pinecone/core-2020-05-10-deduplication huggingface dataset:
Thermal and non-thermal emission from circumstellar interaction

It has become clear during the last decades that the interaction between the
supernova ejecta and the circumstellar medium is playing a major role both for
the observational properties of the supernova and for understanding the
evolution of the progenitor star leading up to the explosion. In addition, it
provides an opportunity to understand the shock physics connected to both
thermal and non-thermal processes, including relativistic particle
acceleration, radiation processes and the hydrodynamics of shock waves. This
chapter has an emphasis on the information we can get from radio and X-ray
observations, but also their connection to observations in the optical and
ultraviolet. We first review the different physical processes involved in
circumstellar interaction, including hydrodynamics, thermal X-ray emission,
acceleration of relativistic particles and non-emission processes in the radio
and X-ray ranges. Finally, we discuss applications of these to different types
of supernovae.Comment: 63 pages, 18 figures. Submitted as Chapter for the 'Supernova
  Handbook' to be published by Springer (eds. A. Alsabti and P. Murdin). Major
  update of the review in 'Supernovae and Gamma-Ray Bursters', Ed. K. Weiler.,
  Springer Lecture Notes in Physics, vol. 598, p.171-194 Springer
  (arXiv:astro-ph/0110060). Comments welcom
Observational and Physical Classification of Supernovae

This chapter describes the current classification scheme of supernovae (SNe).
This scheme has evolved over many decades and now includes numerous SN Types
and sub-types. Many of these are universally recognized, while there are
controversies regarding the definitions, membership and even the names of some
sub-classes; we will try to review here the commonly-used nomenclature, noting
the main variants when possible. SN Types are defined according to
observational properties; mostly visible-light spectra near maximum light, as
well as according to their photometric properties. However, a long-term goal of
SN classification is to associate observationally-defined classes with specific
physical explosive phenomena. We show here that this aspiration is now finally
coming to fruition, and we establish the SN classification scheme upon direct
observational evidence connecting SN groups with specific progenitor stars.
Observationally, the broad class of Type II SNe contains objects showing strong
spectroscopic signatures of hydrogen, while objects lacking such signatures are
of Type I, which is further divided to numerous subclasses. Recently a class of
super-luminous SNe (SLSNe, typically 10 times more luminous than standard
events) has been identified, and it is discussed. We end this chapter by
briefly describing a proposed alternative classification scheme that is
inspired by the stellar classification system. This system presents our
emerging physical understanding of SN explosions, while clearly separating
robust observational properties from physical inferences that can be debated.
This new system is quantitative, and naturally deals with events distributed
along a continuum, rather than being strictly divided into discrete classes.
Thus, it may be more suitable to the coming era where SN numbers will quickly
expand from a few thousands to millions of events.Comment: Extended final draft of a chapter in the "SN Handbook". Comments most
  welcom
The Extremes of Thermonuclear Supernovae

The majority of thermonuclear explosions in the Universe seem to proceed in a
rather standardised way, as explosions of carbon-oxygen (CO) white dwarfs in
binary systems, leading to 'normal' Type Ia supernovae (SNe Ia). However, over
the years a number of objects have been found which deviate from normal SNe Ia
in their observational properties, and which require different and not seldom
more extreme progenitor systems. While the 'traditional' classes of peculiar
SNe Ia - luminous '91T-like' and faint '91bg-like' objects - have been known
since the early 1990s, other classes of even more unusual transients have only
been established 20 years later, fostered by the advent of new wide-field SN
surveys such as the Palomar Transient Factory. These include the faint but
slowly declining '02es-like' SNe, 'Ca-rich' transients residing in the
luminosity gap between classical novae and supernovae, extremely short-lived,
fast-declining transients, and the very luminous so-called
'super-Chandrasekhar' SNe Ia. Not all of them are necessarily thermonuclear
explosions, but there are good arguments in favour of a thermonuclear origin
for most of them. The aim of this chapter is to provide an overview of the zoo
of potentially thermonuclear transients, reviewing their observational
characteristics and discussing possible explosion scenarios.Comment: Author version of a chapter for the 'Handbook of Supernovae', edited
  by A. Alsabti and P. Murdin, Springer. 50 pages, 7 figure
Interacting Supernovae: Types IIn and Ibn

Supernovae (SNe) that show evidence of strong shock interaction between their
ejecta and pre-existing, slower circumstellar material (CSM) constitute an
interesting, diverse, and still poorly understood category of explosive
transients. The chief reason that they are extremely interesting is because
they tell us that in a subset of stellar deaths, the progenitor star may become
wildly unstable in the years, decades, or centuries before explosion. This is
something that has not been included in standard stellar evolution models, but
may significantly change the end product and yield of that evolution, and
complicates our attempts to map SNe to their progenitors. Another reason they
are interesting is because CSM interaction is an efficient engine for making
bright transients, allowing super-luminous transients to arise from normal SN
explosion energies, and allowing transients of normal SN luminosities to arise
from sub-energetic explosions or low radioactivity yield. CSM interaction
shrouds the fast ejecta in bright shock emission, obscuring our normal view of
the underlying explosion, and the radiation hydrodynamics of the interaction is
challenging to model. The CSM interaction may also be highly non-spherical,
perhaps linked to binary interaction in the progenitor system. In some cases,
these complications make it difficult to definitively tell the difference
between a core-collapse or thermonuclear explosion, or to discern between a
non-terminal eruption, failed SN, or weak SN. Efforts to uncover the physical
parameters of individual events and connections to possible progenitor stars
make this a rapidly evolving topic that continues to challenge paradigms of
stellar evolution.Comment: Final draft of a chapter in the "SN Handbook". Accepted. 25 pages, 3
  fig
Hydrogen-rich Core Collapse Supernovae

Hydrogen-rich core collapse supernovae, known as "Type II" supernovae, are
the most common type of stellar explosion realized in nature. They are defined
by the presence of prominent hydrogen lines in their spectra. Type II
supernovae are observed only in star-forming galaxies, and several events have
been directly linked to massive star progenitors. Five main subclasses are
identified: Type IIP (displaying a plateau in their light curve), Type IIL
(displaying a light curve decline), Type IIn (displaying narrow emission
lines), Type IIb (displaying increasingly strong He features with time) and
87A-likes (displaying long-rising light curves similar to that of SN 1987A).
Type IIP supernovae have been robustly established as the explosions of red
supergiants, while the progenitors of Type IIL's remain elusive. Type IIn's are
likely linked to luminous blue variables, Type IIb progenitors may be
interacting binary systems and the prototype of the 87A-like class was observed
to be the explosion of a blue supergiant. The diversity in progenitor mass,
metallicity, binarity and rotation is likely responsible for the diversity in
observed explosion types, but the connection between progenitor parameters and
supernova properties is not yet entirely understood theoretically nor fully
mapped observationally. New observational methods for constraining this
connection are currently being implemented, including the analyses of large
samples of events, making use of very early data (obtained hours to days from
explosion) and statistical studies of host-galaxy properties.Comment: Author version of a chapter in the 'Handbook of Supernovae', edited
  by A. Alsabti and P. Murdin, Springer. 38 pages, 23 figure
Neutrino Emission from Supernovae

Supernovae are the most powerful cosmic sources of MeV neutrinos. These
elementary particles play a crucial role when the evolution of a massive star
is terminated by the collapse of its core to a neutron star or a black hole and
the star explodes as supernova. The release of electron neutrinos, which are
abundantly produced by electron captures, accelerates the catastrophic infall
and causes a gradual neutronization of the stellar plasma by converting protons
to neutrons as dominant constituents of neutron star matter. The emission of
neutrinos and antineutrinos of all flavors carries away the gravitational
binding energy of the compact remnant and drives its evolution from the hot
initial to the cold final state. The absorption of electron neutrinos and
antineutrinos in the surroundings of the newly formed neutron star can power
the supernova explosion and determines the conditions in the innermost
supernova ejecta, making them an interesting site for the nucleosynthesis of
iron-group elements and trans-iron nuclei. In this Chapter the basic neutrino
physics in supernova cores and nascent neutron stars will be discussed. This
includes the most relevant neutrino production, absorption, and scattering
processes, elementary aspects of neutrino transport in dense environments, the
characteristic neutrino emission phases with their typical signal features, and
the perspectives connected to a measurement of the neutrino signal from a
future galactic supernova.Comment: Author version of chapter for 'Handbook of Supernovae,' edited by A.
  Alsabti and P. Murdin, Springer. 30 pages, 9 figure
Supernova of 1006 (G327.6+14.6)

SN 1006 (G327.6+14.6) was the brightest supernova (SN) witnessed in human
history. As of one thousand years later, it stands out as an ideal laboratory
to study Type Ia SNe and shocks in supernova remnants (SNRs). The present state
of knowledge about SN 1006 is reviewed in this article. No star consistent with
a surviving companion expected in the traditional single-degenerate scenario
has been found, which favors a double-degenerate scenario for the progenitor of
SN 1006. Both unshocked and shocked SN ejecta have been probed through
absorption lines in ultraviolet spectra of background sources and thermal X-ray
emission, respectively. The absorption studies suggest that the amount of iron
is < 0.16 M_sun, which is significantly less than the range for normal SNe Ia.
On the other hand, analyses of X-ray data reveal the distribution of shocked
ejecta to be highly asymmetric especially for iron. Therefore, most of iron
might have escaped from the ultraviolet background sources. Another important
aspect with SN 1006 is that it was the first SNR in which synchrotron X-ray
emission was detected from shells of the remnant, providing evidence that
electrons are accelerated up to ~100 TeV energies at forward shocks. The
bilateral symmetry of the synchrotron emission (bright in northeastern and
southwestern limbs) is likely due to a polar cap geometry. The broadband
(radio, X-ray, and gamma-ray) spectral energy distribution suggests that the
gamma-ray emission is predominantly leptonic. At the northwestern shock,
evidence for extreme, but less than mass proportional, temperature
non-equilibration has been found by optical, ultraviolet, and X-ray
observations.Comment: A chapter in "Handbook of Supernovae" edited by Athem W. Alsabti and
  Paul Murdin (20 pages, 6 figures). Final print version can be found here:
  http://link.springer.com/referenceworkentry/10.1007/978-3-319-20794-0_45-
Supernova 1604, Kepler's supernova, and its remnant

Supernova 1604 is the last Galactic supernova for which historical records
exist. Johannes Kepler's name is attached to it, as he published a detailed
account of the observations made by himself and European colleagues. Supernova
1604 was very likely a Type Ia supernova, which exploded 350 pc to 750 pc above
the Galactic plane. Its supernova remnant, known as Kepler's supernova remnant,
shows clear evidence for interaction with nitrogen-rich material in the
north/northwest part of the remnant, which, given the height above the Galactic
plane, must find its origin in mass loss from the supernova progenitor system.
The combination of a Type Ia supernova and the presence of circumstellar
material makes Kepler's supernova remnant a unique object to study the origin
of Type Ia supernovae. The evidence suggests that the progenitor binary system
of supernova 1604 consisted of a carbon- oxygen white dwarf and an evolved
companion star, which most likely was in the (post) asymptotic giant branch of
its evolution. A problem with this scenario is that the companion star must
have survived the explosion, but no trace of its existence has yet been found,
despite a deep search.
  1 Introduction; 2 The supernova remnant, its distance and multiwavelength
properties; 2.1 Position, distance estimates and SN1604 as a runaway system;
2.2 X-ray imaging spectroscopy and SN1604 as a Type Ia supernova 2.3 The
circumstellar medium as studied in the optical and infrared; 3 The dynamics of
Kepler's SNR; 3.1 Velocity measurements; 3.2 Hydrodynamical simulations; 4 The
progenitor system of SN 1604; 4.1 Elevated circumstellar nitrogen abundances,
silicates and a single degenerate scenario for SN1604; 4.2 Problems with a
single degenerate Type Ia scenario for SN 1604; 4.3 Was SN 1604 a
core-degenerate Type Ia explosion?; 4.4 What can we learn from the historical
light curve of SN 1604? ; 5 ConclusionsComment: Final draft of a chapter in "Handbook of Supernovae" edited by Athem
  W. Alsabti and Paul Murdin (23 pages, 5 figures). V2 has a small mistake
  corrected. Final print version can be found here:
  http://link.springer.com/referenceworkentry/10.1007/978-3-319-20794-0_49-
Neutrino Signatures From Young Neutron Stars

After a successful core collapse supernova (CCSN) explosion, a hot dense
proto-neutron star (PNS) is left as a remnant. Over a time of twenty or so
seconds, this PNS emits the majority of the neutrinos that come from the CCSN,
contracts, and loses most of its lepton number. This is the process by which
all neutron stars in our galaxy are likely born. The emitted neutrinos were
detected from SN 1987A and they will be detected in much greater numbers from
any future galactic CCSN. These detections can provide a direct window into the
properties of the dense matter encountered inside neutron stars, and they can
affect nucleosynthesis in the mate- rial ejected during the CCSN. In this
chapter, we review the basic physics of PNS cooling, including the basic
equations of PNS structure and neutrino diffusion in dense matter. We then
discuss how the nuclear equation of state, neutrino opacities in dense matter,
and convection can shape the temporal behavior of the neutrino signal. We also
discuss what was learned from the late time SN 1987A neutrinos, the prospects
for detection of these neutrinos from future galactic CCSNe, and the effects
these neutrinos can have on nucleosynthesis.Comment: Chapter of the forthcoming Handbook of Supernovae, edited by Athem W.
  Alsabti and Paul Murdi
Combustion in thermonuclear supernova explosions

Type Ia supernovae are associated with thermonuclear explosions of white
dwarf stars. Combustion processes convert material in nuclear reactions and
release the energy required to explode the stars. At the same time, they
produce the radioactive species that power radiation and give rise to the
formation of the observables. Therefore, the physical mechanism of the
combustion processes, as reviewed here, is the key to understand these
astrophysical events. Theory establishes two distinct modes of propagation for
combustion fronts: subsonic deflagrations and supersonic detonations. Both are
assumed to play an important role in thermonuclear supernovae. The physical
nature and theoretical models of deflagrations and detonations are discussed
together with numerical implementations. A particular challenge arises due to
the wide range of spatial scales involved in these phenomena. Neither the
combustion waves nor their interaction with fluid flow and instabilities can be
directly resolved in simulations. Substantial modeling effort is required to
consistently capture such effects and the corresponding techniques are
discussed in detail. They form the basis of modern multidimensional
hydrodynamical simulations of thermonuclear supernova explosions. The problem
of deflagration-to-detonation transitions in thermonuclear supernova explosions
is briefly mentioned.Comment: Author version of chapter for 'Handbook of Supernovae,' edited by A.
  Alsabti and P. Murdin, Springer. 24 pages, 4 figure
Young neutron stars with soft gamma ray emission and anomalous X-ray
  pulsar

The observational properties of Soft Gamma Repeaters and Ano\-malous X-ray
Pulsars (SGR/AXP) indicate to necessity of the energy source different from a
rotational energy of a neutron star. The model, where the source of the energy
is connected with a magnetic field dissipation in a highly magnetized neutron
star (magnetar) is analyzed. Some observational inconsistencies are indicated
for this interpretation. The alternative energy source, connected with the
nuclear energy of superheavy nuclei stored in the nonequilibrium layer of low
mass neutron star is discussed.Comment: 29 pages, 13 figures, Springer International Publishing Switzerland
  2016 A.W. Alsabti, P. Murdin (eds.), Handbook of Supernova
Nucleosynthesis in thermonuclear supernovae

The explosion energy of thermonuclear (Type Ia) supernovae is derived from
the difference in nuclear binding energy liberated in the explosive fusion of
light 'fuel' nuclei, predominantly carbon and oxygen, into more tightly bound
nuclear 'ash' dominated by iron and silicon group elements. The very same
explosive thermonuclear fusion event is also one of the major processes
contributing to the nucleosynthesis of the heavy elements, in particular the
iron-group elements. For example, most of the iron and manganese in the sun and
its planetary system were produced in thermonuclear supernovae. Here, we review
the physics of explosive thermonuclear burning in carbon-oxygen white dwarf
material and the methodologies utilized in calculating predicted
nucleosynthesis from hydrodynamic explosion models. While the dominant
explosion scenario remains unclear, many aspects of the nuclear combustion and
nucleosynthesis are common to all models and must occur in some form in order
to produce the observed yields. We summarize the predicted nucleosynthetic
yields for existing explosion models, placing particular emphasis on
characteristic differences in the nucleosynthetic signatures of the different
suggested scenarios leading to Type Ia supernovae. Following this, we discuss
how these signatures compare with observations of several individual
supernovae, remnants, and the composition of material in our galaxy and galaxy
clusters.Comment: Author version of a chapter for the 'Handbook of Supernovae', edited
  by A. Alsabti and P. Murdin, Springer. 22 pages, 2 figure
Dynamical Evolution and Radiative Processes of Supernova Remnants

I outline the dynamical evolution of the shell remnants of supernovae (SNRs),
from initial interaction of supernova ejecta with circumstellar material (CSM)
through to the final dissolution of the remnant into the interstellar medium
(ISM). Supernova ejecta drive a blast wave through any CSM from the progenitor
system; as material is swept up, a reverse shock forms in the ejecta, reheating
them. This ejecta-driven phase lasts until ten or more times the ejected mass
is swept up, and the remnant approaches the Sedov or self-similar evolutionary
phase. The evolution up to this time is approximately adiabatic. Eventually, as
the blast wave slows, the remnant age approaches the cooling time for immediate
post-shock gas, and the shock becomes radiative and highly compressive.
Eventually the shock speed drops below the local ISM sound speed and the
remnant dissipates. I then review the various processes by which remnants
radiate. At early times, during the adiabatic phases, thermal X-rays and
nonthermal radio, X-ray, and gamma-ray emission dominate, while optical
emission is faint and confined to a few strong lines of hydrogen and perhaps
helium. Once the shock is radiative, prominent optical and infrared emission is
produced. Young remnants are profoundly affected by interaction with often
anisotropic CSM, while even mature remnants can still show evidence of ejecta.Comment: 23 pages, 10 figures. Author's version of chapter for Handbook of
  Supernova
Galactic and Extragalactic Samples of Supernova Remnants: How They Are
  Identified and What They Tell Us

Supernova remnants (SNRs) arise from the interaction between the ejecta of a
supernova (SN) explosion and the surrounding circumstellar and interstellar
medium. Some SNRs, mostly nearby SNRs, can be studied in great detail. However,
to understand SNRs as a whole, large samples of SNRs must be assembled and
studied. Here, we describe the radio, optical, and X-ray techniques which have
been used to identify and characterize almost 300 Galactic SNRs and more than
1200 extragalactic SNRs. We then discuss which types of SNRs are being found
and which are not. We examine the degree to which the luminosity functions,
surface-brightness distributions and multi-wavelength comparisons of the
samples can be interpreted to determine the class properties of SNRs and
describe efforts to establish the type of SN explosion associated with a SNR.
We conclude that in order to better understand the class properties of SNRs, it
is more important to study (and obtain additional data on) the SNRs in galaxies
with extant samples at multiple wavelength bands than it is to obtain samples
of SNRs in other galaxiesComment: Final 2016 draft of a chapter in "Handbook of Supernovae" edited by
  Athem W. Alsabti and Paul Murdin. Final version available at
  https://doi.org/10.1007/978-3-319-20794-0_90-
The Supernova -- Supernova Remnant Connection

Many aspects of the progenitor systems, environments, and explosion dynamics
of the various subtypes of supernovae are difficult to investigate at
extragalactic distances where they are observed as unresolved sources.
Alternatively, young supernova remnants in our own galaxy and in the Large and
Small Magellanic Clouds offer opportunities to resolve, measure, and track
expanding stellar ejecta in fine detail, but the handful that are known exhibit
widely different properties that reflect the diversity of their parent
explosions and local circumstellar and interstellar environments. A way of
complementing both supernova and supernova remnant research is to establish
strong empirical links between the two separate stages of stellar explosions.
Here we briefly review recent progress in the development of
supernova---supernova remnant connections, paying special attention to
connections made through the study of "middle-aged" (10-100 yr) supernovae and
young (< 1000 yr) supernova remnants. We highlight how this approach can
uniquely inform several key areas of supernova research, including the origins
of explosive mixing, high-velocity jets, and the formation of dust in the
ejecta.Comment: Final draft of chapter in "Handbook of Supernovae" edited by Athem W.
  Alsabti and Paul Murdin (24 pages, 8 figures). Final print version can be
  found here:
  http://link.springer.com/referenceworkentry/10.1007/978-3-319-20794-0_97-