The surface signature of the tidal dissipation of the core in a two
... Hubbard et al. (2009) for Saturn, from which we are able to build two-layer synthetic planetary models with a dense central icy/rocky core and a fluid envelope made of hydrogen and helium: – Jupiter-like: RJc = 0.126 × RJp and McJ = 6.41 × M⊕ , – Saturn-like: RSc = 0.219 × RSp and McS = 18.65 × M⊕ , ...
... Hubbard et al. (2009) for Saturn, from which we are able to build two-layer synthetic planetary models with a dense central icy/rocky core and a fluid envelope made of hydrogen and helium: – Jupiter-like: RJc = 0.126 × RJp and McJ = 6.41 × M⊕ , – Saturn-like: RSc = 0.219 × RSp and McS = 18.65 × M⊕ , ...
Chandra Characterization of X-ray Emission in the Young F
... 113766A+B spectrum, extracted over both sources with an r=20 pixel circular aperture. The combined spectrum is shown in Figure 3a, and is rather soft. We estimate a total HD 113766 A+B system luminosity of Lx = 2.2 x 1029 erg s-1. We also extracted separate spectra for the “West” and “East” sources, ...
... 113766A+B spectrum, extracted over both sources with an r=20 pixel circular aperture. The combined spectrum is shown in Figure 3a, and is rather soft. We estimate a total HD 113766 A+B system luminosity of Lx = 2.2 x 1029 erg s-1. We also extracted separate spectra for the “West” and “East” sources, ...
Astrophysics for Physicists.
... Sciences as well as our Joint Astronomy and Astrophysics Programme. I must have taught this course to more than half a dozen batches. Over the years, several excellent textbooks suitable for use in one-semester courses on particle physics and solid state physics have been written. The situation with ...
... Sciences as well as our Joint Astronomy and Astrophysics Programme. I must have taught this course to more than half a dozen batches. Over the years, several excellent textbooks suitable for use in one-semester courses on particle physics and solid state physics have been written. The situation with ...
Tracers of Discs and Winds around Intermediate and High Mass
... have additional opacity due to dust, but a similar partially ionised zone will exist within them. Fluorescent excitation typically occurs when an atom/ion is irradiated by either UV continuum or Lyman series photons. The excited atom/ion cascades back down to the ground state, leading to transitions ...
... have additional opacity due to dust, but a similar partially ionised zone will exist within them. Fluorescent excitation typically occurs when an atom/ion is irradiated by either UV continuum or Lyman series photons. The excited atom/ion cascades back down to the ground state, leading to transitions ...
Project Description - SDSS-III
... Universe imprint a characteristic scale on the clustering of dark matter, galaxies, and intergalactic gas. By measuring this scale with tracers seen at different redshifts, we can create a “Hubble diagram” of unprecedented precision covering most of cosmic history and can thereby pin down the prope ...
... Universe imprint a characteristic scale on the clustering of dark matter, galaxies, and intergalactic gas. By measuring this scale with tracers seen at different redshifts, we can create a “Hubble diagram” of unprecedented precision covering most of cosmic history and can thereby pin down the prope ...
Annual Report 2006/2007
... contain relics which are clues to their formation? What are the influences of the environment, of nuclear activity, and of the original large-scale distribution of dark matter? What is the role of massive black holes in galactic nuclei? • Network 2: Formation of stars and planetary systems New star ...
... contain relics which are clues to their formation? What are the influences of the environment, of nuclear activity, and of the original large-scale distribution of dark matter? What is the role of massive black holes in galactic nuclei? • Network 2: Formation of stars and planetary systems New star ...
Chapter 16
... dust content and some are more “active” than others • Galaxies tend to cluster together and these clusters appear to be separating from each other, caught up in a Universe that is expanding • The why for all this diversity is as yet unanswered ...
... dust content and some are more “active” than others • Galaxies tend to cluster together and these clusters appear to be separating from each other, caught up in a Universe that is expanding • The why for all this diversity is as yet unanswered ...
The science case for - Astrophysics
... of which we are made. Perhaps most exotic of all, some new force seems to be stretching space-time, accelerating the expansion of the Universe. The nature of this force, which controls the future of the Universe, remains quite unknown. Astronomy is a technology-enabled science: progress in astronom ...
... of which we are made. Perhaps most exotic of all, some new force seems to be stretching space-time, accelerating the expansion of the Universe. The nature of this force, which controls the future of the Universe, remains quite unknown. Astronomy is a technology-enabled science: progress in astronom ...
adc - VizieR
... edition (constellations Andromeda-Vulpecula), although two additional volumes of the published catalog are planned. The machine version contains the same data as in the first three volumes of the printed catalog, but only the data tables without the textual material (introduction, bibliography, rema ...
... edition (constellations Andromeda-Vulpecula), although two additional volumes of the published catalog are planned. The machine version contains the same data as in the first three volumes of the printed catalog, but only the data tables without the textual material (introduction, bibliography, rema ...
The Milky Way-Pulsars and Isolated Neutron Stars
... 8 The Milky Way − Pulsars and Isolated Neutron Stars 8.1 Introduction: Historical Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2 Physics and Astrophysics of Isolated Neutron Stars . . . . . . . . . . . . . . . . . . 8.2.1 Rotation-powered Pulsars: The Magnetic Braking Model . . ...
... 8 The Milky Way − Pulsars and Isolated Neutron Stars 8.1 Introduction: Historical Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2 Physics and Astrophysics of Isolated Neutron Stars . . . . . . . . . . . . . . . . . . 8.2.1 Rotation-powered Pulsars: The Magnetic Braking Model . . ...
Ch17_lecture
... dust content and some are more “active” than others • Galaxies tend to cluster together and these clusters appear to be separating from each other, caught up in a Universe that is expanding • The reason for all this diversity is as yet unanswered ...
... dust content and some are more “active” than others • Galaxies tend to cluster together and these clusters appear to be separating from each other, caught up in a Universe that is expanding • The reason for all this diversity is as yet unanswered ...
Chapter 17 Galaxies Galaxies Early Observations
... – Cold gas because this gas would be detectable at radio wavelengths – Hot gas would be detectable in the optical, radio, and x-ray regions of the spectrum ...
... – Cold gas because this gas would be detectable at radio wavelengths – Hot gas would be detectable in the optical, radio, and x-ray regions of the spectrum ...
the harps-terra project. i. description of the algorithms, performance
... multiplying the stellar spectrum by a weighted binary mask and finding the minimum of the product as a function of the Doppler shift. It is known that CCF is suboptimal in exploiting the Doppler information in the stellar spectrum. Here we describe an algorithm to obtain precision radial velocity me ...
... multiplying the stellar spectrum by a weighted binary mask and finding the minimum of the product as a function of the Doppler shift. It is known that CCF is suboptimal in exploiting the Doppler information in the stellar spectrum. Here we describe an algorithm to obtain precision radial velocity me ...
The Tip of the Red Giant Branch and Distance of the Magellanic
... in order to suppress one step which already makes an assumption on the spectral distribution of the source. We only use the integrated flux measured over the J and KS DENIS passbands. Theoretical spectral distributions, i.e. blackbodies with temperatures ranging from 10, 000 to 300 K and the models ...
... in order to suppress one step which already makes an assumption on the spectral distribution of the source. We only use the integrated flux measured over the J and KS DENIS passbands. Theoretical spectral distributions, i.e. blackbodies with temperatures ranging from 10, 000 to 300 K and the models ...
IGR J18483-0311: a new intermediate supergiant fast X
... optical and NIR magnitudes are listed in Table 1. It is worth noting that our optical magnitudes are about 1 magnitude lower than those given in the USNO catalogue, this difference probably due to the strong uncertainty (≥ 1 magnitude) of the USNO magnitudes for very faint sources (≥17 in the B band ...
... optical and NIR magnitudes are listed in Table 1. It is worth noting that our optical magnitudes are about 1 magnitude lower than those given in the USNO catalogue, this difference probably due to the strong uncertainty (≥ 1 magnitude) of the USNO magnitudes for very faint sources (≥17 in the B band ...
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.