Do neutron stars produce jets?

1986 ◽  
Vol 64 (4) ◽  
pp. 474-478 ◽  
Author(s):  
Eric D. Feigelson
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Supernova Remnants ◽  
Binary Systems ◽  
Crab Nebula ◽  
Compact Object ◽  
Radio Pulsars ◽  
X Ray ◽  
The Crab Nebula ◽  
X Ray Binaries

The evidence for jets emanating from neutron stars is reviewed. Isolated radio pulsars do not appear to produce collimated outflows. A few supernova remnants, notably the Crab nebula, exhibit jetlike protrusions at their outer boundaries. These are probably "blowouts" of the plasma in the remnant rather than true jets from a neutron star. However, several cases of degenerate stars in X-ray binary systems do make jets. SS433 has twin precessing jets moving outward at v ~ 0.26c, and Sco X-1 has radio lobes with v ~ 0.0001c. Cyg X-3 appears to eject synchrotron plasmoids at high velocities. Other X-ray binaries associated with variable radio sources are discussed; some are interesting candidates for collimated outflow. G109.1-1.0 is an X-ray binary in a supernova remnant that may have radio or X-ray jets. It is not clear in all these cases, however, that the compact object is a neutron star and not a black hole or white dwarf.A tentative conclusion is reached that isolated neutron stars do not produce jets, but degenerate stars in accreting binary systems can. This suggests that the presence of an accretion disk, rather than the characteristics of an isolated pulsar's dipole magnetosphere, is critical in making collimated outflows.

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 A Machine Learning Approach For Classifying Low-mass X-ray Binaries Based On Their Compact Object Nature

2020 ◽  
Author(s):  
R Pattnaik ◽  
K Sharma ◽  
K Alabarta ◽  
D Altamirano ◽  
M Chakraborty ◽  
...  
Keyword(s):  
Machine Learning ◽  
Black Hole ◽  
Neutron Star ◽  
Binary Systems ◽  
Compact Object ◽  
X Ray ◽  
Average Accuracy ◽  
Machine Learning Approach ◽  
Low Mass ◽  
X Ray Binaries

Abstract Low Mass X-ray binaries (LMXBs) are binary systems where one of the components is either a black hole or a neutron star and the other is a less massive star. It is challenging to unambiguously determine whether a LMXB hosts a black hole or a neutron star. In the last few decades, multiple observational works have tried, with different levels of success, to address this problem. In this paper, we explore the use of machine learning to tackle this observational challenge. We train a random forest classifier to identify the type of compact object using the energy spectrum in the energy range 5-25 keV obtained from the Rossi X-ray Timing Explorer archive. We report an average accuracy of 87±13% in classifying the spectra of LMXB sources. We further use the trained model for predicting the classes for LMXB systems with unknown or ambiguous classification. With the ever-increasing volume of astronomical data in the X-ray domain from present and upcoming missions (e.g., SWIFT, XMM-Newton, XARM, ATHENA, NICER), such methods can be extremely useful for faster and robust classification of X-ray sources and can also be deployed as part of the data reduction pipeline.

scholarly journals Superfluidity in Neutron Stars

1974 ◽  
Vol 53 ◽  
pp. 151-165
Author(s):  
George Greenstein
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Crab Nebula ◽  
Crab Pulsar ◽  
X Ray ◽  
Effects Of Rotation ◽  
The Crab Nebula

We present a short Cook's tour of the possible effects of rotation coupled with superfluid properties of neutron star interiors. A suggestion is made to take advantage of forthcoming lunar occultations of the Crab Nebula in order to search for blackbody X-ray emission from the Crab pulsar.

scholarly journals Anisotropic neutron stars by gravitational decoupling

2019 ◽  
Vol 79 (10) ◽  
Author(s):  
V. A. Torres-Sánchez ◽  
E. Contreras
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Perfect Fluid ◽  
Compact Object ◽  
Adiabatic Index ◽  
X Ray ◽  
Binary Pulsar ◽  
Stable Solutions ◽  
X Ray Binaries ◽  
Fluid Configuration

Abstract In this work we obtain an anisotropic neutron star solution by gravitational decoupling starting from a perfect fluid configuration which has been used to model the compact object PSR J0348+0432. Additionally, we consider the same solution to model the Binary Pulsar SAX J1808.4-3658 and X-ray Binaries Her X-1 and Cen X-3 ones. We study the acceptability conditions and obtain that the MGD-deformed solution obey the same physical requirements as its isotropic counterpart. Finally, we conclude that the most stable solutions, according to the adiabatic index and gravitational cracking criterion, are those with the smallest compactness parameters, namely SAX J1808.4-3658 and Her X-1.

High Speed Photometry at Mt Stromlo Observatory

1974 ◽  
Vol 2 (5) ◽  
pp. 278-280 ◽  
Author(s):  
B. A. Peterson
Keyword(s):  
Black Holes ◽  
Neutron Star ◽  
High Speed ◽  
Crab Nebula ◽  
Binary Star ◽  
Rotation Period ◽  
Radio Pulsars ◽  
X Ray ◽  
High Speed Photometry ◽  
The Crab Nebula

Important observations of X-ray sources and searches for the optical counterparts of X-ray and radio pulsars require a capability of detecting and analysing light variations with a time scale of milliseconds. X-ray sources in binary star systems are expected to be collapsed objects – neutron stars or black holes (Peterson 1973) – and are expected to produce light variations. In the case of a neutron star, pulses with the same period as the rotation period of the neutron star would be produced, and such have been observed from Cen X-3 (schreier et al. 1972) in the X-ray, and from Her X-1 (Middleditch and Nelson 1973) and the Crab Nebula pulsar (Cocke et al. 1969) in the X-ray optical.

scholarly journals Neutron Star Powered Accelerators

2000 ◽  
Vol 195 ◽  
pp. 463-471
Author(s):  
M. Ruderman
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Gamma Ray ◽  
Crab Nebula ◽  
Surrounding Medium ◽  
Radio Pulsars ◽  
X Ray ◽  
Energetic Radiation ◽  
Γ Ray ◽  
Star Binary

Neutron stars can be the underlying source of energetic particle acceleration in several ways. The huge gravitational-collapse energy released in their birth, or the violent fusion at the end of the life of a neutron-star binary, is the energy source for an accelerator in the surrounding medium far from the star. This would be the case for: (a) cosmic rays from supernova explosions with neutron-star remnants; (b) energetic radiation from “plerions” around young neutron stars (e.g., the Crab Nebula, see Pacini 2000); and (c) “afterglow” and γ-rays of cosmic Gamma-Ray Burst (GRB) sources with possible neutron-star central engines. Particles can also be energetically accelerated if a neutron star's gravitational pull sustains an accretion disk fed by a companion. Examples are accretion-powered X-ray pulsars and low-mass X-ray binaries. A third family of “neutron-star powered” accelerators consists of those which do not depend on the surrounding environment. These are the accelerators which must exist in the magnetospheres of many solitary, spinning-down, magnetized neutron stars (“spinsters”) when they are observed as radio pulsars or γ-ray pulsars. (There are probably ~ 103 dead radio pulsars for each one in our Galaxy that is still active; the ratio for γ-ray pulsars may well exceed 105.)

scholarly journals Supernova Remnants with Central Pulsars

1983 ◽  
Vol 101 ◽  
pp. 405-416 ◽  
Author(s):  
Frederick D. Seward
Keyword(s):  
Kinetic Energy ◽  
Supernova Remnants ◽  
Crab Nebula ◽  
Diffuse Emission ◽  
Radio Pulsars ◽  
X Ray ◽  
The Third ◽  
Synchrotron Nebula ◽  
The Crab Nebula ◽  
Central Pulsar

The recent discovery of a central pulsing X-ray source makes MSH 15–52 the third SNR to contain a radio pulsar surrounded by diffuse X-ray emission. The pulsar periods are all increasing with time and the consequent loss of rotational kinetic energy is enough, in each remnant, to power a synchrotron nebula with the observed luminosity and volume.After a review of the properties of the Crab Nebula it will be shown that both Vela X and MSH 15–52 have the same relationship between central pulsar and diffuse emission. Using empirical rules derived from these SNR, it is demonstrated that other plerionic remnants have similar characteristics. Two accretion-powered central sources can be distinguished from radio pulsars in SNR by the relatively high X-ray luminosity of the central source compared to that of possible synchrotron diffuse emission.

scholarly journals Masses of Neutron Stars in X-ray Binary Systems

1981 ◽  
Vol 95 ◽  
pp. 353-356
Author(s):  
R. L. Kelley ◽  
S. Rappaport
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Binary Systems ◽  
Radio Pulsars ◽  
X Ray ◽  
The Masses

The masses of 6 neutron stars have now been established through studies of binary X-ray and radio pulsars. All of the masses are found to be consistent with, but not necessarily constrained to, the range 1.2–1.6 M⊙. In this talk we discuss the methods and assumptions used in determining the masses of neutron stars in binary X-ray pulsar systems. For other recent reviews of this subject, the reader is referred to Bahcall (1978), Rappaport and Joss (1981), and references therein. Neutron-star parameters may also be obtained from studies of X-ray bursts that result from thermonuclear flashes near the surface of an accreting neutron star (see Joss 1980 and references therein), which we will not discuss here.

scholarly journals Pulsar Observations and Neutron Star Models

1974 ◽  
Vol 53 ◽  
pp. 227-236
Author(s):  
Gerhard Börner ◽  
Jeffrey M. Cohen
Keyword(s):  
Neutron Stars ◽  
Binary Systems ◽  
Gamma Ray ◽  
Crab Nebula ◽  
Physical Parameters ◽  
X Ray ◽  
Star Models ◽  
Degree Of Confidence ◽  
The Masses ◽  
The Crab Nebula

Information about the physical parameters of neutron stars is obtained from pulsar observations. The energy balance of the Crab Nebula and the Vela X remnant allows one to derive limits for the masses of the Crab and Vela pulsars. Glitch observations provide further clues on the masses of these two pulsars. The degree of confidence with which one should believe the derived numbers is pointed out. The possibility of observing neutron stars in binary systems as pulsating X-ray sources is discussed. Finally, the importance of observing redshifted gamma ray lines from the surface of neutron stars, and thus directly measuring either individual or statistical properties of these objects, is pointed out.

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.

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