CENTRAL TEXAS COLLEGE
... Astronomy was the first of the sciences, and when colleges and universities were established in the middle Ages, it was one of the seven subjects taught to all students. It has always had important applications, including calendar making, time keeping, and navigation. Nowadays, astronomy is adding o ...
... Astronomy was the first of the sciences, and when colleges and universities were established in the middle Ages, it was one of the seven subjects taught to all students. It has always had important applications, including calendar making, time keeping, and navigation. Nowadays, astronomy is adding o ...
Definition of a Twelve-Point Polygonal SAA boundary for the GLAST
... at locating gamma ray sources throughout the universe and studying their properties. What makes GLAST so special? huge energy range of gamma rays detected (20MeV300GeV) more sensitive than previous gamma ray telescopes determines positions of gamma ray sources with high precision. GLAST’s Larg ...
... at locating gamma ray sources throughout the universe and studying their properties. What makes GLAST so special? huge energy range of gamma rays detected (20MeV300GeV) more sensitive than previous gamma ray telescopes determines positions of gamma ray sources with high precision. GLAST’s Larg ...
What Are the Faint X-ray Transients Near the Galactic Center?
... • Radio observations can reveal jets, which are common from X-ray binaries. – Likewise, we need to determine whether the radio transients seen near the Galactic center have X-ray counterparts. ...
... • Radio observations can reveal jets, which are common from X-ray binaries. – Likewise, we need to determine whether the radio transients seen near the Galactic center have X-ray counterparts. ...
Starburst Galaxies Encyclopedia of Astronomy & Astrophysics eaa.iop.org T Heckman
... in the visible and near infrared, and rapid advances in submillimeter astronomy, it is now possible to detect and study such high-redshift galaxies. The ultraviolet-selected galaxies at high redshift strongly resemble similarly selected local starbursts: they have similar values for SFR , similar ...
... in the visible and near infrared, and rapid advances in submillimeter astronomy, it is now possible to detect and study such high-redshift galaxies. The ultraviolet-selected galaxies at high redshift strongly resemble similarly selected local starbursts: they have similar values for SFR , similar ...
Our Place in Space
... should print out the cards (preferably in color) and laminate them so that the information on each object appears on the reverse side of the image of that object. ...
... should print out the cards (preferably in color) and laminate them so that the information on each object appears on the reverse side of the image of that object. ...
- Wiley Online Library
... the large sample from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) [Smith et al., 2005]. The microphysics is believed to be well understood: electrons are accelerated to high energies in strong electric fields by the Relativistic Runaway Electron Avalanche (RREA) process, emitti ...
... the large sample from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) [Smith et al., 2005]. The microphysics is believed to be well understood: electrons are accelerated to high energies in strong electric fields by the Relativistic Runaway Electron Avalanche (RREA) process, emitti ...
Today in Astronomy 102: black hole observations, v.2
... The center of the Milky Way is obscured by dust; it cannot be seen at visible through longer X-ray wavelengths. It is bright at infrared and radio wavelengths, and hard (shortwavelength) X rays, which are transmitted through the dust. The name Sagittarius A indicates that it’s the brightest radi ...
... The center of the Milky Way is obscured by dust; it cannot be seen at visible through longer X-ray wavelengths. It is bright at infrared and radio wavelengths, and hard (shortwavelength) X rays, which are transmitted through the dust. The name Sagittarius A indicates that it’s the brightest radi ...
Supernova! Toledo Astronomical Association, February 2009
... They can briefly outshine their entire galaxy ...
... They can briefly outshine their entire galaxy ...
Constituents of the Milky Way
... Measuring Ages of Individual Stars For individual stars that aren’t in clusters (like the Sun), we can’t use the cluster turnoff method to measure an age. For instance, a lone G star might be young, or it might be 10 billion years old. How do we measure its age? The universe contained only hydrogen ...
... Measuring Ages of Individual Stars For individual stars that aren’t in clusters (like the Sun), we can’t use the cluster turnoff method to measure an age. For instance, a lone G star might be young, or it might be 10 billion years old. How do we measure its age? The universe contained only hydrogen ...
π of the Sky
... Energy: 10 milliards years of the Sun life Duration: 0.01...100s Distance: up to 13 milliards light years Intensity: 2...3 per day (currently observed by satellites) Origin: outside of the Galaxy - hipernova – massive star collaps to a black hole? - merging two neutron stars into a black hole? ...
... Energy: 10 milliards years of the Sun life Duration: 0.01...100s Distance: up to 13 milliards light years Intensity: 2...3 per day (currently observed by satellites) Origin: outside of the Galaxy - hipernova – massive star collaps to a black hole? - merging two neutron stars into a black hole? ...
The Milky Way
... 90% of the universe is made of matter that does not emit detectable radiation at any wavelength. Evidence to date suggests that only a very small fraction of the dark matter is made of familiar matter (baryons). Dark matter is not stars or stellar remnants, galaxies, dust clouds, or anything else ma ...
... 90% of the universe is made of matter that does not emit detectable radiation at any wavelength. Evidence to date suggests that only a very small fraction of the dark matter is made of familiar matter (baryons). Dark matter is not stars or stellar remnants, galaxies, dust clouds, or anything else ma ...
The presence of gamma rays in space was known before they were
... Peterson and Winckler in 1958. This was in the same year the first few satellites to have gamma ray detectors were launched. Gamma rays from outer space are now one of the best ways we have of studying our galaxy and beyond, able to penetrate matter where optical radiation cannot, and more easy to s ...
... Peterson and Winckler in 1958. This was in the same year the first few satellites to have gamma ray detectors were launched. Gamma rays from outer space are now one of the best ways we have of studying our galaxy and beyond, able to penetrate matter where optical radiation cannot, and more easy to s ...
neutron star
... The event horizon of a 3MSun black hole is also about as big as a small city. Tuesday, March 5, 13 ...
... The event horizon of a 3MSun black hole is also about as big as a small city. Tuesday, March 5, 13 ...
Type II Supernovae
... An observer in the orbital plane has θ = π/2 and h× = 0. The observed frequency of gravitational waves is ν = Ω/π. The intensity of gravitational waves decreases as 1/r. Consider two 1.4 M⊙ neutron stars in a binary with separation of R⊙ observed from a distance of 1 kpc: P ≃ 7000 s, ν ≃ 2.9 · 10−4 ...
... An observer in the orbital plane has θ = π/2 and h× = 0. The observed frequency of gravitational waves is ν = Ω/π. The intensity of gravitational waves decreases as 1/r. Consider two 1.4 M⊙ neutron stars in a binary with separation of R⊙ observed from a distance of 1 kpc: P ≃ 7000 s, ν ≃ 2.9 · 10−4 ...
Folie 1
... (protostellar) luminosity problem Young stars are fainter than expected Young stars accrete not enough material T-Tauri accretion rates are 10-7MSUN/yr or lower.... it would take 10 million years to assemble the Sun ...
... (protostellar) luminosity problem Young stars are fainter than expected Young stars accrete not enough material T-Tauri accretion rates are 10-7MSUN/yr or lower.... it would take 10 million years to assemble the Sun ...
PHYS3380_113015_bw - The University of Texas at Dallas
... Virtual particle pairs constantly created near the horizon of the black hole, as they are everywhere - quantum fluctuations. Normally, they are created as a particleantiparticle pair and they quickly annihilate each other. But near the horizon of a black hole, it's possible for one to fall in before ...
... Virtual particle pairs constantly created near the horizon of the black hole, as they are everywhere - quantum fluctuations. Normally, they are created as a particleantiparticle pair and they quickly annihilate each other. But near the horizon of a black hole, it's possible for one to fall in before ...
Chap 16: Galaxies
... From the measurement of stellar velocities near the center of a galaxy: Infer mass in the very center central black holes! Several million, up to more than a billion solar masses! Supermassive ...
... From the measurement of stellar velocities near the center of a galaxy: Infer mass in the very center central black holes! Several million, up to more than a billion solar masses! Supermassive ...
CH. 7 - science1d
... group of three stars that orbit each other. This group is called the Centauri system (Figure 7.8). It lies about 4.3 ly away from the solar system. If it were possible for you to have a cellphone conversation with someone living near these stars, just saying hello to each other would require more th ...
... group of three stars that orbit each other. This group is called the Centauri system (Figure 7.8). It lies about 4.3 ly away from the solar system. If it were possible for you to have a cellphone conversation with someone living near these stars, just saying hello to each other would require more th ...
Early Star-Forming Galaxies
... Rodighiero used Herschel ’s far-infrared camera to look for galaxies hidden from visible-light observations because of their intervening dust. This allowed the astronomers to assemble a more complete picture of star birth than ever before. The team targeted two well-known regions of the sky that ha ...
... Rodighiero used Herschel ’s far-infrared camera to look for galaxies hidden from visible-light observations because of their intervening dust. This allowed the astronomers to assemble a more complete picture of star birth than ever before. The team targeted two well-known regions of the sky that ha ...
First firm spectral classification of an early-B PMS star
... et al. 2004; Kraus et al. 2010; Chapter 3) but the physical properties of the forming massive stars remain uncertain. The mass of the central object has to be estimated from the emerging flux, and the direct detection of the photospheric spectrum turns out to be very difficult at this early stage of ...
... et al. 2004; Kraus et al. 2010; Chapter 3) but the physical properties of the forming massive stars remain uncertain. The mass of the central object has to be estimated from the emerging flux, and the direct detection of the photospheric spectrum turns out to be very difficult at this early stage of ...
Abstract - UChicago High Energy Physics
... place. Neutrinos emitted from mergers can undergo the same types of transformations that neutrinos from supernovae do [17], as well as oscillations not previously seen elsewhere (except for in collapsars [18]), called Matter-Neutrino Resonance (MNR) transitions [19]. The MNR takes place when the mat ...
... place. Neutrinos emitted from mergers can undergo the same types of transformations that neutrinos from supernovae do [17], as well as oscillations not previously seen elsewhere (except for in collapsars [18]), called Matter-Neutrino Resonance (MNR) transitions [19]. The MNR takes place when the mat ...
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.