scholarly journals Central Compact Objects in Kes 79 and RCW 103 as ‘Hidden’ Magnetars with Crustal Activity

2015 ◽  
Vol 32 ◽  
Author(s):  
S. B. Popov ◽  
A. A. Kaurov ◽  
A. D. Kaminker
Keyword(s):  
Magnetic Fields ◽  
Neutron Stars ◽  
Time Scale ◽  
Compact Objects ◽  
High State ◽  
2D Modelling ◽  
Variable Activity ◽  
Error Bars ◽  
Central Compact Objects

AbstractWe propose that observations of ‘hidden’ magnetars in central compact objects can be used to probe crustal activity of neutron stars with large internal magnetic fields. Estimates based on calculations by Perna & Pons, Pons & Rea and Kaminker et al. suggest that central compact objects, which are proposed to be ‘hidden’ magnetars, must demonstrate flux variations on the time scale of months–years. However, the most prominent candidate for the ‘hidden’ magnetars — CXO J1852.6+0040 in Kes 79 — shows constant (within error bars) flux. This can be interpreted by lower variable crustal activity than in typical magnetars. Alternatively, CXO J1852.6+0040 can be in a high state of variable activity during the whole period of observations. Then we consider the source 1E161348 − 5055 in RCW103 as another candidate. Employing a simple 2D-modelling we argue that properties of the source can be explained by the crustal activity of the magnetar type. Thus, this object may be supplemented for the three known candidates for the ‘hidden’ magnetars among central compact objects discussed in literature.

scholarly journals Central compact objects and their magnetic fields

2012 ◽  
Vol 8 (S291) ◽  
pp. 101-106 ◽  
Author(s):  
Wynn C. G. Ho
Keyword(s):  
Magnetic Fields ◽  
Neutron Stars ◽  
Supernova Remnants ◽  
Compact Objects ◽  
Spectral Measurements ◽  
X Ray ◽  
Surface Field ◽  
Weak Surface ◽  
Central Compact Objects ◽  
Weak Fields

AbstractCentral compact objects (CCOs) are neutron stars that are found near the center of supernova remnants, and their association with supernova remnants indicates these neutron stars are young (≲ 104 yr). Here we review the observational properties of CCOs and discuss implications, especially their inferred magnetic fields. X-ray timing and spectral measurements suggest CCOs have relatively weak surface magnetic fields (~ 1010 − 1011 G). We argue that, rather than being created with intrinsically weak fields, CCOs are born with strong fields and we are only seeing a weak surface field that is transitory and evolving. This could imply that CCOs are one manifestation in a unified picture of neutron stars.

scholarly journals Very young neutron stars and millisecond pulsars: the role of the accretion

2012 ◽  
Vol 8 (S290) ◽  
pp. 231-232
Author(s):  
Alexander F. Kholtygin ◽  
Andrei P. Igoshev
Keyword(s):  
Magnetic Fields ◽  
Neutron Stars ◽  
Binary Systems ◽  
Compact Objects ◽  
Millisecond Pulsars ◽  
Know How ◽  
Central Compact Objects ◽  
Low Magnetic Field ◽  
Age Determinations

AbstractWe consider the evolution of the very young neutron stars (NS) with moderate and low magnetic field values around 1E8 G to know how large is the share of the these objects among the those attributed as the millisecond pulsars (MSP). To exclude the contamination of accreted NS and young NS with moderate magnetic fields we study the observational evidences of the accretion on NS in the binary systems and different methods of age determinations. It was concluded that only central compact objects are appropriate candidates for NSs with small initial magnetic fields.

scholarly journals Off-equatorial circular orbits in magnetic fields of compact objects

2008 ◽  
Vol 4 (S259) ◽  
pp. 125-126 ◽  
Author(s):  
Zdeněk Stuchlík ◽  
Jiří Kovář ◽  
Vladimír Karas
Keyword(s):  
Black Holes ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Compact Objects ◽  
Circular Orbits ◽  
Naked Singularities ◽  
Plasma Ring

AbstractWe present results of investigation of the off-equatorial circular orbits existence in the vicinity of neutron stars, Schwarzschild black holes with plasma ring, and near Kerr-Newman black holes and naked singularities.

scholarly journals Magnetic Field Decay, or Just Period-Dependent Beaming?

2004 ◽  
Vol 218 ◽  
pp. 41-44 ◽  
Author(s):  
Joeri van Leeuwen ◽  
Frank Verbunt
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Velocity Distribution ◽  
Neutron Stars ◽  
Time Scale ◽  
Radio Pulsar ◽  
New Born ◽  
Field Decay ◽  
The Magnetic Field

Several recent papers conclude that radio-pulsar magnetic fields decay on a time-scale of 10 Myr, apparently contradicting earlier results. We have implemented the methods of these papers in our code and show that this preference for rapid field decay is caused by the assumption that the beaming fraction does not depend on the period. When we do include this dependence, we find that the observed pulsar properties are reproduced best when the modeled field does not decay. When we assume that magnetic fields of new-born neutron stars are from a distribution sufficiently wide to explain magnetars, the magnetic field and period distributions we predict for radio are pulsars wider than observed. Finally we find that the observed velocities overestimate the intrinsic velocity distribution.

scholarly journals What causes the absence of pulsations in Central Compact Objects in supernova remnants?

2021 ◽  
Vol 21 (11) ◽  
pp. 294
Author(s):  
Qi Wu ◽  
Adriana M. Pires ◽  
Axel Schwope ◽  
Guang-Cheng Xiao ◽  
Shu-Ping Yan ◽  
...  
Keyword(s):  
Neutron Stars ◽  
Supernova Remnants ◽  
Compact Objects ◽  
Evolutionary Path ◽  
Spectral Components ◽  
Periodic Signals ◽  
The Common ◽  
Central Compact Objects ◽  
Star Surface ◽  
Homogeneous Temperature

Abstract Most young neutron stars belonging to the class of Central Compact Objects (CCOs) in supernova remnants do not have known periodicities. We investigated seven such CCOs to understand the common reasons for the absence of detected pulsations. Making use of XMM-Newton, Chandra, and NICER observations, we perform a systematic timing and spectral analysis to derive updated sensitivity limits for both periodic signals and multi-temperature spectral components that could be associated with radiation from hotspots on the neutron star surface. Based on these limits, we then investigated for each target the allowed viewing geometry that could explain the lack of pulsations. We find that it is unlikely (< 10−6) to attribute that we do not see pulsations to an unfavorable viewing geometry for five considered sources. Alternatively, the carbon atmosphere model, which assumes homogeneous temperature distribution on the surface, describes the spectra equally well and provides a reasonable interpretation for the absence of detected periodicities within current limits. The unusual properties of CCOs with respect to other young neutron stars could suggest a different evolutionary path, as that proposed for sources experiencing episodes of significant fallback accretion after the supernova event.

scholarly journals Searches for Young Pulsars

2004 ◽  
Vol 218 ◽  
pp. 97-104 ◽  
Author(s):  
Fernando Camilo
Keyword(s):  
Neutron Stars ◽  
Compact Objects ◽  
Pulsar Wind Nebulae ◽  
X Ray ◽  
Γ Ray ◽  
Pulsar Wind ◽  
Central Compact Objects

I review the results of radio and X-ray searches for pulsations from young neutron stars, emphasizing work accomplished in the last five years. I cover undirected searches, as well as directed searches of pulsar wind nebulae, EGRET γ-ray sources, and also the search for pulsations from “isolated neutron stars” and “central compact objects”.

scholarly journals Central Compact Objects in Supernova Remnants

2004 ◽  
Vol 218 ◽  
pp. 239-246 ◽  
Author(s):  
George G. Pavlov ◽  
Divas Sanwal ◽  
Marcus A. Teter
Keyword(s):  
Neutron Stars ◽  
Supernova Remnants ◽  
Compact Objects ◽  
X Ray ◽  
Central Regions ◽  
Supernova Explosions ◽  
Central Compact Objects

There are point-like sources in central regions of several supernova remnants which have not been detected outside the X-ray range. The X-ray spectra of these Central Compact Objects (CCOs) have thermal components with blackbody temperatures of 0.2–0.5 keV and characteristic sizes of 0.3-3 km. Most likely, the CCOs are neutron stars born in supernova explosions. We overview their observational properties, emphasizing the Chandra data, and compare them with magnetars.

scholarly journals Searching for X-ray Pulsations from Neutron Stars Using NICER

2017 ◽  
Vol 13 (S337) ◽  
pp. 187-190 ◽  
Author(s):  
Paul S. Ray ◽  
Zaven Arzoumanian ◽  
Keith C. Gendreau ◽  
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Compact Objects ◽  
Large Area ◽  
Pulse Profile ◽  
Millisecond Pulsars ◽  
X Ray ◽  
Event Time ◽  
Time Stamps ◽  
Central Compact Objects

AbstractThe Neutron Star Interior Composition Explorer (NICER) presents an exciting new capability for exploring the modulation properties of X-ray emitting neutron stars, including large area, low background, extremely precise absolute event time stamps, superb low-energy response and flexible scheduling. The Pulsation Searches and Multiwavelength Coordination working group has designed a 2.5 Ms observing program to search for emission and characterize the modulation properties of about 30 known or suspected neutron star sources across a number of source categories. A key early goal will be to search for pulsations from millisecond pulsars that might exhibit thermal pulsations from the surface suitable for pulse profile modeling to constrain the neutron star equation of state. In addition, we will search for pulsations from transitional millisecond pulsars, isolated neutron stars, low-mass X-ray binaries (LMXBs), accretion-powered millisecond pulsars, central compact objects and other sources. We present our science plan and initial results from the first months of the NICER mission, including the discovery of pulsations from the millisecond pulsar J1231–1411.

scholarly journals Imprints of Neutron Stars in the Interstellar Medium

2004 ◽  
Vol 218 ◽  
pp. 277-278 ◽  
Author(s):  
Estela M. Reynoso ◽  
Simon Johnston ◽  
Anne J. Green ◽  
W. M. Goss ◽  
Gloria M. Dubner ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Neutron Stars ◽  
Supernova Remnants ◽  
Compact Objects ◽  
X Ray ◽  
Central Compact Objects

We have carried out an H I survey towards X-ray central compact objects (CCOs) inside supernova remnants (SNRs), which shows that many of them are placed within local H I minimA. The nature of these minima is not clear, but the most likely explanation is that the CCOs have evacuated the neighboring gas. This survey also allowed us to detect a weak, diffuse radio nebula inside the SNR G266.2−1.2, probably created by the winds of its associated CCO.

scholarly journals The Neutron Star Zoo

2017 ◽  
Vol 13 (S337) ◽  
pp. 3-8
Author(s):  
Victoria M. Kaspi
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Physical Theory ◽  
Compact Objects ◽  
Grand Unification ◽  
X Rays ◽  
Radio Pulsars ◽  
Γ Rays ◽  
Central Compact Objects

AbstractSince their discovery 50 years ago, neutron stars have continually astonished. From the first-discovered radio pulsars to the powerful “magnetars” that emit sudden bursts of X-rays and γ-rays, from the so-called Isolated Neutron Stars to Central Compact Objects, observational manifestations of neutron stars are surprisingly varied, with most properties totally unpredicted. The challenge is to cement an overarching physical theory of neutron stars and their birth properties that can explain this great diversity. Here I briefly survey the disparate neutron star classes, describe their properties, highlight recent results, and describe efforts at “grand unification” of this wealth of observational phenomena.

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