Fundamentals in Nuclear Physics
... accelerators of Berkeley, Caen, Darmstadt and Dubna continue to produce new nuclei whose characteristics challenge models of nuclear structure. It has major technological applications, most notably in medicine and in energy production where a knowledge of some nuclear physics is essential for partic ...
... accelerators of Berkeley, Caen, Darmstadt and Dubna continue to produce new nuclei whose characteristics challenge models of nuclear structure. It has major technological applications, most notably in medicine and in energy production where a knowledge of some nuclear physics is essential for partic ...
Analysis of cool DO-type white dwarfs from the Sloan Digital Sky
... absorption lines. Our non-LTE model atmosphere analyses of these objects and two not previously analyzed hot-wind DO WDs, revealed effective temperatures and gravities in the ranges T eff = 45−80 kK and log g = 7.50−8.75. In eight of the spectra we found traces of C (0.001−0.01, by mass). Two of these ...
... absorption lines. Our non-LTE model atmosphere analyses of these objects and two not previously analyzed hot-wind DO WDs, revealed effective temperatures and gravities in the ranges T eff = 45−80 kK and log g = 7.50−8.75. In eight of the spectra we found traces of C (0.001−0.01, by mass). Two of these ...
Evolution of Stars and Stellar Populations
... those properties that are needed to understand and apply the methods discussed in the rest of the book, that is, the evolution with time of the photometric and chemical properties (i.e. evolution of effective temperatures, luminosities, surface chemical abundances) of stars, as a function of their i ...
... those properties that are needed to understand and apply the methods discussed in the rest of the book, that is, the evolution with time of the photometric and chemical properties (i.e. evolution of effective temperatures, luminosities, surface chemical abundances) of stars, as a function of their i ...
Early Star-Forming Galaxies and the Reionisation of the Universe
... study of the earliest-known galaxies corresponding to a period when the Universe was only ~800 million years old. Intense ultraviolet radiation from these early galaxies probably induced a major event in cosmic history: the reionisation of intergalactic hydrogen. New techniques are being developed t ...
... study of the earliest-known galaxies corresponding to a period when the Universe was only ~800 million years old. Intense ultraviolet radiation from these early galaxies probably induced a major event in cosmic history: the reionisation of intergalactic hydrogen. New techniques are being developed t ...
Dust in Proto-Planetary Disks: Properties and Evolution
... with very different mass and luminosity, from intermediatemass objects (Herbig AeBe stars, or HAeBe in the following) to T Tauri stars (TTS) and brown dwarfs (BDs). On the theoretical side, there is a revived effort in modeling grain processing in disks (via coalescence, sedimentation, fragmentation ...
... with very different mass and luminosity, from intermediatemass objects (Herbig AeBe stars, or HAeBe in the following) to T Tauri stars (TTS) and brown dwarfs (BDs). On the theoretical side, there is a revived effort in modeling grain processing in disks (via coalescence, sedimentation, fragmentation ...
Dust in Proto-Planetary Disks: Properties and Evolution
... with very different mass and luminosity, from intermediatemass objects (Herbig AeBe stars, or HAeBe in the following) to T Tauri stars (TTS) and brown dwarfs (BDs). On the theoretical side, there is a revived effort in modeling grain processing in disks (via coalescence, sedimentation, fragmentation ...
... with very different mass and luminosity, from intermediatemass objects (Herbig AeBe stars, or HAeBe in the following) to T Tauri stars (TTS) and brown dwarfs (BDs). On the theoretical side, there is a revived effort in modeling grain processing in disks (via coalescence, sedimentation, fragmentation ...
Annual Report 2014 - Max Planck Institute for Astrophysics
... particles, and the calculation of transition probThe Max-Planck-Institut für Astrophysik, usually abilities and cross–sections for astrophysical procalled MPA for short, was founded in 1958 under cesses in rarefied media. From its inception the the directorship of Ludwig Biermann. It was estab- MPA h ...
... particles, and the calculation of transition probThe Max-Planck-Institut für Astrophysik, usually abilities and cross–sections for astrophysical procalled MPA for short, was founded in 1958 under cesses in rarefied media. From its inception the the directorship of Ludwig Biermann. It was estab- MPA h ...
Stars as cosmological tools: giving light to Dark Matter
... the DM problem, the identication of its nature remains elusive. In this Thesis we propose a complementary approach to present DM searches: the use of the properties of stars to investigate the nature of DM. We studied the capture and self-annihilation of DM particles on the cores of low-mass stars ...
... the DM problem, the identication of its nature remains elusive. In this Thesis we propose a complementary approach to present DM searches: the use of the properties of stars to investigate the nature of DM. We studied the capture and self-annihilation of DM particles on the cores of low-mass stars ...
Variability of young solar-type stars: Spot cycles, rotation
... akin to the 11 year spot cycle of the Sun, and other possible regularities present in the distribution of the starspots. Measurements of the chromospheric emission level by high resolution spectroscopy will furthermore directly provide useful estimates of the activity level of a star. Despite the fa ...
... akin to the 11 year spot cycle of the Sun, and other possible regularities present in the distribution of the starspots. Measurements of the chromospheric emission level by high resolution spectroscopy will furthermore directly provide useful estimates of the activity level of a star. Despite the fa ...
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 ...
Theory of Motion of Matter on the Formation of Galaxy and Star
... Way Galaxy will not have been the current state, but a huge solid celestial body formed by the gathering of all material celestial bodies in Milky Way Galaxy. Only the energy change of relative motion among numerous material particles can produce material systems independent to each other. At the in ...
... Way Galaxy will not have been the current state, but a huge solid celestial body formed by the gathering of all material celestial bodies in Milky Way Galaxy. Only the energy change of relative motion among numerous material particles can produce material systems independent to each other. At the in ...
Chemical gradients in the Milky Way from the RAVE data
... The magnitude and spatial distributions of the RAVE sample may generate observational biases that can lead to misinterpretations. To avoid this, we created an equivalent mock sample with the stellar population synthesis code GALAXIA (Sharma et al. 2011), which uses analytical density profiles based ...
... The magnitude and spatial distributions of the RAVE sample may generate observational biases that can lead to misinterpretations. To avoid this, we created an equivalent mock sample with the stellar population synthesis code GALAXIA (Sharma et al. 2011), which uses analytical density profiles based ...
Leaky Stars: Pulsations, Waves, and Turbulence in Stellar Winds
... • When a subsonic wind is considered, ALL frequencies are able to propagate! Leaky Stars: Pulsations, Waves, and Turbulence in Stellar Winds across the H-R Diagram ...
... • When a subsonic wind is considered, ALL frequencies are able to propagate! Leaky Stars: Pulsations, Waves, and Turbulence in Stellar Winds across the H-R Diagram ...
400 YEARS OF STELLAR ROTATION - DFTE
... S01: Pre-main Sequence and Low Mass Stars (chair: Alejandra Recio-Blanco) 09:00 - 09:45 Jerome Bouvier (invited review): Angular momentum evolution of solar-type stars, low-mass stars and brown dwarfs: observations and models 09:45 - 10:05 Silvia Alencar (invited): Magnetometry of T Tauri Stars, dyn ...
... S01: Pre-main Sequence and Low Mass Stars (chair: Alejandra Recio-Blanco) 09:00 - 09:45 Jerome Bouvier (invited review): Angular momentum evolution of solar-type stars, low-mass stars and brown dwarfs: observations and models 09:45 - 10:05 Silvia Alencar (invited): Magnetometry of T Tauri Stars, dyn ...
Astronomy Astrophysics Kuiper belts around nearby stars &
... and submillimetre emission compared to that expected from stellar photospheres, suggests that leftover planetesimal belts analogous to the asteroid- and comet reservoirs of the solar system are common. Aims. Sensitive submillimetre observations are essential to detect and characterise cold extended ...
... and submillimetre emission compared to that expected from stellar photospheres, suggests that leftover planetesimal belts analogous to the asteroid- and comet reservoirs of the solar system are common. Aims. Sensitive submillimetre observations are essential to detect and characterise cold extended ...
Zhu Qualifier Solutions - University of Toronto Astronomy
... 3.1.1. What is the IMF useful for? 3.1.2. Is there a universal IMF? 3.1.3. Why are the lower and upper limits of the IMF poorly understood compared to that of the middle (several M stars)? What constraints are there? 3.1.4. What’s the difference between a field and stellar cluster IMF? 3.1.5. How d ...
... 3.1.1. What is the IMF useful for? 3.1.2. Is there a universal IMF? 3.1.3. Why are the lower and upper limits of the IMF poorly understood compared to that of the middle (several M stars)? What constraints are there? 3.1.4. What’s the difference between a field and stellar cluster IMF? 3.1.5. How d ...
The Lagoon Nebula and its Vicinity
... can be seen in maps of CO 1–0 (Lada et al. 1976) and far-IR continuum emission (Lightfoot et al. 1984), both with resolutions of 1′ –2′ . Lada et al. found 3 bright spots, BS 1–3: The most prominent (BS 1) corresponds to the inner core of the H II region, centred on the Hourglass (clump HG and surro ...
... can be seen in maps of CO 1–0 (Lada et al. 1976) and far-IR continuum emission (Lightfoot et al. 1984), both with resolutions of 1′ –2′ . Lada et al. found 3 bright spots, BS 1–3: The most prominent (BS 1) corresponds to the inner core of the H II region, centred on the Hourglass (clump HG and surro ...
Chapter 6 in the LSST Science Book
... complex is essential for understanding the early history of these objects and their place in the ΛCDM hierarchy. In our Galaxy the most metal poor, and (plausibly) the oldest observed stars are distributed in a halo that extends beyond 25 kpc. Their spatial distribution, chemical composition and kin ...
... complex is essential for understanding the early history of these objects and their place in the ΛCDM hierarchy. In our Galaxy the most metal poor, and (plausibly) the oldest observed stars are distributed in a halo that extends beyond 25 kpc. Their spatial distribution, chemical composition and kin ...
The Nuclear Equation of State and Neutron Star Masses
... nd /d n = + p. Beginning from the center, where m = r = 0, p = p c , and ε = εc , these equations are integrated to the surface, where p = p surf = 0, r = R, and m = M. For hadronic EOSs, εsurf = 0, but this is not the case for pure strange quark matter (SQM) stars, for which the energy density r ...
... nd /d n = + p. Beginning from the center, where m = r = 0, p = p c , and ε = εc , these equations are integrated to the surface, where p = p surf = 0, r = R, and m = M. For hadronic EOSs, εsurf = 0, but this is not the case for pure strange quark matter (SQM) stars, for which the energy density r ...
the red supergiant content of m31
... massive star population suggests that only a few percent of the total number O stars and B supergiants have been identified (Massey et al. 2016). In this paper we set out to complete our identification of the RSG population of M31 down to ∼15Me, using a combination of spectroscopy and photometry. Mass ...
... massive star population suggests that only a few percent of the total number O stars and B supergiants have been identified (Massey et al. 2016). In this paper we set out to complete our identification of the RSG population of M31 down to ∼15Me, using a combination of spectroscopy and photometry. Mass ...
Investigating the Spectral Energy Distribution TARA JILL PARKIN
... In particular, the present-day structure of the ISM of a galaxy is strongly dependent on the evolution of its star formation rate (SFR). Clues as to previous episodes of star formation rates can be found in the various stellar populations within the galaxy (Tielens, 1995). Low-mass stars with long l ...
... In particular, the present-day structure of the ISM of a galaxy is strongly dependent on the evolution of its star formation rate (SFR). Clues as to previous episodes of star formation rates can be found in the various stellar populations within the galaxy (Tielens, 1995). Low-mass stars with long l ...
Star Formation and Dynamics in the Galactic Centre
... The first attempts to estimate the mass enclosed in the central parsec are radial velocity measurements of ionized gas located in the structure which is known as minispiral (Lacy et al. 1980). On the other hand, the radial velocity of ionized gas may be affected by a plethora of processes besides gr ...
... The first attempts to estimate the mass enclosed in the central parsec are radial velocity measurements of ionized gas located in the structure which is known as minispiral (Lacy et al. 1980). On the other hand, the radial velocity of ionized gas may be affected by a plethora of processes besides gr ...
how dry is the brown dwarf desert? quantifying the
... zone and stay there (e.g., Udry et al. 2003). Various types of migration have been proposed to meet this challenge. The most important factors in determining the result of the migration is the time of formation and mass of the secondary and its relation to the mass and time evolution of the disk (e. ...
... zone and stay there (e.g., Udry et al. 2003). Various types of migration have been proposed to meet this challenge. The most important factors in determining the result of the migration is the time of formation and mass of the secondary and its relation to the mass and time evolution of the disk (e. ...
Chapter 12
... Discovering a Pattern, continued • Predicting Properties of Missing Elements Mendeleev’s arrangement had gaps in its pattern. Mendeleev predicted that elements yet to be found would fill these gaps. He also predicted the properties of the missing elements. • By 1886, all of the gaps had been filled ...
... Discovering a Pattern, continued • Predicting Properties of Missing Elements Mendeleev’s arrangement had gaps in its pattern. Mendeleev predicted that elements yet to be found would fill these gaps. He also predicted the properties of the missing elements. • By 1886, all of the gaps had been filled ...
Hypervelocity Stars and the Galactic Center
... conclusive evidence of origin, however. A- and B-type stars exhibit 0.5 - 1 dex scatter in elemental abundances within a single cluster, due to gravitational settling and radiative levitation in the atmospheres of the stars (Varenne & Monier 1999; Monier 2005; Fossati et al. 2007; Gebran et al. 2008 ...
... conclusive evidence of origin, however. A- and B-type stars exhibit 0.5 - 1 dex scatter in elemental abundances within a single cluster, due to gravitational settling and radiative levitation in the atmospheres of the stars (Varenne & Monier 1999; Monier 2005; Fossati et al. 2007; Gebran et al. 2008 ...
Nucleosynthesis
Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons, primarily protons and neutrons. The first nuclei were formed about three minutes after the Big Bang, through the process called Big Bang nucleosynthesis. It was then that hydrogen and helium formed to become the content of the first stars, and this primeval process is responsible for the present hydrogen/helium ratio of the cosmos.With the formation of stars, heavier nuclei were created from hydrogen and helium by stellar nucleosynthesis, a process that continues today. Some of these elements, particularly those lighter than iron, continue to be delivered to the interstellar medium when low mass stars eject their outer envelope before they collapse to form white dwarfs. The remains of their ejected mass form the planetary nebulae observable throughout our galaxy.Supernova nucleosynthesis within exploding stars by fusing carbon and oxygen is responsible for the abundances of elements between magnesium (atomic number 12) and nickel (atomic number 28). Supernova nucleosynthesis is also thought to be responsible for the creation of rarer elements heavier than iron and nickel, in the last few seconds of a type II supernova event. The synthesis of these heavier elements absorbs energy (endothermic) as they are created, from the energy produced during the supernova explosion. Some of those elements are created from the absorption of multiple neutrons (the R process) in the period of a few seconds during the explosion. The elements formed in supernovas include the heaviest elements known, such as the long-lived elements uranium and thorium.Cosmic ray spallation, caused when cosmic rays impact the interstellar medium and fragment larger atomic species, is a significant source of the lighter nuclei, particularly 3He, 9Be and 10,11B, that are not created by stellar nucleosynthesis.In addition to the fusion processes responsible for the growing abundances of elements in the universe, a few minor natural processes continue to produce very small numbers of new nuclides on Earth. These nuclides contribute little to their abundances, but may account for the presence of specific new nuclei. These nuclides are produced via radiogenesis (decay) of long-lived, heavy, primordial radionuclides such as uranium and thorium. Cosmic ray bombardment of elements on Earth also contribute to the presence of rare, short-lived atomic species called cosmogenic nuclides.