Light
... space to peer into star-forming regions and into the central areas of our galaxy Cool stars and cold interstellar clouds which are invisible in optical light are also observed in the infrared ...
... space to peer into star-forming regions and into the central areas of our galaxy Cool stars and cold interstellar clouds which are invisible in optical light are also observed in the infrared ...
Astronomy - SAVE MY EXAMS!
... Suggest why radio telescopes do not have to be placed high up a mountain. ...
... Suggest why radio telescopes do not have to be placed high up a mountain. ...
telescopes and sites
... • Not all sources that exhibit continuous spectra are thermal, meaning that their temperature does not determine how their apparent brightness changes with wavelength. => non-thermal sources • The most important source of non-thermal radiation is synchrotron emission, which is emitted when very fast ...
... • Not all sources that exhibit continuous spectra are thermal, meaning that their temperature does not determine how their apparent brightness changes with wavelength. => non-thermal sources • The most important source of non-thermal radiation is synchrotron emission, which is emitted when very fast ...
SAMPLE PUBLIC SERVICE ANNOUNCEMENTS
... Moon, comets, star birth, and distant galaxies, and compares how astronomers centuries ago viewed these phenomena with the discoveries of modern day space ...
... Moon, comets, star birth, and distant galaxies, and compares how astronomers centuries ago viewed these phenomena with the discoveries of modern day space ...
Slides from fourth lecture
... • Result is huge – 120 orders of magnitude larger than observed! • Physicists have no idea why • First major headache ...
... • Result is huge – 120 orders of magnitude larger than observed! • Physicists have no idea why • First major headache ...
What Do We Really Know About the Universe?
... HOW DO WE KNOW WHAT’S IN A STAR? • In a laboratory, we see an emission spectrum of bright lines against a dark background. • However, the interior of a star is so hot that the electrons are knocked completely away from the atoms. (This is called a plasma.) The star’s light is NOT from electrons jum ...
... HOW DO WE KNOW WHAT’S IN A STAR? • In a laboratory, we see an emission spectrum of bright lines against a dark background. • However, the interior of a star is so hot that the electrons are knocked completely away from the atoms. (This is called a plasma.) The star’s light is NOT from electrons jum ...
Weighing the universe—6 Dec AST207 F2010 12/6/2010
... • A Type II supernova is a massive star that explodes when it runs out of fuel and pressure is insufficient to counter gravity. • A Type I supernova is a white dwarf that explodes. – A WD and giant orbit each other. – Mass moves from the giant to the WD. – WD explodes when it gets so much mass f ...
... • A Type II supernova is a massive star that explodes when it runs out of fuel and pressure is insufficient to counter gravity. • A Type I supernova is a white dwarf that explodes. – A WD and giant orbit each other. – Mass moves from the giant to the WD. – WD explodes when it gets so much mass f ...
Primary-centric World-View proposes a Fractal Architecture
... • Milky Way Rotation Curve dynamics can be explained by Dark Matter only. • the observed value of the tangential velocity is almost constant with increasing distance from the center of Milky Way . • and this is solely due to 90% excess dark matter. This gives a ratio of 1:1.89 =Baryonic Matter: Dark ...
... • Milky Way Rotation Curve dynamics can be explained by Dark Matter only. • the observed value of the tangential velocity is almost constant with increasing distance from the center of Milky Way . • and this is solely due to 90% excess dark matter. This gives a ratio of 1:1.89 =Baryonic Matter: Dark ...
Pop Goes the Universe
... Agency held an international press conference to announce new results from a satellite called Planck. The spacecraft had mapped the cosmic microwave background (CMB) radiation, light emitted more than 13 billion years ago just after the big bang, in better detail than ever before. The new map, scien ...
... Agency held an international press conference to announce new results from a satellite called Planck. The spacecraft had mapped the cosmic microwave background (CMB) radiation, light emitted more than 13 billion years ago just after the big bang, in better detail than ever before. The new map, scien ...
Astro-2: History of the Universe
... was filled with an absorbing medium, like fog However, if light is absorbed it will also re-radiate, producing light albeit at different wavelengths, so this doesn’t work! ...
... was filled with an absorbing medium, like fog However, if light is absorbed it will also re-radiate, producing light albeit at different wavelengths, so this doesn’t work! ...
Lecture6
... was filled with an absorbing medium, like fog However, if light is absorbed it will also re-radiate, producing light albeit at different wavelengths, so this doesn’t work! ...
... was filled with an absorbing medium, like fog However, if light is absorbed it will also re-radiate, producing light albeit at different wavelengths, so this doesn’t work! ...
Physics116_L42
... evolution of the Universe) work - but this concept came from studies of Grand Unified Theories (GUTs) of particle physics Our Universe may be just one bubble in a foam of other universes… The net energy of the Universe could be zero and our Universe could be just a quantum fluctuation which has not ...
... evolution of the Universe) work - but this concept came from studies of Grand Unified Theories (GUTs) of particle physics Our Universe may be just one bubble in a foam of other universes… The net energy of the Universe could be zero and our Universe could be just a quantum fluctuation which has not ...
Scientists confirm most distant galaxy ever
... Astronomers were looking for a special radiation signature from hydrogen called the Lymanalpha emission line. This radiation represents the particular wavelength of light that gets emitted when hydrogen atoms get excited in a particular way. Researchers were able to detect this emission line coming ...
... Astronomers were looking for a special radiation signature from hydrogen called the Lymanalpha emission line. This radiation represents the particular wavelength of light that gets emitted when hydrogen atoms get excited in a particular way. Researchers were able to detect this emission line coming ...
Topic/Objective: ______ _____ Full Name: __________ Class: __
... objects with telescopes and experimenting with matter on Earth Approximately 10-20 billion years ago all matter in the universe existed in an incredibly hot and dense state, from which it expanded and cooled slowly condensing into stars and galaxies. It is expanding at a very slow rate and is st ...
... objects with telescopes and experimenting with matter on Earth Approximately 10-20 billion years ago all matter in the universe existed in an incredibly hot and dense state, from which it expanded and cooled slowly condensing into stars and galaxies. It is expanding at a very slow rate and is st ...
Transcript of this week`s podcast
... after the Big Bang. For the effects of what happened from this time can still be observed today. From 10-35 of a second after its creation, the universe entered a phase that scientists since the early 1980s have called the inflationary epoch. During this inflationary epoch, the universe began expand ...
... after the Big Bang. For the effects of what happened from this time can still be observed today. From 10-35 of a second after its creation, the universe entered a phase that scientists since the early 1980s have called the inflationary epoch. During this inflationary epoch, the universe began expand ...
Localized wave packet around R 0
... The last decade is considered as a big success, for inflationary cosmology. ...
... The last decade is considered as a big success, for inflationary cosmology. ...
Fujihara09 - Cardiff Physics and Astronomy
... Stochastic backgrounds of gravitational waves are difficult to detect, but the current work on theoretical modelling and comparison of primordial, cosmological, astrophysical backgrounds, as well as data analysis techniques, must continue. The relic gravitational waves are a unique probe of the birt ...
... Stochastic backgrounds of gravitational waves are difficult to detect, but the current work on theoretical modelling and comparison of primordial, cosmological, astrophysical backgrounds, as well as data analysis techniques, must continue. The relic gravitational waves are a unique probe of the birt ...
Slide 1
... Before Einstein, the believe was among physicists that there existed a frame of reference absolutely at rest, in which the aether sat motionless. Only in this frame, the speed of light was exactly c. Then, an observer in a frame can measure the velocity of light. If it is equal c, then her frame wa ...
... Before Einstein, the believe was among physicists that there existed a frame of reference absolutely at rest, in which the aether sat motionless. Only in this frame, the speed of light was exactly c. Then, an observer in a frame can measure the velocity of light. If it is equal c, then her frame wa ...
Astronomy Unit Outline
... Describe the different models of the universe and the evidence that supports each model. Describe the structure of the Milky Way Describe and identify different types of galaxies Describe the difference between the two spectra Describe the information that can be found in the spectra. ...
... Describe the different models of the universe and the evidence that supports each model. Describe the structure of the Milky Way Describe and identify different types of galaxies Describe the difference between the two spectra Describe the information that can be found in the spectra. ...
PHY418 Particle Astrophysics - Particle Physics and Particle
... by local magnetic fields • smaller-scale anisotropies may be due to source distribution or magnetic field variations • in fact, level of anisotropy is ...
... by local magnetic fields • smaller-scale anisotropies may be due to source distribution or magnetic field variations • in fact, level of anisotropy is ...
Cosmology and Particle Physics
... Big Bang. Extrapolating backward in time, the Big Bang would have occurred between 13 and 15 billion years ago when all matter would have been at a point. Questions instantly arise. What caused the explosion? What happened before the Big Bang? Was there a before, or did time start then? Will the uni ...
... Big Bang. Extrapolating backward in time, the Big Bang would have occurred between 13 and 15 billion years ago when all matter would have been at a point. Questions instantly arise. What caused the explosion? What happened before the Big Bang? Was there a before, or did time start then? Will the uni ...
Teacher`s Guide Understanding: The Universe
... What is significant about the redshifted spectra of galaxies? (The redshift in the spectra of galaxies implies that they are moving away from one another, and that could mean that the universe is expanding.) ...
... What is significant about the redshifted spectra of galaxies? (The redshift in the spectra of galaxies implies that they are moving away from one another, and that could mean that the universe is expanding.) ...
Cosmic microwave background
The cosmic microwave background (CMB) is the thermal radiation left over from the time of recombination in Big Bang cosmology. In older literature, the CMB is also variously known as cosmic microwave background radiation (CMBR) or ""relic radiation."" The CMB is a cosmic background radiation that is fundamental to observational cosmology because it is the oldest light in the universe, dating to the epoch of recombination. With a traditional optical telescope, the space between stars and galaxies (the background) is completely dark. However, a sufficiently sensitive radio telescope shows a faint background glow, almost exactly the same in all directions, that is not associated with any star, galaxy, or other object. This glow is strongest in the microwave region of the radio spectrum. The accidental discovery of CMB in 1964 by American radio astronomers Arno Penzias and Robert Wilson was the culmination of work initiated in the 1940s, and earned the discoverers the 1978 Nobel Prize.The CMB is a snapshot of the oldest light in our Universe, imprinted on the sky when the Universe was just 380,000 years old. It shows tiny temperature fluctuations that correspond to regions of slightly different densities, representing the seeds of all future structure: the stars and galaxies of today.The CMB is well explained as radiation left over from an early stage in the development of the universe, and its discovery is considered a landmark test of the Big Bang model of the universe. When the universe was young, before the formation of stars and planets, it was denser, much hotter, and filled with a uniform glow from a white-hot fog of hydrogen plasma. As the universe expanded, both the plasma and the radiation filling it grew cooler. When the universe cooled enough, protons and electrons combined to form neutral atoms. These atoms could no longer absorb the thermal radiation, and so the universe became transparent instead of being an opaque fog. Cosmologists refer to the time period when neutral atoms first formed as the recombination epoch, and the event shortly afterwards when photons started to travel freely through space rather than constantly being scattered by electrons and protons in plasma is referred to as photon decoupling. The photons that existed at the time of photon decoupling have been propagating ever since, though growing fainter and less energetic, since the expansion of space causes their wavelength to increase over time (and wavelength is inversely proportional to energy according to Planck's relation). This is the source of the alternative term relic radiation. The surface of last scattering refers to the set of points in space at the right distance from us so that we are now receiving photons originally emitted from those points at the time of photon decoupling.Precise measurements of the CMB are critical to cosmology, since any proposed model of the universe must explain this radiation. The CMB has a thermal black body spectrum at a temperature of 7000272548000000000♠2.72548±0.00057 K. The spectral radiance dEν/dν peaks at 160.2 GHz, in the microwave range of frequencies. (Alternatively if spectral radiance is defined as dEλ/dλ then the peak wavelength is 1.063 mm.) The glow is very nearly uniform in all directions, but the tiny residual variations show a very specific pattern, the same as that expected of a fairly uniformly distributed hot gas that has expanded to the current size of the universe. In particular, the spectral radiance at different angles of observation in the sky contains small anisotropies, or irregularities, which vary with the size of the region examined. They have been measured in detail, and match what would be expected if small thermal variations, generated by quantum fluctuations of matter in a very tiny space, had expanded to the size of the observable universe we see today. This is a very active field of study, with scientists seeking both better data (for example, the Planck spacecraft) and better interpretations of the initial conditions of expansion. Although many different processes might produce the general form of a black body spectrum, no model other than the Big Bang has yet explained the fluctuations. As a result, most cosmologists consider the Big Bang model of the universe to be the best explanation for the CMB.The high degree of uniformity throughout the observable universe and its faint but measured anisotropy lend strong support for the Big Bang model in general and the ΛCDM (""Lambda Cold Dark Matter"") model in particular. Moreover, the fluctuations are coherent on angular scales that are larger than the apparent cosmological horizon at recombination. Either such coherence is acausally fine-tuned, or cosmic inflation occurred.