X-ray astronomy - University of Warwick
... – Each photon has ~1000x energy, so 1000x fewer photons for same energy flux – Effective area of X-ray telescopes tends to be small (e.g. XMM is ~0.1m2) – So data tends to be Poisson dominated ...
... – Each photon has ~1000x energy, so 1000x fewer photons for same energy flux – Effective area of X-ray telescopes tends to be small (e.g. XMM is ~0.1m2) – So data tends to be Poisson dominated ...
5 Report of the Panel on Stars and Stellar Evolution
... exploding stars at redshift 8.3. It includes understanding processes of exquisite complexity that connect the rotation of stars with their magnetic fields and areas of nearly total ignorance about phenomena that have been imagined, but not yet been observed, such as accretion-induced collapse. Becau ...
... exploding stars at redshift 8.3. It includes understanding processes of exquisite complexity that connect the rotation of stars with their magnetic fields and areas of nearly total ignorance about phenomena that have been imagined, but not yet been observed, such as accretion-induced collapse. Becau ...
D ASTROPHYSICS
... the mass of the protostar is large enough, the temperature and pressure at the centre will be sufficient for hydrogen to fuse into helium, with the release of very large amounts of energy – the star has “ignited”. Ignition produces emission of radiation from the core, producing a radiation pressure ...
... the mass of the protostar is large enough, the temperature and pressure at the centre will be sufficient for hydrogen to fuse into helium, with the release of very large amounts of energy – the star has “ignited”. Ignition produces emission of radiation from the core, producing a radiation pressure ...
THE OFFSET AND HOST LIGHT DISTRIBUTIONS OF LONG
... being drawn from the same fractional flux distribution as LGRBs, whereas Type II and Ib SNe uniformly track the light of their hosts. They suggest that LGRBs and Type Ic SNe share a common progenitor, and that a factor such as metallicity may determine whether core-collapse results in a LGRB with an ...
... being drawn from the same fractional flux distribution as LGRBs, whereas Type II and Ib SNe uniformly track the light of their hosts. They suggest that LGRBs and Type Ic SNe share a common progenitor, and that a factor such as metallicity may determine whether core-collapse results in a LGRB with an ...
Studying the Universe Studying the Universe
... Figure 12 The Milky Way at Different Wavelengths X ray ...
... Figure 12 The Milky Way at Different Wavelengths X ray ...
ASPEN WORKSHOP 2003
... Simulations show that AI stays above 0.35 for about 700 Myears, but NOT for face-on HDF application: rest frame B morphologies, NICMOS extends out to z=3 Correcting for selection effects by simulating 38 nearer galaxies, which tends to drop AI by up to 0.1 at z>2, similarly “sizes” appear systematic ...
... Simulations show that AI stays above 0.35 for about 700 Myears, but NOT for face-on HDF application: rest frame B morphologies, NICMOS extends out to z=3 Correcting for selection effects by simulating 38 nearer galaxies, which tends to drop AI by up to 0.1 at z>2, similarly “sizes” appear systematic ...
Section 6 The Expanding Universe The Doppler Effect
... would appear to contract and create a blue shift in the wavelength. However, Slipher was to also discover that the stars were all moving away from the Earth and created a cosmic red shift. Slipher’s observations did not receive much notice, although they were essential to the pioneering work of Edw ...
... would appear to contract and create a blue shift in the wavelength. However, Slipher was to also discover that the stars were all moving away from the Earth and created a cosmic red shift. Slipher’s observations did not receive much notice, although they were essential to the pioneering work of Edw ...
Journey through the cosmos
... Our galaxy, the Milky Way The galaxy in which we live is commonly known as the Milky Way. It is called the Milky Way because it looks like a giant splash or river of milk across a dark sky. But you probably haven’t seen it look like this, unless you live somewhere a long way away from a town. Until ...
... Our galaxy, the Milky Way The galaxy in which we live is commonly known as the Milky Way. It is called the Milky Way because it looks like a giant splash or river of milk across a dark sky. But you probably haven’t seen it look like this, unless you live somewhere a long way away from a town. Until ...
AST1100 Lecture Notes
... cluster which is located so far away that parallax measurements are impossible. We have measured the surface temperature (how?) and the apparent magnitude of all stars. We now make an HR-diagram where we, as usual, plot the surface temperature on the x-axis. However, we do not know the distance to t ...
... cluster which is located so far away that parallax measurements are impossible. We have measured the surface temperature (how?) and the apparent magnitude of all stars. We now make an HR-diagram where we, as usual, plot the surface temperature on the x-axis. However, we do not know the distance to t ...
X-ray polarimetry in astrophysics
... Gamma Ray Bursts (GRB) Gamma-ray bursts are the most energetic events in the Universe, with radiated energy up to 1054 erg. The collapse of a massive rotating star produces a hot fireball which is ejected at relativistic velocity in form of a jet. Internal shocks are responsible for the observed va ...
... Gamma Ray Bursts (GRB) Gamma-ray bursts are the most energetic events in the Universe, with radiated energy up to 1054 erg. The collapse of a massive rotating star produces a hot fireball which is ejected at relativistic velocity in form of a jet. Internal shocks are responsible for the observed va ...
The evolution of spiral galaxies in clusters Kutdemir, Elif
... and 340 Gyr respectively. A merger between spirals of unequal mass can form an S0 galaxy (Bekki 1998), while major mergers likely result in a giant elliptical galaxy (Naab & Burkert 2003). Fig. 1.3 from Moran (2008) shows the regions where these mechanisms are expected to be effective for two interm ...
... and 340 Gyr respectively. A merger between spirals of unequal mass can form an S0 galaxy (Bekki 1998), while major mergers likely result in a giant elliptical galaxy (Naab & Burkert 2003). Fig. 1.3 from Moran (2008) shows the regions where these mechanisms are expected to be effective for two interm ...
Lifecycle of Dust in Galaxies - The National Academies of Sciences
... type of dust (scattered light) and the heating sources (hot stars). The spatial resolution of GALEX is sufficient for the dust scattering (5′′ ), but it is likely not sufficient to deal with the confusion due to crowding of the hot stars. Something like 1′′ (2.5 m) would likely be sufficient, especi ...
... type of dust (scattered light) and the heating sources (hot stars). The spatial resolution of GALEX is sufficient for the dust scattering (5′′ ), but it is likely not sufficient to deal with the confusion due to crowding of the hot stars. Something like 1′′ (2.5 m) would likely be sufficient, especi ...
Chapter 19 Stars Galaxies and the Universe
... Scientists use the light from stars to find out what the stars are made of. When you look at white light through a glass prism, you can see a rainbow of colors. This rainbow is called a spectrum ( plural, spectra). Millions of colors make up a spectrum, including red, orange, yellow, green, blue, in ...
... Scientists use the light from stars to find out what the stars are made of. When you look at white light through a glass prism, you can see a rainbow of colors. This rainbow is called a spectrum ( plural, spectra). Millions of colors make up a spectrum, including red, orange, yellow, green, blue, in ...
Geoscience Astronomy Formative on Stellar Evolution and
... the speed of light d. Many astronomers believe that black dwarfs a. are hotter than white dwarfs c. are more massive than white dwarfs b. are more dense than white dwarfs d. do not exist yet A rapidly spinning neutron star that emits bursts of radio and optical energy is a a. supernova c. black hole ...
... the speed of light d. Many astronomers believe that black dwarfs a. are hotter than white dwarfs c. are more massive than white dwarfs b. are more dense than white dwarfs d. do not exist yet A rapidly spinning neutron star that emits bursts of radio and optical energy is a a. supernova c. black hole ...
the Local Group - Simon P Driver
... – these are dense enough to halt cosmological expansion locally, and so the galaxies remain bound to each other • the other half of galaxies are loosely spread out in large ...
... – these are dense enough to halt cosmological expansion locally, and so the galaxies remain bound to each other • the other half of galaxies are loosely spread out in large ...
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 ...
Distances in Cosmology One of the most basic measurements that
... direction appears to change, by an amount that is inversely proportional to its distance from the viewing points. This is one of the ways we obtain depth perception; looking out with first one eye, then the other, shows that close things appear to move more than distant things. If you know the dista ...
... direction appears to change, by an amount that is inversely proportional to its distance from the viewing points. This is one of the ways we obtain depth perception; looking out with first one eye, then the other, shows that close things appear to move more than distant things. If you know the dista ...
NASA FUSE Satellite Solves the Case of the Missing Deuterium
... leaving less than the amount seen in the Milky Way. But only about 15 percent of the deuterium has been destroyed, FUSE has found, suggesting that less than the amount expected has cycled through stars. "The peak galactic detection levels are likely close to the real total deuterium abundance in the ...
... leaving less than the amount seen in the Milky Way. But only about 15 percent of the deuterium has been destroyed, FUSE has found, suggesting that less than the amount expected has cycled through stars. "The peak galactic detection levels are likely close to the real total deuterium abundance in the ...
AST1100 Lecture Notes
... to this in later lectures). In the same figure (upper plot) you see the HRdiagram taken from a cluster with a known distance (measured by parallax). Since the distance is known, the apparent magnitudes could be converted to absolute magnitudes and for this reason we plot absolute magnitude on the y- ...
... to this in later lectures). In the same figure (upper plot) you see the HRdiagram taken from a cluster with a known distance (measured by parallax). Since the distance is known, the apparent magnitudes could be converted to absolute magnitudes and for this reason we plot absolute magnitude on the y- ...
Gamma-ray burst
Gamma-ray bursts (GRBs) are flashes of gamma rays associated with extremely energetic explosions that have been observed in distant galaxies. They are the brightest electromagnetic events known to occur in the universe. Bursts can last from ten milliseconds to several hours. The initial burst is usually followed by a longer-lived ""afterglow"" emitted at longer wavelengths (X-ray, ultraviolet, optical, infrared, microwave and radio).Most observed GRBs are believed to consist of a narrow beam of intense radiation released during a supernova or hypernova as a rapidly rotating, high-mass star collapses to form a neutron star, quark star, or black hole. A subclass of GRBs (the ""short"" bursts) appear to originate from a different process – this may be due to the merger of binary neutron stars. The cause of the precursor burst observed in some of these short events may be due to the development of a resonance between the crust and core of such stars as a result of the massive tidal forces experienced in the seconds leading up to their collision, causing the entire crust of the star to shatter.The sources of most GRBs are billions of light years away from Earth, implying that the explosions are both extremely energetic (a typical burst releases as much energy in a few seconds as the Sun will in its entire 10-billion-year lifetime) and extremely rare (a few per galaxy per million years). All observed GRBs have originated from outside the Milky Way galaxy, although a related class of phenomena, soft gamma repeater flares, are associated with magnetars within the Milky Way. It has been hypothesized that a gamma-ray burst in the Milky Way, pointing directly towards the Earth, could cause a mass extinction event.GRBs were first detected in 1967 by the Vela satellites, a series of satellites designed to detect covert nuclear weapons tests. Hundreds of theoretical models were proposed to explain these bursts in the years following their discovery, such as collisions between comets and neutron stars. Little information was available to verify these models until the 1997 detection of the first X-ray and optical afterglows and direct measurement of their redshifts using optical spectroscopy, and thus their distances and energy outputs. These discoveries, and subsequent studies of the galaxies and supernovae associated with the bursts, clarified the distance and luminosity of GRBs. These facts definitively placed them in distant galaxies and also connected long GRBs with the explosion of massive stars, the only possible source for the energy outputs observed.