6 research outputs found
Supernovae from massive stars
Massive stars, by which we mean those stars exploding as core collapse
supernovae, play a pivotal role in the evolution of the Universe. Therefore,
the understanding of their evolution and explosion is fundamental in many
branches of physics and astrophysics, among which, galaxy evolution,
nucleosynthesis, supernovae, neutron stars and pulsars, black holes, neutrinos
and gravitational waves. In this chapter, the author presents an overview of
the presupernova evolution of stars in the range between 13 and 120 , with initial metallicities between [Fe/H]=-3 and [Fe/H]=0 and initial
rotation velocities . Emphasis is placed upon those
evolutionary properties that determine the final fate of the star with special
attention to the interplay among mass loss, mixing and rotation. A general
picture of the evolution and outcome of a generation of massive stars, as a
function of the initial mass, metallicity and rotation velocity, is finally
outlined.Comment: Author version of a chapter for 'Handbook of Supernovae,' edited by
A. Alsabti and P. Murdin, Springer. 59 pages, 27 figure
Supernova remnants: the X-ray perspective
Supernova remnants are beautiful astronomical objects that are also of high
scientific interest, because they provide insights into supernova explosion
mechanisms, and because they are the likely sources of Galactic cosmic rays.
X-ray observations are an important means to study these objects.And in
particular the advances made in X-ray imaging spectroscopy over the last two
decades has greatly increased our knowledge about supernova remnants. It has
made it possible to map the products of fresh nucleosynthesis, and resulted in
the identification of regions near shock fronts that emit X-ray synchrotron
radiation.
In this text all the relevant aspects of X-ray emission from supernova
remnants are reviewed and put into the context of supernova explosion
properties and the physics and evolution of supernova remnants. The first half
of this review has a more tutorial style and discusses the basics of supernova
remnant physics and thermal and non-thermal X-ray emission. The second half
offers a review of the recent advances.The topics addressed there are core
collapse and thermonuclear supernova remnants, SN 1987A, mature supernova
remnants, mixed-morphology remnants, including a discussion of the recent
finding of overionization in some of them, and finally X-ray synchrotron
radiation and its consequences for particle acceleration and magnetic fields.Comment: Published in Astronomy and Astrophysics Reviews. This version has 2
column-layout. 78 pages, 42 figures. This replaced version has some minor
language edits and several references have been correcte
Displacement and Resettlement: Understanding the Role of Climate Change in Contemporary Migration
How do we understand displacement and resettlement in the context of climate change? This chapter outlines challenges and debates in the literature connecting climate change to the growing global flow of people. We begin with an outline of the literature on environmental migration, specifically the definitions, measurements, and forms of environmental migration. The discussion then moves to challenges in the reception of migrants, treating the current scholarship on migrant resettlement. We detail a selection of cases in which the environment plays a role in the displacement of a population, including sea level rise in Pacific Island States, cyclonic storms in Bangladesh, and desertification in West Africa, as well as the role of deforestation in South America’s Southern Cone as a driver of both climate change and migration. We outline examples of each, highlighting the complex set of losses and damages incurred by populations in each case