Observational Data
... by assuming intrinsic ratio of Hβ/Hα constant) as metallicity indicator. If these z~2 starbursts are progenitors of z~1 EROs and local ellipticals, their metallicity should be high, at least near-solar or more. Metallicity is a good indicator of stellar mass. ...
... by assuming intrinsic ratio of Hβ/Hα constant) as metallicity indicator. If these z~2 starbursts are progenitors of z~1 EROs and local ellipticals, their metallicity should be high, at least near-solar or more. Metallicity is a good indicator of stellar mass. ...
Stages of star formation (the classical view)
... A rough analysis of the transfer equation shows that intensity is amplified exponentially. The brightness temperature of a maser transition can be extremely high. For example, for Tex= -20 K, |τ0| = 20, we have T0 = 1010 K. Maser radiations is produced in very compact regions (maser spots), and the ...
... A rough analysis of the transfer equation shows that intensity is amplified exponentially. The brightness temperature of a maser transition can be extremely high. For example, for Tex= -20 K, |τ0| = 20, we have T0 = 1010 K. Maser radiations is produced in very compact regions (maser spots), and the ...
Lecture1-1
... The actual measured data (left) and constructed models (model) are compared on the Dn(4000), HdA index plane. The solid lines in the left panels are tracks of burst star formation model and the points are “continuus” star formation model. ...
... The actual measured data (left) and constructed models (model) are compared on the Dn(4000), HdA index plane. The solid lines in the left panels are tracks of burst star formation model and the points are “continuus” star formation model. ...
H2CO and CO in S140
... Emission lines of simple non-symmetric polar molecules are needed to study cold gas CO (J = 1-0), at 115.27 GHz is usually optically thick, so its intensity depends on the kinetic temperature, of the emitting gas. All molecular traces share these disadvantages Absorption lines can be detected ev ...
... Emission lines of simple non-symmetric polar molecules are needed to study cold gas CO (J = 1-0), at 115.27 GHz is usually optically thick, so its intensity depends on the kinetic temperature, of the emitting gas. All molecular traces share these disadvantages Absorption lines can be detected ev ...
Part1
... o Key components of a galaxy and its ISM? Which are observable from the 30m? o What does the zoomed out SED of a galaxy look like? Where do IR and mm fit in? o Scaling relations in nearby galaxies and their relation to IR and mm work. ...
... o Key components of a galaxy and its ISM? Which are observable from the 30m? o What does the zoomed out SED of a galaxy look like? Where do IR and mm fit in? o Scaling relations in nearby galaxies and their relation to IR and mm work. ...
Galaxies have different sizes and shapes.
... more than 100,000 light-years in diameter. The bulge of densely packed stars at the center is located about 26,000 light-years from the Sun. A large but very faint layer of stars surrounds the disk and bulge. In addition to stars, the Milky Way contains clouds of gas and dust called nebulae. The sta ...
... more than 100,000 light-years in diameter. The bulge of densely packed stars at the center is located about 26,000 light-years from the Sun. A large but very faint layer of stars surrounds the disk and bulge. In addition to stars, the Milky Way contains clouds of gas and dust called nebulae. The sta ...
1 Introduction - Wiley-VCH
... The contribution of these multifrequency surveys to the study of galaxy evolution is invaluable, since it simultaneously provides us with information on the different components of any extragalactic object (see Table 1.1 for a summary). The modern instrumentation now in our hands enables us to measu ...
... The contribution of these multifrequency surveys to the study of galaxy evolution is invaluable, since it simultaneously provides us with information on the different components of any extragalactic object (see Table 1.1 for a summary). The modern instrumentation now in our hands enables us to measu ...
Our Local Group of Galaxies
... How complete is the list of Milky Way dSph companions? • Grey area shows region of the sky covered in Data Release 6 of the SDSS. Previously known MW satellites are marked in blue, new discoveries in red. Solid black line and middle grey stripe are at declination zero - inside is the region to be s ...
... How complete is the list of Milky Way dSph companions? • Grey area shows region of the sky covered in Data Release 6 of the SDSS. Previously known MW satellites are marked in blue, new discoveries in red. Solid black line and middle grey stripe are at declination zero - inside is the region to be s ...
Introduction
... balance between gravity, radiation, and nuclear processes. The structure of a galaxy, on the other hand, is basically determined by gravity – other forces only enter indirectly. The three key ingredients of galaxies – stars, interstellar matter, and dark matter – are usually present in different for ...
... balance between gravity, radiation, and nuclear processes. The structure of a galaxy, on the other hand, is basically determined by gravity – other forces only enter indirectly. The three key ingredients of galaxies – stars, interstellar matter, and dark matter – are usually present in different for ...
ACTIVE GALAXIES
... • Head-tail radio galaxies arise when jets are bent by the ram-pressure of gas as the host galaxy moves through it. • For powerful sources only one jet is seen: this is because of RELATIVISTIC DOPPER BOOSTING: the approaching jet appears MUCH brighter than an intrinsically equal receding jet since m ...
... • Head-tail radio galaxies arise when jets are bent by the ram-pressure of gas as the host galaxy moves through it. • For powerful sources only one jet is seen: this is because of RELATIVISTIC DOPPER BOOSTING: the approaching jet appears MUCH brighter than an intrinsically equal receding jet since m ...
Part2
... Apologies in advance (but not really): I’m going to be very “CO-centric” (though not “COexclusive”). The reason, which I hope you’ll appreciate is that CO - by far the brightest mm line is already very sensitivity limited at extragalactic distances. ...
... Apologies in advance (but not really): I’m going to be very “CO-centric” (though not “COexclusive”). The reason, which I hope you’ll appreciate is that CO - by far the brightest mm line is already very sensitivity limited at extragalactic distances. ...
Research proposal uploaded for ESO fellowship
... global star formation rate decline of the universe? Supernova feedback represents a long standing problem in galaxy formation model. Currently, toy models are used to treat supernova feedback, which are parametrized to reproduce the faint-end of the luminosity function (Cole et al. 2000; Guo et al. ...
... global star formation rate decline of the universe? Supernova feedback represents a long standing problem in galaxy formation model. Currently, toy models are used to treat supernova feedback, which are parametrized to reproduce the faint-end of the luminosity function (Cole et al. 2000; Guo et al. ...
The APEX Telescope Large Area Survey of the Galaxy (ATLASGAL)
... regions The Spitzer–GLIMPSE images at 8 µm have unveiled a “bubbling Galactic disc”. More than 600 bubbles with diameters of a few arcminutes have been catalogued by Churchwell et al. (2006, 2007). As shown by Deharveng et al. (2010), more than 85 % of these 8 µm bubbles enclose H ii regions and con ...
... regions The Spitzer–GLIMPSE images at 8 µm have unveiled a “bubbling Galactic disc”. More than 600 bubbles with diameters of a few arcminutes have been catalogued by Churchwell et al. (2006, 2007). As shown by Deharveng et al. (2010), more than 85 % of these 8 µm bubbles enclose H ii regions and con ...
An analogy
... – distant galaxies are younger than those used to define the Hubble Sequence – more peculiar galaxies are observed: could be due to patchy star formation (younger age) or to interactions being more frequent (denser Universe) – resolution is poor compared to local galaxies and usually limited to a fe ...
... – distant galaxies are younger than those used to define the Hubble Sequence – more peculiar galaxies are observed: could be due to patchy star formation (younger age) or to interactions being more frequent (denser Universe) – resolution is poor compared to local galaxies and usually limited to a fe ...
Friday03
... luminosities, morphologies, and emission line fraction well-known • Early-types consistent with passive evolution since z>2 • Small fraction of actively star-forming galaxies ...
... luminosities, morphologies, and emission line fraction well-known • Early-types consistent with passive evolution since z>2 • Small fraction of actively star-forming galaxies ...
STEPHAN`S QUINTET
... Stephan's Quintet in the constellation Pegasus is al grouping of five galaxies of which four form the first compact galaxy group ever discovered. The group was discovered by Édouard Stephan in 1877 at Marseilles Observatory. These galaxies are of interest because of their violent collisions. Four of ...
... Stephan's Quintet in the constellation Pegasus is al grouping of five galaxies of which four form the first compact galaxy group ever discovered. The group was discovered by Édouard Stephan in 1877 at Marseilles Observatory. These galaxies are of interest because of their violent collisions. Four of ...
solar.gmu.edu
... collectively called active galaxies •Active galaxies possess active galactic nuclei, which cause intense radiations, fast variations, jets, lobes, et al. ...
... collectively called active galaxies •Active galaxies possess active galactic nuclei, which cause intense radiations, fast variations, jets, lobes, et al. ...
Molecular Outflows Driven by Young Brown Dwarfs And VLMs. New
... Tau 6 and FU Tau A with high angular resolution observations with the Plateau de Bure Interferometer (PdBI). These sources were chosen because their associated CO emission showed clear evidence of an outflow and / or their spectral energy distributions (SEDs) showed strong evidence of a massive accr ...
... Tau 6 and FU Tau A with high angular resolution observations with the Plateau de Bure Interferometer (PdBI). These sources were chosen because their associated CO emission showed clear evidence of an outflow and / or their spectral energy distributions (SEDs) showed strong evidence of a massive accr ...
Galaxies Galaxies M81
... Spiral galaxies are so-named because of the graceful shapes of arms emanating from a bright central nucleus. Spirals are classified according to how tightly or loosely wound the arms are, and it turns out that the brightness of the central nucleus is correlated to the tightness of the arm. The galax ...
... Spiral galaxies are so-named because of the graceful shapes of arms emanating from a bright central nucleus. Spirals are classified according to how tightly or loosely wound the arms are, and it turns out that the brightness of the central nucleus is correlated to the tightness of the arm. The galax ...
Nature template - PC Word 97
... statistically significant fluctuations are seemingly rare and localized in the extended atmosphere, they are expected to be due to a variety of phenomena. Coronal flux loops, magnetic clouds or Jovian magnetospheres3 provide suitable explanations. Our study opens the way to future observations combi ...
... statistically significant fluctuations are seemingly rare and localized in the extended atmosphere, they are expected to be due to a variety of phenomena. Coronal flux loops, magnetic clouds or Jovian magnetospheres3 provide suitable explanations. Our study opens the way to future observations combi ...
Interacting Galaxies
... Far from being solitary and isolated island universes, many galaxies are found to be interacting. Their close encounters can lead to spectacular mergers and spawn vast amounts of new star formation. Astronomers estimate that in the nearby universe, 1 out of every 20 gas-rich disk galaxies, like our ...
... Far from being solitary and isolated island universes, many galaxies are found to be interacting. Their close encounters can lead to spectacular mergers and spawn vast amounts of new star formation. Astronomers estimate that in the nearby universe, 1 out of every 20 gas-rich disk galaxies, like our ...
Megamaser
A megamaser is a type of astrophysical maser, which is a naturally occurring source of stimulated spectral line emission. Megamasers are distinguished from astrophysical masers by their large isotropic luminosity. Megamasers have typical luminosities of 103 solar luminosities (L☉), which is 100 million times brighter than masers in the Milky Way, hence the prefix mega. Likewise, the term kilomaser is used to describe masers outside the Milky Way that have luminosities of order L☉, or thousands of times stronger than the average maser in the Milky Way, gigamaser is used to describe masers billions of times stronger than the average maser in the Milky Way, and extragalactic maser encompasses all masers found outside the Milky Way. Most known extragalactic masers are megamasers, and the majority of megamasers are hydroxyl (OH) megamasers, meaning the spectral line being amplified is one due to a transition in the hydroxyl molecule. There are known megamasers for three other molecules: water (H2O), formaldehyde (H2CO), and methine (CH).Water megamasers were the first type of megamaser discovered. The first water megamaser was found in 1979 in NGC 4945, a galaxy in the nearby Centaurus A/M83 Group. The first hydroxyl megamaser was found in 1982 in Arp 220, which is the nearest ultraluminous infrared galaxy to the Milky Way. All subsequent OH megamasers that have been discovered are also in luminous infrared galaxies, and there are a small number of OH kilomasers hosted in galaxies with lower infrared luminosities. Most luminous infrared galaxies have recently merged or interacted with another galaxy, and are undergoing a burst of star formation. Many of the characteristics of the emission in hydroxyl megamasers are distinct from that of hydroxyl masers within the Milky Way, including the amplification of background radiation and the ratio of hydroxyl lines at different frequencies. The population inversion in hydroxyl molecules is produced by far infrared radiation that results from absorption and re-emission of light from forming stars by surrounding interstellar dust. Zeeman splitting of hydroxyl megamaser lines may be used to measure magnetic fields in the masing regions, and this application represents the first detection of Zeeman splitting in a galaxy other than the Milky Way.Water megamasers and kilomasers are found primarily associated with active galactic nuclei, while galactic and weaker extragalactic water masers are found in star forming regions. Despite different environments, the circumstances that produce extragalactic water masers do not seem to be very different from those that produce galactic water masers. Observations of water megamasers have been used to make accurate measurements of distances to galaxies in order to provide constraints on the Hubble constant.