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Zhu Qualifier Solutions - University of Toronto Astronomy
Zhu Qualifier Solutions - University of Toronto Astronomy

... 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 do you determine an a present-day mass function (PDMF) from an IMF? 3 ...
3D LTE spectral line formation with scattering in red giant stars
3D LTE spectral line formation with scattering in red giant stars

90377 Sedna
90377 Sedna

Satta Suriya Sutta
Satta Suriya Sutta

Does feedback help or hinder star formation? The effect of
Does feedback help or hinder star formation? The effect of

... (Górski et al. 2005). Each star particle has an ionising luminosity of 3 × 1046 ph/s/M⊙ (Schaerer 2003). This value assumes solar metallicity and a Salpeter initial mass function between 1 − 100 M⊙ . Within this range, the IMF gradient does not depend strongly on model choice, for example giving a ...
DISSERTATION
DISSERTATION

... distribution. Studying AGB stellar atmospheres is essential for a better comprehension of the late stage of stellar evolution, to understand the complicate influence of pulsation on the stellar atmosphere, the dynamic process of dust formation and mass loss. Due to their extended atmospheres and bri ...
Chapter 7 Elliptical Galaxies Chapter 16 Elliptical Galaxies
Chapter 7 Elliptical Galaxies Chapter 16 Elliptical Galaxies

... 7.1.4 Central regions of elliptical galaxies and bulges They are important for the dynamical structure (population of stellar orbits, see below) of ellipticals and probably all bulges and ellipticals host supermassive black holes (see below). The structure of the central regions seems intimately lin ...
Dust temperature maps of the Galactic plane: The Herschel spectral
Dust temperature maps of the Galactic plane: The Herschel spectral

... T dust is dust temperature, and β is the emissivity spectral index that modifies the blackbody emission. Boulanger et al. (1996) found that β = 2 for the solar neighborhood derived from diffuse FIR emission, which is measured by Diffuse InfraRed Background Experiment (DIRBE) and Far InfraRed Absolute ...
Exoplanetary Atmospheres
Exoplanetary Atmospheres

... In systems with multiple gravitationally interacting transiting planets, masses can also be estimated from the measured transit timing variations (Agol et al. 2005; Holman and Murray 2005; Lithwick et al. 2012). For directly imaged planets, masses and radii are typically constrained as part of a glo ...
The First Galaxies: Assembly under Radiative Feedback from the
The First Galaxies: Assembly under Radiative Feedback from the

... heats the gas inside the first halos and the intergalactic medium (IGM). The associated increase in pressure drives the gas outside halos with virial temperatures . 104 K, suppressing star formation in both minihalos and the first atomic cooling halos (e.g., Thoul & Weinberg 1996; Barkana & Loeb 199 ...
Galactic Evolution of Silicon Isotopes: Application to Presolar SiC
Galactic Evolution of Silicon Isotopes: Application to Presolar SiC

... carbonaceous meteorites, has opened unique views on stellar nucleosynthesis, star-formation processes, local mixing processes in the interstellar medium (henceforth ISM), and chemical evolution (Clayton 1982). The most clearcut cases involve grains possessing such large isotopic anomalies that they ...
Persistence of the Gleissberg 88-year solar cycle over
Persistence of the Gleissberg 88-year solar cycle over

... whole-range 8000-year record by Lin et al. [1975] provides a good indication of the periodicity in the region of 80 years whereas another analysis of the post-700 A.D. rates of 14C production did not indicate any spectral power increase in the 60– 100-year period range. In another work on spectral a ...
On some properties of coronal mass ejections in solar cycle 23
On some properties of coronal mass ejections in solar cycle 23

The VLT LEGA-C Spectroscopic Survey: The Physics of Galaxies at
The VLT LEGA-C Spectroscopic Survey: The Physics of Galaxies at

... typically well over 5 Gyr and it is difficult to resolve star formation histories from integrated spectra. Now LEGA-C is obtaining spectra of similar quality for ∼3200 K-band selected galaxies in the redshift range 0.6 < z < 1.0, at a look-back time of 6 − 8 Gyr. LEGA-C is a 4-year, 128-night Public ...
Foreword You`ll notice here that I hardly make mention of gravity, if
Foreword You`ll notice here that I hardly make mention of gravity, if

Latitudinal and radial gradients of galactic cosmic ray protons in the
Latitudinal and radial gradients of galactic cosmic ray protons in the

... experiment was launched on 15 June 2006 and is continuously collecting data since then. The apparatus measures electrons, positrons, protons, anti-protons and heavier nuclei from about 100 MeV to several hundreds of GeV. Thus the combination of Ulysses and PAMELA measurements is ideally suited to de ...
astronomy and the limits of vision
astronomy and the limits of vision

... population sets its festivals and fast periods by the visibility of the thin crescent moon and times its daily prayers on astronomical events. The ancient Egyptians, Mayans, and Aztecs based their calendars and festivals on the heliacal risings of Sirius, Venus, and the Pleiades. Neolithic man appar ...
Astronomy Astrophysics - Max Planck Institut für Radioastronomie
Astronomy Astrophysics - Max Planck Institut für Radioastronomie

... continuum region (Malbet et al. 2007). Surprisingly, observations on the less luminous Herbig Ae star HD 104237 did not show any change in visibility along the Brγ line (Tatulli et al. 2007a). Eisner (2007) found a visibility increase within the Brγ line for the Herbig Ae star MWC 480. This might su ...
The Formation of Massive Stars - Max-Planck
The Formation of Massive Stars - Max-Planck

Galactic Evolution of Silicon Isotopes: Applications to
Galactic Evolution of Silicon Isotopes: Applications to

... We calculate and discuss the chemical evolution of the isotopic silicon abundances in the interstellar medium (ISM) at distances and times appropriate to the birth of the solar system. This has several objectives, some of which are related to anomalous silicon isotope ratios within presolar grains e ...
Gamma-ray burst investigation via polarimetry and spectroscopy
Gamma-ray burst investigation via polarimetry and spectroscopy

... in the γ -ray range. The most prominent and astrophysically relevant are the nuclear excitation and Pygmy resonances (element-specific narrow lines between 5–9 MeV), the Giant Dipole resonance (GDR; proton versus neutron fluid oscillations; ∼25 MeV; two nucleons and more) and the Delta-resonance (in ...
Stars, neutral hydrogen and ionised gas in early
Stars, neutral hydrogen and ionised gas in early

... as 5.9×109 M . On the basis of these observations, we included IC 4200 in our sample for the study of the relation between stellar and H i properties in early-type galaxies. We characterised the environment of IC 4200 by looking for extragalactic objects within 100 arcmin (∼1.6 Mpc at this redshift ...
Near-uniform internal rotation of the main sequence γ Doradus
Near-uniform internal rotation of the main sequence γ Doradus

... the efficiency of various transport mechanisms have been renewed (Tayar & Pinsonneault 2013; Fuller et al. 2014). Magnetism is one such angular momentum transport mechanism that has seen a recent revival of interest. Cantiello et al. (2014) showed that magnetic torques in radiative regions cannot si ...
University of Groningen Photo-ionization studies of nebulae
University of Groningen Photo-ionization studies of nebulae

THE DYNAMICAL STRUCTURE AND EVOLUTION OF GIANT
THE DYNAMICAL STRUCTURE AND EVOLUTION OF GIANT

... The term on the LHS reects variations in the rate of change of the size and shape of the cloud. This term is usually neglected, but it may be signicant for a turbulent cloud. In contrast to the terms on the RHS of the equation, it can be of either sign, and as a result its eects can be averaged o ...
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Standard solar model

The standard solar model (SSM) is a mathematical treatment of the Sun as a spherical ball of gas (in varying states of ionisation, with the hydrogen in the deep interior being a completely ionised plasma). This model, technically the spherically symmetric quasi-static model of a star, has stellar structure described by several differential equations derived from basic physical principles. The model is constrained by boundary conditions, namely the luminosity, radius, age and composition of the Sun, which are well determined. The age of the Sun cannot be measured directly; one way to estimate it is from the age of the oldest meteorites, and models of the evolution of the Solar System. The composition in the photosphere of the modern-day Sun, by mass, is 74.9% hydrogen and 23.8% helium. All heavier elements, called metals in astronomy, account for less than 2 percent of the mass. The SSM is used to test the validity of stellar evolution theory. In fact, the only way to determine the two free parameters of the stellar evolution model, the helium abundance and the mixing length parameter (used to model convection in the Sun), are to adjust the SSM to ""fit"" the observed Sun.
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