Summary Of the Structure of the Milky Way
... nature of the Milky Way galaxy, but are not “deep” enough probes to fully reveal the structure of the Milky Way. • Open clusters can define the thickness of the Milky Way’s thin disk where star formation is active. • Globular clusters allow astronomers to know the direction to the center of our gala ...
... nature of the Milky Way galaxy, but are not “deep” enough probes to fully reveal the structure of the Milky Way. • Open clusters can define the thickness of the Milky Way’s thin disk where star formation is active. • Globular clusters allow astronomers to know the direction to the center of our gala ...
Galaxy Formation and Evolution
... Since galaxies are observed over cosmological length and time scales, the description of their formation and evolution must involve cosmology, the study of the properties of space-time on large scales. Modern cosmology is based upon the Cosmological Principle, the hypothesis that the Universe is spa ...
... Since galaxies are observed over cosmological length and time scales, the description of their formation and evolution must involve cosmology, the study of the properties of space-time on large scales. Modern cosmology is based upon the Cosmological Principle, the hypothesis that the Universe is spa ...
THE INNER CORE OF A NEUTRON STAR Part 1
... During the last ten years, the launch of X-Ray telescopes, such as the Chandra X-Ray Observatory, have also opened up new windows of opportunity, helping astronomers and astrophysicists to acquire a much better understanding of the properties of star accretion. This assists in the analysis and asses ...
... During the last ten years, the launch of X-Ray telescopes, such as the Chandra X-Ray Observatory, have also opened up new windows of opportunity, helping astronomers and astrophysicists to acquire a much better understanding of the properties of star accretion. This assists in the analysis and asses ...
Measuring Astronomical Distances
... Just like Rome, the cosmological distance ladder wasn’t built in one day! Without the hard work of those who dared to believe the universe was larger than they could fathom, we wouldn’t be able to study ...
... Just like Rome, the cosmological distance ladder wasn’t built in one day! Without the hard work of those who dared to believe the universe was larger than they could fathom, we wouldn’t be able to study ...
SXDS Highlights : Subaru / FOCAS Spectroscopy
... Natural guide star AO system on Subaru telescope with IRCS. 154 hours of observation in total. 13 FoVs with 36 LBGs , 1 RadioG., and 7 DRGs are observed. Typical on-source effective integration is 5 hours. Typical PSF size at the target position is FWHM=0.2” (~1.5kpc@z=3) ...
... Natural guide star AO system on Subaru telescope with IRCS. 154 hours of observation in total. 13 FoVs with 36 LBGs , 1 RadioG., and 7 DRGs are observed. Typical on-source effective integration is 5 hours. Typical PSF size at the target position is FWHM=0.2” (~1.5kpc@z=3) ...
PH607 – Galaxies
... 7.2 Clusters of Galaxies Clusters are systems a few Mpc across, typically containing at least 50-100 luminous galaxies within the central 1 Mpc Clusters are gravitationally bound Clusters are filled with hot X-ray gas Only ~20% of galaxies live in clusters, most live in groups or in the “fi ...
... 7.2 Clusters of Galaxies Clusters are systems a few Mpc across, typically containing at least 50-100 luminous galaxies within the central 1 Mpc Clusters are gravitationally bound Clusters are filled with hot X-ray gas Only ~20% of galaxies live in clusters, most live in groups or in the “fi ...
The Hubble Ultra Deep Field Project Overview
... Concordance Model is assumed, but you can change these parameters and explore how varying the relative densities of “stuff” in the Universe can change this distance measure. Exercise 1: Galaxy morphology over cosmic time In this exercise you will consider a variety of galaxies over a range of redshi ...
... Concordance Model is assumed, but you can change these parameters and explore how varying the relative densities of “stuff” in the Universe can change this distance measure. Exercise 1: Galaxy morphology over cosmic time In this exercise you will consider a variety of galaxies over a range of redshi ...
San Pedro Mártir observations of microvariability in obscured quasars
... effects would also affect the comparison stars, which we have detected as not variable. Because we observed during dark nights, we can rule out any variation caused by significant change in the background level. We also controlled the airmass of the observations. Since the airmass does not rise abov ...
... effects would also affect the comparison stars, which we have detected as not variable. Because we observed during dark nights, we can rule out any variation caused by significant change in the background level. We also controlled the airmass of the observations. Since the airmass does not rise abov ...
Quiz 2 Lecture 12
... Which of the following statements is FALSE? a. Ring galaxies can be produced by head-on collisions between galaxies. b. The ratio of the number of elliptical to spiral galaxies remains constant over time. c. The Magellanic Clouds may eventually be "cannibalized" by our Galaxy. d. The shape of a gala ...
... Which of the following statements is FALSE? a. Ring galaxies can be produced by head-on collisions between galaxies. b. The ratio of the number of elliptical to spiral galaxies remains constant over time. c. The Magellanic Clouds may eventually be "cannibalized" by our Galaxy. d. The shape of a gala ...
Stars and Galaxies
... star uses up all its fuel and explodes, the gases and dust that remain collapse to form the black hole.) ...
... star uses up all its fuel and explodes, the gases and dust that remain collapse to form the black hole.) ...
Ch 13 Death of Stars(4-5?-13)
... size of Earth. Atoms stop further collapse. M less than 1.4 solar masses • Neutron Stars: even denser, about mass of Sun in size of Orlando. Neutrons stop further collapse. M between 1.4 and 3 solar masses. Some neutron stars can be detected as pulsars • Black Holes: M more than 3 solar masses. Noth ...
... size of Earth. Atoms stop further collapse. M less than 1.4 solar masses • Neutron Stars: even denser, about mass of Sun in size of Orlando. Neutrons stop further collapse. M between 1.4 and 3 solar masses. Some neutron stars can be detected as pulsars • Black Holes: M more than 3 solar masses. Noth ...
Stellar-mass Black Hole Formation
... Masses greater than the maximum NS mass: 1.5-2.5 Msun (from detailed EOS calculations); 3.2 Msun (upper limit from causality; Lattimer & Prakash ) ~109 SMBHs in the Galaxy, from stellar popn modeling (Brown & Bethe 1994) 20 confirmed black holes in X-ray binaries, with secure masses (as of 2006) mas ...
... Masses greater than the maximum NS mass: 1.5-2.5 Msun (from detailed EOS calculations); 3.2 Msun (upper limit from causality; Lattimer & Prakash ) ~109 SMBHs in the Galaxy, from stellar popn modeling (Brown & Bethe 1994) 20 confirmed black holes in X-ray binaries, with secure masses (as of 2006) mas ...
The cosmic distance scale
... distance moduli of (mV – MV) ~ 25 from the ground and (mV – MV) ~ 28 using HST. This allows one to reach the nearest galaxy cluster Virgo. ...
... distance moduli of (mV – MV) ~ 25 from the ground and (mV – MV) ~ 28 using HST. This allows one to reach the nearest galaxy cluster Virgo. ...
First firm spectral classification of an early-B pre-main
... Figure 3 shows the flux-calibrated X-shooter spectrum (300− 2500 nm) of B275. The photometric data points demonstrate the accuracy of the spectrophotometric calibration. The long standing debate over the distance to M 17 (ranging from 1.3 to 2.1 kpc) has recently been settled by the measurement of t ...
... Figure 3 shows the flux-calibrated X-shooter spectrum (300− 2500 nm) of B275. The photometric data points demonstrate the accuracy of the spectrophotometric calibration. The long standing debate over the distance to M 17 (ranging from 1.3 to 2.1 kpc) has recently been settled by the measurement of t ...
File
... describe the structure of space–time inside a black hole. In particular, one would need to travel through space faster than the speed of light (which nobody can do) to avoid the singularity and end up in a different region. Thus, non-rotating black holes definitely seem to be excluded as passageways ...
... describe the structure of space–time inside a black hole. In particular, one would need to travel through space faster than the speed of light (which nobody can do) to avoid the singularity and end up in a different region. Thus, non-rotating black holes definitely seem to be excluded as passageways ...
The National Centre for Radio Astrophysics
... Poonam Chandra Supernovae and Gamma Ray bursts: Transient objects, such as supernovae and gamma-ray bursts (GRBs), represent the most energetic explosions in the Universe. A supernova, with an explosion energy 1E+51 ergs, often briefly outshines an entire galaxy before fading from view over several ...
... Poonam Chandra Supernovae and Gamma Ray bursts: Transient objects, such as supernovae and gamma-ray bursts (GRBs), represent the most energetic explosions in the Universe. A supernova, with an explosion energy 1E+51 ergs, often briefly outshines an entire galaxy before fading from view over several ...
Chapter 15
... The star is so bright in part because it's nearing the end of its life, so it's puffed up a bit. It's "burned" through the hydrogen fuel in its core to make helium. The helium is basically just sitting there, so it's not producing any energy. Instead, the core is shrinking and getting hotter. Before ...
... The star is so bright in part because it's nearing the end of its life, so it's puffed up a bit. It's "burned" through the hydrogen fuel in its core to make helium. The helium is basically just sitting there, so it's not producing any energy. Instead, the core is shrinking and getting hotter. Before ...
Document
... 5-10 in each starburst galaxy observed *Whatever process ins forming these very luminous BHs is enhanced when many stars, particularly one of large mass and size, form simultaneously. And the production of the high-brightness X-ray sources goes away as fast as the star formation subsides. Recent stu ...
... 5-10 in each starburst galaxy observed *Whatever process ins forming these very luminous BHs is enhanced when many stars, particularly one of large mass and size, form simultaneously. And the production of the high-brightness X-ray sources goes away as fast as the star formation subsides. Recent stu ...
ppt - SLAC
... 2. Atmospheric pressure depends on the star's surface gravity and so, roughly, on its size —a giant, dwarf, or in between. The size and surface brightness yield the star's luminosity and often its evolutionary status (young, middle-aged, or nearing death). Apparent brightness then gives an idea of t ...
... 2. Atmospheric pressure depends on the star's surface gravity and so, roughly, on its size —a giant, dwarf, or in between. The size and surface brightness yield the star's luminosity and often its evolutionary status (young, middle-aged, or nearing death). Apparent brightness then gives an idea of t ...
ch 31, stars
... • A spectroscope uses a prism or diffraction grating to disperse the light into its component wavelengths. • The separated wavelengths are called the spectrum of the star. • The spectrum can determine a star’s chemical composition, its surface temperature, and whether it is moving away from or towar ...
... • A spectroscope uses a prism or diffraction grating to disperse the light into its component wavelengths. • The separated wavelengths are called the spectrum of the star. • The spectrum can determine a star’s chemical composition, its surface temperature, and whether it is moving away from or towar ...
The Milky Way Galaxy
... hot to be retained by the gravity of the visible matter in a cluster. If all the mass there really were only that of visible matter, its gravity would not be enough to retain the hot gas, which would evaporate rapidly. Since the gas is there, there must be more gravity, hence dark matter. ...
... hot to be retained by the gravity of the visible matter in a cluster. If all the mass there really were only that of visible matter, its gravity would not be enough to retain the hot gas, which would evaporate rapidly. Since the gas is there, there must be more gravity, hence dark matter. ...
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.