THE SPATIALLY RESOLVED [Cii] COOLING LINE DEFICIT IN
... of 0.48±0.21%. We find that the surface density of 24 μm emission dominates this trend, with [C II]/TIR dropping as nIn (24 m m) increases. Deviations from this overall decline are correlated with changes in the gas-phase metal abundance, with higher metallicity associated with deeper deficits at a ...
... of 0.48±0.21%. We find that the surface density of 24 μm emission dominates this trend, with [C II]/TIR dropping as nIn (24 m m) increases. Deviations from this overall decline are correlated with changes in the gas-phase metal abundance, with higher metallicity associated with deeper deficits at a ...
Where are the First Stars now?
... end up inside the cluster. Thus half the stars which lie within the final virial radius form before z = 4 while half the stars outside this radius form after z = 2. The first 1.5% of stars in cluster galaxies have already formed by z = 13 while one has to wait until z = 7.5 to form a similar fractio ...
... end up inside the cluster. Thus half the stars which lie within the final virial radius form before z = 4 while half the stars outside this radius form after z = 2. The first 1.5% of stars in cluster galaxies have already formed by z = 13 while one has to wait until z = 7.5 to form a similar fractio ...
Quantitative constraints on starburst cycles in galaxies with stellar
... libraries contain models with burst fractions very close to zero, which are essentially identical to the models in the continuous library, so the new minimum χ2 is guaranteed to be equal to or smaller than the old one. If the new χ2min /Nd lies in the range 2.37-6.25, the probability that the model ...
... libraries contain models with burst fractions very close to zero, which are essentially identical to the models in the continuous library, so the new minimum χ2 is guaranteed to be equal to or smaller than the old one. If the new χ2min /Nd lies in the range 2.37-6.25, the probability that the model ...
StructForm
... Somewhat after recombination -density perturbations are small on nearly all spatial scales. Dark Ages, prior to z=10 -density perturbations in dark matter and baryons grow; on smaller scales perturbations have gone non-linear, d>>1; small (low mass) dark matter halos form; massive stars form in thei ...
... Somewhat after recombination -density perturbations are small on nearly all spatial scales. Dark Ages, prior to z=10 -density perturbations in dark matter and baryons grow; on smaller scales perturbations have gone non-linear, d>>1; small (low mass) dark matter halos form; massive stars form in thei ...
High-z Universe – cont`d
... For each theme we will also indicate the relevant DRM programs highlighting those which are enabled by WFC3 and would otherwise be impossible from the ground or with other existing space observatories. This uniqueness can be due to either one or a combination of the following factors: • wavelength r ...
... For each theme we will also indicate the relevant DRM programs highlighting those which are enabled by WFC3 and would otherwise be impossible from the ground or with other existing space observatories. This uniqueness can be due to either one or a combination of the following factors: • wavelength r ...
Star formation and dust extinction properties of local galaxies A. Sakurai
... 2.3 Sample construction 2.3.1 Matching AKARI BSC with IRAS IIFSCz As a basis for the construction of our galaxy sample, we used the AKARI FIS bright source catalog (BSC) v.1 from the AKARI All-Sky survey (Yamamura et al., 2010). The sources in the AKARI FIS BSC v. 1 have an S/N ratio three times bet ...
... 2.3 Sample construction 2.3.1 Matching AKARI BSC with IRAS IIFSCz As a basis for the construction of our galaxy sample, we used the AKARI FIS bright source catalog (BSC) v.1 from the AKARI All-Sky survey (Yamamura et al., 2010). The sources in the AKARI FIS BSC v. 1 have an S/N ratio three times bet ...
Star formation rate in spiral galaxies
... exclusively by O5 stars, which are also very rare, this number can be useful to compare the possible number of young and hot stars in each galaxy. Therefore, among our galaxies, there are some of them that reach only 2400 O5 stars (like object 5 in the table below), while some other galaxies contain ...
... exclusively by O5 stars, which are also very rare, this number can be useful to compare the possible number of young and hot stars in each galaxy. Therefore, among our galaxies, there are some of them that reach only 2400 O5 stars (like object 5 in the table below), while some other galaxies contain ...
H I in Early-Type Galaxies. II. Mass Loss and Galactic Winds
... from Paper I are discussed. If gas shed by dying stars is completely retained by these galaxies and exists as H I, these upper limits will be exceeded in only lo9 yr for E's and SO'S and in only 2 x lo8 yr for NGC 4472. Evidently, gas either is hidden in some undetectable form or is removed from the ...
... from Paper I are discussed. If gas shed by dying stars is completely retained by these galaxies and exists as H I, these upper limits will be exceeded in only lo9 yr for E's and SO'S and in only 2 x lo8 yr for NGC 4472. Evidently, gas either is hidden in some undetectable form or is removed from the ...
Luminosity and Mass Functions of Galaxies
... parameters (e.g. Dn (4000), Sérsic index, Hubble type, quantitative morphology parameters) are nearly uncorrelated with environment. Significant differences between Nn = 0 and Nn = 1. Degeneracy between center of small group and edge of large cluster, but Blanton & Berlind (2007) show this does not ...
... parameters (e.g. Dn (4000), Sérsic index, Hubble type, quantitative morphology parameters) are nearly uncorrelated with environment. Significant differences between Nn = 0 and Nn = 1. Degeneracy between center of small group and edge of large cluster, but Blanton & Berlind (2007) show this does not ...
Galaxies - WordPress.com
... A galaxies occasionally collide with one another, particularly within cluster of galaxies B galaxies are so closely packed in the universe that they are always interacting with one another C galaxies are so widely separated that they never interact or collide D the universe is composed of one giant ...
... A galaxies occasionally collide with one another, particularly within cluster of galaxies B galaxies are so closely packed in the universe that they are always interacting with one another C galaxies are so widely separated that they never interact or collide D the universe is composed of one giant ...
Geometrically Derived Timescales for Star Formation in Spiral
... develop the scenario of spiral arm driven star formation in galaxy disks. In this picture a spiral density wave induces gravitational compression and shocks in the neutral hydrogen gas, which in turn leads to the collapse of (molecular) gas clouds that results in star formation. This work already po ...
... develop the scenario of spiral arm driven star formation in galaxy disks. In this picture a spiral density wave induces gravitational compression and shocks in the neutral hydrogen gas, which in turn leads to the collapse of (molecular) gas clouds that results in star formation. This work already po ...
Clusters as laboratories for the study of galaxy evolution
... Back in 1984, (and still?) the prevalent view was that clusters were themselves agents that influenced the evolution of galaxies, so that the processes that produced different morphological types, for example, could be observed at work in (today’s) rich clusters. This notion is very different than t ...
... Back in 1984, (and still?) the prevalent view was that clusters were themselves agents that influenced the evolution of galaxies, so that the processes that produced different morphological types, for example, could be observed at work in (today’s) rich clusters. This notion is very different than t ...
The Milky Way
... shortest-lived ones) => Look for very young clusters or associations containing O and B stars: O/B Associations! ...
... shortest-lived ones) => Look for very young clusters or associations containing O and B stars: O/B Associations! ...
The Milky Way
... shortest-lived ones) => Look for very young clusters or associations containing O and B stars: O/B Associations! ...
... shortest-lived ones) => Look for very young clusters or associations containing O and B stars: O/B Associations! ...
The Milky Way Galaxy Chapter 15 Guidepost Guidepost
... Massive Stars and Open Clusters Problem: Many stars in the field of the O/B association do not belong to the association (foreground and background stars) Members of the association have been formed together and move in the same direction ...
... Massive Stars and Open Clusters Problem: Many stars in the field of the O/B association do not belong to the association (foreground and background stars) Members of the association have been formed together and move in the same direction ...
Family Space Day Overview – Galaxies
... Galaxies are large collections of stars and gas and dust. They have millions to billions of stars, all held into a cluster by gravitational attraction. Most galaxies are flat, but there are different shapes — some are spirals, some are elliptical, and some are irregular. Our Galaxy The Milky Way is ...
... Galaxies are large collections of stars and gas and dust. They have millions to billions of stars, all held into a cluster by gravitational attraction. Most galaxies are flat, but there are different shapes — some are spirals, some are elliptical, and some are irregular. Our Galaxy The Milky Way is ...
A Zoo of Galaxies - Cambridge University Press
... In his 1927 defence of the classification scheme, Hubble claimed to have examined “upward of a thousand galaxies” in its construction. However for true physical understanding of a galaxy, more than just an image is required – we also need an estimate of its distance in order to reveal its size and ma ...
... In his 1927 defence of the classification scheme, Hubble claimed to have examined “upward of a thousand galaxies” in its construction. However for true physical understanding of a galaxy, more than just an image is required – we also need an estimate of its distance in order to reveal its size and ma ...
Clustering of far-infrared galaxies in the AKARI All-Sky Survey North
... This result is supported by tests based on a sample of AKARI All-Sky Survey sources identified in public databases, in a similar way as used in Pollo et al. (2010). The counterpart from the literature was searched in a radius of 40 centered on each AKARI FIS source. In the cases when multiple coun ...
... This result is supported by tests based on a sample of AKARI All-Sky Survey sources identified in public databases, in a similar way as used in Pollo et al. (2010). The counterpart from the literature was searched in a radius of 40 centered on each AKARI FIS source. In the cases when multiple coun ...
Far-infrared line emission from high
... lines are [O I] 63 μm, tracing neutral (higher density) gas, and [N II] 122 μm probing the ionized ISM phase. [O I] detections have been reported in two lensed ultraluminous infrared galaxies at z = 1.3 and z = 2.3 (Sturm et al. 2010); z > 4 nitrogen lines (including the [N II] 205 μm) have been det ...
... lines are [O I] 63 μm, tracing neutral (higher density) gas, and [N II] 122 μm probing the ionized ISM phase. [O I] detections have been reported in two lensed ultraluminous infrared galaxies at z = 1.3 and z = 2.3 (Sturm et al. 2010); z > 4 nitrogen lines (including the [N II] 205 μm) have been det ...
Elliptical Galaxies
... where Re , the effective radius, is the radius that contains half the total light of the galaxy and Ie is the surface brightness (the amount of light from a square arc second of the galaxy) at Re . This law can be integrated to give a finite total light of Itot = 7.22πRe 2 Ie . de Vaucouleurs’ law, ...
... where Re , the effective radius, is the radius that contains half the total light of the galaxy and Ie is the surface brightness (the amount of light from a square arc second of the galaxy) at Re . This law can be integrated to give a finite total light of Itot = 7.22πRe 2 Ie . de Vaucouleurs’ law, ...
ASTRO-114--Lecture 49-
... into stars very quickly. And so you get a pretty quiet looking galaxy that has mostly middleaged stars. Now, here are two galaxies that have collided. Again, over on the left C we actually have two separate photographs here C on the left you have the photograph from the Earth, what it looks like thr ...
... into stars very quickly. And so you get a pretty quiet looking galaxy that has mostly middleaged stars. Now, here are two galaxies that have collided. Again, over on the left C we actually have two separate photographs here C on the left you have the photograph from the Earth, what it looks like thr ...
Galaxy formation in the Planck cosmology - II. Star
... over time. The latter follows only the history of the main component of the galaxy (along the ‘main branch’ of the merger tree) and has been investigated for the Millennium Simulation by Cohn & van de Voort (2015). The difference between the two reflects the merger history of galaxies. The term SFH ...
... over time. The latter follows only the history of the main component of the galaxy (along the ‘main branch’ of the merger tree) and has been investigated for the Millennium Simulation by Cohn & van de Voort (2015). The difference between the two reflects the merger history of galaxies. The term SFH ...
Distance Determination of the Hubble Constant Ho by the
... Why do we want to know Ho? • The Hubble constant is one of the most important parameters in Big Bang cosmology. – The square of the Hubble constant relates the total energy density of the Universe to its geometry. – It sets the age of the Universe. – It sets the size of the observable Universe (Rob ...
... Why do we want to know Ho? • The Hubble constant is one of the most important parameters in Big Bang cosmology. – The square of the Hubble constant relates the total energy density of the Universe to its geometry. – It sets the age of the Universe. – It sets the size of the observable Universe (Rob ...
The properties and evolution of low surface brightness galaxies de
... The values for the total masses of galaxies one derives from rotation curves are always lower limits. The flatness of the rotation curves shows that the cumulative mass keeps increasing with radius. When comparing masses of galaxies one thus has to measure the mass at a consistently defined radius t ...
... The values for the total masses of galaxies one derives from rotation curves are always lower limits. The flatness of the rotation curves shows that the cumulative mass keeps increasing with radius. When comparing masses of galaxies one thus has to measure the mass at a consistently defined radius t ...
A Zoo of Galaxies - Portsmouth Research Portal
... fraction of the numbers of normal spirals” (at least in the photographic plates he used). In between the spirals and ellipticals was the (then hypothetical) S0, or lenticular type, which shows a disc, but no spiral arms. The small number of galaxies Hubble found not fitting this scheme were called “ ...
... fraction of the numbers of normal spirals” (at least in the photographic plates he used). In between the spirals and ellipticals was the (then hypothetical) S0, or lenticular type, which shows a disc, but no spiral arms. The small number of galaxies Hubble found not fitting this scheme were called “ ...
Atlas of Peculiar Galaxies
The Atlas of Peculiar Galaxies is a catalog of peculiar galaxies produced by Halton Arp. A total of 338 galaxies are presented in the atlas, which was originally published in 1966 by the California Institute of Technology.The primary goal of the catalog was to present photographs of examples of the different kinds of peculiar structures found among nearby galaxies. Arp realized that the reason why galaxies formed into spiral or elliptical shapes was not well understood. He perceived peculiar galaxies as small ""experiments"" that astronomers could use to understand the physical processes that distort spiral or elliptical galaxies. With this atlas, astronomers had a sample of peculiar galaxies that they could study in more detail. The atlas does not present a complete overview of every peculiar galaxy in the sky but instead provides examples of the different phenomena as observed in nearby galaxies.Because little was known at the time of publication about the physical processes that caused the different shapes, the galaxies in the atlas are sorted based on their appearance. Objects 1–101 are individual peculiar spiral galaxies or spiral galaxies that apparently have small companions. Objects 102–145 are elliptical and elliptical-like galaxies. Individual or groups of galaxies with neither elliptical nor spiral shapes are listed as objects 146–268. Objects 269–327 are double galaxies. Finally, objects that simply do not fit into any of the above categories are listed as objects 332–338. Most objects are best known by their other designations, but a few galaxies are best known by their Arp numbers (such as Arp 220).Today, the physical processes that lead to the peculiarities seen in the Arp atlas are now well understood. A large number of the objects are interacting galaxies, including M51 (Arp 85), Arp 220, and the Antennae Galaxies (NGC 4038/NGC 4039, or Arp 244). A few of the galaxies are simply dwarf galaxies that do not have enough mass to produce enough gravity to allow the galaxies to form any cohesive structure. NGC 1569 (Arp 210) is an example of one of the dwarf galaxies in the atlas. A few other galaxies are radio galaxies. These objects contain active galactic nuclei that produce powerful jets of gas called radio jets. The atlas includes the nearby radio galaxies M87 (Arp 152) and Centaurus A (Arp 153).