Chapter 17. Creating New Domains
... 17.3 What happens when a Universe is run Now that you have some idea of what classes exist in the Ptolemy kernel, this section will try to explain flow of control when a Universe is run. By knowing this, you will get an idea of what additions or changes might be needed to get the functionality you d ...
... 17.3 What happens when a Universe is run Now that you have some idea of what classes exist in the Ptolemy kernel, this section will try to explain flow of control when a Universe is run. By knowing this, you will get an idea of what additions or changes might be needed to get the functionality you d ...
The Structure and Evolution of Protoplanetary Disks: an Infrared and
... (Lissauer 1993; Boss et al. 2000). However, the relative importance and timescales of these processes are still not fully understood. Describing each of these processes is beyond the scope of this review. Instead, we focus on IR and submillimeter† observational results, while providing a global view ...
... (Lissauer 1993; Boss et al. 2000). However, the relative importance and timescales of these processes are still not fully understood. Describing each of these processes is beyond the scope of this review. Instead, we focus on IR and submillimeter† observational results, while providing a global view ...
Slide 1
... • Spectral fitting and observations in X-rays/radio provide a strong support for the presence of an IMBH - Mass range = 6000 - 92000 M • Sub-Eddington radiation-pressure dominated accretion disk with a high (~4x10-4 M yr-1) at the outburst peak. • ~1yr recurrence timescale in the outbursts seen in t ...
... • Spectral fitting and observations in X-rays/radio provide a strong support for the presence of an IMBH - Mass range = 6000 - 92000 M • Sub-Eddington radiation-pressure dominated accretion disk with a high (~4x10-4 M yr-1) at the outburst peak. • ~1yr recurrence timescale in the outbursts seen in t ...
Core and conal component analysis of pulsar B1237 +25 Zuzana Srostlik,
... component V is now SPM-dominated as is a leading-edge region of component I, but also we see evidence of PPM power on the extreme outer edges. Only the regions under and following component II and just after the core remain PPM-dominated – this in stark contrast to the normal or total profiles where ...
... component V is now SPM-dominated as is a leading-edge region of component I, but also we see evidence of PPM power on the extreme outer edges. Only the regions under and following component II and just after the core remain PPM-dominated – this in stark contrast to the normal or total profiles where ...
Understanding the Cool DA White Dwarf, G29-38
... The white dwarfs are particularly rewarding objects for asteroseismology, the gains from which increase with the number of identified modes. (Modes are identified by specifying the values of the three integers, k, ℓ, and m, along with ν or P , the frequency or period.) Cepheids pulsate in one or two ...
... The white dwarfs are particularly rewarding objects for asteroseismology, the gains from which increase with the number of identified modes. (Modes are identified by specifying the values of the three integers, k, ℓ, and m, along with ν or P , the frequency or period.) Cepheids pulsate in one or two ...
STAR FORMATION IN ISOLATED DISK GALAXIES. II. SCHMIDT
... 121 nearby disk galaxies by Bell & de Jong (2000) shows that the star formation history of a galaxy is strongly correlated with the surface mass density. Similar conclusions were drawn by Kauffmann et al. (2003) from a sample of over 105 galaxies from the Sloan Digital Sky Survey. Recently, MacArthu ...
... 121 nearby disk galaxies by Bell & de Jong (2000) shows that the star formation history of a galaxy is strongly correlated with the surface mass density. Similar conclusions were drawn by Kauffmann et al. (2003) from a sample of over 105 galaxies from the Sloan Digital Sky Survey. Recently, MacArthu ...
Slide 1
... • Planet formation by gravitational instability requires extreme properties of protoplanetary disks, but is feasible beyond 100 AU from the star • Star formation around SMBH in the Galactic Center is natural at distances of 0.1 pc ...
... • Planet formation by gravitational instability requires extreme properties of protoplanetary disks, but is feasible beyond 100 AU from the star • Star formation around SMBH in the Galactic Center is natural at distances of 0.1 pc ...
Compact High-Redshift Galaxies Are the Cores of the Most Massive
... and comparison of profiles from different instruments and wavebands in these samples are discussed extensively in Hopkins et al. (2009a, 2008a); the differences are much smaller than the scatter between individual profiles, and do not affect our conclusions. In Figure 1, we restrict our comparison t ...
... and comparison of profiles from different instruments and wavebands in these samples are discussed extensively in Hopkins et al. (2009a, 2008a); the differences are much smaller than the scatter between individual profiles, and do not affect our conclusions. In Figure 1, we restrict our comparison t ...
The X-shooter Spectral Library (XSL): I. DR1. Near
... high/moderate resolution of the X-shooter spectrograph at ESO’s VLT (Vernet et al. 2011), we can now fill the gap between highresolution theoretical stellar libraries and low-resolution empirical stellar libraries. To this end, we developed the X-shooter Spectral Library (XSL, PI: Trager), which is ...
... high/moderate resolution of the X-shooter spectrograph at ESO’s VLT (Vernet et al. 2011), we can now fill the gap between highresolution theoretical stellar libraries and low-resolution empirical stellar libraries. To this end, we developed the X-shooter Spectral Library (XSL, PI: Trager), which is ...
The formation of carbon dioxide in molecular
... combined with previous observational, theoretical and experimental data, suggest a complex CO2 formation scenario with multiple epochs and mechanisms. At early stages in the molecular cloud, CO2 could form concurrently with H2 O via the OH radical pathway investigated here. This produces the CO2 com ...
... combined with previous observational, theoretical and experimental data, suggest a complex CO2 formation scenario with multiple epochs and mechanisms. At early stages in the molecular cloud, CO2 could form concurrently with H2 O via the OH radical pathway investigated here. This produces the CO2 com ...
The Properties of Super Star Clusters in A Sample of
... regimes. Using optical photometry, I estimate the ages and masses, as well as construct luminosity functions for the super star cluster systems. Additional H observations allow me to place tighter constraints on the burst ages and trace very recent star formation. The super star clusters ...
... regimes. Using optical photometry, I estimate the ages and masses, as well as construct luminosity functions for the super star cluster systems. Additional H observations allow me to place tighter constraints on the burst ages and trace very recent star formation. The super star clusters ...
The extinction map of the OMC-1 molecular cloud behind the Orion
... A number of previous studies provide results relevant to the issue of the galactic reddening in the direction of OMC-1. Schlegel et al. (1998) (SFD98 hereafter) combined the COBE/DIRBE observations (100 μm and 240 μm) and the IRAS/ISSA observations (100 μm) to obtain a full-sky 100 μm map with ∼6 r ...
... A number of previous studies provide results relevant to the issue of the galactic reddening in the direction of OMC-1. Schlegel et al. (1998) (SFD98 hereafter) combined the COBE/DIRBE observations (100 μm and 240 μm) and the IRAS/ISSA observations (100 μm) to obtain a full-sky 100 μm map with ∼6 r ...
Systematic variation in the apparent burning area of thermonuclear
... due to the scattering of photons by the electrons in a neutron star atmosphere. From equation (3) we see that for a given source with fixed z, R 2∞ can change only if the colour factor f changes, and/or the actual burning region area (∝ R 2BB ) evolves, perhaps in combination with the change in the ...
... due to the scattering of photons by the electrons in a neutron star atmosphere. From equation (3) we see that for a given source with fixed z, R 2∞ can change only if the colour factor f changes, and/or the actual burning region area (∝ R 2BB ) evolves, perhaps in combination with the change in the ...
Turbulence-driven Polar Winds from T Tauri Stars Energized by
... What sets the Sun’s mass loss? • Coronal heating must be ultimately responsible for the solar wind. • A fraction of the “coronal heating” is channeled downward by conduction. • Hammer (1982) & Withbroe (1988) suggested a balance between conduction (downward), enthalpy (upward), and radiation losses ...
... What sets the Sun’s mass loss? • Coronal heating must be ultimately responsible for the solar wind. • A fraction of the “coronal heating” is channeled downward by conduction. • Hammer (1982) & Withbroe (1988) suggested a balance between conduction (downward), enthalpy (upward), and radiation losses ...
Astronomy Astrophysics Gaia-ESO Survey: The analysis of high-resolution The
... are needed to homogenize the final results, correcting systematic effects where needed. This additional step is taken to ensure that the results for early- and late-type stars, for dwarfs, giants, and pre-main-sequence stars are all on a single consistent scale. This Survey wide homogenization proces ...
... are needed to homogenize the final results, correcting systematic effects where needed. This additional step is taken to ensure that the results for early- and late-type stars, for dwarfs, giants, and pre-main-sequence stars are all on a single consistent scale. This Survey wide homogenization proces ...
The birth rate of subluminous and overluminous type Ia supernovae
... subluminous SNe Ia from equal-mass DD systems is between 0.1 and 0.3 Gyr for α-formalism with α = 3.0, but longer than 9 Gyr for α = 1.0. The range of the delay time for γ-algorithm is very wide, i.e. longer than 0.22 Gyr, even as long as 15 Gyr. The subluminous SNe Ia from equal-mass DD systems may ...
... subluminous SNe Ia from equal-mass DD systems is between 0.1 and 0.3 Gyr for α-formalism with α = 3.0, but longer than 9 Gyr for α = 1.0. The range of the delay time for γ-algorithm is very wide, i.e. longer than 0.22 Gyr, even as long as 15 Gyr. The subluminous SNe Ia from equal-mass DD systems may ...
Stellar evolution
Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star.Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.