scholarly journals Anomalous X-ray pulsars and soft gamma-ray repeaters in supernova remnants

2000 ◽  
Vol 177 ◽  
pp. 703-706
Author(s):  
B. M. Gaensler
Keyword(s):  
Neutron Stars ◽  
High Velocity ◽  
Supernova Remnants ◽  
Gamma Ray ◽  
The State ◽  
Low Velocity ◽  
X Ray ◽  
Different Populations

AbstractI consider the state of play regarding associations of supernova remnants (SNRs) with anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs). The three AXP/SNR associations are convincing, and are consistent with AXPs being young, low-velocity neutron stars. The three SGR/SNR associations are far more likely to be chance superpositions, and rely on SGRs being high velocity (>1000 km s−1) objects. These results imply either that AXPs evolve into SGRs, or that SGRs and AXPs represent different populations of object.

scholarly journals A high-energy catalogue of Galactic supernova remnants and pulsar wind nebulae

2012 ◽  
Vol 8 (S291) ◽  
pp. 483-485 ◽  
Author(s):  
Samar Safi-Harb ◽  
Gilles Ferrand ◽  
Heather Matheson
Keyword(s):  
Neutron Stars ◽  
Supernova Remnants ◽  
Gamma Ray ◽  
High Energy ◽  
Public Database ◽  
Pulsar Wind Nebulae ◽  
X Ray ◽  
Global View ◽  
Pulsar Wind ◽  
New Instruments

AbstractMotivated by the wealth of past, existing, and upcoming X-ray and gamma-ray missions, we have developed the first public database of high-energy observations of all known Galactic Supernova Remnants (SNRs): http://www.physics.umanitoba.ca/snr/SNRcat. The catalogue links to, and complements, other existing related catalogues, including Dave Green's radio SNRs catalogue. We here highlight the features of the high-energy catalogue, including allowing users to filter or sort data for various purposes. The catalogue is currently targeted to Galactic SNR observations with X-ray and gamma-ray missions, and is timely with the upcoming launch of X-ray missions (including Astro-H in 2014). We are currently developing the existing database to include an up-to-date Pulsar Wind Nebulae (PWNe)-dedicated webpage, with the goal to provide a global view of PWNe and their associated neutron stars/pulsars. This extensive database will be useful to both theorists to apply their models or design numerical simulations, and to observers to plan future observations or design new instruments. We welcome input and feedback from the SNR/PWN/neutron stars community.

The Progenitors of Gamma-Ray Bursts

2011 ◽  
Author(s):  
Joshua S. Bloom
Keyword(s):  
Neutron Stars ◽  
Supernova Remnants ◽  
Gamma Ray ◽  
Galactic Plane ◽  
Gamma Ray Bursts ◽  
X Ray ◽  
Lines Of Evidence

This chapter discusses the object or objects responsible for gramma-ray bursts (GRBs). Until now, there are few absolute certainties with regard to the progenitors of GRBs. One clear standout is the progenitors of soft gamma-ray repeaters (SGRs) which are very obviously neutron stars. There are a number of corroborating lines of evidence for this progenitor association: (1) some well-localized SGRs are associated with supernova remnants, suggesting they are byproducts of recent supernovae; (2) there is quiescent X-ray emission from the sites of SGRs, similar to a class of neutron stars called “anomalous X-ray pulsars”; (3) Galactic SGRs tend to be found in the Galactic plane, where most young neutron stars reside; and (4) the ringdown emission after SGR pulses is periodic, with periods comparable to that of slowly rotating neutron stars (few seconds).

scholarly journals A New View on Young Pulsars in Supernova Remnants: Slow, Radio-quiet & X-ray Bright

2000 ◽  
Vol 177 ◽  
pp. 699-702 ◽  
Author(s):  
E. V. Gotthelf ◽  
G. Vasisht
Keyword(s):  
Magnetic Field ◽  
Neutron Stars ◽  
Supernova Remnants ◽  
Simple Explanation ◽  
Crab Pulsar ◽  
Radio Pulsars ◽  
Substantial Fraction ◽  
Subsequent Evolution ◽  
X Ray ◽  
Field Decay

AbstractWe propose a simple explanation for the apparent dearth of radio pulsars associated with young supernova remnants (SNRs). Recent X-ray observations of young remnants have revealed slowly rotating (P∼ 10s) central pulsars with pulsed emission above 2 keV, lacking in detectable radio emission. Some of these objects apparently have enormous magnetic fields, evolving in a manner distinct from the Crab pulsar. We argue that these X-ray pulsars can account for a substantial fraction of the long sought after neutron stars in SNRs and that Crab-like pulsars are perhaps the rarer, but more highly visible example of these stellar embers. Magnetic field decay likely accounts for their high X-ray luminosity, which cannot be explained as rotational energy loss, as for the Crab-like pulsars. We suggest that the natal magnetic field strength of these objects control their subsequent evolution. There are currently almost a dozen slow X-ray pulsars associated with young SNRs. Remarkably, these objects, taken together, represent at least half of the confirmed pulsars in supernova remnants. This being the case, these pulsars must be the progenitors of a vast population of previously unrecognized neutron stars.

scholarly journals Fermi-LAT and WMAP observations of the supernova remnant Puppis A

2013 ◽  
Vol 9 (S296) ◽  
pp. 295-299
Author(s):  
Marie-Hélène Grondin ◽  
John W. Hewitt ◽  
Marianne Lemoine-Goumard ◽  
Thierry Reposeur ◽  
Keyword(s):  
Supernova Remnants ◽  
Supernova Remnant ◽  
Gamma Ray ◽  
High Energy ◽  
Radio Spectrum ◽  
Wilkinson Microwave Anisotropy Probe ◽  
Large Area ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Γ Ray

AbstractThe supernova remnant (SNR) Puppis A (aka G260.4-3.4) is a middle-aged supernova remnant, which displays increasing X-ray surface brightness from West to East corresponding to an increasing density of the ambient interstellar medium at the Eastern and Northern shell. The dense IR photon field and the high ambient density around the remnant make it an ideal case to study in γ-rays. Gamma-ray studies based on three years of observations with the Large Area Telescope (LAT) aboard Fermi have revealed the high energy gamma-ray emission from SNR Puppis A. The γ-ray emission from the remnant is spatially extended, and nicely matches the radio and X-ray morphologies. Its γ-ray spectrum is well described by a simple power law with an index of ~2.1, and it is among the faintest supernova remnants yet detected at GeV energies. To constrain the relativistic electron population, seven years of Wilkinson Microwave Anisotropy Probe (WMAP) data were also analyzed, and enabled to extend the radio spectrum up to 93 GHz. The results obtained in the radio and γ-ray domains are described in detail, as well as the possible origins of the high energy γ-ray emission (Bremsstrahlung, Inverse Compton scattering by electrons or decay of neutral pions produced by proton interactions).

scholarly journals Physical Processes and Parameters in the Magnetosphere of NP 0532

1971 ◽  
Vol 46 ◽  
pp. 394-406
Author(s):  
F. Pacini
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Supernova Remnants ◽  
Crab Nebula ◽  
General Relation ◽  
Energy Generation ◽  
Main Pulse ◽  
Physical Processes ◽  
X Ray ◽  
The Crab Nebula

The Crab Nebula pulsar conforms to the model of a rotating magnetised neutron star in the rate of energy generation and the exponent of the rotation law.It is suggested that the main pulse is due to electrons and the precursor to protons. Both must radiate in coherent bunches. Optical and X-ray radiation is by the synchrotron process.The wisps observed in the Nebula may represent the release of an instability storing about 1043 erg and 1047–48 particles.Finally, some considerations are made about the general relation between supernova remnants and rotating neutron stars.

scholarly journals X-ray and Gamma-ray Radiation from the Switched-off Radiopulsars

1983 ◽  
Vol 101 ◽  
pp. 505-507
Author(s):  
A. I. Tsygan
Keyword(s):  
Neutron Stars ◽  
Magnetic Dipole ◽  
Gamma Ray ◽  
Neutral Hydrogen ◽  
Dipole Radiation ◽  
X Ray ◽  
Electron Positron ◽  
Hard Radiation ◽  
Γ Ray ◽  
Generate Electron

It is shown that pulsars that have ceased to generate electron-positron pairs (switched-off radiopulsars) may be the sources of X-ray and γ-ray radiation. The magnetic dipole radiation from these rotating neutron stars is transformed near the “light radius” into hard radiation by the plasma that is created due to ionization of interstellar neutral hydrogen.

scholarly journals 60Fe in core-collapse supernovae and prospects for X-ray and gamma-ray detection in supernova remnants

2019 ◽  
Vol 485 (3) ◽  
pp. 4287-4310 ◽  
Author(s):  
Samuel W Jones ◽  
Heiko Möller ◽  
Chris L Fryer ◽  
Christopher J Fontes ◽  
Reto Trappitsch ◽  
...  
Keyword(s):  
Cross Section ◽  
Supernova Remnants ◽  
Gamma Ray ◽  
Flux Ratio ◽  
Core Collapse ◽  
Line Broadening ◽  
X Ray ◽  
Core Collapse Supernova ◽  
Structure Line ◽  
Solar Metallicity

Abstract We investigate 60Fe in massive stars and core-collapse supernovae focussing on uncertainties that influence its production in 15, 20, and 25 M$\odot$ stars at solar metallicity. We find that the 60Fe yield is a monotonic increasing function of the uncertain 59Fe(n, γ)60Fe cross-section and that a factor of 10 reduction in the reaction rate results in a factor of 8–10 reduction in the 60Fe yield, while a factor of 10 increase in the rate increases the yield by a factor of 4–7. We find that none of the 189 simulations we have performed are consistent with a core-collapse supernova triggering the formation of the Solar system, and that only models using 59Fe(n, γ)60Fe cross-section that is less than or equal to that from NON-SMOKER can reproduce the observed 60Fe/26Al line flux ratio in the diffuse interstellar medium. We examine the prospects of detecting old core-collapse supernova remnants (SNRs) in the Milky Way from their gamma-ray emission from the decay of 60Fe, finding that the next generation of gamma-ray missions could be able to discover up to ∼100 such old SNRs as well as measure the 60Fe yields of a handful of known Galactic SNRs. We also predict the X-ray spectrum that is produced by atomic transitions in 60Co following its ionization by internal conversion and give theoretical X-ray line fluxes as a function of remnant age as well as the Doppler and fine-structure line broadening effects. The X-ray emission presents an interesting prospect for addressing the missing SNR problem with future X-ray missions.

scholarly journals Interaction between molecular clouds and MeV–TeV cosmic-ray protons escaped from supernova remnants

2019 ◽  
Vol 71 (4) ◽  
Author(s):  
Ken Makino ◽  
Yutaka Fujita ◽  
Kumiko K Nobukawa ◽  
Hironori Matsumoto ◽  
Yutaka Ohira
Keyword(s):  
Gamma Rays ◽  
Molecular Clouds ◽  
Supernova Remnants ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
Iron Line ◽  
X Ray ◽  
Line Intensities ◽  
Neutral Gas ◽  
Additional Support

Abstract Recent discovery of the X-ray neutral iron line (Fe  i Kα at 6.40 keV) around several supernova remnants (SNRs) show that MeV cosmic-ray (CR) protons are distributed around the SNRs and are interacting with neutral gas there. We propose that these MeV CRs are the ones that have been accelerated at the SNRs together with GeV–TeV CRs. In our analytical model, the MeV CRs are still confined in the SNR when the SNR collides with molecular clouds. After the collision, the MeV CRs leak into the clouds and produce the neutral iron line emissions. On the other hand, GeV–TeV CRs had already escaped from the SNRs and emitted gamma-rays through interaction with molecular clouds surrounding the SNRs. We apply this model to the SNRs W 28 and W 44 and show that it can reproduce the observations of the iron line intensities and the gamma-ray spectra. This could be additional support of the hadronic scenario for the gamma-ray emissions from these SNRs.

scholarly journals Model Atmospheres for Cooling Neutron Stars

1987 ◽  
Vol 125 ◽  
pp. 459-459
Author(s):  
Roger W. Romani ◽  
Roger D. Blandford ◽  
Lars Hernquist
Keyword(s):  
Neutron Stars ◽  
Supernova Remnants ◽  
Equations Of State ◽  
Black Body ◽  
X Ray ◽  
Electron Heat ◽  
Parallel Field ◽  
Effective Temperatures ◽  
Calculated Model ◽  
Magnetic Case

The failure of Einstein X-ray observations to detect central neutron stars in most young supernova remnants (Helfand and Becker 1984) has provided interesting constraints on cooling theories (cf. review by Tsuruta 1985). The comparison of the measured fluxes with the predicted effective temperatures is sensitive to the nature of the emitted spectrum, commonly assumed to be blackbody. The presence of a substantial absorbing atmosphere can, however, produce significant departures. We have calculated model atmospheres for unmagnetized neutron stars with effective temperatures 105K ≦ Teff ≦ 106.5K using Los Alamos opacities and equations of state (Romani 1986). We consider a range of surface compositions, since the accretion of ∼10−19M⊙ will cover the surface to the X-ray photosphere and subsequent settling in the strong gravitational field can severely deplete the heavy species. In a low Z atmosphere (eg. He) the measured X-ray flux will substantially exceed the blackbody value–the Einstein limits on Teff are correspondingly lowered (eg. by ∼1.6 for SN1006 with a helium surface). For high Z atmospheres, the flux is close to the black body value, but prominent absorption edges are present. Recent calculations of the electron heat transport in magnetized neutron star envelopes (Hernquist 1984, 1985) have shown that, contrary to earlier estimates, magnetic fields will have a small effect on the heat flux (≳ 3 for parallel field geometries and ∼1 for tangled fields). Extension of the atmosphere computations to the magnetic case is important for comparison with X-ray observations of known pulsars.

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