimensionless amplitude, h(x,t). This is gravitational radiation, which propagates away at speed of light. A Binary MBH ten billion light years away with orbit of 5y will produce a distortion of space by just 0.0000000000000001 (16 zeroes!). ...
... dimensionless amplitude, h(x,t). This is gravitational radiation, which propagates away at speed of light. A Binary MBH ten billion light years away with orbit of 5y will produce a distortion of space by just 0.0000000000000001 (16 zeroes!). ...
Super-solar Metal Abundances in Two Galaxies at ζ ∼ 3.57
... and effective Doppler parameter b > 30 km s−1 ; Spitzer 1978). For stronger lines, the COG gives reliable results if several lines with different oscillator strengths of the same ion are detected. This idea is supported, for instance, by the spectral analysis of the afterglow of GRB 081008 by D’Elia ...
... and effective Doppler parameter b > 30 km s−1 ; Spitzer 1978). For stronger lines, the COG gives reliable results if several lines with different oscillator strengths of the same ion are detected. This idea is supported, for instance, by the spectral analysis of the afterglow of GRB 081008 by D’Elia ...
Astrophysical explosions: from solar flares to cosmic gamma
... microseconds (or less!) to billions of years. Relevant densities range from nuclear densities of 1014 g cm−3 to the rarified gas between stars with scarcely one particle per cubic centimetre or 10−24 g cm−3 . Atomic, nuclear and plasma physics are all intimately involved. Turbulence and transport—of ...
... microseconds (or less!) to billions of years. Relevant densities range from nuclear densities of 1014 g cm−3 to the rarified gas between stars with scarcely one particle per cubic centimetre or 10−24 g cm−3 . Atomic, nuclear and plasma physics are all intimately involved. Turbulence and transport—of ...
Collapse of rapidly rotating massive stellar core to a black hole
... Collapse of stellar cores Association with supernova explosion (SN) Association with long GRBs (BH + Disk formation) ...
... Collapse of stellar cores Association with supernova explosion (SN) Association with long GRBs (BH + Disk formation) ...
Starburst Galaxies - Beck-Shop
... by the arms. The reason why the arms stand out so sharply from the rest of the disk is that they contain numerous star-forming regions. In those regions the massive hot young stars are extremely bright and outshine the far more numerous less massive stars. Few starforming regions are to be found in ...
... by the arms. The reason why the arms stand out so sharply from the rest of the disk is that they contain numerous star-forming regions. In those regions the massive hot young stars are extremely bright and outshine the far more numerous less massive stars. Few starforming regions are to be found in ...
The National Centre for Radio Astrophysics
... progenitor stars that lead to supernovae and GRB explosions is the main focus of my research, which mainly uses the radio and X-ray bands. I use the Giant Metrewave Radio Telescope (GMRT) and the Very Large Array (VLA), for radio measurements and the Swift-XRT, Chandra and XMM-Newton telescopes for ...
... progenitor stars that lead to supernovae and GRB explosions is the main focus of my research, which mainly uses the radio and X-ray bands. I use the Giant Metrewave Radio Telescope (GMRT) and the Very Large Array (VLA), for radio measurements and the Swift-XRT, Chandra and XMM-Newton telescopes for ...
A Very Dense Low-Mass Molecular Condensation in Taurus
... fall motion with the existing theoretical models. One of the most fundamental models is inside-out collapse (Shu 1977); another is run-away collapse (e.g., Larson 1969; Penston 1969). These two models have been well studied theoretically to describe the collapsing process of a dense condensation. Ou ...
... fall motion with the existing theoretical models. One of the most fundamental models is inside-out collapse (Shu 1977); another is run-away collapse (e.g., Larson 1969; Penston 1969). These two models have been well studied theoretically to describe the collapsing process of a dense condensation. Ou ...
AGN surveys to study galaxy evolution along cosmic times
... survey of AGNs in the 14-195 keV band. Using archival X-ray data or follow-up Swift XRT observations, 129 (103 AGNs) objects have been identified (out of 130) detected at |b|>15 deg and with significance >4.8σ. Integration of the luminosity function gives a local volume density of AGNs above 1041 erg/ ...
... survey of AGNs in the 14-195 keV band. Using archival X-ray data or follow-up Swift XRT observations, 129 (103 AGNs) objects have been identified (out of 130) detected at |b|>15 deg and with significance >4.8σ. Integration of the luminosity function gives a local volume density of AGNs above 1041 erg/ ...
The Stellar Population Synthesis Technique Charlie Conroy Princeton
... • Extended HBs common at low metallicity, also ...
... • Extended HBs common at low metallicity, also ...
File 11 - School of Astronomy, IPM
... Galaxy Morphology Galaxy classification Nomenclature: Early and Late type • Galaxies along the sequence often referred to as being either an early-type or a late type • Elliptical and Lenticular galaxies are collectively called an early-type and spirals are called late-type • Within spirals, an Sa ...
... Galaxy Morphology Galaxy classification Nomenclature: Early and Late type • Galaxies along the sequence often referred to as being either an early-type or a late type • Elliptical and Lenticular galaxies are collectively called an early-type and spirals are called late-type • Within spirals, an Sa ...
Chapter 15 Stars, Galaxies, and Universe
... the Milky Way appears to be a narrow disk with a bulge in the middle. The galaxy’s spiral structure is visible only from above or below. Center is 25,000 light years away from Earth ...
... the Milky Way appears to be a narrow disk with a bulge in the middle. The galaxy’s spiral structure is visible only from above or below. Center is 25,000 light years away from Earth ...
Supernovae
... mass being that of a white dwarf at the Chandrasekhar limit, 1.4 M . The luminosity reaches its maximum 15 to 20 days after the explosion and then decreases slowly until all the 56 Co decays. The maximum brightness is comparable to the brightness of an entire galaxy and can vary by an order of magn ...
... mass being that of a white dwarf at the Chandrasekhar limit, 1.4 M . The luminosity reaches its maximum 15 to 20 days after the explosion and then decreases slowly until all the 56 Co decays. The maximum brightness is comparable to the brightness of an entire galaxy and can vary by an order of magn ...
Lambda-CDM model
The ΛCDM (Lambda cold dark matter) or Lambda-CDM model is a parametrization of the Big Bang cosmological model in which the universe contains a cosmological constant, denoted by Lambda (Greek Λ), associated with dark energy, and cold dark matter (abbreviated CDM). It is frequently referred to as the standard model of Big Bang cosmology, because it is the simplest model that provides a reasonably good account of the following properties of the cosmos: the existence and structure of the cosmic microwave background the large-scale structure in the distribution of galaxies the abundances of hydrogen (including deuterium), helium, and lithium the accelerating expansion of the universe observed in the light from distant galaxies and supernovaeThe model assumes that general relativity is the correct theory of gravity on cosmological scales.It emerged in the late 1990s as a concordance cosmology, after a period of time when disparate observed properties of the universe appeared mutually inconsistent, and there was no consensus on the makeup of the energy density of the universe.The ΛCDM model can be extended by adding cosmological inflation, quintessence and other elements that are current areas of speculation and research in cosmology.Some alternative models challenge the assumptions of the ΛCDM model. Examples of these are modified Newtonian dynamics, modified gravity and theories of large-scale variations in the matter density of the universe.