The effects of galaxy interactions on star formation
... This dissertation explores the effects of galaxy interactions on star formation through three separate projects. In the first two projects, we examine enhanced star formation by studying the star cluster populations of the interacting galaxies Arp 284 (NGC 7714/5) and Arp 261, using data from the Hu ...
... This dissertation explores the effects of galaxy interactions on star formation through three separate projects. In the first two projects, we examine enhanced star formation by studying the star cluster populations of the interacting galaxies Arp 284 (NGC 7714/5) and Arp 261, using data from the Hu ...
Thesis (complete) - Research Explorer
... produced by nuclear burning continuously replenishes what is lost by radiation and allows stars to remain in stable configurations for long periods of time. As these stars evolve they undergo many different processes that are triggered mainly by the exhaustion of fuel. Those changes are reflected in ...
... produced by nuclear burning continuously replenishes what is lost by radiation and allows stars to remain in stable configurations for long periods of time. As these stars evolve they undergo many different processes that are triggered mainly by the exhaustion of fuel. Those changes are reflected in ...
Population effects on the red giant clump absolute magnitude, and
... In this paper, we re-address the problem of these systematic `population' effects. First, we present tables with the theoretically predicted I-band clump magnitude as a function of age and metallicity. Simple equations, taken from basic population synthesis theory, are provided for the easy computat ...
... In this paper, we re-address the problem of these systematic `population' effects. First, we present tables with the theoretically predicted I-band clump magnitude as a function of age and metallicity. Simple equations, taken from basic population synthesis theory, are provided for the easy computat ...
The Evolution of Protostars - Max-Planck
... How do surveys find protostars and distinguish them from background galaxies, AGB stars, and more evolved star plus disk systems? What is the resulting census of protostars and young stars in nearby molecular clouds? Various identification methods have been employed and are compared in §2, leading t ...
... How do surveys find protostars and distinguish them from background galaxies, AGB stars, and more evolved star plus disk systems? What is the resulting census of protostars and young stars in nearby molecular clouds? Various identification methods have been employed and are compared in §2, leading t ...
Full Text - Digital Access to Scholarship at Harvard
... Still, were dust inert, like dark matter, the Galaxy would be a very different place—the dust plays an outsize role in the physics of the Galaxy. As a solid, dust has a broad range of energy levels and can interact with light over much of a star’s spectrum, whereas atomic hydrogen gas, for instance, ...
... Still, were dust inert, like dark matter, the Galaxy would be a very different place—the dust plays an outsize role in the physics of the Galaxy. As a solid, dust has a broad range of energy levels and can interact with light over much of a star’s spectrum, whereas atomic hydrogen gas, for instance, ...
Constraints on the physical properties and chemical evolution of star
... The emission from interstellar gas heated by young stars in galaxies contains valuable clues about both the nature of these stars and the physical conditions in the interstellar medium. In particular, prominent emission lines produced by H ii regions, diffuse ionized gas and a potential active galac ...
... The emission from interstellar gas heated by young stars in galaxies contains valuable clues about both the nature of these stars and the physical conditions in the interstellar medium. In particular, prominent emission lines produced by H ii regions, diffuse ionized gas and a potential active galac ...
arXiv:1410.8731v2 [astro
... Given that at wavelengths shorter than ∼ 2.08 µm the emission is highly absorbed by tellurics, we did not included this spectral region in the fit of the overall background-spectral shape, but used only the selected spectral windows as described above. For this reason, the background continuum in th ...
... Given that at wavelengths shorter than ∼ 2.08 µm the emission is highly absorbed by tellurics, we did not included this spectral region in the fit of the overall background-spectral shape, but used only the selected spectral windows as described above. For this reason, the background continuum in th ...
Cool Subdwarf Investigations (CSI) I: New Thoughts for the Spectral
... were high luminosity blue stars, their distances would be outside the Milky Way, so it was surmised that these stars should be underluminous, and therefore closer. Although their temperatures are similar to O and B dwarfs, their spectral features are, in fact, quite different. Generally, O-type subd ...
... were high luminosity blue stars, their distances would be outside the Milky Way, so it was surmised that these stars should be underluminous, and therefore closer. Although their temperatures are similar to O and B dwarfs, their spectral features are, in fact, quite different. Generally, O-type subd ...
A SUB-SATURN MASS PLANET ORBITING HD 36511 Debra A
... this APT are described in Henry (1999). The external precision of the photometric observations, defined as the standard deviation of a seasonal set of differential magnitudes, is typically around 0.0014 mag for the T4 APT, as determined from pairs of constant stars. The differential magnitudes of HD ...
... this APT are described in Henry (1999). The external precision of the photometric observations, defined as the standard deviation of a seasonal set of differential magnitudes, is typically around 0.0014 mag for the T4 APT, as determined from pairs of constant stars. The differential magnitudes of HD ...
X-ray spectra of highly magnetized neutron stars in binary systems
... If a CRSF is observed in the spectrum of a neutron star, the strength of the magnetic field can be directly assessed from the energy of the CRSF (after taking gravitational redshift into account which amounts to ∼25%). As in quantum theory, the electrons can not only occupy the fundamental and first ...
... If a CRSF is observed in the spectrum of a neutron star, the strength of the magnetic field can be directly assessed from the energy of the CRSF (after taking gravitational redshift into account which amounts to ∼25%). As in quantum theory, the electrons can not only occupy the fundamental and first ...
The growth of planets by pebble accretion in evolving protoplanetary
... drops with increasing orbital distance (Bitsch et al. 2013). Lowmass planets are in this so-called type-I-migration phase, where the perturbation of the planet onto the disc is small. When the planets become more massive, for example, when it is caused by gas accretion, they start to open a gap insi ...
... drops with increasing orbital distance (Bitsch et al. 2013). Lowmass planets are in this so-called type-I-migration phase, where the perturbation of the planet onto the disc is small. When the planets become more massive, for example, when it is caused by gas accretion, they start to open a gap insi ...
Some Constraints on the Effects of Age and Metallicity - UvA-DARE
... We have studied the low-mass X-ray binary (LMXB) populations within and outside globular clusters (GCs) in NGC 4365 and NGC 3115. Using published age and metallicity constraints from optical and IR observations of their GCs, we do not find any evidence for an increase in the LMXB formation rate in t ...
... We have studied the low-mass X-ray binary (LMXB) populations within and outside globular clusters (GCs) in NGC 4365 and NGC 3115. Using published age and metallicity constraints from optical and IR observations of their GCs, we do not find any evidence for an increase in the LMXB formation rate in t ...
ppt - ciera
... BSS have been detected for the first time by Sandage (1953) according to their position in the CMD, BSS should be more massive than normal stars ...
... BSS have been detected for the first time by Sandage (1953) according to their position in the CMD, BSS should be more massive than normal stars ...
09-03-08_Meixner
... – Dominated by imaging and photometry – What are these newly discovered sources? Need spectroscopy…. ...
... – Dominated by imaging and photometry – What are these newly discovered sources? Need spectroscopy…. ...
Cepheids
... any color: W(BV), W(VK) etc. • W incorporates intrinsic color (and Period – Color relation) • The advantage of using the Wesenheit index W instead of the absolute magnitude M is that – (a) Wesenheit index is almost free of any ...
... any color: W(BV), W(VK) etc. • W incorporates intrinsic color (and Period – Color relation) • The advantage of using the Wesenheit index W instead of the absolute magnitude M is that – (a) Wesenheit index is almost free of any ...
Stars and dust in the Galactic Center
... Mean radial velocities along the Galactic plane for our SINFONI Ks-surface brightness profile of the central Galaxy . . . . . . . . Extinction corrected radial distribution of stars and flux . . . . Stellar density in and orthogonal to the Galactic plane . . . . . Nuker fits to the late-type stars surf ...
... Mean radial velocities along the Galactic plane for our SINFONI Ks-surface brightness profile of the central Galaxy . . . . . . . . Extinction corrected radial distribution of stars and flux . . . . Stellar density in and orthogonal to the Galactic plane . . . . . Nuker fits to the late-type stars surf ...
The Destruction of an Oort Cloud in a rich stellar cluster
... source for 26 Al and 60 Fe traced in chondritic meteorites. The dynamical fate of the Sun was not addressed, but it seems possible that the Sun stayed gravitationally bound to the initial complex of stars and gas, thus becoming a member of a massive stellar cluster. Thus, the Sun’s birth cluster may ...
... source for 26 Al and 60 Fe traced in chondritic meteorites. The dynamical fate of the Sun was not addressed, but it seems possible that the Sun stayed gravitationally bound to the initial complex of stars and gas, thus becoming a member of a massive stellar cluster. Thus, the Sun’s birth cluster may ...
Testing the Initial-Final Mass Relationship of White Dwarfs Silvia Catal´ an Ruiz
... total age or metallicity, are available. Most of the works carried out up to now have focused in studying white dwarfs in open clusters (Ferrario et al. 2005, Dobbie et al. 2006), whose ages can be determined from model fits to the turn-off location in a color-magnitude diagram. One of the aims of t ...
... total age or metallicity, are available. Most of the works carried out up to now have focused in studying white dwarfs in open clusters (Ferrario et al. 2005, Dobbie et al. 2006), whose ages can be determined from model fits to the turn-off location in a color-magnitude diagram. One of the aims of t ...
Giant Molecular Clouds in Local Group Galaxies
... is a good value to use in most galaxies (except the SMC) if the GMCs are virialized. However, if the clouds are only marginally self-gravitating, as appears to be the case judging from their appearance, half the virial value may be more appropriate. There is no clear trend of XCO with metallicity. T ...
... is a good value to use in most galaxies (except the SMC) if the GMCs are virialized. However, if the clouds are only marginally self-gravitating, as appears to be the case judging from their appearance, half the virial value may be more appropriate. There is no clear trend of XCO with metallicity. T ...
Universe of Motion - Reciprocal System of theory
... characteristics that the physical universe must necessarily have if it is composed entirely of discrete units of motion, and to show that the universe thus defined is identical, item by item, with the observed physical universe. The specific objective of this present volume is to extend the physical ...
... characteristics that the physical universe must necessarily have if it is composed entirely of discrete units of motion, and to show that the universe thus defined is identical, item by item, with the observed physical universe. The specific objective of this present volume is to extend the physical ...
Pluto: improved astrometry from 19 years of observations ⋆⋆⋆⋆⋆⋆
... such correction for right ascension. However, there is still a small correction in declination to be applied. The determination of the position of Pluto may also be affected by Charon’s light, since its angular separation from Pluto is less than 100 . If there is not enough angular resolution, what ...
... such correction for right ascension. However, there is still a small correction in declination to be applied. The determination of the position of Pluto may also be affected by Charon’s light, since its angular separation from Pluto is less than 100 . If there is not enough angular resolution, what ...
high-precision c17o, c18o, and c16o measurements in
... of the embedded, low-mass pre-main sequence star HL Tau, showing a ratio of column densities for C16 O and C18 O, N (C16 O)/N (C18 O), of 800 ± 200 (2σ ). Typical [16 O]/[18 O] in the local interstellar medium (ISM) is 557 ± 30, (Wilson 1999), similar to the solar system value of 499. The apparent o ...
... of the embedded, low-mass pre-main sequence star HL Tau, showing a ratio of column densities for C16 O and C18 O, N (C16 O)/N (C18 O), of 800 ± 200 (2σ ). Typical [16 O]/[18 O] in the local interstellar medium (ISM) is 557 ± 30, (Wilson 1999), similar to the solar system value of 499. The apparent o ...
Evidence of suppression of star formation by quasar
... tribution of galaxy colors. If AGN feedback couples to the gas as efficiently as required by galaxy formation models, then massive, early-type galaxies will be gas-poor and passively aging, while younger galaxies, typically lower-mass, late-type galaxies will still have enough star formation materia ...
... tribution of galaxy colors. If AGN feedback couples to the gas as efficiently as required by galaxy formation models, then massive, early-type galaxies will be gas-poor and passively aging, while younger galaxies, typically lower-mass, late-type galaxies will still have enough star formation materia ...
JOA Vol 1 No. 2 - Apr 2011 - RASNZ Occultation Section
... very near the one covered by me. Eric Frappa at Euraster.net calculated the diameter of the asteroid to be at least 117 km. Exactly two month later on November 01, 2010 the asteroid (1889) Pakhmutova occulted the star TYC 1854-00266-1 (10.7 mag) in Taurus. My observing location was at chord +67 insi ...
... very near the one covered by me. Eric Frappa at Euraster.net calculated the diameter of the asteroid to be at least 117 km. Exactly two month later on November 01, 2010 the asteroid (1889) Pakhmutova occulted the star TYC 1854-00266-1 (10.7 mag) in Taurus. My observing location was at chord +67 insi ...
Properties of simulated Milky Way-mass galaxies in loose group and
... automatically refines according to the local particle density in addition to a static refinement of nested regions that reduces the run-time while maintaining high resolution around the galaxy of interest. Details of the refinement scheme are described by Teyssier (2002). ramses includes density- an ...
... automatically refines according to the local particle density in addition to a static refinement of nested regions that reduces the run-time while maintaining high resolution around the galaxy of interest. Details of the refinement scheme are described by Teyssier (2002). ramses includes density- an ...
Planetary nebula
A planetary nebula, often abbreviated as PN or plural PNe, is a kind of emission nebula consisting of an expanding glowing shell of ionized gas ejected from old red giant stars late in their lives. The word ""nebula"" is Latin for mist or cloud and the term ""planetary nebula"" is a misnomer that originated in the 1780s with astronomer William Herschel because when viewed through his telescope, these objects appeared to him to resemble the rounded shapes of planets. Herschel's name for these objects was popularly adopted and has not been changed. They are a relatively short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years.A mechanism for formation of most planetary nebulae is thought to be the following: at the end of the star's life, during the red giant phase, the outer layers of the star are expelled by strong stellar winds. Eventually, after most of the red giant's atmosphere is dissipated, the exposed hot, luminous core emits ultraviolet radiation to ionize the ejected outer layers of the star. Absorbed ultraviolet light energises the shell of nebulous gas around the central star, appearing as a bright coloured planetary nebula at several discrete visible wavelengths.Planetary nebulae may play a crucial role in the chemical evolution of the Milky Way, returning material to the interstellar medium from stars where elements, the products of nucleosynthesis (such as carbon, nitrogen, oxygen and neon), have been created. Planetary nebulae are also observed in more distant galaxies, yielding useful information about their chemical abundances.In recent years, Hubble Space Telescope images have revealed many planetary nebulae to have extremely complex and varied morphologies. About one-fifth are roughly spherical, but the majority are not spherically symmetric. The mechanisms which produce such a wide variety of shapes and features are not yet well understood, but binary central stars, stellar winds and magnetic fields may play a role.