Astronomy Astrophysics Spectral energy distributions of an AKARI-SDSS-GALEX sample of galaxies
... Methods. A sample of 363 galaxies is built from the AKARI /FIS all sky survey cross-correlated with the SDSS and GALEX surveys. Broad-band spectral energy distributions are fitted with the CIGALE code optimized to analyse variations in the dust attenuation curves and SFR measurements and based on an ...
... Methods. A sample of 363 galaxies is built from the AKARI /FIS all sky survey cross-correlated with the SDSS and GALEX surveys. Broad-band spectral energy distributions are fitted with the CIGALE code optimized to analyse variations in the dust attenuation curves and SFR measurements and based on an ...
Introduction to Observational Cosmology
... 3. (?) the universe expanded from a very dense, hot initial state (=big bang) 4. The expansion of the universe is determined by its mass/energy content and the laws of General Relativity 5. On “small scales” (<10-100 Mpc) a great deal of structure has formed through gravitational self-organization. ...
... 3. (?) the universe expanded from a very dense, hot initial state (=big bang) 4. The expansion of the universe is determined by its mass/energy content and the laws of General Relativity 5. On “small scales” (<10-100 Mpc) a great deal of structure has formed through gravitational self-organization. ...
Chemical analysis of 24 dusty (pre-) main
... Despite the broad wavelength coverage, for several program stars only a few lines turned out to be appropriate for detailed abundance analyses. Such a circumstance is not unusual for A/B-type stars, where the condition that spectral lines with equivalent widths higher than 150 mÅ should be avoided i ...
... Despite the broad wavelength coverage, for several program stars only a few lines turned out to be appropriate for detailed abundance analyses. Such a circumstance is not unusual for A/B-type stars, where the condition that spectral lines with equivalent widths higher than 150 mÅ should be avoided i ...
KIC 10449976: discovery of an extreme helium
... a CuNe+CuAr arc taken shortly after the object spectrum was taken. A flux standard was observed so that the spectra could be flux calibrated. The individual spectra were combined to give a mean spectrum which shows all the characteristics of a helium-rich star (Fig. 1), including all expected He I l ...
... a CuNe+CuAr arc taken shortly after the object spectrum was taken. A flux standard was observed so that the spectra could be flux calibrated. The individual spectra were combined to give a mean spectrum which shows all the characteristics of a helium-rich star (Fig. 1), including all expected He I l ...
... Question-Answer Book. Do not write in the margins. Answers written in the margins will not be marked. Supplementary answer sheets will be provided on request. Write your Candidate Number, mark the question number box and stick a barcode label on each sheet. Tie them loosely but securely with a ...
Behavior of Li abundances in solar-analog stars
... (2006) questioned its reality. If the Li abundance at the stellar surface depends on whether a star has a planet or not, what physical process is involved? Third, ALi in the Sun appears to be located nearly at the lowest end (i.e., an outlier) in the considerable spread exhibited by similar solar-ty ...
... (2006) questioned its reality. If the Li abundance at the stellar surface depends on whether a star has a planet or not, what physical process is involved? Third, ALi in the Sun appears to be located nearly at the lowest end (i.e., an outlier) in the considerable spread exhibited by similar solar-ty ...
Chemical composition of 90 F and G disk dwarfs
... than stars with Rm > 9 kpc, indicating a higher star formation rate (SFR) in the inner disk than that in the outer disk. Since essentially all the oldest stars in EAGLNT have small Rm , it is, however, difficult to know upon which, Rm or age, the main dependence of [α/Fe] is. (4) At a given age and ...
... than stars with Rm > 9 kpc, indicating a higher star formation rate (SFR) in the inner disk than that in the outer disk. Since essentially all the oldest stars in EAGLNT have small Rm , it is, however, difficult to know upon which, Rm or age, the main dependence of [α/Fe] is. (4) At a given age and ...
The Most Luminous Protostars in Molecular Clouds: A Hint to
... masses listed by Cohen et al. (1988) were adopted after rescaling using more recent measurements of the N (H2 )/WCO ratio 2.3 × 1020 cm−2 K−1 km−1 s (e.g., Chin et al. 1997; Johansson et al. 1998). The masses of the bright-rimmed clouds were estimated from their apparent sizes on the optical images ...
... masses listed by Cohen et al. (1988) were adopted after rescaling using more recent measurements of the N (H2 )/WCO ratio 2.3 × 1020 cm−2 K−1 km−1 s (e.g., Chin et al. 1997; Johansson et al. 1998). The masses of the bright-rimmed clouds were estimated from their apparent sizes on the optical images ...
Zhu Qualifier Solutions - University of Toronto Astronomy
... 3.7.2. Why is the mean [Fe/H] not -∞ at the birth of the MW? 3.8. Question 9 3.9. Question 10 3.9.1. Given a cross-section, how would you calculate the amount of extinction? 3.9.2. What percentage of the light is absorbed (rather than scattered) by the light? 3.9.3. Why is dust scattering polarized? ...
... 3.7.2. Why is the mean [Fe/H] not -∞ at the birth of the MW? 3.8. Question 9 3.9. Question 10 3.9.1. Given a cross-section, how would you calculate the amount of extinction? 3.9.2. What percentage of the light is absorbed (rather than scattered) by the light? 3.9.3. Why is dust scattering polarized? ...
SPATIAL STUDY WITH THE VERY LARGE TELESCOPE OF A NEW
... origin of the peculiar, asymmetrical NIR color properties of this object. Subject headings: circumstellar matter — infrared: stars — open clusters and associations: individual ( Ophiuchi Dark Cloud) — stars: formation — stars: individual (2MASSI J1628137243139) — stars: pre–main-sequence al. 1996) ...
... origin of the peculiar, asymmetrical NIR color properties of this object. Subject headings: circumstellar matter — infrared: stars — open clusters and associations: individual ( Ophiuchi Dark Cloud) — stars: formation — stars: individual (2MASSI J1628137243139) — stars: pre–main-sequence al. 1996) ...
Herschel far-infrared observations of the Carina Nebula complex⋆
... For this, the lists of point-like sources detected in each individual Herschel band were matched. The matching radius was chosen as 15 to account for the different angular resolution in the five bands. Starting with the shortest wavelength of 70 μm, i.e. the band with the best angular resolution, e ...
... For this, the lists of point-like sources detected in each individual Herschel band were matched. The matching radius was chosen as 15 to account for the different angular resolution in the five bands. Starting with the shortest wavelength of 70 μm, i.e. the band with the best angular resolution, e ...
Efficiency of gas cooling and accretion at the disc-corona
... For decades, HVCs have been considered as the main candidates for accreting cold and low-metallicity material on to the Milky Way, but the most recent estimates of their accretion indicate that the accretion rate is merely ∼0.08 M yr−1 (Putman, Peek & Joung 2012), more than an order of magnitude lo ...
... For decades, HVCs have been considered as the main candidates for accreting cold and low-metallicity material on to the Milky Way, but the most recent estimates of their accretion indicate that the accretion rate is merely ∼0.08 M yr−1 (Putman, Peek & Joung 2012), more than an order of magnitude lo ...
Luminosity and Mass Functions of Galaxies
... history (e.g. Dn (4000) or Sérsic index). When galaxies are classified by star-formation history, other parameters (e.g. Dn (4000), Sérsic index, Hubble type, quantitative morphology parameters) are nearly uncorrelated with environment. Significant differences between Nn = 0 and Nn = 1. Degeneracy ...
... history (e.g. Dn (4000) or Sérsic index). When galaxies are classified by star-formation history, other parameters (e.g. Dn (4000), Sérsic index, Hubble type, quantitative morphology parameters) are nearly uncorrelated with environment. Significant differences between Nn = 0 and Nn = 1. Degeneracy ...
The ATLAS3D Project – XXX. Star formation histories and stellar
... The Fe5015 index lies on top of the strong [O III] emission line at 5007Å. For this index, the apparent scatter is driven by a number of galaxies sitting below the main relation. To test whether this is the result of infill from poorly subtracted [O III] emission or genuinely weaker iron, we use the ...
... The Fe5015 index lies on top of the strong [O III] emission line at 5007Å. For this index, the apparent scatter is driven by a number of galaxies sitting below the main relation. To test whether this is the result of infill from poorly subtracted [O III] emission or genuinely weaker iron, we use the ...
Timescales for the evolution of oxygen isotope compositions in the
... ciated with CO self-shielding, with a short discussion of mass-independent fractionation (MIF) in high-temperature CAI-forming reactions. The preliminary results for the oxygen isotopic composition of the solar wind from Genesis (McKeegan et al., 2008b) are not in agreement with supernova injection ...
... ciated with CO self-shielding, with a short discussion of mass-independent fractionation (MIF) in high-temperature CAI-forming reactions. The preliminary results for the oxygen isotopic composition of the solar wind from Genesis (McKeegan et al., 2008b) are not in agreement with supernova injection ...
Behaviour of elements from lithium to europium in stars with and
... The atmospheric parameters of the target stars were determined in our previous works. The methods and techniques applied are described in detail in Mishenina et al. (2004) and Mishenina et al. (2008). The effective temperatures Teff were estimated by the calibration of the ratio of the central depth ...
... The atmospheric parameters of the target stars were determined in our previous works. The methods and techniques applied are described in detail in Mishenina et al. (2004) and Mishenina et al. (2008). The effective temperatures Teff were estimated by the calibration of the ratio of the central depth ...
Life Histories Of Some Stars
... all? Describe the shape of the graph? Is it a straight line? A curve? 5. Give each group the list of stars attached and the HR diagram attached. Instead of height and weight, the information is in Luminosity (compared to sun) and Surface Temperature (in K). The chart also gives the star’s current st ...
... all? Describe the shape of the graph? Is it a straight line? A curve? 5. Give each group the list of stars attached and the HR diagram attached. Instead of height and weight, the information is in Luminosity (compared to sun) and Surface Temperature (in K). The chart also gives the star’s current st ...
Impact of atmospheric refraction: How deeply can we probe exo
... planet occults the central region of its star, is a purely geometrical effect linked to the angular size of the host star with respect to the planet, and has only been included in a few papers (Garcı́a Muñoz & Mills 2012; Garcı́a Muñoz et al. 2012; Bétrémieux & Kaltenegger 2013; Rodler & López- ...
... planet occults the central region of its star, is a purely geometrical effect linked to the angular size of the host star with respect to the planet, and has only been included in a few papers (Garcı́a Muñoz & Mills 2012; Garcı́a Muñoz et al. 2012; Bétrémieux & Kaltenegger 2013; Rodler & López- ...
Historic mass loss from the RS Ophiuchi system
... Stars with an initial mass between ∼ 1 and ∼ 40 M¯ become hydrogen/heliumshell-burning Asymptotic Giant Branch (AGB) stars or core-helium-burning red supergiants (RSG). These phases are characterised by cool, molecular atmospheres giving rise to M spectral types (S or C for some chemically peculiar ...
... Stars with an initial mass between ∼ 1 and ∼ 40 M¯ become hydrogen/heliumshell-burning Asymptotic Giant Branch (AGB) stars or core-helium-burning red supergiants (RSG). These phases are characterised by cool, molecular atmospheres giving rise to M spectral types (S or C for some chemically peculiar ...
Molecular Clouds and the Onset of Star Formation
... in general they are not collapsing. The linewidths in CO (several km/s) are always greater than the thermal width at 10 K (full width at half maximum of 0.13 km/s for CO), implying that some other mechanism, such as turbulence or magnetic fields, is helping to support the cloud against gravity. In f ...
... in general they are not collapsing. The linewidths in CO (several km/s) are always greater than the thermal width at 10 K (full width at half maximum of 0.13 km/s for CO), implying that some other mechanism, such as turbulence or magnetic fields, is helping to support the cloud against gravity. In f ...
Binarity in carbon-enhanced metal-poor stars
... for instance, Ito et al. 2013; Norris et al. 2013b). It has also been suggested that in very low metallicity AGB stars with very high neutron-to-Fe-peak-element seed ratios, the s-process runs to completion and a large overabundance of Pb is produced instead of Ba (Busso, Gallino & Wasserburg 1999; ...
... for instance, Ito et al. 2013; Norris et al. 2013b). It has also been suggested that in very low metallicity AGB stars with very high neutron-to-Fe-peak-element seed ratios, the s-process runs to completion and a large overabundance of Pb is produced instead of Ba (Busso, Gallino & Wasserburg 1999; ...
Conference Abstract Booklet here.
... light curves of Cepheid variables using the Fourier decomposition and principal component analysis methods. The theoretical Cepheid light curves are obtained using the full amplitude, nonlinear, convective hydrodynamical models for chemical compositions relative to Cepheids in the Galaxy (Y=0.28, Z= ...
... light curves of Cepheid variables using the Fourier decomposition and principal component analysis methods. The theoretical Cepheid light curves are obtained using the full amplitude, nonlinear, convective hydrodynamical models for chemical compositions relative to Cepheids in the Galaxy (Y=0.28, Z= ...
Distance determination for RAVE stars using stellar models
... metallicity) and (J − Ks ) photometry from archival sources to derive absolute magnitudes. In combination with apparent magnitudes, sky coordinates, proper motions from a variety of sources and radial velocities from RAVE, we are able to derive the full 6D phasespace coordinates for a large sample o ...
... metallicity) and (J − Ks ) photometry from archival sources to derive absolute magnitudes. In combination with apparent magnitudes, sky coordinates, proper motions from a variety of sources and radial velocities from RAVE, we are able to derive the full 6D phasespace coordinates for a large sample o ...
Mn, Cu, and Zn abundances in barium stars and their correlations
... In the present work we derived the abundances based on a spectrum synthesis for 14 stars that were previously analyzed by Smiljanic et al. (2007). Although the focus of this paper is on performing relations between abundances of some iron peak and heavy elements, other elements than those discussed ...
... In the present work we derived the abundances based on a spectrum synthesis for 14 stars that were previously analyzed by Smiljanic et al. (2007). Although the focus of this paper is on performing relations between abundances of some iron peak and heavy elements, other elements than those discussed ...
Galactic Chemical Evolution and the Oxygen Isotopic Composition
... is to use the simplest non-trivial models to explore which effects are most important in the GCE of oxygen. We caution that all GCE models have substantial uncertainties and a model is often considered successful even it only approximately reproduces observations , i.e. the metallicity distribution ...
... is to use the simplest non-trivial models to explore which effects are most important in the GCE of oxygen. We caution that all GCE models have substantial uncertainties and a model is often considered successful even it only approximately reproduces observations , i.e. the metallicity distribution ...
H II region
An H II region is a large, low-density cloud of partially ionized gas in which star formation has recently taken place. The short-lived blue stars forged in these regions emit copious amounts of ultraviolet light that ionize the surrounding gas. H II regions—sometimes several hundred light-years across—are often associated with giant molecular clouds. The first known H II region was the Orion Nebula, which was discovered in 1610 by Nicolas-Claude Fabri de Peiresc.H II regions are named for the large amount of ionised atomic hydrogen they contain, referred to as H II, pronounced H-two by astronomers (an H I region being neutral atomic hydrogen, and H2 being molecular hydrogen). Such regions have extremely diverse shapes, because the distribution of the stars and gas inside them is irregular. They often appear clumpy and filamentary, sometimes showing bizarre shapes such as the Horsehead Nebula. H II regions may give birth to thousands of stars over a period of several million years. In the end, supernova explosions and strong stellar winds from the most massive stars in the resulting star cluster will disperse the gases of the H II region, leaving behind a cluster of birthed stars such as the Pleiades.H II regions can be seen to considerable distances in the universe, and the study of extragalactic H II regions is important in determining the distance and chemical composition of other galaxies. Spiral and irregular galaxies contain many H II regions, while elliptical galaxies are almost devoid of them. In the spiral galaxies, including the Milky Way, H II regions are concentrated in the spiral arms, while in the irregular galaxies they are distributed chaotically. Some galaxies contain huge H II regions, which may contain tens of thousands of stars. Examples include the 30 Doradus region in the Large Magellanic Cloud and NGC 604 in the Triangulum Galaxy.