Browsing by Title
Now showing items 16276-16295 of 24473
-
The origin of elliptical galaxies inferred from their metallicity gradients
(2003-04)We simulate the chemodynamical evolution of elliptical galaxies using our GRAPE-SPH code. We succeed in reproducing the observed variety of the radial metallicity gradients, from which we discuss the origin of elliptical galaxies. -
The Origin of Helium-Rich Subdwarf O Stars
(Astronomical Society of the Pacific, 2008)The origin of helium-rich subdwarf O stars (He-sdO) is still unclear. Significant progress has been made recently in placing them in the Hertzsprung–Russell diagram. However, the question of their progenitors is still ... -
The Origin of High-energy Emission in the Young Radio Source PKS 1718–649
(2022-12-12)We present a model for the broadband radio-to-γ-ray spectral energy distribution of the compact radio source PKS 1718 − 649. Because of its young age (≃100 yr) and proximity (z = 0.014), PKS 1718 − 649 offers a unique ... -
The origin of kinematically distinct cores and misaligned gas discs in galaxies from cosmological simulations
(2018-09-01)Integral field spectroscopy surveys provide spatially resolved gas and stellar kinematics of galaxies. They have unveiled a range of atypical kinematic phenomena, which require detailed modelling to understand. We present ... -
The origin of low [alpha/Fe] ratios in extremely metal-poor stars
(2014-03-25)We show that the low ratios of $\alpha$ elements (Mg, Si, and Ca) to Fe recently found for a small fraction of extremely metal-poor stars can be naturally explained with the nucleosynthesis yields of core-collapse supernovae, ... -
The origin of low-surface-brightness galaxies in the dwarf regime
(2021-01-13)Low-surface-brightness galaxies (LSBGs) -- defined as systems that are fainter than the surface-brightness limits of past wide-area surveys -- form the overwhelming majority of galaxies in the dwarf regime (M* < 10^9 MSun). ... -
Origin of metals in old Milky Way halo stars based on GALAH and Gaia
(2021-10-01)Stellar and supernova nucleosynthesis in the first few billion years of the cosmic history have set the scene for early structure formation in the Universe, while little is known about their nature. Making use of stellar ... -
The origin of the Ca-Ti-Cr-Fe-Ni isotopic anomalies in the inclusion EK-1-4-1 of the Allende meteorite
(2003)The origin of the correlated Ca-Ti-Cr-Fe-Ni isotopic anomalies in the Ca-Al-rich inclusion of the EK-1-4-1 of the Allende is a longstanding puzzle. The search for a stellar environment which could explain the enrichment ... -
The origin of the diversity of Type Ia supernovae and the environmental effects
(1999-09-01)Observations suggest that the properties of Type Ia supernovae (SNe Ia) may depend on environmental characteristics, such as the morphology, metallicity, and age of the host galaxies. The influence of these environmental ... -
Origin of the p-Nuclei in Explosive Nucleosynthesis
(SISSA, 2011-01)A number of naturally occurring, proton-rich nuclides (the p-nuclei) cannot be made in the s- and r-process. It has been found that massive stars can produce p-nuclei through photodisintegration of pre-existing intermediate ... -
The origin of the visual and infrared pulsations in the intermediate polar FO AQR (H2215-086)
(1986)Simultaneous visual and infrared polarimetry of the intermediate polar FO Aqr (H2215-086) shows that its visual and infrared pulsations, seen at the rotation period of the white dwarf, are not circularly polarized. This ... -
The origins of narrative: In search of the transactional format of narratives in humans and other social animals
(2002)This article presents work in progress towards a better understanding of the origins of narrative. Assuming an evolutionary and developmental continuity of mental experiences, we propose a grounding of human narrative ... -
Origins of scaling in genetic code
(2011)The principle of least effort in communications has been shown, by Ferrer i Cancho and Sol´e, to explain emergence of power laws (e.g., Zipf’s law) in human languages. This paper applies the principle and the informationtheoretic ... -
The origins of the English financial markets : investment and speculation before the south sea bubble
(Cambridge University Press, 2009)In English financial history, the late 1600s was a critical period. Many joint-stock companies appeared creating opportunity for investment in projects that ranged from paper manufacturing to the search for sunken treasure. ... -
Origins of the extragalactic background at 1 mm from a combined analysis of the AzTEC and MAMBO data in GOODS-N
(2011-02-01)We present a study of the cosmic infrared background, which is a measure of the dust-obscured activity in all galaxies in the Universe. We venture to isolate the galaxies responsible for the background at 1 mm; with ... -
The Origins of the Ultramassive White Dwarf GD50
(Astronomical Society of the Pacific, 2007)On the basis of astrometric and spectroscopic data we argue that the ultramassive white dwarf GD 50 is associated with the star formation event that created the Pleiades and is potentially a former cluster member. Its ... -
The Orion Protostellar Explosion and Runaway Stars Revisited : Stellar Masses, Disk Retention, and an Outflow from the Becklin-Neugebauer Object
(2020-02-01)The proper motions of the three stars ejected from Orion's OMC1 cloud core are combined with the requirement that their center of mass is gravitationally bound to OMC1 to show that radio source I (Src I) is likely to have ... -
Orion revisited III. The Orion Belt population
(2017-02-13)This paper continues our study of the foreground population to the Orion molecular clouds. The goal is to characterize the foreground population north of NGC 1981 and to investigate the star formation history in the large ...