March 2010 - Pomona Valley Amateur Astronomers
... What's Up? Aliens From A Nearby Galaxy? In science fiction stories, aliens often proclaim that they "come from a nearby galaxy." For astronomers this seems to be a joke, the close Sagittarius Dwarf Galaxy (NGC 6822) is a million light years away. That's a long was for any alien to travel. This teles ...
... What's Up? Aliens From A Nearby Galaxy? In science fiction stories, aliens often proclaim that they "come from a nearby galaxy." For astronomers this seems to be a joke, the close Sagittarius Dwarf Galaxy (NGC 6822) is a million light years away. That's a long was for any alien to travel. This teles ...
The Mass of Quasar Broad Emission Line Regions
... of most interest in trying to trace the evolution of chemical abundances at large look-back times. We take as representative of these objects a monochromatic continuum luminosity at rest wavelength 1450 Å of L1450 1044 ergs s1 Å1, which is about a decade below the highest luminosities of high- ...
... of most interest in trying to trace the evolution of chemical abundances at large look-back times. We take as representative of these objects a monochromatic continuum luminosity at rest wavelength 1450 Å of L1450 1044 ergs s1 Å1, which is about a decade below the highest luminosities of high- ...
OVERVIEW: Stars and space
... • to explain how stars are able to maintain their energy output for millions of years • to explain why the early Universe contained only hydrogen but now contains a large variety of different elements. Skills, knowledge and understanding of how science works set in the context of: • Our Sun is one o ...
... • to explain how stars are able to maintain their energy output for millions of years • to explain why the early Universe contained only hydrogen but now contains a large variety of different elements. Skills, knowledge and understanding of how science works set in the context of: • Our Sun is one o ...
Measuring the Rotational Speed of Spiral Galaxies and
... value of r and Vrotation. Inform the teacher of your results. After the entire class completes the table, use the dynamical mass calculated at the largest radius (Mdynamical at redge = Mtotal) to determine the mass in dark matter, Mdarkmatter. ...
... value of r and Vrotation. Inform the teacher of your results. After the entire class completes the table, use the dynamical mass calculated at the largest radius (Mdynamical at redge = Mtotal) to determine the mass in dark matter, Mdarkmatter. ...
SS_L4
... R~10 pc, n~5 109 atoms/m3, T~10 K. Galaxy is pervaded by a magnetic field with field lines approximately parallel to the galactic plane. Field strongly tied to the ionized plasma in the ISM. Small local perturbations in the field lead to local potential wells. ISM condenses in these wells, increasin ...
... R~10 pc, n~5 109 atoms/m3, T~10 K. Galaxy is pervaded by a magnetic field with field lines approximately parallel to the galactic plane. Field strongly tied to the ionized plasma in the ISM. Small local perturbations in the field lead to local potential wells. ISM condenses in these wells, increasin ...
LOFAR - Veres Péter
... Things to know about LFR: • deeply burried inside the host galaxy • size less than a few tenths of arcsecs • the cause: Refractive Interstellar Scintilation • only present at low frequencies Things to expect • if the LFVs turn out to be high redshift objects they define a clean sample of galaxies • ...
... Things to know about LFR: • deeply burried inside the host galaxy • size less than a few tenths of arcsecs • the cause: Refractive Interstellar Scintilation • only present at low frequencies Things to expect • if the LFVs turn out to be high redshift objects they define a clean sample of galaxies • ...
A galaxy rapidly forming stars 700 million years after the Big Bang at
... that a typical galaxy at z < 7 has SFR 5 10 M[ yr21; the measured SFR of z8_GND_5296 is a factor of more than 30 times greater. If this SFR function is accurate, the expected space density per co-moving Mpc3 for this galaxy would be =1025. The implied rarity of this galaxy could indicate that it is ...
... that a typical galaxy at z < 7 has SFR 5 10 M[ yr21; the measured SFR of z8_GND_5296 is a factor of more than 30 times greater. If this SFR function is accurate, the expected space density per co-moving Mpc3 for this galaxy would be =1025. The implied rarity of this galaxy could indicate that it is ...
Multiple Choice, continued
... • The galaxy in which we live, the Milky Way, is a spiral galaxy in which the sun is one of hundreds of billions of stars. • Two irregular galaxies, the Large Magellanic Cloud and Small Magellanic Cloud, are our closest neighbors. • These three galaxies are called the Local Group. ...
... • The galaxy in which we live, the Milky Way, is a spiral galaxy in which the sun is one of hundreds of billions of stars. • Two irregular galaxies, the Large Magellanic Cloud and Small Magellanic Cloud, are our closest neighbors. • These three galaxies are called the Local Group. ...
MHD_of_Accretion_Disks
... Our Sun is unusual in that it is alone - most stars occur in multiple or binary systems. In a binary system, the higher mass star will evolve faster and will eventually become a compact object - either a white dwarf star, a neutron star, or black hole. When the lower mass star later evolves into an ...
... Our Sun is unusual in that it is alone - most stars occur in multiple or binary systems. In a binary system, the higher mass star will evolve faster and will eventually become a compact object - either a white dwarf star, a neutron star, or black hole. When the lower mass star later evolves into an ...
Star formation bursts in isolated spiral galaxies
... Figure 3. Images of the calculations shown in Fig. 2 showing gravitational potential in blue (dark areas correspond to potential valleys) and gas surface density in red. Images are shown at times t = 0.4 Gyr (left-hand panel) and 0.8 Gyr (right-hand panel), for the cases a = 5 km s−1 (top panel) and ...
... Figure 3. Images of the calculations shown in Fig. 2 showing gravitational potential in blue (dark areas correspond to potential valleys) and gas surface density in red. Images are shown at times t = 0.4 Gyr (left-hand panel) and 0.8 Gyr (right-hand panel), for the cases a = 5 km s−1 (top panel) and ...
The Southern Winter PDF
... The image reveals a complex history of ejections from the star, which first evolved into a huge red giant, with a diameter of about 1000 times that of our Sun. It then lost its extended outer layers. Some of this gas was cast off from its equator at a relatively slow speed, perhaps as low as 32,000 ...
... The image reveals a complex history of ejections from the star, which first evolved into a huge red giant, with a diameter of about 1000 times that of our Sun. It then lost its extended outer layers. Some of this gas was cast off from its equator at a relatively slow speed, perhaps as low as 32,000 ...
How Big Is Our Universe? - Harvard
... how far are the sun and planets? The Sun is so far away that it would take the Space Shuttle seven months to fly there. That’s why the Sun, which is one hundred times the diameter of the Earth, looks so small! Three hundred years ago, astronomer Edmund Halley found a way to measure the distance to ...
... how far are the sun and planets? The Sun is so far away that it would take the Space Shuttle seven months to fly there. That’s why the Sun, which is one hundred times the diameter of the Earth, looks so small! Three hundred years ago, astronomer Edmund Halley found a way to measure the distance to ...
Galaxies - SD43 Teacher Sites
... oxygen is a product of photosynthesis. If these gases are found in the atmosphere of a planet, it may indicate the presence of some form of life. Astronomers have already detected more than 200 planets revolving around stars thousands of trillions of kilometres away from us. Although most of these p ...
... oxygen is a product of photosynthesis. If these gases are found in the atmosphere of a planet, it may indicate the presence of some form of life. Astronomers have already detected more than 200 planets revolving around stars thousands of trillions of kilometres away from us. Although most of these p ...
Star Formation in Isolated Disk Galaxies. I. Models and
... on other processors. Following the paradigm for SPH particles in GADGET v1.1, the sink particle data is then broadcast to all processors. Every processor searches for gas particles in its domain that lie within the accretion radius of the sink particle and processes them, passing data back to the pr ...
... on other processors. Following the paradigm for SPH particles in GADGET v1.1, the sink particle data is then broadcast to all processors. Every processor searches for gas particles in its domain that lie within the accretion radius of the sink particle and processes them, passing data back to the pr ...
A forming disk at z 0.6: collapse of a gaseous disk or major merger
... ) and turbulent phase that is found to be rotating on large spatial scales. We identified two unusual properties of J033241.88-274853.9. (1) The spatial distributions of the ionized gaseous and young stars show a strong decoupling; while almost no stars can be detected in the southern part down to t ...
... ) and turbulent phase that is found to be rotating on large spatial scales. We identified two unusual properties of J033241.88-274853.9. (1) The spatial distributions of the ionized gaseous and young stars show a strong decoupling; while almost no stars can be detected in the southern part down to t ...
Expected Coalescence Rate of NS/NS Binaries for Laser Beam
... weighted average over spiral (fS=65%) and elliptical (fE=35%) galaxies same fb and NS as for the Milky Way spiral galaxy coalescence rate equal to the Milky Way rate: S = MW = (1.7±1)x10-5 yr-1 ...
... weighted average over spiral (fS=65%) and elliptical (fE=35%) galaxies same fb and NS as for the Milky Way spiral galaxy coalescence rate equal to the Milky Way rate: S = MW = (1.7±1)x10-5 yr-1 ...
Molecular Line Emission in Star
... A particular case of molecular lines are Masers (Microwave Amplification by the Stimulated Emission of Radiation): Under normal conditions of thermal equilibrium, the number of particles in lower energy levels is always greater than the number in higher energy levels, this leads to radiation being a ...
... A particular case of molecular lines are Masers (Microwave Amplification by the Stimulated Emission of Radiation): Under normal conditions of thermal equilibrium, the number of particles in lower energy levels is always greater than the number in higher energy levels, this leads to radiation being a ...
Fulltext PDF
... nuclear bulge contains the highest density of stars in the galaxy. The primary population of stars in the nucleus is similar to the old stars found in the halo, with a few hot young stars. The core of the Galaxy is highly obscured by dust and gas at visible wavelengths, but can be observed at other ...
... nuclear bulge contains the highest density of stars in the galaxy. The primary population of stars in the nucleus is similar to the old stars found in the halo, with a few hot young stars. The core of the Galaxy is highly obscured by dust and gas at visible wavelengths, but can be observed at other ...
The role of black holes in galaxy formation and evolution
... process that can be almost 100% efficient, but dust must cover a large solid angle. The low momentum of photons with respect to their energy also limits the mass that can be ejected through this mechanism, as photons are massless particles. If the momentum in the photons radiated by an AGN was trans ...
... process that can be almost 100% efficient, but dust must cover a large solid angle. The low momentum of photons with respect to their energy also limits the mass that can be ejected through this mechanism, as photons are massless particles. If the momentum in the photons radiated by an AGN was trans ...
Bar Formation in Milky Way type Galaxies
... form a bar. We analyze this discrepancy by performing accurate and diverse N -body simulations and calculating the normal modes. We show that bar formation in cuspy galaxies can be explained by taking into account the disk thickness. The exponential growth time is moderate (about 250 Myr) for typica ...
... form a bar. We analyze this discrepancy by performing accurate and diverse N -body simulations and calculating the normal modes. We show that bar formation in cuspy galaxies can be explained by taking into account the disk thickness. The exponential growth time is moderate (about 250 Myr) for typica ...
observing the universe
... Based on X-ray emission, many galaxies have black holes at the center. A black hole is an extremely dense body of matter, formed by the collapse of a massive star’s core, with a gravitational pull so strong nothing can escape. The study of this celestial phenomenon is somewhat tough. A black hole ca ...
... Based on X-ray emission, many galaxies have black holes at the center. A black hole is an extremely dense body of matter, formed by the collapse of a massive star’s core, with a gravitational pull so strong nothing can escape. The study of this celestial phenomenon is somewhat tough. A black hole ca ...