20_Testbank
... the Milky Way. Therefore, they serve as a bridge between us and standard candles in other galaxies. Once we determine the distance to another galaxy for which we have observed a whitedwarf supernova, we then can calibrate the average luminosity of white-dwarf supernovae. White-dwarf supernovae and C ...
... the Milky Way. Therefore, they serve as a bridge between us and standard candles in other galaxies. Once we determine the distance to another galaxy for which we have observed a whitedwarf supernova, we then can calibrate the average luminosity of white-dwarf supernovae. White-dwarf supernovae and C ...
Age-Dating of Young Stars and Stellar Systems
... is very different from, e.g., a globular cluster isochrone where most of the luminosity comes from a small mass interval close to the turn-off mass. In a typical massive-star population of single age, stars with vastly different zero-age-mainsequence masses can have similar Teff and L and contribute ...
... is very different from, e.g., a globular cluster isochrone where most of the luminosity comes from a small mass interval close to the turn-off mass. In a typical massive-star population of single age, stars with vastly different zero-age-mainsequence masses can have similar Teff and L and contribute ...
Title: Binary interaction dominates the evolution of massive stars
... orbital periods up to about 1500 days exchange mass (6). The more massive star can be stripped of its entire envelope, and thus loses much of its original mass. The companion star gains mass and angular momentum, which trigger mixing processes in the stellar interior and modifies its evolutionary pa ...
... orbital periods up to about 1500 days exchange mass (6). The more massive star can be stripped of its entire envelope, and thus loses much of its original mass. The companion star gains mass and angular momentum, which trigger mixing processes in the stellar interior and modifies its evolutionary pa ...
13.1 Galaxy Evolution: Introduction
... formed - because stars of different masses can evolve at very different pace. Then, for each stellar mass and and age we need a spectrum. So, we need libraries of stellar spectra that can be associated with all components of the stellar population at any given age. This is actually ...
... formed - because stars of different masses can evolve at very different pace. Then, for each stellar mass and and age we need a spectrum. So, we need libraries of stellar spectra that can be associated with all components of the stellar population at any given age. This is actually ...
The 2008 RBSE Journal - National Optical Astronomy Observatory
... and usually end up being bigger than the originating galaxy. The smallest known are only a few tens of parsecs across, while the largest are known to be up to several megaparsecs. The average radio galaxy is usually typically hundreds of kiloparsecs across. This is about twice the size of the Milky ...
... and usually end up being bigger than the originating galaxy. The smallest known are only a few tens of parsecs across, while the largest are known to be up to several megaparsecs. The average radio galaxy is usually typically hundreds of kiloparsecs across. This is about twice the size of the Milky ...
Multiwavelength properties of γ-ray loud binary systems.
... is found in the directions of known γ-ray-loud binary systems: LSI +61 303, V407 Cyg, Cyg X-3 and PSR B1259-63. Remarkably, there are no signatures of weaker variability which could be clearly associated to other binary systems with black holes and /or neutron stars. Recent discovery of the γ-ray fl ...
... is found in the directions of known γ-ray-loud binary systems: LSI +61 303, V407 Cyg, Cyg X-3 and PSR B1259-63. Remarkably, there are no signatures of weaker variability which could be clearly associated to other binary systems with black holes and /or neutron stars. Recent discovery of the γ-ray fl ...
1Cmoles.pdf
... spectroscopic surveys cannot go as deep as the photometric surveys, reaching only I ≈ 24 with the use of large telescopes. The covered fields are necessarily small and cannot cope with the complex variety of objects in the Universe. To get the optimum compromise between large area and depth, good sp ...
... spectroscopic surveys cannot go as deep as the photometric surveys, reaching only I ≈ 24 with the use of large telescopes. The covered fields are necessarily small and cannot cope with the complex variety of objects in the Universe. To get the optimum compromise between large area and depth, good sp ...
PPT-Version - EPS 2003, Aachen
... So we selected among these 20 sources the ones that have several at the same redshift and we kept 7. ...
... So we selected among these 20 sources the ones that have several at the same redshift and we kept 7. ...
star
... Sometimes the smaller star in a binary star is too dim to be seen easily from Earth but can still be detected from the motion of the other star. If one star passes in front of the other, blocking some of the light from reaching Earth, the star system is called an eclipsing binary. The brightness of ...
... Sometimes the smaller star in a binary star is too dim to be seen easily from Earth but can still be detected from the motion of the other star. If one star passes in front of the other, blocking some of the light from reaching Earth, the star system is called an eclipsing binary. The brightness of ...
Chapter 15 THE MILKY WAY IN RELATION TO OTHER GALAXIES
... including color determinations, have been done by Bothun and Thompson (1988) with a CCD behind a 85–mm lens (the “parking lot camera”) in B, V and R. The luminosity profiles are shown in fig. 15.1. Both can be fitted with exponentials. The LMC has a central surface brightness of 21.3 B-mag arcsec−2 ...
... including color determinations, have been done by Bothun and Thompson (1988) with a CCD behind a 85–mm lens (the “parking lot camera”) in B, V and R. The luminosity profiles are shown in fig. 15.1. Both can be fitted with exponentials. The LMC has a central surface brightness of 21.3 B-mag arcsec−2 ...
Galaxies - Valhalla High School
... Arms emerge from ends of elongated central region or bar 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 ...
... Arms emerge from ends of elongated central region or bar 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 ...
Chapter 12: Stars and Galaxies
... When light from a star is passed through a spectroscope, astronomers see dark absorption lines that are produced as light passes through the star’s cooler, less dense atmosphere. Each element contributes its own set of absorption lines to this absorption spectrum, such as those shown in Figure 5. Wh ...
... When light from a star is passed through a spectroscope, astronomers see dark absorption lines that are produced as light passes through the star’s cooler, less dense atmosphere. Each element contributes its own set of absorption lines to this absorption spectrum, such as those shown in Figure 5. Wh ...
Survey of Astrophysics A110 The Milky Way Galaxy
... where new stars will form. The rotation of the galaxy, which can be observed by studying stellar proper motions and Doppler shifts, then orders these concentrations of stars into a spiral-like pattern. – 2. The density wave theory of spiral structure predicts that the rotation and gravity of the mas ...
... where new stars will form. The rotation of the galaxy, which can be observed by studying stellar proper motions and Doppler shifts, then orders these concentrations of stars into a spiral-like pattern. – 2. The density wave theory of spiral structure predicts that the rotation and gravity of the mas ...
A Study of the Nature and Representative Features of Supernova
... The nature of supernovae was not initially understood. They were referred to as “guest stars” and seen as omens in a variety of cultures in Asian and European countries. Approximately 231 confirmed nearby (Galactic) supernovae remnants exist, with a few dozen other heavily suspected. For a listing a ...
... The nature of supernovae was not initially understood. They were referred to as “guest stars” and seen as omens in a variety of cultures in Asian and European countries. Approximately 231 confirmed nearby (Galactic) supernovae remnants exist, with a few dozen other heavily suspected. For a listing a ...
Formation of Globular Clusters: In and Out of Dwarf Galaxies
... earlier than the majority of field stars in host galaxy. ...
... earlier than the majority of field stars in host galaxy. ...
Star Formation in Our Galaxy - Wiley-VCH
... Along with their gas, molecular clouds contain an admixture of small solid particles, the interstellar dust grains. These particles efficiently absorb light with wavelengths smaller than their diameters (about 0.1 µm) and reradiate this energy into the infrared. Regions where the dust effectively bl ...
... Along with their gas, molecular clouds contain an admixture of small solid particles, the interstellar dust grains. These particles efficiently absorb light with wavelengths smaller than their diameters (about 0.1 µm) and reradiate this energy into the infrared. Regions where the dust effectively bl ...
October 2016 BRAS Newsletter - The Baton Rouge Astronomical
... ‘The burst of the century’ “This was the burst of the century!” exclaimed James A. Wren, an engineer at Los Alamos National Laboratory and coauthor of one of the papers. Indeed, GRB 130427A (as it is now called) was the most powerful gamma-ray burst and the secondbrightest optical flash measured in ...
... ‘The burst of the century’ “This was the burst of the century!” exclaimed James A. Wren, an engineer at Los Alamos National Laboratory and coauthor of one of the papers. Indeed, GRB 130427A (as it is now called) was the most powerful gamma-ray burst and the secondbrightest optical flash measured in ...
The fate of black hole singularities and the parameters of the
... One of the great puzzles of astronomy and physics is what happens inside of black holes, where general relativity breaks down because of the presence of singularities[1]. That this is not just a problem of mathematical physics is apparent if one reflects on the fact that the rate of formation of bla ...
... One of the great puzzles of astronomy and physics is what happens inside of black holes, where general relativity breaks down because of the presence of singularities[1]. That this is not just a problem of mathematical physics is apparent if one reflects on the fact that the rate of formation of bla ...
Practical cosmology with the Local Volume galaxies
... constellation. According to Tully et al. (2008) this phenomena (the Local Velocity Anomaly) is caused by motion of the Local Sheet as a whole from the large Local Void towards the neighboring Leo cloud. Fig.2 presents the distribution of nearby galaxies in Supergalactic coordinates. The vector exten ...
... constellation. According to Tully et al. (2008) this phenomena (the Local Velocity Anomaly) is caused by motion of the Local Sheet as a whole from the large Local Void towards the neighboring Leo cloud. Fig.2 presents the distribution of nearby galaxies in Supergalactic coordinates. The vector exten ...
Lectures 19-20 The Milky Way Galaxy
... The Morphology of the Galaxy Structure of Thin and Thick Disks Galactic Disk has two major components, the thin disk, and the thick disk. Thin disk: composed of young stars, dust, and gas, with Hnthin = 350 pc (youngest stars found with scale height of 35-90 pc). Thick disk: older stars with a scal ...
... The Morphology of the Galaxy Structure of Thin and Thick Disks Galactic Disk has two major components, the thin disk, and the thick disk. Thin disk: composed of young stars, dust, and gas, with Hnthin = 350 pc (youngest stars found with scale height of 35-90 pc). Thick disk: older stars with a scal ...
When Stars Attack! In Search of Killer Supernovae
... In our Milky Way galaxy: Ø About 1 SN/century Ø Most far away: spectacular but ...
... In our Milky Way galaxy: Ø About 1 SN/century Ø Most far away: spectacular but ...
404.06 Stephen Drake
... • New study of optical photometry: what is the cause of the periodic variation and what is the ‘true’ period? • Magnetic field measurement would be very desirable • Is the (wide) binarity of this system a factor in flare properties? ...
... • New study of optical photometry: what is the cause of the periodic variation and what is the ‘true’ period? • Magnetic field measurement would be very desirable • Is the (wide) binarity of this system a factor in flare properties? ...
1: Properties of Pulsars
... from the central "strange" star, identifying it as a pulsar. It turned out later, that these "giant pulses" which they observed, occur every two minutes or so, and that the true pulse period was in fact as short as 33 milliseconds. The short period of 33 milliseconds ruled out white dwarfs for being ...
... from the central "strange" star, identifying it as a pulsar. It turned out later, that these "giant pulses" which they observed, occur every two minutes or so, and that the true pulse period was in fact as short as 33 milliseconds. The short period of 33 milliseconds ruled out white dwarfs for being ...
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.