Full Text - University of Toronto Astronomy
... envelopes from dust forming in the wind at large distances from the surface of the star. The mass-loss rates are found to be plausible explanation for the Cepheid mass discrepancy. We also compute mass-loss rates from optical and infrared observations of Large Magellanic Cloud Cepheids from the infr ...
... envelopes from dust forming in the wind at large distances from the surface of the star. The mass-loss rates are found to be plausible explanation for the Cepheid mass discrepancy. We also compute mass-loss rates from optical and infrared observations of Large Magellanic Cloud Cepheids from the infr ...
HUBBLE SPACE TELESCOPE AND GROUND-BASED
... We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instea ...
... We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instea ...
Accretion Power in Astrophysics, Third Editiion
... where accretion is believed to make an important contribution to the total light of an astrophysical system. Our discussion therefore centres mainly on close binary systems containing compact objects and on active nuclei. The reader is assumed to possess a basic knowledge of physics at first degree l ...
... where accretion is believed to make an important contribution to the total light of an astrophysical system. Our discussion therefore centres mainly on close binary systems containing compact objects and on active nuclei. The reader is assumed to possess a basic knowledge of physics at first degree l ...
Th`ese d`astrophysique Chemodynamical Simulations of Evolution
... and infrared emission, well studied since the advance of modern space observatories. Although dust is negligible in mass, it is of primary importance to accurately know its effects on light in order to produce high quality astronomical data. Dust also receive attention to itself. Interstellar extinc ...
... and infrared emission, well studied since the advance of modern space observatories. Although dust is negligible in mass, it is of primary importance to accurately know its effects on light in order to produce high quality astronomical data. Dust also receive attention to itself. Interstellar extinc ...
Systematic Study of Mass Loss in the Evolution of Massive Stars
... that I implemented for this work. I also describe the setup of the simulations in detail, with the explicit aim of providing all the information needed to reproduce the results. Chapter 2 also contains the description of the simplified procedure to simulate a violent, short, eruptive mass loss event ...
... that I implemented for this work. I also describe the setup of the simulations in detail, with the explicit aim of providing all the information needed to reproduce the results. Chapter 2 also contains the description of the simplified procedure to simulate a violent, short, eruptive mass loss event ...
Evolution of Stars and Stellar Populations
... The theory of stellar evolution is by now well established, after more than half a century of continuous development, and its main predictions confirmed by various empirical tests. As a consequence, we can now use its results with some confidence, and obtain vital information about the structure and ...
... The theory of stellar evolution is by now well established, after more than half a century of continuous development, and its main predictions confirmed by various empirical tests. As a consequence, we can now use its results with some confidence, and obtain vital information about the structure and ...
SN 2006gy: DISCOVERY OF THE MOST LUMINOUS
... We report the discovery and early observations of the peculiar Type IIn supernova (SN) 2006gy in NGC 1260. With a peak visual magnitude of about 22, it is the most luminous supernova ever recorded. Its very slow rise to maximum took 70 days, and it stayed brighter than 21 mag for about 100 days. ...
... We report the discovery and early observations of the peculiar Type IIn supernova (SN) 2006gy in NGC 1260. With a peak visual magnitude of about 22, it is the most luminous supernova ever recorded. Its very slow rise to maximum took 70 days, and it stayed brighter than 21 mag for about 100 days. ...
Fundamentals of Stellar Evolution Theory: Understanding the HRD
... approach the Hayashi line, a convective envelope develops whose base extends inward until it reaches layers in which hydrogen has been converted into helium and carbon into nitrogen via the CNO cycle. As a consequence, the surface abundance of those elements ...
... approach the Hayashi line, a convective envelope develops whose base extends inward until it reaches layers in which hydrogen has been converted into helium and carbon into nitrogen via the CNO cycle. As a consequence, the surface abundance of those elements ...
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... A twofold model of turbulent accretion for massive star formation was proposed by Krumholz et al. (2006), where Bondi accretion is assumed, with the Bondi velocity dispersion set either to the turbulent velocity dispersion or to the velocity dispersion due to vorticity. Models of accretion onto a st ...
... A twofold model of turbulent accretion for massive star formation was proposed by Krumholz et al. (2006), where Bondi accretion is assumed, with the Bondi velocity dispersion set either to the turbulent velocity dispersion or to the velocity dispersion due to vorticity. Models of accretion onto a st ...
Photometric Variability and Rotation in Magnetic White Dwarfs
... To start, thank you to my supervisor, Matt Burleigh, for your guidance over the years; for initiating me into the mysteries of observing and the techniques of operating the INT in La Palma and the 1.0m telescope in South Africa. There are many memories, especially from observing trips, that will sta ...
... To start, thank you to my supervisor, Matt Burleigh, for your guidance over the years; for initiating me into the mysteries of observing and the techniques of operating the INT in La Palma and the 1.0m telescope in South Africa. There are many memories, especially from observing trips, that will sta ...
Cool Subdwarf Investigations (CSI) I: New Thoughts for the Spectral
... stellar evolution cycle of an evolved star, and they happen to be crossing the main sequence at the moment of observation. Because they are different kinds of stellar objects, we suggest that the two classes should not share the same spectral classification notation, “sd.” Roman (1955) argued that f ...
... stellar evolution cycle of an evolved star, and they happen to be crossing the main sequence at the moment of observation. Because they are different kinds of stellar objects, we suggest that the two classes should not share the same spectral classification notation, “sd.” Roman (1955) argued that f ...
Analysis of cool DO-type white dwarfs from the Sloan Digital Sky
... in any of the currently known theories of post-AGB evolution. They are considered to be the cooler counterpart of the unique and extensively studied PG1159 star H1504+65 (Nousek et al. 1986; Werner 1991; Werner et al. 2004a) and might form a new evolutionary sequence that follows the AGB. Another ca ...
... in any of the currently known theories of post-AGB evolution. They are considered to be the cooler counterpart of the unique and extensively studied PG1159 star H1504+65 (Nousek et al. 1986; Werner 1991; Werner et al. 2004a) and might form a new evolutionary sequence that follows the AGB. Another ca ...
Ch a n d
... pulsars (MSPs). However, so far only circumstantial evidence has existed for the evolutionary connection between the two classes. The recently discovered binary MSP PSR J1023+0038 appears to be the long sought-after ”missing link”. Archival observations indicate that an accretion disk was present in ...
... pulsars (MSPs). However, so far only circumstantial evidence has existed for the evolutionary connection between the two classes. The recently discovered binary MSP PSR J1023+0038 appears to be the long sought-after ”missing link”. Archival observations indicate that an accretion disk was present in ...
Farthest Neighbor: The Distant Milky Way Satellite Eridanus II
... dwarf Leo T, which is slightly more distant and more luminous (D = 420 kpc, MV∼−8; Irwin et al. 2007; de Jong et al. 2008; Ryan-Weber et al. 2008) and has undergone multiple epochs of star formation (de Jong et al. 2008; Weisz et al. 2012). If this were the case, EriII would be the least luminous ...
... dwarf Leo T, which is slightly more distant and more luminous (D = 420 kpc, MV∼−8; Irwin et al. 2007; de Jong et al. 2008; Ryan-Weber et al. 2008) and has undergone multiple epochs of star formation (de Jong et al. 2008; Weisz et al. 2012). If this were the case, EriII would be the least luminous ...
space telescope imaging spectrograph survey of far
... and an absolute wavelength calibration compared with using the Chandra or XMM-Newton grating spectrometers to observe permitted transitions of the same ion stages in the kilovolt X-ray region. Fe xii 1242, 1349 (T 2 106 K) and Fe xxi 1354 (107 K) are well known from solar studies and have bee ...
... and an absolute wavelength calibration compared with using the Chandra or XMM-Newton grating spectrometers to observe permitted transitions of the same ion stages in the kilovolt X-ray region. Fe xii 1242, 1349 (T 2 106 K) and Fe xxi 1354 (107 K) are well known from solar studies and have bee ...
EXTREMELY EXTENDED DUST SHELLS AROUND EVOLVED
... led to this position I am in today. During heavy moments while writing this thesis, I got encouraged by looking back in time when my friend and I used stones and the sticks arguing about space geometry from our mathematics class, while taking our long walks back from school. This has been / still is ...
... led to this position I am in today. During heavy moments while writing this thesis, I got encouraged by looking back in time when my friend and I used stones and the sticks arguing about space geometry from our mathematics class, while taking our long walks back from school. This has been / still is ...
the reality of the wolf 630 moving group - TigerPrints
... has resulted in distance measurements for thousands of nearby, seemingly isolated stars. With these newly determined distances, a high resolution spectroscopic abundance analysis can be brought to bear on many of the alleged members of these relic associations. If a structure is a relic of an open c ...
... has resulted in distance measurements for thousands of nearby, seemingly isolated stars. With these newly determined distances, a high resolution spectroscopic abundance analysis can be brought to bear on many of the alleged members of these relic associations. If a structure is a relic of an open c ...
The dark matter crisis: falsification of the current standard model of
... stars and gas with baryonic mass > 107 M⊙ formed within a tidal arm in a galaxy–galaxy encounter. With this definition, self-gravitating objects formed in a tidal arm but with lower masses would not constitute TDGs and we might then not be allowed to associate them with the dSph satellite galaxies of ...
... stars and gas with baryonic mass > 107 M⊙ formed within a tidal arm in a galaxy–galaxy encounter. With this definition, self-gravitating objects formed in a tidal arm but with lower masses would not constitute TDGs and we might then not be allowed to associate them with the dSph satellite galaxies of ...
Massive Star Formation - Max-Planck
... Σ ∼ 100 M pc−2 (Solomon et al., 1987) (see Tan et al., 2013a for detailed discussion of the methods for estimating Σ for the objects plotted here), although denser examples have been found in Henize 2-10 (Santangelo et al., 2009). The 13 CO-defined clouds of RomanDuval et al. (2010) are indicated, ...
... Σ ∼ 100 M pc−2 (Solomon et al., 1987) (see Tan et al., 2013a for detailed discussion of the methods for estimating Σ for the objects plotted here), although denser examples have been found in Henize 2-10 (Santangelo et al., 2009). The 13 CO-defined clouds of RomanDuval et al. (2010) are indicated, ...
The enigmatic pair of dwarf galaxies Leo IV and Leo V: coincidence
... them. Orbit calculations demonstrate that the two systems cannot share the exact same orbit, while a compromise orbit does not approach the Galactic center more than ∼160 kpc, rendering it unlikely that they are remnants of a single disrupted progenitor. A comparison with cosmological simulations sh ...
... them. Orbit calculations demonstrate that the two systems cannot share the exact same orbit, while a compromise orbit does not approach the Galactic center more than ∼160 kpc, rendering it unlikely that they are remnants of a single disrupted progenitor. A comparison with cosmological simulations sh ...
The evolution and explosion of massive stars
... Like all true stars, massive stars are gravitationally confined thermonuclear reactors whose composition evolves as energy is lost to radiation and neutrinos. Unlike lower-mass stars ( M ⱗ8M 䉺 ) , however, no point is ever reached at which a massive star can be fully supported by electron degeneracy ...
... Like all true stars, massive stars are gravitationally confined thermonuclear reactors whose composition evolves as energy is lost to radiation and neutrinos. Unlike lower-mass stars ( M ⱗ8M 䉺 ) , however, no point is ever reached at which a massive star can be fully supported by electron degeneracy ...
A Theory of Extrasolar Giant Planets
... down to giant planets like Saturn. It follows from the high convective eciency found in these low-Te objects that the interior structure is adiabatic. Models are obtained by integrating the equation of hydrostatic equilibrium along adiabats generated with the equation of state (EOS) of Saumon, Cha ...
... down to giant planets like Saturn. It follows from the high convective eciency found in these low-Te objects that the interior structure is adiabatic. Models are obtained by integrating the equation of hydrostatic equilibrium along adiabats generated with the equation of state (EOS) of Saumon, Cha ...
View/Open - University of Hertfordshire
... distinguish between members of NGC 6822 and foreground stars in the Milky Way and that the analysis tools available could be used to obtain useful velocity results from the spectra. This led to the discovery of a rotating population of intermediate age stars in the halo of NGC 6822, which constitute ...
... distinguish between members of NGC 6822 and foreground stars in the Milky Way and that the analysis tools available could be used to obtain useful velocity results from the spectra. This led to the discovery of a rotating population of intermediate age stars in the halo of NGC 6822, which constitute ...
Munshi_washington_0250E_12611
... baryonic physics. In the smaller halos, this is not the case and these halos must have reduced accretion to account for the change in virial radius. Figure courtesy of Alyson Brooks. . . . . . . . . . . . . . . . . . . . . . . . 45 ...
... baryonic physics. In the smaller halos, this is not the case and these halos must have reduced accretion to account for the change in virial radius. Figure courtesy of Alyson Brooks. . . . . . . . . . . . . . . . . . . . . . . . 45 ...