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 ...
... 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 ...
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 ...
... (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
... 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 ...
... 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
... 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 ...
... 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
... 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 ...
... 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
... 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 ...
... 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
... 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 ...
... 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
... 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 ...
... 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
... 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 ...
... 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 ...
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 ...
... 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 ...
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 ...
... 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
... 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 ...
... 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
... 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 ...
... 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 ...
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 ...
... 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
... 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 ...
... 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
... 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 ...
... 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
... 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 ...
... 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 ...
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 ...
... 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 ...