scholarly journals Thermal Spectrum and Neutrino Cooling Rate of the Vela Pulsar

Particles ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 14 ◽  
Author(s):  
Dmitry Ofengeim ◽  
Dmitry Zyuzin
Keyword(s):  
Spectral Analysis ◽  
Neutron Star ◽  
Surface Temperature ◽  
Neutron Star Matter ◽  
Space Observatory ◽  
X Ray ◽  
Wide Range ◽  
Vela Pulsar ◽  
Neutron Star Cooling ◽  
State Models

We reanalyse the X-ray spectrum of the PSR B0833–45 (the Vela pulsar) using the data of the Chandra space observatory. In contrast to previous works, we consider a wide range of possible masses and radii of the pulsar. The derived surface temperature of the star Ts∞=0.66−0.01+0.04MK (1σ level over the entire mass and radius range of our study) is consistent with earlier results. However, the preferable values of Vela’s mass and radius given by the spectral analysis are different from those used previously; they are consistent with modern equation of state models of neutron star matter. In addition, we evaluate the Vela’s surface temperature as a function of assumed values of its mass and radius. This allows us to analyse the neutrino cooling rates consistent with the evaluated surface temperatures and explore the additional restrictions that could be set on the Vela’s mass and radius using different versions of the neutron star cooling theory.

scholarly journals Neutron Star Cooling and the Vela Pulsar

1987 ◽  
Vol 125 ◽  
pp. 456-456
Author(s):  
Ken'ichi Nomoto ◽  
Sachiko Tsuruta
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Supernova Remnants ◽  
Cooling Curves ◽  
X Ray ◽  
Vela Pulsar ◽  
Neutron Star Cooling

We have calculated cooling models of young neutron stars.3 The theoretical cooling curves for several models are compared with the Einstein X-ray observations of young supernova remnants (Figure 1).

scholarly journals Swift/XRT, Chandra, and XMM–Newton observations of IGR J17091–3624 as it returns into quiescence

2020 ◽  
Vol 497 (1) ◽  
pp. 1115-1126
Author(s):  
M Pereyra ◽  
D Altamirano ◽  
J M C Court ◽  
N Degenaar ◽  
R Wijnands ◽  
...  
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Time Scales ◽  
Strong Evidence ◽  
Spectral Properties ◽  
X Ray ◽  
Term Evolution ◽  
Wide Range ◽  
Low Mass

ABSTRACT IGR J17091–3624 is a low-mass X-ray binary (LMXB), which received wide attention from the community thanks to its similarities with the bright black hole system GRS 1915+105. Both systems exhibit a wide range of highly structured X-ray variability during outburst, with time-scales from few seconds to tens of minutes, which make them unique in the study of mass accretion in LMXBs. In this work, we present a general overview into the long-term evolution of IGR J17091–3624, using Swift/XRT observations from the onset of the 2011–2013 outburst in 2011 February till the end of the last bright outburst in 2016 November. We found four re-flares during the decay of the 2011 outburst, but no similar re-flares appear to be present in the latter one. We studied, in detail, the period with the lowest flux observed in the last 10 yr, just at the tail end of the 2011–2013 outburst, using Chandra and XMM-Newton observations. We observed changes in flux as high as a factor of 10 during this period of relative quiescence, without strong evidence of softening in the spectra. This result suggests that the source has not been observed at its true quiescence so far. By comparing the spectral properties at low luminosities of IGR J17091–3624 and those observed for a well-studied population of LMXBs, we concluded that IGR J17091–3624 is most likely to host a black hole as a compact companion rather than a neutron star.

scholarly journals Neutron Star Cooling: Effects of Envelope Physics

1983 ◽  
Vol 101 ◽  
pp. 513-516
Author(s):  
Kenneth A. Van Riper
Keyword(s):  
Neutron Star ◽  
Surface Temperature ◽  
Supernova Remnants ◽  
Temperature Drop ◽  
Magnetic Star ◽  
Pion Condensate ◽  
Neutron Star Cooling ◽  
Cooling Mechanism ◽  
Cooling Effects ◽  
Star Surface

Neutron star cooling calculations are reported which employ improved physics in the calculation of the temperature drop through the atmosphere. The atmosphere microphysics is discussed briefly. The predicted neutron star surface temperatures, in the interesting interval 300 ≤ t (yr) ≤ 105, do not differ appreciably from the earlier results of Van Riper and Lamb (1981) for a non-magnetic star; for a magnetic star, the surface temperature is lower than in the previous work. Comparison with observational limits show that an exotic cooling mechanism such as neutrino emission from a pion-condensate or in the presence of percolating quarks, is not required, unless the existence of a neutron star in the Tycho or SN1006 supernova remnants is established.

scholarly journals Solar activity and solar oscillations

1997 ◽  
Vol 181 ◽  
pp. 277-285
Author(s):  
Y. Elsworth
Keyword(s):  
Magnetic Field ◽  
Solar Activity ◽  
Radio Emission ◽  
Surface Temperature ◽  
The Sun ◽  
Solar Oscillations ◽  
Thermal Component ◽  
X Ray ◽  
Convective Flows ◽  
Wide Range

Helioseismology provides us with the tools to probe solar activity. So that we can consider how the solar oscillations are influenced by that activity, we first consider the phenomena that we associate with the active Sun. The surface of the Sun is not quiet but shows evidence of convection on a wide range of scales from a few hundred kilometres through to several tens-of-thousands of kilometres. The surface temperature shows signs of the convection structures with the temperature in the bright granules being some 100 K to 200 K hotter than the surrounding dark lanes. Sunspots, which are regions of high magnetic field that suppress convective flows, are clearly visible to even quite crude observations. They are several tens-of-thousands of kilometres in diameter and about 2000 K cooler than their surroundings. Ultraviolet and X-ray pictures from satellites show that the higher layers of the solar atmosphere are very non-uniform with bright regions of high activity. Contemporaneous magnetograms show that these regions are associated with sunspots. Flares - regions of magnetic reconnections - are seen at all wavelengths from X-ray through the visible to radio. They are the non-thermal component of the radio emission of the Sun. There are many other indicators of activity on the Sun.

scholarly journals Neutron star cooling and the rp process in thermonuclear X-ray bursts

2017 ◽  
Vol 606 ◽  
pp. A130 ◽  
Author(s):  
J. J. M. in ’t Zand ◽  
M. E. B. Visser ◽  
D. K. Galloway ◽  
J. Chenevez ◽  
L. Keek ◽  
...  
Keyword(s):  
Neutron Star ◽  
X Ray ◽  
Rp Process ◽  
Neutron Star Cooling

scholarly journals Shall we Observe a Radio Binary Pulsar in SN 1987A?

1992 ◽  
Vol 128 ◽  
pp. 222-224
Author(s):  
Qiao G. J.
Keyword(s):  
Neutron Star ◽  
Surface Temperature ◽  
High Surface ◽  
Star Model ◽  
Single Star ◽  
X Ray ◽  
Binary Pulsar ◽  
Collapse Model ◽  
High Surface Temperature ◽  
Γ Ray

AbstractAn induced-collapse model [hereafter IC model; He et al. (1990)] can overcome the problems of the single star model of SN1987A. According to the IC model, there is a possibility that the SN1987A remnant will be a binary system with two neutron stars, one of them (SK-69 202) will have a strong magnetic field and a high surface temperature which favors detection as an X-ray or γ-ray pulsar. If the surface temperature of the neutron star cools down to T = 107 K, a radio binary pulsar is expected. There is also the possibility that an X-ray or γ-ray pulsar will be observed first, and only later will a radio pulsar will be detected.A newly formed neutron star is thought to have a short (millisecond) period. In this case, the core emission beam is then very large (Qiao 1992) and is thus very likely to swing in the direction of the Earth.

scholarly journals IGR J17503–2636: a candidate supergiant fast X-ray transient

2019 ◽  
Vol 624 ◽  
pp. A142 ◽  
Author(s):  
C. Ferrigno ◽  
E. Bozzo ◽  
A. Sanna ◽  
G. K. Jaisawal ◽  
J. M. Girard ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Neutron Star ◽  
Energy Distribution ◽  
Power Law ◽  
Spectral Energy Distribution ◽  
High Energy ◽  
Spectral Energy ◽  
X Ray ◽  
Broad Feature

The object IGR J17503–2636 is a hard X-ray transient discovered by INTEGRAL on 2018 August 11. This was the first ever reported X-ray emission from this source. Following the discovery, follow-up observations were carried out with Swift, Chandra, NICER, and NuSTAR. Here we report on the analysis of all of these X-ray data and the results obtained. Based on the fast variability in the X-ray domain, the spectral energy distribution in the 0.5–80 keV energy range, and the reported association with a highly reddened OB supergiant at ∼10 kpc, we conclude that IGR J17503–2636 is most likely a relatively faint new member of the supergiant fast X-ray transients. Spectral analysis of the NuSTAR data revealed a broad feature in addition to the typical power-law with exponential roll-over at high energy. This can be modeled either in emission or as a cyclotron scattering feature in absorption. If confirmed by future observations, this feature would indicate that IGR J17503–2636 hosts a strongly magnetized neutron star with B ∼ 2 × 1012 G.

scholarly journals Thermal luminosities of cooling neutron stars

2020 ◽  
Vol 496 (4) ◽  
pp. 5052-5071 ◽  
Author(s):  
A Y Potekhin ◽  
D A Zyuzin ◽  
D G Yakovlev ◽  
M V Beznogov ◽  
Yu A Shibanov
Keyword(s):  
Spectral Analysis ◽  
Neutron Star ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Cooling Curves ◽  
Middle Aged ◽  
Superdense Matter ◽  
Strong Magnetic Fields ◽  
Stellar Core ◽  
Neutron Star Cooling

ABSTRACT Ages and thermal luminosities of neutron stars, inferred from observations, can be interpreted with the aid of the neutron star cooling theory to gain information on the properties of superdense matter in neutron-star interiors. We present a survey of estimated ages, surface temperatures, and thermal luminosities of middle-aged neutron stars with relatively weak or moderately strong magnetic fields, which can be useful for these purposes. The catalogue includes results selected from the literature, supplemented with new results of spectral analysis of a few cooling neutron stars. The data are compared with the theory. We show that overall agreement of theoretical cooling curves with observations improves substantially for models where neutron superfluidity in stellar core is weak.

scholarly journals Neutron star cooling after deep crustal heating in the X-ray transient KS 1731-260

2007 ◽  
Vol 382 (1) ◽  
pp. L43-L47 ◽  
Author(s):  
P. S. Shternin ◽  
D. G. Yakovlev ◽  
P. Haensel ◽  
A. Y. Potekhin
Keyword(s):  
Neutron Star ◽  
X Ray ◽  
Neutron Star Cooling
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