Characteristics of Our Galaxy
... variables (useful for judging distances), pre-main sequence stars, T-Tauri stars, Herbigharo objects, and even some A stars can be found in the arms. These stars are very metal rich and have highly circular orbits, although they comprise likely less than one percent of Milky Way stars. Young thin d ...
... variables (useful for judging distances), pre-main sequence stars, T-Tauri stars, Herbigharo objects, and even some A stars can be found in the arms. These stars are very metal rich and have highly circular orbits, although they comprise likely less than one percent of Milky Way stars. Young thin d ...
Why do we Still Believe in Newton`s Law? Facts, Myths and Methods
... really mean. A soulmate of King Alfonso, the astronomer Aguirre [2] commented: ‘these new discoveries... have been achieved at the expense of simplicity’. The question why nature comes up with a bunch of numbers like 0.73 must be allowed or at least not forgotten. Though standard cosmology has vario ...
... really mean. A soulmate of King Alfonso, the astronomer Aguirre [2] commented: ‘these new discoveries... have been achieved at the expense of simplicity’. The question why nature comes up with a bunch of numbers like 0.73 must be allowed or at least not forgotten. Though standard cosmology has vario ...
Slides_Pisin_Chen
... After completing his formulation of general relativity (GR), Einstein (1917) introduced a cosmological constant (CC) to his eq. for the universe to be static: ...
... After completing his formulation of general relativity (GR), Einstein (1917) introduced a cosmological constant (CC) to his eq. for the universe to be static: ...
The Formation of Primordial Luminous Objects - SLAC
... (iii) The flatness problem: a flat Friedman-Robertson-Walker model universe (i.e. with Ω(t) ≡ ρtot (t)/ρcrit (t) = 1, where ρtot (t) is the cosmological mean density, including the “dark energy” term, and ρcrit (t) = 3H(t)2 /8πG, H(t) ≡ ȧ(t)/a(t) being the Hubble parameter) always remains flat, but ...
... (iii) The flatness problem: a flat Friedman-Robertson-Walker model universe (i.e. with Ω(t) ≡ ρtot (t)/ρcrit (t) = 1, where ρtot (t) is the cosmological mean density, including the “dark energy” term, and ρcrit (t) = 3H(t)2 /8πG, H(t) ≡ ȧ(t)/a(t) being the Hubble parameter) always remains flat, but ...
Lecture 2
... The greater the redshift, the further back in time – redshift of 0.1 is 1.4 billion ly which means we are looking 1.4 billion years into the past. All galaxies are moving away from each other à in the past all galaxies were closer to each other. All the way back in time, it would mean that everythi ...
... The greater the redshift, the further back in time – redshift of 0.1 is 1.4 billion ly which means we are looking 1.4 billion years into the past. All galaxies are moving away from each other à in the past all galaxies were closer to each other. All the way back in time, it would mean that everythi ...
Lectures on Astronomy, Astrophysics, and
... Even in Messier’s time it was clear that these extended objects are not all the same. Some are star clusters, groups of stars which are so numerous that they appeared to be a cloud. Others are glowing clouds of gas or dust and it is for these that we now mainly reserve the word nebula. Most fascinat ...
... Even in Messier’s time it was clear that these extended objects are not all the same. Some are star clusters, groups of stars which are so numerous that they appeared to be a cloud. Others are glowing clouds of gas or dust and it is for these that we now mainly reserve the word nebula. Most fascinat ...
Galaxies at High Redshift Encyclopedia of Astronomy & Astrophysics eaa.iop.org Mauro Giavalisco
... high redshifts play a central role in cosmology because they provide insight into the epochs and the mechanisms of GALAXY FORMATION, if one can reach redshifts that are high enough to correspond to the cosmic epochs when galaxies were forming their first populations of stars and began to shine light ...
... high redshifts play a central role in cosmology because they provide insight into the epochs and the mechanisms of GALAXY FORMATION, if one can reach redshifts that are high enough to correspond to the cosmic epochs when galaxies were forming their first populations of stars and began to shine light ...
Galaxies
... Galaxy mass measurements show that galaxies need between 3 and 10 times more mass than can be observed to explain their rotation curves. The discrepancy is even larger in galaxy clusters, which need 10 to 100 times more mass. The total needed is more than the sum of the dark matter associated with e ...
... Galaxy mass measurements show that galaxies need between 3 and 10 times more mass than can be observed to explain their rotation curves. The discrepancy is even larger in galaxy clusters, which need 10 to 100 times more mass. The total needed is more than the sum of the dark matter associated with e ...
Galaxies over the Latter Half of Cosmic Time
... A new survey project called All-Wavelength Extended Groth Strip International Survey (AEGIS) has created one of the largest Hubble pictures to date. The image is 1/6º wide by 1º long, stretching twice the width of the full Moon. It is a mosaic of 63 tiles, each exposed through green and red filters, ...
... A new survey project called All-Wavelength Extended Groth Strip International Survey (AEGIS) has created one of the largest Hubble pictures to date. The image is 1/6º wide by 1º long, stretching twice the width of the full Moon. It is a mosaic of 63 tiles, each exposed through green and red filters, ...
Gamma-Ray Bursts: The Brightest Explosions in the Universe Arne
... (Introduction to the The ultra-luminous Universe: Gamma-Ray Bursts and Active Galactic Nuclei Session) ...
... (Introduction to the The ultra-luminous Universe: Gamma-Ray Bursts and Active Galactic Nuclei Session) ...
astro-ph/0311464 PDF
... Consider two coaxial buckets A and B rotating with equal and opposite angular velocities. One would observe the same concavity in the two buckets. The extension of Newton’s reasoning is straightforward and treats A and B equally and independently. A literal application of Mach’s Statement 1 would ha ...
... Consider two coaxial buckets A and B rotating with equal and opposite angular velocities. One would observe the same concavity in the two buckets. The extension of Newton’s reasoning is straightforward and treats A and B equally and independently. A literal application of Mach’s Statement 1 would ha ...
Gravitational-Wave Astronomy
... the only means of directly observing certain sources, such as binaries of black holes, which are `dark' in the electromagnetic spectrum. Furthermore, the interaction of gravitational waves with matter is extremely weak, which is a great advantage for astronomy. This means that these waves arrive at ...
... the only means of directly observing certain sources, such as binaries of black holes, which are `dark' in the electromagnetic spectrum. Furthermore, the interaction of gravitational waves with matter is extremely weak, which is a great advantage for astronomy. This means that these waves arrive at ...
The figure below shows what scientists over 1000 years ago thought
... Over 300 years ago, the famous scientist Isaac Newton proposed, with a ‘thought experiment’, the idea of satellites. Newton suggested that if an object was fired at the right speed from the top of a high mountain, it would circle the Earth. Why did many people accept Isaac Newton’s idea as being pos ...
... Over 300 years ago, the famous scientist Isaac Newton proposed, with a ‘thought experiment’, the idea of satellites. Newton suggested that if an object was fired at the right speed from the top of a high mountain, it would circle the Earth. Why did many people accept Isaac Newton’s idea as being pos ...
1 Introduction - Wiley-VCH
... and lenticulars for 20% [12]. The fraction of late-type galaxies, however, strongly decreases in high-density environments such as in rich clusters [13, 14]. Dwarfs exceed in number massive objects. However, despite their relatively low number, ellipticals, lenticulars, and spiral bulges contain ...
... and lenticulars for 20% [12]. The fraction of late-type galaxies, however, strongly decreases in high-density environments such as in rich clusters [13, 14]. Dwarfs exceed in number massive objects. However, despite their relatively low number, ellipticals, lenticulars, and spiral bulges contain ...
Next Generation Sunshine State Standards Chapter 24
... away—roughly 100 million times farther than the Moon. To appreciate how far this is, imagine that the Earth and Moon are dots on a sheet of paper one millimeter apart. On this scale, the Sun is 390 millimeters (about 15 inches) away, and Proxima Centauri is about 100,000 kilometers (62,000 miles) aw ...
... away—roughly 100 million times farther than the Moon. To appreciate how far this is, imagine that the Earth and Moon are dots on a sheet of paper one millimeter apart. On this scale, the Sun is 390 millimeters (about 15 inches) away, and Proxima Centauri is about 100,000 kilometers (62,000 miles) aw ...
REVIEWS The formation of the first stars and galaxies Volker Bromm
... growth of the protostar cannot be followed accurately without implementing additional radiative physics. For now, inferring the subsequent evolution of the protostar requires approximate analytic calculations. By generalizing a theory for contemporary massive-star formation28, it is possible to appr ...
... growth of the protostar cannot be followed accurately without implementing additional radiative physics. For now, inferring the subsequent evolution of the protostar requires approximate analytic calculations. By generalizing a theory for contemporary massive-star formation28, it is possible to appr ...
Introduction to Dark Matter
... in the study of dark matter. The notion that gravity can bend rays of light was proposed already by Newton, although the magnitude of this effect cannot be correctly predicted by Newtonian gravity. Instead, the full machinery of Einstein´s theory of general relativity is required. In 1919, Eddington ...
... in the study of dark matter. The notion that gravity can bend rays of light was proposed already by Newton, although the magnitude of this effect cannot be correctly predicted by Newtonian gravity. Instead, the full machinery of Einstein´s theory of general relativity is required. In 1919, Eddington ...
Interactive 4 - Hertzsprung-Russell Diagram Explorer
... hydrogen and helium provided in the Periodic Table rather than adding individual proton and neutron masses) ...
... hydrogen and helium provided in the Periodic Table rather than adding individual proton and neutron masses) ...
Glencoe Earth Science
... Earth. Almost all of the life on Earth depends on energy from the Sun. Notice the different layers of the Sun, shown in Figure 6, as you read about them. Like other stars, the Sun is an enormous ball of gas that produces energy by fusing hydrogen into helium in its core. This energy travels outward ...
... Earth. Almost all of the life on Earth depends on energy from the Sun. Notice the different layers of the Sun, shown in Figure 6, as you read about them. Like other stars, the Sun is an enormous ball of gas that produces energy by fusing hydrogen into helium in its core. This energy travels outward ...
Physics case for Antares+
... in ”hidden” regions where the particle accelerators could be located. This concerns, first of all, the regions associated with compact objects - black holes, pulsars, the initial epochs of supernovae explosions, etc. The penetrating potential of neutrinos is important not only for extremely dense en ...
... in ”hidden” regions where the particle accelerators could be located. This concerns, first of all, the regions associated with compact objects - black holes, pulsars, the initial epochs of supernovae explosions, etc. The penetrating potential of neutrinos is important not only for extremely dense en ...
Secular Pseudoscience - Heinz Lycklama`s Website
... “I describe the history of the development of the standard big bang cosmology and how it is understood in terms of its philosophical underpinnings. The Cosmological Principle is explained as the major and essential assumption upon which it all depends. Due to this it has been required to invent unkn ...
... “I describe the history of the development of the standard big bang cosmology and how it is understood in terms of its philosophical underpinnings. The Cosmological Principle is explained as the major and essential assumption upon which it all depends. Due to this it has been required to invent unkn ...
ASTR 31: Descriptive Astronomy
... This continues, making the rest of the elements through bismuth-209 (83 protons + 126 neutrons), including such famous elements as copper, silver, lead, gold, etc. Rapid neutron capture (r-process): To make elements heavier than bismuth-209, neutron capture must proceed more rapidly than it ta ...
... This continues, making the rest of the elements through bismuth-209 (83 protons + 126 neutrons), including such famous elements as copper, silver, lead, gold, etc. Rapid neutron capture (r-process): To make elements heavier than bismuth-209, neutron capture must proceed more rapidly than it ta ...
Galactic Evolution - Harvard-Smithsonian Center for Astrophysics
... distant galaxies and quasars. Yet, the galaxies could not have formed earlier than z ≈ 1500, which is the time (~0.5 My) when matter began recombining and decoupling from radiation. So there are some observational bounds to what did happen long ago. The figure below expansively sketches the status ...
... distant galaxies and quasars. Yet, the galaxies could not have formed earlier than z ≈ 1500, which is the time (~0.5 My) when matter began recombining and decoupling from radiation. So there are some observational bounds to what did happen long ago. The figure below expansively sketches the status ...
Exam 2 Solution
... 20.) Lalande 21185 is an M2 red dwarf about 8 LY away and Betelgeuse is an M2 red supergiant about 600 LY away. Both have a temperature of about 3500 K, but we can see Betelgeuse and not Lalande 21185 with the naked eye because… A – Betelgeuse is so much more luminous. B – Betelgeuse has an apparent ...
... 20.) Lalande 21185 is an M2 red dwarf about 8 LY away and Betelgeuse is an M2 red supergiant about 600 LY away. Both have a temperature of about 3500 K, but we can see Betelgeuse and not Lalande 21185 with the naked eye because… A – Betelgeuse is so much more luminous. B – Betelgeuse has an apparent ...
3D Tour of the Universe Template
... regions, resulting in the formation of new young stars. As is common in these kinds of encounters, spiral structure was induced in the more massive galaxy. M51 is an easily found astronomical showpiece if the sky is dark, where suggestions of its spiral arms may be visible. As is also common with th ...
... regions, resulting in the formation of new young stars. As is common in these kinds of encounters, spiral structure was induced in the more massive galaxy. M51 is an easily found astronomical showpiece if the sky is dark, where suggestions of its spiral arms may be visible. As is also common with th ...
Chronology of the universe
The chronology of the universe describes the history and future of the universe according to Big Bang cosmology, the prevailing scientific model of how the universe developed over time from the Planck epoch, using the cosmological time parameter of comoving coordinates. The model of the universe's expansion is known as the Big Bang. As of 2015, this expansion is estimated to have begun 13.799 ± 0.021 billion years ago. It is convenient to divide the evolution of the universe so far into three phases.