The Properties of Super Star Clusters in A Sample of
... Perhaps the greatest irony of a thesis text is that the pages most likely to be read are those of the acknowledgments. The weight of these pages is all the heavier because it is precisely the people most likely to read them who most deserve to acknowledged, and I will undoubtedly realize as soon as ...
... Perhaps the greatest irony of a thesis text is that the pages most likely to be read are those of the acknowledgments. The weight of these pages is all the heavier because it is precisely the people most likely to read them who most deserve to acknowledged, and I will undoubtedly realize as soon as ...
DISSERTATION
... This thesis deals with the comparison of interferometric data of Asymptotic Giant Branch (AGB) stars with hydrostatic and dynamic model atmospheres. The AGB is the late evolutionary stage of stars with masses below 8 M! . These stars are characterised by a C-O degenerated core and 2 shell with ongoi ...
... This thesis deals with the comparison of interferometric data of Asymptotic Giant Branch (AGB) stars with hydrostatic and dynamic model atmospheres. The AGB is the late evolutionary stage of stars with masses below 8 M! . These stars are characterised by a C-O degenerated core and 2 shell with ongoi ...
The APEX-CHAMP+ view of the Orion Molecular Cloud 1 core
... with the Receiver Lab Telescope (84 resolution) showed that the hot and broad velocity emission in the line profiles arises mainly from the BN/KL region, while much of the narrower (∼3−6 km s−1 wide) emission arises from the PDR. This was also observed in the spectra of the 12 CO J = 9−8 transitio ...
... with the Receiver Lab Telescope (84 resolution) showed that the hot and broad velocity emission in the line profiles arises mainly from the BN/KL region, while much of the narrower (∼3−6 km s−1 wide) emission arises from the PDR. This was also observed in the spectra of the 12 CO J = 9−8 transitio ...
Catalogs of Hot White Dwarfs in the Milky Way from GALEX`s
... 2010). Intermediate mass stars are the main providers of carbon and nitrogen, whereas low-mass stars are the most relevant component for the mass budget of stellar remnants in galaxies. Most of the stellar mass is shed in the AGB and PN phases, but the evolution through these phases is still subject ...
... 2010). Intermediate mass stars are the main providers of carbon and nitrogen, whereas low-mass stars are the most relevant component for the mass budget of stellar remnants in galaxies. Most of the stellar mass is shed in the AGB and PN phases, but the evolution through these phases is still subject ...
Multiwavelength optical observations of chromospherically active
... Individual results about stellar parameters and the behaviour of the chromospheric excess emission in each system is reported in Sect. 4. Finally, in Sect. 5 the discussion and conclusions are given. 2. Observations and data reduction The spectroscopic echelle observations of the chromospherically a ...
... Individual results about stellar parameters and the behaviour of the chromospheric excess emission in each system is reported in Sect. 4. Finally, in Sect. 5 the discussion and conclusions are given. 2. Observations and data reduction The spectroscopic echelle observations of the chromospherically a ...
The physics of neutron stars
... the mass M ∼ M⊙ have the radius R ∼ 104 km, which is comparable to Earth’s radius but almost 1000 times greater than the radius of a neutron star [3]. Therefore, the matter density in their interiors is less than one-thousandth of ρ0 . On the other hand, according to theoretical models, quark stars ...
... the mass M ∼ M⊙ have the radius R ∼ 104 km, which is comparable to Earth’s radius but almost 1000 times greater than the radius of a neutron star [3]. Therefore, the matter density in their interiors is less than one-thousandth of ρ0 . On the other hand, according to theoretical models, quark stars ...
CO emissions from optically selected galaxies at z ∼0.1–0.2: Tight
... the strength of the 4000 Å break, instead of the commonly used far-infrared (FIR) flux. We successfully detected the CO emissions from eight galaxies with signal-to-noise ratio larger than three, demonstrating the effectiveness of the Dn(4000)-based sample selection. For the first time, we find a t ...
... the strength of the 4000 Å break, instead of the commonly used far-infrared (FIR) flux. We successfully detected the CO emissions from eight galaxies with signal-to-noise ratio larger than three, demonstrating the effectiveness of the Dn(4000)-based sample selection. For the first time, we find a t ...
Fundamental properties of core-collapse Supernova and GRB
... to the observations when a dense stellar wind is present. This is the case for massive stars, in particular at their post-Main Sequence evolution, when they lose mass at enormous rates (10−6 to 10−3 M⊙ yr−1 ). When the stellar wind becomes dense, eventually the photosphere becomes extended and is fo ...
... to the observations when a dense stellar wind is present. This is the case for massive stars, in particular at their post-Main Sequence evolution, when they lose mass at enormous rates (10−6 to 10−3 M⊙ yr−1 ). When the stellar wind becomes dense, eventually the photosphere becomes extended and is fo ...
the harps-terra project. i. description of the algorithms, performance
... The proposed algorithm is based on minimizing the differences of the observed spectrum against a parameterized template. In our particular implementation, we first use the higherS/N observation as a preliminary template. In a second iteration, a very high S/N template is obtained by co-adding all th ...
... The proposed algorithm is based on minimizing the differences of the observed spectrum against a parameterized template. In our particular implementation, we first use the higherS/N observation as a preliminary template. In a second iteration, a very high S/N template is obtained by co-adding all th ...
Astronomy 112: The Physics of Stars Class 1 Notes
... extended mnemonic Oh Be A Fine Girl/guy, Kiss Me Like That, which proves one thing – astronomers have way too much time on their hands. There has been a theoretical proposal that a new type of spectral class should appear for objects even dimmer than T dwarfs, although no examples of such an object ...
... extended mnemonic Oh Be A Fine Girl/guy, Kiss Me Like That, which proves one thing – astronomers have way too much time on their hands. There has been a theoretical proposal that a new type of spectral class should appear for objects even dimmer than T dwarfs, although no examples of such an object ...
The X-shooter Spectral Library (XSL): I. DR1. Near
... variable stars, especially very cool stars, like AGB stars, whose spectra may vary substantially during their pulsation cycles. X-shooter offers multiple spectroscopic observation modes; we used the longslit SLIT mode for all observations. Three observing strategies are supported in SLIT mode: class ...
... variable stars, especially very cool stars, like AGB stars, whose spectra may vary substantially during their pulsation cycles. X-shooter offers multiple spectroscopic observation modes; we used the longslit SLIT mode for all observations. Three observing strategies are supported in SLIT mode: class ...
Galactic spiral structure - Proceedings of the Royal Society A
... and a smooth background distribution (figure 2). We smoothed the velocity distribution by replacing each discrete point with a two-dimensional Gaussian function and finding the sum. The choice of smoothing parameter depends on the density of stars in the plot, and the required visual balance between o ...
... and a smooth background distribution (figure 2). We smoothed the velocity distribution by replacing each discrete point with a two-dimensional Gaussian function and finding the sum. The choice of smoothing parameter depends on the density of stars in the plot, and the required visual balance between o ...
The Milky Way-Pulsars and Isolated Neutron Stars
... on old V-2 (captured in Germany after the World War II) and Aerobee rockets, they were the first who detected X-rays from the very hot gas in the solar corona. However, the intensity of this radiation was found to be a factor 106 lower than that measured at optical wavelengths. In the late 1 X-rays ...
... on old V-2 (captured in Germany after the World War II) and Aerobee rockets, they were the first who detected X-rays from the very hot gas in the solar corona. However, the intensity of this radiation was found to be a factor 106 lower than that measured at optical wavelengths. In the late 1 X-rays ...
Ionized gas discs in elliptical and S0 galaxies at z < 1
... galactic nuclei (AGN), or OB stars. It remains unclear, however, the degree to which these processes contribute to the ISM ionization of ETGs One way to understand the formation and evolution of ETGs is by studying their scaling relations (e.g. the Fundamental Plane, Faber– Jackson relation, or colo ...
... galactic nuclei (AGN), or OB stars. It remains unclear, however, the degree to which these processes contribute to the ISM ionization of ETGs One way to understand the formation and evolution of ETGs is by studying their scaling relations (e.g. the Fundamental Plane, Faber– Jackson relation, or colo ...
Applications of Photospheric Spot Temperature Models ... Stellar Angular Momentum Evolution
... disk-locking models of young stars ascribe spot temperatures hotter than the photosphere to active accretion from a circumstellar disk. If accretion acts to brake stellar rotation, spot temperatures hotter than the photosphere should be more prevalent among slow rotators. From the variability amplit ...
... disk-locking models of young stars ascribe spot temperatures hotter than the photosphere to active accretion from a circumstellar disk. If accretion acts to brake stellar rotation, spot temperatures hotter than the photosphere should be more prevalent among slow rotators. From the variability amplit ...
Feedback in low-mass galaxies in the early Universe
... lthough feedback from star formation is a complex phenomenon involving many processes over a wide range of physical scales, its most basic consequences are not difficult to understand: stars form out of gas, and therefore any process which either removes gas from a galaxy or prevents gas from conden ...
... lthough feedback from star formation is a complex phenomenon involving many processes over a wide range of physical scales, its most basic consequences are not difficult to understand: stars form out of gas, and therefore any process which either removes gas from a galaxy or prevents gas from conden ...
THE NEW GALAXY: Signatures of Its Formation
... to a disk for the first time. Two key observations emphasize what we consider to be the mystery of the main epoch of baryon dissipation. First, there are no stars with [Fe/H] < −2.2 that rotate with the disk. Second, despite all the activity associated with the Golden Age, at least 80% of the baryon ...
... to a disk for the first time. Two key observations emphasize what we consider to be the mystery of the main epoch of baryon dissipation. First, there are no stars with [Fe/H] < −2.2 that rotate with the disk. Second, despite all the activity associated with the Golden Age, at least 80% of the baryon ...
EXTREMELY EXTENDED DUST SHELLS AROUND EVOLVED
... from your spirit and courage. I would also like to thank my wife, Heather Shawver, and our beautiful children, Rosemary and Brianna , for making me see life with a new meaning of hope and prosperity. I also thank my long - term child-hood friend, Tholinhlanhla Henry Ngcobo for helping me during tryi ...
... from your spirit and courage. I would also like to thank my wife, Heather Shawver, and our beautiful children, Rosemary and Brianna , for making me see life with a new meaning of hope and prosperity. I also thank my long - term child-hood friend, Tholinhlanhla Henry Ngcobo for helping me during tryi ...
The occurrence of nitrogen-enhanced metal
... stars are produced in binary systems with AGB primaries of 3.5–6 M . From an assumed CEMP-no/CEMP-s ratio of at least 1/3, consistent with observations available to them, they find consistency with both the CEMP-s fraction (10–25%) and the CEMP-no/CEMP-s ratio for a top-heavy IMF, with a median mas ...
... stars are produced in binary systems with AGB primaries of 3.5–6 M . From an assumed CEMP-no/CEMP-s ratio of at least 1/3, consistent with observations available to them, they find consistency with both the CEMP-s fraction (10–25%) and the CEMP-no/CEMP-s ratio for a top-heavy IMF, with a median mas ...
the optical colors of giant elliptical galaxies and their metal
... the sense that the parent galaxies are redder by ∼ 0.12 – 0.20 mag at a given galactocentric distance. However, spectroscopic indices in the blue indicate that the luminosity-weighted ages and metallicities of such galaxies are equal to that of their averaged massive metal-rich GCs at a given galact ...
... the sense that the parent galaxies are redder by ∼ 0.12 – 0.20 mag at a given galactocentric distance. However, spectroscopic indices in the blue indicate that the luminosity-weighted ages and metallicities of such galaxies are equal to that of their averaged massive metal-rich GCs at a given galact ...
SKA and VLBI synergies
... extragalactic (Sect. 2), intermediate black holes (Sect. 2.2), and stellar astronomy (Sect. 3), respectively, and discuss some technical considerations in Sect. 4. ...
... extragalactic (Sect. 2), intermediate black holes (Sect. 2.2), and stellar astronomy (Sect. 3), respectively, and discuss some technical considerations in Sect. 4. ...
Leaky Stars: Pulsations, Waves, and Turbulence in Stellar Winds
... Cool stars: younger/older Sun • How do outflows & inflows co-exist around young T Tauri stars, and does the disk accretion power the wind? ...
... Cool stars: younger/older Sun • How do outflows & inflows co-exist around young T Tauri stars, and does the disk accretion power the wind? ...
Fundamentals of Stellar Evolution Theory: Understanding the HRD
... Because the evolutionary path of a star in the HRD is a natural consequence of the interplay between those physical processes, they will be the main guide-lines of our summary of the stellar evolution theory. 2.1. Low-, Intermediate-, and High-Mass Stars: definition By low mass stars we define those ...
... Because the evolutionary path of a star in the HRD is a natural consequence of the interplay between those physical processes, they will be the main guide-lines of our summary of the stellar evolution theory. 2.1. Low-, Intermediate-, and High-Mass Stars: definition By low mass stars we define those ...
Debris disks: seeing dust, thinking of planetesimals and planets
... where L? /L¯ and M? /M¯ are luminosity and mass of the star in solar units, respectively. If, by fragmentation or any other erosive process, smaller particles are released from larger ones, they start to “feel” a photogravitational force rather than gravitational force. The smaller the grains, the m ...
... where L? /L¯ and M? /M¯ are luminosity and mass of the star in solar units, respectively. If, by fragmentation or any other erosive process, smaller particles are released from larger ones, they start to “feel” a photogravitational force rather than gravitational force. The smaller the grains, the m ...
Non-thermal emission processes in massive binaries*
... - the emission of thermal X-rays, likely produced by hydrodynamic shocks between plasma shells travelling at different velocities in the wind of isolated stars, and leading to local temperature enhancements of a few 106 K (see Feldmeier et al (1997)). The thermal nature of the X-rays produced within ...
... - the emission of thermal X-rays, likely produced by hydrodynamic shocks between plasma shells travelling at different velocities in the wind of isolated stars, and leading to local temperature enhancements of a few 106 K (see Feldmeier et al (1997)). The thermal nature of the X-rays produced within ...
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.