Recent Star Formation in Nearby Early-type Galaxies
... [O iii]/Hβ line ratios nonetheless suggest ongoing star formation in at least four objects, or 8% of the sample. In fact, that stars are forming in these galaxies is proven also by the finding of disk-like gas kinematics, regular dust morphology, young stellar populations, and molecular gas in all of ...
... [O iii]/Hβ line ratios nonetheless suggest ongoing star formation in at least four objects, or 8% of the sample. In fact, that stars are forming in these galaxies is proven also by the finding of disk-like gas kinematics, regular dust morphology, young stellar populations, and molecular gas in all of ...
'Death Star' Galaxy Black Hole Fires at Neighboring Galaxy
... pressure and collapse. Surrounded by a disk of accreting matter, a black hole formed inside. Within a few seconds, streaming particle jets were launched along the rotation axis. The jets, combined with vigorous winds of newly formed radioactive metals blowing off the disk inside, shattered the star. ...
... pressure and collapse. Surrounded by a disk of accreting matter, a black hole formed inside. Within a few seconds, streaming particle jets were launched along the rotation axis. The jets, combined with vigorous winds of newly formed radioactive metals blowing off the disk inside, shattered the star. ...
D109: A Spectactularly Forgotten Galaxy Aggregate
... In this supplementary cycle of HST we request a small amount of time to obtain high resolution imaging (with WFPC2) of this collection of knots in as many filters as practical. Having a better photometric characterization of the knots over a broader color baseline than obtainable from the ground cou ...
... In this supplementary cycle of HST we request a small amount of time to obtain high resolution imaging (with WFPC2) of this collection of knots in as many filters as practical. Having a better photometric characterization of the knots over a broader color baseline than obtainable from the ground cou ...
galaxies2_3_complete
... i.e. the gas was pre-enriched (by earlier star formation?) when it arrived at the solar neighbourhood (see examples 6) o However, the abundances of different heavy elements vary relative to each other. Also, abundances show a large scatter even for stars of a given age. This suggests that subsequent ...
... i.e. the gas was pre-enriched (by earlier star formation?) when it arrived at the solar neighbourhood (see examples 6) o However, the abundances of different heavy elements vary relative to each other. Also, abundances show a large scatter even for stars of a given age. This suggests that subsequent ...
Unit 1
... If we observe a star cluster which has all the stars of main sequence present, this cluster is a. old b. young c. was born as a result of supernova explosion d. both a. and c. ...
... If we observe a star cluster which has all the stars of main sequence present, this cluster is a. old b. young c. was born as a result of supernova explosion d. both a. and c. ...
An Analysis of Collisional Ring Galaxies
... galaxy rotate at a higher rate than those stars located further from the galactic center. The stars found in the halo do not seem to show any uniform rotation about the center.1 Overall these inner motions tend to keep to themselves, with the galactic stars rotating “calmly” about a central axis. W ...
... galaxy rotate at a higher rate than those stars located further from the galactic center. The stars found in the halo do not seem to show any uniform rotation about the center.1 Overall these inner motions tend to keep to themselves, with the galactic stars rotating “calmly” about a central axis. W ...
Chapter 18 - AstroStop
... Dimmer Distant Supernova •These HST images show the galaxy in which the supernova SN 1997ff occurred. •This supernova was dimmer than expected. •The distance to it is greater than it would be if the universe had been continually slowing down. •An outward force is acting over vast distances in the u ...
... Dimmer Distant Supernova •These HST images show the galaxy in which the supernova SN 1997ff occurred. •This supernova was dimmer than expected. •The distance to it is greater than it would be if the universe had been continually slowing down. •An outward force is acting over vast distances in the u ...
spatially resolved properties of the stellar populations
... Models predict that massive early type galaxies form in a two-phase scenario. First, galaxies assembled their mass through dissipative processes and in-situ star formation. The star formation is induced by cold flow accretion or by gas-rich mergers. Then, ex-situ star formation formed by minor merge ...
... Models predict that massive early type galaxies form in a two-phase scenario. First, galaxies assembled their mass through dissipative processes and in-situ star formation. The star formation is induced by cold flow accretion or by gas-rich mergers. Then, ex-situ star formation formed by minor merge ...
Absolute vs. relative distance measures
... Henrietta Swan Leavitt, at Harvard Observatory, discovered that the Cepheids in the Magellanic Clouds pulsated with periods that were directly proportional to their average luminosities ...
... Henrietta Swan Leavitt, at Harvard Observatory, discovered that the Cepheids in the Magellanic Clouds pulsated with periods that were directly proportional to their average luminosities ...
The Spiral Galaxy Messier 81 - Cool Cosmos
... The Spiral Galaxy Messier 81 The magnificent, dusty, star-studded arms of a nearby spiral galaxy, Messier 81, are illuminated in this image from NASA's Spitzer Space Telescope. Located in the northern constellation of Ursa Major (which also includes the Big Dipper), this galaxy is easily visible th ...
... The Spiral Galaxy Messier 81 The magnificent, dusty, star-studded arms of a nearby spiral galaxy, Messier 81, are illuminated in this image from NASA's Spitzer Space Telescope. Located in the northern constellation of Ursa Major (which also includes the Big Dipper), this galaxy is easily visible th ...
Word version - GyVe
... galaxy clusters. The format expected for each of these files is below. Each file is white space delimited (tabs or space). An example of these formats can be found in the documentation section of the sourceforge site for this project. It should also be noted that GyVe actually only uses the RA decim ...
... galaxy clusters. The format expected for each of these files is below. Each file is white space delimited (tabs or space). An example of these formats can be found in the documentation section of the sourceforge site for this project. It should also be noted that GyVe actually only uses the RA decim ...
Seminar I: Tidal dwarf galaxies
... A team of astronomers claim to have found a faint, recently formed dwarf galaxy in the HI tidal arm of an advanced galaxy merger (Fig. 1). By combining an Hα rotation curve with optical (Bband) photometry, HI and H2 data, they argue that this object has M/LB ≈ 125 and is likely to be the most dark m ...
... A team of astronomers claim to have found a faint, recently formed dwarf galaxy in the HI tidal arm of an advanced galaxy merger (Fig. 1). By combining an Hα rotation curve with optical (Bband) photometry, HI and H2 data, they argue that this object has M/LB ≈ 125 and is likely to be the most dark m ...
Lecture 15
... Observations in the 1990s finally detected the glow of gamma ray bursts at visible wavelengths. These observations identified the host galaxies of gamma ray bursts. The distance can now be measured by the redshift of the galaxy. They must be among the most powerful explosions in the universe (105 ...
... Observations in the 1990s finally detected the glow of gamma ray bursts at visible wavelengths. These observations identified the host galaxies of gamma ray bursts. The distance can now be measured by the redshift of the galaxy. They must be among the most powerful explosions in the universe (105 ...
From Cosmic Birth to Living Earth - Association of Universities for
... towards constructing a general purpose, long-life, space-based observatory that is capable of finding planets showing signs of life. Such an observatory would be able to survey hundreds of planetary systems and detect dozens of Earth-like planets in the habitable zones around their stars. It would a ...
... towards constructing a general purpose, long-life, space-based observatory that is capable of finding planets showing signs of life. Such an observatory would be able to survey hundreds of planetary systems and detect dozens of Earth-like planets in the habitable zones around their stars. It would a ...
Optical Studies of Star Formation in Normal Spiral Galaxies: Radial
... formation distribution with star formation rate. Our technique integrates all the Ha: flux in the elliptical annuli, including the diffuse component from unresolved H II regions which can be significant especially in the early-type galaxies and inter-arm regions. This may partly explain the differen ...
... formation distribution with star formation rate. Our technique integrates all the Ha: flux in the elliptical annuli, including the diffuse component from unresolved H II regions which can be significant especially in the early-type galaxies and inter-arm regions. This may partly explain the differen ...
The Doppler Effect
... • Hubble’s Law states that galaxies are retreating from each other at a speed that is proportional to their distance. • This means that galaxies that were farther apart at their beginning travel a greater distance than those originally located closer together during the same amount of time. ...
... • Hubble’s Law states that galaxies are retreating from each other at a speed that is proportional to their distance. • This means that galaxies that were farther apart at their beginning travel a greater distance than those originally located closer together during the same amount of time. ...
Lecture 18, Structure of spiral galaxies
... Stars: Halo vs. Disk • Stars in the disk are relatively young. • fraction of heavy elements same as or greater than the Sun • plenty of high and lowmass stars, blue and red • Stars in the halo are old. • fraction of heavy elements much less than the Sun • mostly lowmass, red stars • Stars in th ...
... Stars: Halo vs. Disk • Stars in the disk are relatively young. • fraction of heavy elements same as or greater than the Sun • plenty of high and lowmass stars, blue and red • Stars in the halo are old. • fraction of heavy elements much less than the Sun • mostly lowmass, red stars • Stars in th ...
Cosmology Physics 466E Olbers Paradox Cosmological principle
... Vera Rubin determined the velocities as a function of distance from the galactic center of clouds of ionized hydrogen (in astrophysical terminology, HII regions). This was done by measurement of the Doppler shift of their H-alpha emission lines. The hydrogen clouds move with the stars and other vis ...
... Vera Rubin determined the velocities as a function of distance from the galactic center of clouds of ionized hydrogen (in astrophysical terminology, HII regions). This was done by measurement of the Doppler shift of their H-alpha emission lines. The hydrogen clouds move with the stars and other vis ...
Galaxies, Cosmology and Dark Matter - IA
... The Hα -line strength and the far-infrared luminosity provide information about the present star formation rate Ψ in galaxies. The Hα strength is directly proportional to the ionizing flux of massive, hot stars and thus to the number of these stars that is a measure of the actual star formation rate ...
... The Hα -line strength and the far-infrared luminosity provide information about the present star formation rate Ψ in galaxies. The Hα strength is directly proportional to the ionizing flux of massive, hot stars and thus to the number of these stars that is a measure of the actual star formation rate ...
The Red-Sequence Cluster Survey
... structures to collapse under the influence of gravity, and even then only if the initial fluctuations which seed the growth of structure are relatively large (high σ8). Conversely, in a universe with much greater mass content (large Ωm) structure continues to form as the universe expands and ages, e ...
... structures to collapse under the influence of gravity, and even then only if the initial fluctuations which seed the growth of structure are relatively large (high σ8). Conversely, in a universe with much greater mass content (large Ωm) structure continues to form as the universe expands and ages, e ...
The Host Galaxies of the Brightest Quasars: Gas
... approach is implemented, based on spatial deconvolution and decomposition of the spectra. Our clean, deep, spectra of quasar host galaxies show that the brightest quasars reside in all types of galaxies, that their stellar populations are compatible with those of young discs, even when the host gala ...
... approach is implemented, based on spatial deconvolution and decomposition of the spectra. Our clean, deep, spectra of quasar host galaxies show that the brightest quasars reside in all types of galaxies, that their stellar populations are compatible with those of young discs, even when the host gala ...
The Hubble Law - Department of Astronomy
... There are a couple of features you should especially note when trying to decipher these spectra: 1. Not all of the "jiggly" lines come from the light of the galaxy. Each spectrum contains noise; we just cannot get away from it. You should notice that some of the spectra are much "noisier" than othe ...
... There are a couple of features you should especially note when trying to decipher these spectra: 1. Not all of the "jiggly" lines come from the light of the galaxy. Each spectrum contains noise; we just cannot get away from it. You should notice that some of the spectra are much "noisier" than othe ...
Chapter 16
... • interstellar gas, • dust, …etc., we find that most of the mass is “invisible”! • The nature of this “dark matter” is not understood at this time. • Some ideas: brown dwarfs, small black holes, exotic elementary particles. ...
... • interstellar gas, • dust, …etc., we find that most of the mass is “invisible”! • The nature of this “dark matter” is not understood at this time. • Some ideas: brown dwarfs, small black holes, exotic elementary particles. ...
Seyfert galaxy
Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei (very luminous, distant and bright sources of electromagnetic radiation) with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable.Seyfert galaxies account for about 10% of all galaxies and are some of the most intensely studied objects in astronomy, as they are thought to be powered by the same phenomena that occur in quasars, although they are closer and less luminous than quasars. These galaxies have supermassive black holes at their centers which are surrounded by accretion discs of in-falling material. The accretion discs are believed to be the source of the observed ultraviolet radiation. Ultraviolet emission and absorption lines provide the best diagnostics for the composition of the surrounding material.Seen in visible light, most Seyfert galaxies look like normal spiral galaxies, but when studied under other wavelengths, it becomes clear that the luminosity of their cores is of comparable intensity to the luminosity of whole galaxies the size of the Milky Way.Seyfert galaxies are named after Carl Seyfert, who first described this class in 1943.