Cosmology Astronomy 1 — Elementary Astronomy LA Mission College Spring F2015
... matter organizing the universe… occurred at about 100s. The actual galaxies appeared much later. “A fraction of a second and the elements were made” Inaccurate. H & He (a little Li) very quickly at few second. Everything else as massive stars fused elements up to iron in their core and then went ...
... matter organizing the universe… occurred at about 100s. The actual galaxies appeared much later. “A fraction of a second and the elements were made” Inaccurate. H & He (a little Li) very quickly at few second. Everything else as massive stars fused elements up to iron in their core and then went ...
New Dark Matter Physics: Clues from Halo Structure
... towards the center of halos which is not seen in close studies of dark-matter-dominated galaxies [57,58,10] (although the observational issue is far from settled [61,16]). The formation of central cusps has been observed for many years in simulations of collapse of cold matter in a wide variety of c ...
... towards the center of halos which is not seen in close studies of dark-matter-dominated galaxies [57,58,10] (although the observational issue is far from settled [61,16]). The formation of central cusps has been observed for many years in simulations of collapse of cold matter in a wide variety of c ...
Chapter 16
... Measuring the Mass of Galaxies • The mass of a galaxy is determined from the modified form of Kepler’s third law • To use this method, one concentrates on some stars or gas on the outer fringes of the galaxy • The semimajor axis distance used in Kepler’s third law is simply half the galaxy’s pre-de ...
... Measuring the Mass of Galaxies • The mass of a galaxy is determined from the modified form of Kepler’s third law • To use this method, one concentrates on some stars or gas on the outer fringes of the galaxy • The semimajor axis distance used in Kepler’s third law is simply half the galaxy’s pre-de ...
Ch17_lecture
... – Census of distant galaxies: In clusters, 60% of members are spirals and S0, while in sparsely populated regions it is 80% – Early (very young) galaxies are much smaller than Milky Way – merging of these small galaxies is thought to have resulted in the larger galaxies of today ...
... – Census of distant galaxies: In clusters, 60% of members are spirals and S0, while in sparsely populated regions it is 80% – Early (very young) galaxies are much smaller than Milky Way – merging of these small galaxies is thought to have resulted in the larger galaxies of today ...
Chapter 17 Galaxies Galaxies Early Observations
... rather than core of galaxy • Classified with letters SB followed by the letters (a-d) • Thought by Hubble to be a separate class of object from normal S spirals, computer simulations show bar may be result of a close encounter between two galaxies • The Milky Way is probably an SB galaxy ...
... rather than core of galaxy • Classified with letters SB followed by the letters (a-d) • Thought by Hubble to be a separate class of object from normal S spirals, computer simulations show bar may be result of a close encounter between two galaxies • The Milky Way is probably an SB galaxy ...
1 The Hubble Story (10:56)
... galaxies enables scientists to investigate the influence of different environments on the lives of stars. These are crucial data that allow us to extend our understanding of the Milky Way galaxy to other galaxies. Hubble uses its exceptionally sharp focus to reveal changes on cosmic scales over peri ...
... galaxies enables scientists to investigate the influence of different environments on the lives of stars. These are crucial data that allow us to extend our understanding of the Milky Way galaxy to other galaxies. Hubble uses its exceptionally sharp focus to reveal changes on cosmic scales over peri ...
Cosmic Strings - University of Amsterdam
... transitions can occur, forcing the fields into a particular vacuum state. A cosmic string is a one-dimensional defect, but defects of other dimensions like monopoles and domain walls can also occur. In the context of the Abelian-Higgs model, a simple formulation of a cosmic string will be derived. T ...
... transitions can occur, forcing the fields into a particular vacuum state. A cosmic string is a one-dimensional defect, but defects of other dimensions like monopoles and domain walls can also occur. In the context of the Abelian-Higgs model, a simple formulation of a cosmic string will be derived. T ...
David AJ Seargent
... The Earth floats on water, All things are full of gods. The magnet is alive because it has the power of moving iron. The last need not concern us, but the first two statements, when taken together, imply a cosmological system in which water is the ultimate “stuff” of the universe. Although we don’t ...
... The Earth floats on water, All things are full of gods. The magnet is alive because it has the power of moving iron. The last need not concern us, but the first two statements, when taken together, imply a cosmological system in which water is the ultimate “stuff” of the universe. Although we don’t ...
The paper on the Hubble constant published in 2010
... 共Received 11 January 2010; accepted 9 March 2010; published online 20 April 2010兲 Abstract: It is shown that the Hubble constant can be derived from the standard luminosity function of galaxies as well as from a new luminosity function as deduced from the mass-luminosity relationship for galaxies. A ...
... 共Received 11 January 2010; accepted 9 March 2010; published online 20 April 2010兲 Abstract: It is shown that the Hubble constant can be derived from the standard luminosity function of galaxies as well as from a new luminosity function as deduced from the mass-luminosity relationship for galaxies. A ...
arXiv:astro-ph/9701131v1 18 Jan 1997
... i.e., the neutron stars, white dwarfs, and brown dwarfs remaining at the end of stellar evolution; this aggregate of remnants defines the “final stellar mass function”. At times exceeding ∼1–10 trillion years, the supply of interstellar gas will be exhausted, yet star formation will continue at a hi ...
... i.e., the neutron stars, white dwarfs, and brown dwarfs remaining at the end of stellar evolution; this aggregate of remnants defines the “final stellar mass function”. At times exceeding ∼1–10 trillion years, the supply of interstellar gas will be exhausted, yet star formation will continue at a hi ...
Galaxies and Their Structure
... The Hubble Law In 1914 Vesto Slipher (lived 1870--1963) announced his results from the spectra of over 40 spiral galaxies (at his time people thought the ``spiral nebulae'' were inside the Milky Way). He found that over 90% of the spectra showed redshifts which meant that they were moving away from ...
... The Hubble Law In 1914 Vesto Slipher (lived 1870--1963) announced his results from the spectra of over 40 spiral galaxies (at his time people thought the ``spiral nebulae'' were inside the Milky Way). He found that over 90% of the spectra showed redshifts which meant that they were moving away from ...
On the Origin of Early-Type Galaxies and the - N
... ““ nurture ÏÏ hypotheses for the formation of early-type galaxies, and speciÐcally of ellipticals (EÏs). In the ““ nature ÏÏ case, star formation occurred at high redshift in a rapid (D1 Gyr) burst within protogalactic halos that then quickly coalesced to form galaxies with a dominant spheroidal com ...
... ““ nurture ÏÏ hypotheses for the formation of early-type galaxies, and speciÐcally of ellipticals (EÏs). In the ““ nature ÏÏ case, star formation occurred at high redshift in a rapid (D1 Gyr) burst within protogalactic halos that then quickly coalesced to form galaxies with a dominant spheroidal com ...
The 2dF QSO Redshift Survey
... Due to the relatively bright magnitude limits of the SDSS and 2QZ surveys, the LF analysis is restricted to relatively bright QSOs – especially at high redshift. What about fainter QSOs? 2SLAQ survey extending 2QZ a magnitude deeper:~10000 g<21.85 QSOs on the way… ...
... Due to the relatively bright magnitude limits of the SDSS and 2QZ surveys, the LF analysis is restricted to relatively bright QSOs – especially at high redshift. What about fainter QSOs? 2SLAQ survey extending 2QZ a magnitude deeper:~10000 g<21.85 QSOs on the way… ...
Introduction to Cosmology - Experimental Elementary Particle
... of our Galaxy is not known as accurately as the mass of the Sun; in round numbers, though, it is Mgal ≈ 1012 M¯ . The Sun, incidentally, also provides the standard unit of power used in astronomy. The Sun’s luminosity (that is, the rate at which it radiates away energy in the form of light) is 1 L¯ ...
... of our Galaxy is not known as accurately as the mass of the Sun; in round numbers, though, it is Mgal ≈ 1012 M¯ . The Sun, incidentally, also provides the standard unit of power used in astronomy. The Sun’s luminosity (that is, the rate at which it radiates away energy in the form of light) is 1 L¯ ...
Summary - X-ray Astronomy Group at ISAS
... Properties of active galaxies • Energy due to accretion onto a Massive Black Hole (but other processes may be at work) exact mechanism which produces radiation is not known • strong dynamical evidence for MBH from optical velocity data and x-ray timing data mass estimates are accurate to ~ 2-4. • S ...
... Properties of active galaxies • Energy due to accretion onto a Massive Black Hole (but other processes may be at work) exact mechanism which produces radiation is not known • strong dynamical evidence for MBH from optical velocity data and x-ray timing data mass estimates are accurate to ~ 2-4. • S ...
A galaxy rapidly forming stars 700 million years after the Big Bang at
... of z8_GND_5296 is a factor of more than 30 times greater. If this SFR function is accurate, the expected space density per co-moving Mpc3 for this galaxy would be =1025. The implied rarity of this galaxy could indicate that it is the progenitor of some of the most massive systems in the high-redshif ...
... of z8_GND_5296 is a factor of more than 30 times greater. If this SFR function is accurate, the expected space density per co-moving Mpc3 for this galaxy would be =1025. The implied rarity of this galaxy could indicate that it is the progenitor of some of the most massive systems in the high-redshif ...
Metallicity, Age, and Mass of Star Forming Galaxies at z~3
... Aging z>4 exLBG should be visible in the HDF images as red sources. There are no such galaxies. But we do see z>4 LBGs. Where are they at Z~3? Recurrent SF? Just bad luck in The HDF? ...
... Aging z>4 exLBG should be visible in the HDF images as red sources. There are no such galaxies. But we do see z>4 LBGs. Where are they at Z~3? Recurrent SF? Just bad luck in The HDF? ...
Chapman
... •Until the mid-1990’s the only z>2 objects known were QSOs, radio galaxies, and QS0 absorbers (DLA/LLS) • How can we go about isolating more normal galaxies during the epoch of star/galaxy formation? • The study of high-redshift (let’s say z>1.5) galaxies has exploded in the last ~10 years, with mul ...
... •Until the mid-1990’s the only z>2 objects known were QSOs, radio galaxies, and QS0 absorbers (DLA/LLS) • How can we go about isolating more normal galaxies during the epoch of star/galaxy formation? • The study of high-redshift (let’s say z>1.5) galaxies has exploded in the last ~10 years, with mul ...
EBL - UCSC Physics - University of California, Santa Cruz
... observed galaxies. New data on attenuation of gamma rays from blazers now lead to statistically significant measurements of the cosmic gamma ray horizon (CGRH) as a function of source redshift and gamma ray energy that are independent of EBL models. These new measurements are consistent with recent ...
... observed galaxies. New data on attenuation of gamma rays from blazers now lead to statistically significant measurements of the cosmic gamma ray horizon (CGRH) as a function of source redshift and gamma ray energy that are independent of EBL models. These new measurements are consistent with recent ...
A 6% measurement of the Hubble parameter at ζ ∼ 0.45: direct
... redshift slices, with ∆z = 0.1 (as discussed in section 5.1) corresponding to a difference in cosmic time of approximatively 0.7 Gyr at z ∼ 0.45. This is a rather short time for a potential significant evolution of these massive and passive systems, in particular considering that on average they wou ...
... redshift slices, with ∆z = 0.1 (as discussed in section 5.1) corresponding to a difference in cosmic time of approximatively 0.7 Gyr at z ∼ 0.45. This is a rather short time for a potential significant evolution of these massive and passive systems, in particular considering that on average they wou ...
The Animate and the Inanimate
... Ionian school, and reappearing at later periods from time to time. On the other hand, the generally accepted theory of the second law of thermodynamics represents a different philosophical tendency, the tendency that considers changes once made as irreparable. Aristotle's philosophy is a good ...
... Ionian school, and reappearing at later periods from time to time. On the other hand, the generally accepted theory of the second law of thermodynamics represents a different philosophical tendency, the tendency that considers changes once made as irreparable. Aristotle's philosophy is a good ...
Exploring the Most Bizarre Ideas in Cosmology Astronomers
... Looking back over so many years, we simply cannot know. But whatever his exact thoughts may have been, the important issue for us is that in these speculations, Thales launched a new endeavor in human though; scientific cosmology or the employment of observation and reason in the bold attempt to wor ...
... Looking back over so many years, we simply cannot know. But whatever his exact thoughts may have been, the important issue for us is that in these speculations, Thales launched a new endeavor in human though; scientific cosmology or the employment of observation and reason in the bold attempt to wor ...
Suppose you tried to determine where we are in the galaxy by
... a) We're in the middle of one of its arms and thus have no perspective. b) It is very large and the edges are far away and faint. c) Dust blocks our view when we look toward the center or in the disk. d) We cannot see it from the outside. e) all of the above ...
... a) We're in the middle of one of its arms and thus have no perspective. b) It is very large and the edges are far away and faint. c) Dust blocks our view when we look toward the center or in the disk. d) We cannot see it from the outside. e) all of the above ...
Big Bang
The Big Bang theory is the prevailing cosmological model for the universe from the earliest known periods through its subsequent large-scale evolution. The model accounts for the fact that the universe expanded from a very high density and high temperature state, and offers a comprehensive explanation for a broad range of observed phenomena, including the abundance of light elements, the cosmic microwave background, large scale structure, and Hubble's Law. If the known laws of physics are extrapolated beyond where they are valid, there is a singularity. Modern measurements place this moment at approximately 13.8 billion years ago, which is thus considered the age of the universe. After the initial expansion, the universe cooled sufficiently to allow the formation of subatomic particles, and later simple atoms. Giant clouds of these primordial elements later coalesced through gravity to form stars and galaxies.Since Georges Lemaître first noted, in 1927, that an expanding universe might be traced back in time to an originating single point, scientists have built on his idea of cosmic expansion. While the scientific community was once divided between supporters of two different expanding universe theories, the Big Bang and the Steady State theory, accumulated empirical evidence provides strong support for the former. In 1929, from analysis of galactic redshifts, Edwin Hubble concluded that galaxies are drifting apart, important observational evidence consistent with the hypothesis of an expanding universe. In 1965, the cosmic microwave background radiation was discovered, which was crucial evidence in favor of the Big Bang model, since that theory predicted the existence of background radiation throughout the universe before it was discovered. More recently, measurements of the redshifts of supernovae indicate that the expansion of the universe is accelerating, an observation attributed to dark energy's existence. The known physical laws of nature can be used to calculate the characteristics of the universe in detail back in time to an initial state of extreme density and temperature.