Galaxies - Stockton University
... In the Solar neighborhood, an average main-sequence star (excluding binary stars) is separated by of order 107 times its size from its nearest neighbors (1 Solar Radius vs. 1 pc). Galaxies on the other hand have sizes ranging from 1 to 100 Kpc, but are separated by of order 1 to 10 Mpc from their ne ...
... In the Solar neighborhood, an average main-sequence star (excluding binary stars) is separated by of order 107 times its size from its nearest neighbors (1 Solar Radius vs. 1 pc). Galaxies on the other hand have sizes ranging from 1 to 100 Kpc, but are separated by of order 1 to 10 Mpc from their ne ...
It is now recognized that the vast majority of ellipticals are of
... Cores of Ellipticals • Only a few E galaxies actually have flat luminosity profiles at small radii; instead, the profiles rise inward to the last measured point. • Cores may exhibit unusual kinematics; for example, about a quarter of all elliptical galaxies have cores which appear to counter-rotate ...
... Cores of Ellipticals • Only a few E galaxies actually have flat luminosity profiles at small radii; instead, the profiles rise inward to the last measured point. • Cores may exhibit unusual kinematics; for example, about a quarter of all elliptical galaxies have cores which appear to counter-rotate ...
High-Energy Astrophysics with Gamma
... by ~1 arcsec (e.g., Scoville et al. 1997, Downes et al. 1998, Soifer et al. 1999, Wiedner et al. 2002). The two radio sources are extended and nonthermal (e.g., Sopp & Alexander 1991; Condon et al. 1991; Baan & Haschick 1995), and likely produced by supernovae in the most active starforming regions. ...
... by ~1 arcsec (e.g., Scoville et al. 1997, Downes et al. 1998, Soifer et al. 1999, Wiedner et al. 2002). The two radio sources are extended and nonthermal (e.g., Sopp & Alexander 1991; Condon et al. 1991; Baan & Haschick 1995), and likely produced by supernovae in the most active starforming regions. ...
Radio observations of the planetary nebula around the OH/IR Star
... nonthermal radio continuum emission, with radio spectral indices comparable to those seen in colliding-wind Wolf-Rayet binaries. We suggest that these represent shocked interactions between the hot, fast stellar wind and the cold nebular shell that represents the PN’s slow wind moving away from the ...
... nonthermal radio continuum emission, with radio spectral indices comparable to those seen in colliding-wind Wolf-Rayet binaries. We suggest that these represent shocked interactions between the hot, fast stellar wind and the cold nebular shell that represents the PN’s slow wind moving away from the ...
Galaxies - science9atsouthcarletonhs
... 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 galaxies M 104 (below) and M 51 (right) respectiv ...
... 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 galaxies M 104 (below) and M 51 (right) respectiv ...
The Intricate Role of Cold Gas and Dust in Galaxy Evolution at Early
... holds, but UV SFRs would be ~2-10x too high with standard (lower-z) dust corrections! ...
... holds, but UV SFRs would be ~2-10x too high with standard (lower-z) dust corrections! ...
Deep Chandra Observations of the Arches and Quintuplet Clusters at... Hui Dong Q. Daniel Wang ( &
... strong 6.7 keV emission line, indicating that they are most likely the colliding wind close binaries of very massive stars. The spectra of the diffuse X-ray emission are significantly flatter than that of point-like sources. The luminosity, spectrum, and spatial distribution of the diffuse emission ...
... strong 6.7 keV emission line, indicating that they are most likely the colliding wind close binaries of very massive stars. The spectra of the diffuse X-ray emission are significantly flatter than that of point-like sources. The luminosity, spectrum, and spatial distribution of the diffuse emission ...
Active Galactic Nuclei: are they important?
... surrounded by plentiful material flowing in and out •This material emits radiation so we can trace what is happening close to a black hole ...
... surrounded by plentiful material flowing in and out •This material emits radiation so we can trace what is happening close to a black hole ...
presentation (PPT format)
... Cepheid (they can be seen out to 30Mpc and we have Period-Luminosity relationship) RR Lyrae can be used in the same way but because they are less luminous they can only be seen until 100Kpc For distant stars astronomers are using Type Ia supernovae (that occurs when a white dward in a close binary s ...
... Cepheid (they can be seen out to 30Mpc and we have Period-Luminosity relationship) RR Lyrae can be used in the same way but because they are less luminous they can only be seen until 100Kpc For distant stars astronomers are using Type Ia supernovae (that occurs when a white dward in a close binary s ...
Ch 18
... “forbidden” transitions; they are not actually forbidden but are so rare that under standard laboratory conditions they are never seen. In a nebula, however, the gas is so thin that an atom, once excited, has only a small probability of interacting before it decays spontaneously. ...
... “forbidden” transitions; they are not actually forbidden but are so rare that under standard laboratory conditions they are never seen. In a nebula, however, the gas is so thin that an atom, once excited, has only a small probability of interacting before it decays spontaneously. ...
Lecture Notes – Galaxies
... Clusters of Galaxies Contain from 10 – 1000s of galaxies, and are gravitationally bound systems. Spacing of galaxies is realtively close, ≈ 100 times diameter of galaxy. (For comparison, in our Galaxy the spacing of stars ≈ 106 diameter of a typical star.) Rich clusters (> 100 members) contain mostl ...
... Clusters of Galaxies Contain from 10 – 1000s of galaxies, and are gravitationally bound systems. Spacing of galaxies is realtively close, ≈ 100 times diameter of galaxy. (For comparison, in our Galaxy the spacing of stars ≈ 106 diameter of a typical star.) Rich clusters (> 100 members) contain mostl ...
A Universe of Galaxies - Pennsylvania State University
... What can outshine ~1000 supernovae for millions of years, and be just slightly larger than our Solar System? Theoretically, not much – only a very, very big black hole. • Start with a black hole with a mass of 10,000,000,000 Mʘ • Have a star come close enough to be tidally disrupted • Have the mater ...
... What can outshine ~1000 supernovae for millions of years, and be just slightly larger than our Solar System? Theoretically, not much – only a very, very big black hole. • Start with a black hole with a mass of 10,000,000,000 Mʘ • Have a star come close enough to be tidally disrupted • Have the mater ...
Quantum effects in astrophysics
... Subscripts e, D, and P, represent electrons, deuterons, and protons. The differences in reduce mass means that the energy levels of deuterium will lie further apart than the levels of ordinary hydrogen by about one part in 2mP / me 3700 . In the visible part of the spectrum, this corresponds to a ...
... Subscripts e, D, and P, represent electrons, deuterons, and protons. The differences in reduce mass means that the energy levels of deuterium will lie further apart than the levels of ordinary hydrogen by about one part in 2mP / me 3700 . In the visible part of the spectrum, this corresponds to a ...
UniverseofGalaxies
... divided into SBa, SBb, SBc, with similar characteristics to regular spirals, except for a centrallyoriented bar ...
... divided into SBa, SBb, SBc, with similar characteristics to regular spirals, except for a centrallyoriented bar ...
The Milky Way and other Galaxies
... galaxies (much smaller and less luminous than the Milky Way) to giant ellipticals and large spirals, a few times the Milky Way’s size and luminosity ...
... galaxies (much smaller and less luminous than the Milky Way) to giant ellipticals and large spirals, a few times the Milky Way’s size and luminosity ...
SIMULATIONS
... and the SFRH in star forming galaxies Consistency observations -simulations The MS and MZ relation for star forming galaxies Are projections of the Fundamental Plane ...
... and the SFRH in star forming galaxies Consistency observations -simulations The MS and MZ relation for star forming galaxies Are projections of the Fundamental Plane ...
2.3 Peculiar galaxies
... Black hole accretion discs. If the available gas simply fell radially downwards towards the black hole, the energy it would gain would be kinetic energy, and it wouldn’t give much radiation; it would just disappear down the black hole. However, if, as is very likely, the gas is rotating around the b ...
... Black hole accretion discs. If the available gas simply fell radially downwards towards the black hole, the energy it would gain would be kinetic energy, and it wouldn’t give much radiation; it would just disappear down the black hole. However, if, as is very likely, the gas is rotating around the b ...
Galaxies - Mike Brotherton
... galaxies (much smaller and less luminous than the Milky Way) to giant ellipticals and large spirals, a few times the Milky Way’s size and luminosity ...
... galaxies (much smaller and less luminous than the Milky Way) to giant ellipticals and large spirals, a few times the Milky Way’s size and luminosity ...
Chapter 27 Quasars, Active Galaxies, and Gamma
... from stars, nebulae, and some galaxies. • There were also point-like, or star-like, radio sources which varied rapidly these are the `quasi-stellar’ radio sources or quasars. • In visible light quasars appear as points, like ...
... from stars, nebulae, and some galaxies. • There were also point-like, or star-like, radio sources which varied rapidly these are the `quasi-stellar’ radio sources or quasars. • In visible light quasars appear as points, like ...
Next Generation VLA Science White Paper
... dipole moment species require densities ∼ 105 or larger to excite and hence trace gas that is ready to form stars (e.g. Gao & Solomon 2004). Excitation of these low J transitions trace cooler, dense gas than regularly do ALMA and Herschel. HC3 N, with its numerous available closely spaced lines, is ...
... dipole moment species require densities ∼ 105 or larger to excite and hence trace gas that is ready to form stars (e.g. Gao & Solomon 2004). Excitation of these low J transitions trace cooler, dense gas than regularly do ALMA and Herschel. HC3 N, with its numerous available closely spaced lines, is ...
The kinematics of Galaxies in Compact Groups
... most have peculiar rotation curves + dynamical properties of the galaxies do not correlate with any galaxy/group parameter. 2) Rubin et al. (1991) studied 32 galaxies – found that 2/3 have peculiar rotation curves. They found a large offset of the TF relation with respect to the field relation in th ...
... most have peculiar rotation curves + dynamical properties of the galaxies do not correlate with any galaxy/group parameter. 2) Rubin et al. (1991) studied 32 galaxies – found that 2/3 have peculiar rotation curves. They found a large offset of the TF relation with respect to the field relation in th ...
Spectroscopic confirmation of a galaxy at redshift z=8.6
... Figure 1 | Two representations of the spectrum of UDFy-38135539 showing its significance. a, The spectrum shows a faint emission line detected at 6s significance at a wavelength of 11,615.6 Å, corresponding to a redshift of z 5 8.5549 6 0.0020 for Lya. The integrated spectrum was extracted from a s ...
... Figure 1 | Two representations of the spectrum of UDFy-38135539 showing its significance. a, The spectrum shows a faint emission line detected at 6s significance at a wavelength of 11,615.6 Å, corresponding to a redshift of z 5 8.5549 6 0.0020 for Lya. The integrated spectrum was extracted from a s ...
Document
... INTRODUCTIONu The hot, diffuse, x-ray emitting interstellar medium of the Milky Way Galaxy appears almost featureless, unless it is observed in the soft x-ray band. In 1995, complex structures, visible only between 0.1 and 2.0keV, were revealed by the ROSAT all-sky survey. The XMM-Newton observatory ...
... INTRODUCTIONu The hot, diffuse, x-ray emitting interstellar medium of the Milky Way Galaxy appears almost featureless, unless it is observed in the soft x-ray band. In 1995, complex structures, visible only between 0.1 and 2.0keV, were revealed by the ROSAT all-sky survey. The XMM-Newton observatory ...
implication on the mass and
... NFGS (Nearby Field Galaxy Survey) by Jansen et al. 2000a,b KISS ( Salzer et al. 2005) SDSS (Tremondi et al. 2004; Bell et al. 2003) ...
... NFGS (Nearby Field Galaxy Survey) by Jansen et al. 2000a,b KISS ( Salzer et al. 2005) SDSS (Tremondi et al. 2004; Bell et al. 2003) ...
Starbursts – from 30 Doradus to Lyman
... local gas surface density (known as the Schmidt–Kennicutt law). Starburst properties, in addition, appear to be continuous across a range of amplitudes – and redshifts – suggesting a galaxy classification sequence similar to the Hubble tuning fork, but now from M82-like starbursts via ultraluminous ...
... local gas surface density (known as the Schmidt–Kennicutt law). Starburst properties, in addition, appear to be continuous across a range of amplitudes – and redshifts – suggesting a galaxy classification sequence similar to the Hubble tuning fork, but now from M82-like starbursts via ultraluminous ...
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.