9 Dwarf Galaxies
... Stars outside this region find that the periodic pull of the spiral is faster than their epicyclic frequency, they don’t respond to the spiral and the wave dissipates. Resonance in narrow annulus can explain why 2 arm spirals are ...
... Stars outside this region find that the periodic pull of the spiral is faster than their epicyclic frequency, they don’t respond to the spiral and the wave dissipates. Resonance in narrow annulus can explain why 2 arm spirals are ...
PH607lec11-4gal2
... fainter lines in this region due to [NII]. HII regions appear reddish in this image because of the prominence of the H alpha line in the red region of the spectrum. The dark features running vertically trace emission in the hydrogen H-alpha line (left and stronger feature, rest wavelength 6563 Angst ...
... fainter lines in this region due to [NII]. HII regions appear reddish in this image because of the prominence of the H alpha line in the red region of the spectrum. The dark features running vertically trace emission in the hydrogen H-alpha line (left and stronger feature, rest wavelength 6563 Angst ...
The Comprehensible Universe
... Abstract -- The Universe perhaps may look and can be modeled as Earth like body and thus the origin of different natural features and their functions, based on certain physical laws, on the Earth can be compared and explained with formation of different features and their functions, based on somewha ...
... Abstract -- The Universe perhaps may look and can be modeled as Earth like body and thus the origin of different natural features and their functions, based on certain physical laws, on the Earth can be compared and explained with formation of different features and their functions, based on somewha ...
Astronomy (ASTR)
... we cannot see nor properly characterize, the so-called 'dark matter,' and of energy whose source is unknown and may defy knowing, the ubiquitous 'dark energy.' This course will attempt to elucidate what we currently understand about the composition, structure and evolution of the universe based on g ...
... we cannot see nor properly characterize, the so-called 'dark matter,' and of energy whose source is unknown and may defy knowing, the ubiquitous 'dark energy.' This course will attempt to elucidate what we currently understand about the composition, structure and evolution of the universe based on g ...
Signals from the Beginnings of the World - Max-Planck
... close eye on nature during such a process. This is where gamma-ray bursts offer an ideal starting point, because they represent the most direct messengers of such spectacular cosmic events. There are two practical paths of progress: Gamma rays of the burst can be measured directly in order to infer ...
... close eye on nature during such a process. This is where gamma-ray bursts offer an ideal starting point, because they represent the most direct messengers of such spectacular cosmic events. There are two practical paths of progress: Gamma rays of the burst can be measured directly in order to infer ...
Our Local Group of Galaxies
... • Finding such objects is very difficult as you need deep photometry (to get beyond the Galaxy) over effectively the entire sky - a task for LSST probably. ...
... • Finding such objects is very difficult as you need deep photometry (to get beyond the Galaxy) over effectively the entire sky - a task for LSST probably. ...
Tyler Gray - Angelfire
... of all three. These two relatively bright and relatively close companions are visible in many photos of M31, including the one in this page. They are only the brightest of a "swarm" of smaller companions which surround the Andromeda Galaxy, and form a subgroup of the Local Group. At the time of this ...
... of all three. These two relatively bright and relatively close companions are visible in many photos of M31, including the one in this page. They are only the brightest of a "swarm" of smaller companions which surround the Andromeda Galaxy, and form a subgroup of the Local Group. At the time of this ...
margarita2007
... We now know the cosmic recipe. Most of the universe is invisible stuff called “nonbaryonic dark matter” (25%) and “dark energy” (70%). ...
... We now know the cosmic recipe. Most of the universe is invisible stuff called “nonbaryonic dark matter” (25%) and “dark energy” (70%). ...
Extragalactic Distances from Planetary Nebulae
... Elliptical galaxies do not have many (any?) 2 M main sequence stars. But they do have large numbers of 1 M stars. If some are in close binary systems which coalesce on the main sequence, the product may evolve into an [O III]-bright planetary. The ratio of bright planetaries to blue stragglers is ...
... Elliptical galaxies do not have many (any?) 2 M main sequence stars. But they do have large numbers of 1 M stars. If some are in close binary systems which coalesce on the main sequence, the product may evolve into an [O III]-bright planetary. The ratio of bright planetaries to blue stragglers is ...
File - Mr. Gray`s Class
... stars or galaxies. The area was the equivalent in angular size to a tennis ball being held up at a distance of 100 meters. 342 exposures and 10 days later, the astronomers were astonished to see that there were more than 3000 galaxies in this small window of space (as shown to the right)! The larges ...
... stars or galaxies. The area was the equivalent in angular size to a tennis ball being held up at a distance of 100 meters. 342 exposures and 10 days later, the astronomers were astonished to see that there were more than 3000 galaxies in this small window of space (as shown to the right)! The larges ...
The evolution of spiral galaxies in clusters Kutdemir, Elif
... Observations of galaxy mergers and signatures of accretion support this picture. Evidence have been accumulating, mainly from HI studies, on the importance of cold gas accretion in the local universe: A large number of galaxies are accompanied by gas-rich dwarfs or are surrounded by HI cloud complex ...
... Observations of galaxy mergers and signatures of accretion support this picture. Evidence have been accumulating, mainly from HI studies, on the importance of cold gas accretion in the local universe: A large number of galaxies are accompanied by gas-rich dwarfs or are surrounded by HI cloud complex ...
2 Galaxy morphology and classification
... The spheroid is the smooth elliptical distribution of stars found in elliptical galaxies. It is composed primarily of an old, metal-poor, population of stars typically having ages „ 12 Gyr or more. The spheroid is thought to be among the first stellar components to form. The stellar halo is a di↵use ...
... The spheroid is the smooth elliptical distribution of stars found in elliptical galaxies. It is composed primarily of an old, metal-poor, population of stars typically having ages „ 12 Gyr or more. The spheroid is thought to be among the first stellar components to form. The stellar halo is a di↵use ...
Chapter 12 Quiz, Nov. 28, 2012, Astro 162, Section 4 12-1
... 3) Red shift: Space expands at a certain rate which increases with distance, stretching the light from a distant object like a receding fire engine. The greater the light is shifted towards the red end of the spectrum, the further away the object emitting it is. 12-35. Why do spiral galaxies have sp ...
... 3) Red shift: Space expands at a certain rate which increases with distance, stretching the light from a distant object like a receding fire engine. The greater the light is shifted towards the red end of the spectrum, the further away the object emitting it is. 12-35. Why do spiral galaxies have sp ...
X-ray Astronomy and the search for Black Holes
... • Above about E~2 keV, there is a highly absorbed, hard component. – There is a clear detection of Fe K complex, indicating thin thermal origin – A single kT (~5 keV) fit would work – But the effective bandpass was narrow (E~2-10 keV) so only weak constraints can be placed on models – Reminescent of ...
... • Above about E~2 keV, there is a highly absorbed, hard component. – There is a clear detection of Fe K complex, indicating thin thermal origin – A single kT (~5 keV) fit would work – But the effective bandpass was narrow (E~2-10 keV) so only weak constraints can be placed on models – Reminescent of ...
1 Dark matter and dark energy comprise over 90% of the Universe
... Livio (2000) presents the analogy using the kinetic energy of the Universe as either smaller or larger than the gravitational energy in determining the expansion rate. In determining the calculation Ω0, it is important to note that (ρ) represents the total mass/energy in the Universe, including bary ...
... Livio (2000) presents the analogy using the kinetic energy of the Universe as either smaller or larger than the gravitational energy in determining the expansion rate. In determining the calculation Ω0, it is important to note that (ρ) represents the total mass/energy in the Universe, including bary ...
Document
... Brown et al. 2006 astro-ph 0609584 -- NOAO and Spitzer IRAC survey: “…the stellar mass contained within the red galaxy population has roughly doubled over the past 8Gyr. This is consistent with starforming galaxies being transformed into
... Brown et al. 2006 astro-ph 0609584 -- NOAO and Spitzer IRAC survey: “…the stellar mass contained within the red galaxy population has roughly doubled over the past 8Gyr. This is consistent with starforming galaxies being transformed into
Lecture 3 - University of Washington
... • The measurements show that rotation curves are “flat” – they are not ap√ proching the vc(R) ∝ 1/ R behavior expected in the outer parts of disks • Therefore, there must be an invisible galaxy component that is capable of producing gravitational force • Earlier (1930’s) suggested by Fritz Zwicky, b ...
... • The measurements show that rotation curves are “flat” – they are not ap√ proching the vc(R) ∝ 1/ R behavior expected in the outer parts of disks • Therefore, there must be an invisible galaxy component that is capable of producing gravitational force • Earlier (1930’s) suggested by Fritz Zwicky, b ...
Word doc - UC-HiPACC - University of California, Santa Cruz
... Supernovae are not alike. For decades, astronomers had known that supernovae fell into different types based on their light curves, that is, their pattern of rising and falling brightness. Later, they found these types actually corresponded to different physical circumstances triggering the explosio ...
... Supernovae are not alike. For decades, astronomers had known that supernovae fell into different types based on their light curves, that is, their pattern of rising and falling brightness. Later, they found these types actually corresponded to different physical circumstances triggering the explosio ...
The Milky Way: Spiral galaxies:
... •! In denser regions of the ISM, collisions between atoms become frequent enough to form molecules. •! The most common molecule is H2, but since H2 is a symmetric molecule, it has no rotational quantum transitions. It is therefore extremely difficult to detect. •! As a tracer of H2, astronomers usua ...
... •! In denser regions of the ISM, collisions between atoms become frequent enough to form molecules. •! The most common molecule is H2, but since H2 is a symmetric molecule, it has no rotational quantum transitions. It is therefore extremely difficult to detect. •! As a tracer of H2, astronomers usua ...
sections 23-25 powerpoint
... Elliptical galaxy (E). A spheroidal galaxy containing millions to billions of old low-mass stars and no gas or dust. Spiral Galaxy (S). A galaxy with a spheroidal bulge of several million old low-mass stars and a flattened pancake-like disk of billions of old low-mass and young high-mass stars, alon ...
... Elliptical galaxy (E). A spheroidal galaxy containing millions to billions of old low-mass stars and no gas or dust. Spiral Galaxy (S). A galaxy with a spheroidal bulge of several million old low-mass stars and a flattened pancake-like disk of billions of old low-mass and young high-mass stars, alon ...
Cepheid Calibration
... The apparent brightness of a light source varies inversely as the square of its distance. In other words, if the distance between an observer and a light source is doubled, the light source will appear four times as faint to the observer. Astronomers can use this inverse square law to estimate dist ...
... The apparent brightness of a light source varies inversely as the square of its distance. In other words, if the distance between an observer and a light source is doubled, the light source will appear four times as faint to the observer. Astronomers can use this inverse square law to estimate dist ...
flare swg usa
... Fitting SEDS: The long-λ fluxes from cool dust have ambiguous SED fits, while higher spatial resolution, near-IR fluxes from clustered sources are often very much fainter. FLARE can reach ~8 mag deeper than IRAC surveys at 3.5 μm, enabling the measurement of the NIR SEDs of young (<104 yr old) ...
... Fitting SEDS: The long-λ fluxes from cool dust have ambiguous SED fits, while higher spatial resolution, near-IR fluxes from clustered sources are often very much fainter. FLARE can reach ~8 mag deeper than IRAC surveys at 3.5 μm, enabling the measurement of the NIR SEDs of young (<104 yr old) ...
OUR SOLAR SYSTEM
... potentially could exist — as a way to identify exoplanets that may be capable of supporting life as we understand it. While we can quibble with the definition — perhaps there’s a biology that uses solvents other than water or maybe life can develop entirely beneath the surface — it’s a place to star ...
... potentially could exist — as a way to identify exoplanets that may be capable of supporting life as we understand it. While we can quibble with the definition — perhaps there’s a biology that uses solvents other than water or maybe life can develop entirely beneath the surface — it’s a place to star ...
3. Cosmology and the Origin and Evolution of Galaxies
... more than 60% of the brightest mm galaxies lie between redshifts z =1.8 - 3.58,9. If we take into account the small fraction (< 10%) of the sub-mm background that corresponds to these bright sub-mm sources, however, it is immediately apparent that some other method has to be found in order to measur ...
... more than 60% of the brightest mm galaxies lie between redshifts z =1.8 - 3.58,9. If we take into account the small fraction (< 10%) of the sub-mm background that corresponds to these bright sub-mm sources, however, it is immediately apparent that some other method has to be found in order to measur ...
Document
... Like stars, many galaxies are found in clusters, and there are also superclusters separated by enormous voids. By looking back in time at very distant galaxies and clusters, we can study how they formed and evolved. Surprisingly, we now know that all these enormous structures consist largely of “dar ...
... Like stars, many galaxies are found in clusters, and there are also superclusters separated by enormous voids. By looking back in time at very distant galaxies and clusters, we can study how they formed and evolved. Surprisingly, we now know that all these enormous structures consist largely of “dar ...
Observable universe
The observable universe consists of the galaxies and other matter that can, in principle, be observed from Earth at the present time because light and other signals from these objects has had time to reach the Earth since the beginning of the cosmological expansion. Assuming the universe is isotropic, the distance to the edge of the observable universe is roughly the same in every direction. That is, the observable universe is a spherical volume (a ball) centered on the observer. Every location in the Universe has its own observable universe, which may or may not overlap with the one centered on Earth.The word observable used in this sense does not depend on whether modern technology actually permits detection of radiation from an object in this region (or indeed on whether there is any radiation to detect). It simply indicates that it is possible in principle for light or other signals from the object to reach an observer on Earth. In practice, we can see light only from as far back as the time of photon decoupling in the recombination epoch. That is when particles were first able to emit photons that were not quickly re-absorbed by other particles. Before then, the Universe was filled with a plasma that was opaque to photons.The surface of last scattering is the collection of points in space at the exact distance that photons from the time of photon decoupling just reach us today. These are the photons we detect today as cosmic microwave background radiation (CMBR). However, with future technology, it may be possible to observe the still older relic neutrino background, or even more distant events via gravitational waves (which also should move at the speed of light). Sometimes astrophysicists distinguish between the visible universe, which includes only signals emitted since recombination—and the observable universe, which includes signals since the beginning of the cosmological expansion (the Big Bang in traditional cosmology, the end of the inflationary epoch in modern cosmology). According to calculations, the comoving distance (current proper distance) to particles from the CMBR, which represent the radius of the visible universe, is about 14.0 billion parsecs (about 45.7 billion light years), while the comoving distance to the edge of the observable universe is about 14.3 billion parsecs (about 46.6 billion light years), about 2% larger.The best estimate of the age of the universe as of 2015 is 7010137990000000000♠13.799±0.021 billion years but due to the expansion of space humans are observing objects that were originally much closer but are now considerably farther away (as defined in terms of cosmological proper distance, which is equal to the comoving distance at the present time) than a static 13.8 billion light-years distance. It is estimated that the diameter of the observable universe is about 28 gigaparsecs (91 billion light-years, 8.8×1026 metres or 5.5×1023 miles), putting the edge of the observable universe at about 46–47 billion light-years away.