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1.
Vasilii Gvaramadze 《Astrophysics and Space Science》2000,274(1-2):195-203
A model of the Vela supernova remnant (SNR) based on a cavity explosion of a supernova (SN) star is proposed. It is suggested
that the general structure of the remnant is determined by the interaction of the SN blast wave with a massive shell created
by the SN progenitor (15-20 M⊙) star. A possible origin of the nebula of hard X-ray emission detected around the Velapulsar is discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
The young shell-type supernova remnant RCW 103 has peculiar properties in the X-ray morphology obtained with Chandra.The southeastern shell is brighter in the X-rays,and the curved border of the shell in this region is flatter than the other part.We investigate the formation of the peculiar periphery of the supernova remnant RCW 103 using 3D hydrodynamical simulation.Assuming that the supernova ejecta has been evolved in the medium with a density gradient,the detected shape of the periphery can be generally reproduced.For RCW 103,with the ejecta mass of 3.0 M,the density of the background material of 2.0 cm-3,and a gradient of 3.3-4.0 cm-3pc-1,the X-ray periphery can be generally reproduced.The simulation turned out that the asymmetry of the SNR RCW 103 is mainly due to the inhomogeneous medium with a density gradient. 相似文献
3.
D. Bhattacharya 《Journal of Astrophysics and Astronomy》1990,11(2):125-140
One of the intriguing aspects of supernova remnants is their morphology. While the majority of them look like hollow shells,
a few, called plerions, are centrally filled like the Crab nebula, and some have a shell-plerion combination morphology. The
centrally-filled component in these remnants is believed to be powered by a central pulsar. In this paper we present results
of model calculations of the evolution of surface brightness and morphology of supernova remnants containing pulsars. We discuss
how the morphology of a supernova remnant will depend on the velocity of expansion, the density of the ambient medium into
which it is expanding, and the initial period and magnetic field strength of the central pulsar 相似文献
4.
X. Ribeyre L. Hallo V. T. Tikhonchuk S. Bouquet J. Sanz 《Astrophysics and Space Science》2007,307(1-3):169-172
The Rayleigh-Taylor instability (RTI) plays an important role in the dynamics of several astronomical objects, in particular,
in the supernovae (SN) evolution. In the present paper we examine the dynamics of a shell (representing a type II SN remnant)
blown-up by a wind emitted by a central pulsar. The shell is accelerated by the pulsar wind and its inner surface experiences
the RTI. We develop an analytical approach by using a specific transformation into the coordinate frame co-moving with the
SN ejecta. We first derive a non-stationary spherically symmetric solution describing an expansion of a gas shell under the
pressure of a central source (pulsar). Then, we analyze its 3D stability with respect to a small perturbation on the inner
shell surface. The dispersion relation is derived in the co-moving reference frame. The growth rate of the perturbation is
found and its temporal evolution is discussed. We compare our result with the previous published studies and apply it to the
Crab nebula evolution. 相似文献
5.
We study analytically the Rayleigh–Taylor instability in expanding supernova gas shell. The instability appears at the inner
shell surface accelerated by blowing pulsar wind. The most dangerous perturbations correspond to wavelengths comparable to
the shell thickness. We analyze the fragility of the supernova remnant shell in function of the initial perturbation amplitude
and the shell thickness. 相似文献
6.
A local void and the accelerating Universe 总被引：1，自引：0，他引：1
K. Tomita 《Monthly notices of the Royal Astronomical Society》2001,326(1):287-292
RCW 114 is a filamentary nebula of about 250 arcmin diameter. Based on its large diameter-to-filament-width ratio, the expansion velocity, distance and size of the shell, it has been suggested that RCW 114 is a supernova remnant in its momentum-conserving phase. Confirmation of this identification is important, as the large angular size and extensive optical emission of this object will allow for detailed study to improve our knowledge of supernova remnants and their interaction with the interstellar medium.
We have used the FLAIR instrument on the UK Schmidt Telescope to obtain optical spectra of several filaments in RCW 114. These confirm that the emission is being produced by the interaction of the shock wave of a supernova remnant with the surrounding interstellar medium. We also obtained narrow-band H α +[N ii ] and [S ii ] images to examine the spatial variation in ionization structure. 相似文献
We have used the FLAIR instrument on the UK Schmidt Telescope to obtain optical spectra of several filaments in RCW 114. These confirm that the emission is being produced by the interaction of the shock wave of a supernova remnant with the surrounding interstellar medium. We also obtained narrow-band H α +[N ii ] and [S ii ] images to examine the spatial variation in ionization structure. 相似文献
7.
We present a high-resolution Chandra X-ray observation of PSR B0540-69, the Crab-like 50 ms pulsar in the Large Magellanic Cloud. We use phase-resolved imaging to decompose the extended X-ray emission, as expected of a synchrotron nebula, from the pointlike emission of the pulsar. The image of the pulsed X-ray emission shows a well-defined point-spread function of the observation, while the resolved nebula has a morphology and size remarkably similar to the Crab nebula, including evidence for a jetlike feature from PSR B0540-69. The patchy outer shell, which most likely represents the expanding blast wave of the supernova, is reminiscent of that seen in radio. Based on morphology, size, and energetics, there can be little doubt that SNR B0540-69 is an analogous system to the Crab but located in our neighboring galaxy. 相似文献
8.
We investigated the kinematics of the pulsar wind nebula (PWN) in the old supernova remnant CTB 80 using the Fabry-Perot interferometer of the 6-m Special Astrophysical Observatory telescope. In addition to the previously known expansion of the system of bright filaments with a velocity of 100–200 km s?1, we detected weak high-velocity features in the Hα line at least up to velocities of 400–450 km s?1. We analyzed the morphology of the PWN in the Hα, [S II], and [O III] lines using HST archival data and discuss its nature. The shape of the central filamentary shell, which is determined by the emission in the [O III] line and in the radio continuum, is shown to be consistent with the bow-shock model for a significant (about 60°) inclination of the pulsar’s velocity vector to the plane of the sky. In this case, the space velocity of the pulsar is twice as high as its tangential velocity, i.e., it reaches ?500 km s?1, and PSR B1951+32 is the first pulsar whose radial velocity about 40 km s?1 has been estimated from PWN observations. The shell-like Hα-structures outside the bow shock front in the east and the west could be associated with both the pulsar’s jets and the pulsar wind breakthrough due to the layered structure of the extended CTB 80 shell. 相似文献
9.
No supernova remnant has been found near the third youngest pulsar PSR 1930+22 down to a -limiting brightness temperature
of 1·4 K at 610 MHz. This is 6–8 times less than expected of a typical remnant whose age is that of the pulsar (3·60×104 years). 相似文献
10.
U. Hwang R. Petre A. E. Szymkowiak S. S. Holt 《Journal of Astrophysics and Astronomy》2002,23(1-2):81-87
We present a newChandra observation of Tycho’s supernova remnant with the Advanced CCD Imaging Spectrometer. Multicolor Xray imaging reveals new
details of the outer shock and ejecta. At energies between 4 and 6 keV, the outline of the outer shock is clearly revealed
in X-rays for the first time. The distribution of the emission from lines of Si and Fe are confirmed to have a different morphology
from each other, and the Si ejecta are shown to extend to the blast shock at several locations. Characteristic spectra of
the outer shock and ejecta are also presented. 相似文献
11.
I. V. Gosachinskii 《Astronomy Letters》2010,36(4):260-268
The neutral hydrogen at 21 cm has been investigated with the RATAN-600 radio telescope around the supernova remnant G 65.3+5.7,
which has the largest angular sizes in the group of shell remnants. An expanding HI shell left after an old supernova explosion
with an energy of ∼1051 erg and an age of 440 000 yr coincident in coordinates with the radio and optical remnant has been discovered. Since an X-ray
emission from a much younger (27 000 yr) supernova remnant is observed in the same region and the shells detected by nebular
lines have probably intermediate ages, we suggest that several successive supernova explosions have occurred here. 相似文献
12.
The recently discovered young supernova remnant (SNR) RX J0852.0−4622 has attracted much interest since its discovery because of the possibility that it may have been generated by the nearest supernova in recent history. We note the presence of two Parkes Multibeam Survey pulsars within the boundary of the remnant. We discuss the properties of the two pulsars and the likelihood of either of them being physically linked to the SNR. We tentatively suggest that, given the current uncertainties in the distance to RX J0852.0−4622, one of these pulsars, the 65-ms period PSR J0855−4644 could indeed be the compact remnant of this supernova explosion. If the pulsar birth site is at the geometrical centre of the nebula, then, for the transverse pulsar velocity to be reasonable, the SNR must be nearby (around 250 pc) and no younger than about 3000 yr old. 相似文献
13.
《New Astronomy》2019
Three decades have passed since the supernova SN 1987A was observed in the Large Magellanic Cloud, inside which the product is most likely a neutron star (NS) formed in the core collapse explosion.Although lots of observations with sensitive radio telescopes have taken place, astronomers have not yet detected any evidence for a radio pulsar around the remnant of 1987A. To investigate pulsars inside the SN remnants, we calculate the cut-off oscillation frequency of the plasma around the presumed NS inside SN1987A, as shown to be about 33 GHz at present (2018 CE), which is much higher than the favorite “searching window” (e.g. L-band ∼ 1.4 GHz) of radio pulsar surveys that have been commonly exploited by astronomers. Since radio waves with frequencies lower than the plasma cut-off frequency cannot penetrate the SN remnant media, we suggest that astronomers use higher frequency bands to search for a pulsar in SN 1987A.Furthermore, with the expansion of SN remnant media, we find that the plasma cut-off frequency can decay to the L-band (1.4 GHz) in the future. The strategy of finding a pulsar of SN 1987A is that either the high frequency bands of radio telescopes, or the high energy detections at Gamma-ray and X-ray bands by space satellites are applied. 相似文献
14.
15.
We present results from the first light observations of the Cassiopeia A supernova remnant (SNR) by the Chandra X-Ray Observatory. Based on representative spectra from four selected regions, we investigate the processes of nucleosynthesis and mixing in Cas A. We make the first unequivocal identification of iron-rich ejecta produced by explosive silicon burning in a young Galactic SNR. Elsewhere in the remnant, we see silicon-rich ejecta from explosive oxygen burning. The Fe-rich ejecta lie outside the Si-rich material, indicating that bulk motions were extensive and energetic enough in Cas A to cause a spatial inversion of a significant portion of the supernova core. It is likely that this inversion was caused by "Fe"-rich ejecta emerging in plumes from the rising bubbles in the neutrino-driven convection layer during the supernova explosion. In addition, the radioactive decay energy from 56Ni may have contributed to the subsequent evolution of the material. We have also discovered faint, well-defined filaments with featureless X-ray spectra that are possibly sites of cosmic-ray acceleration in Cas A. 相似文献
16.
We present narrow band AAO/UKST Hα images and medium and low resolution optical spectra of a nebula shell putatively associated with the Wolf-Rayet star WR 60.
We also present the first identification of this shell in the radio regime at 843 MHz and at 4850 MHz from the Sydney University
Molonglo Sky Survey (SUMSS), and from the Parkes-MIT-NRAO (PMN) survey respectively. This radio emission closely follows the
optical emission. The optical spectra from the shell exhibits the typical shock excitation signatures sometimes seen in Wolf-Rayet
stellar ejecta but also common to supernova remnants. A key finding however, is that the WR 60 star, is not, in fact, anywhere
near the geometrical centre of the putative arcuate nebula ejecta as had been previously stated. This was due to an erroneous
positional identification for the star in the literature which we now correct. This new identification calls into serious
question any association of the nebula with WR 60 as such nebula are usually quite well centred on the WR stars themselves.
We now propose that this fact combined with our new optical spectra, deeper Hα imaging and newly identified radio structures actually imply that the WR 60 nebula should be reclassified as an unassociated
new supernova remnant which we designate G310.5+0.8. 相似文献
17.
The loss of angular momentum owing to unstable r-modes in hot young neutron stars has been proposed as a mechanism for achieving the spin rates inferred for young pulsars. One factor that could have a significant effect on the action of the r-mode instability is fallback of supernova remnant material. The associated accretion torque could potentially counteract any gravitational-wave-induced spin-down, and accretion heating could affect the viscous damping rates and hence the instability. We discuss the effects of various external agents on the r-mode instability scenario within a simple model of supernova fallback on to a hot young magnetized neutron star. We find that the outcome depends strongly on the strength of the magnetic field of the star. Our model is capable of generating spin rates for young neutron stars that accord well with initial spin rates inferred from pulsar observations. The combined action of r-mode instability and fallback appears to cause the spin rates of neutron stars born with very different spin rates to converge, on a time-scale of approximately 1 year. The results suggest that stars with magnetic fields ≤1013 G could emit a detectable gravitational wave signal for perhaps several years after the supernova event. Stars with higher fields (magnetars) are unlikely to emit a detectable gravitational wave signal via the r-mode instability. The model also suggests that the r-mode instability could be extremely effective in preventing young neutron stars from going dynamically unstable to the bar-mode. 相似文献
18.
K. T. S. Brazier O. Reimer G. Kanbach & A. Carramiñana 《Monthly notices of the Royal Astronomical Society》1998,295(4):819-824
We present a detailed analysis of the high-energy gamma-ray source 2EG J0008+7307. The source has a steady flux and a hard spectrum, softening above 2 GeV. The properties of the gamma-ray source are suggestive of emission from a young pulsar in the spatially coincident CTA 1 supernova remnant, which has recently been found to have a non-thermal X-ray plerion. Our 95 per cent uncertainty contour around the > 1 GeV source position includes the point-like X-ray source at the centre of the plerion. We propose that this object is a young pulsar and is the most likely counterpart of 2EG J0008+7307. 相似文献
19.
K. V. Manukovskii 《Astronomy Letters》2010,36(3):191-203
A series of numerical models has been constructed for the three-dimensional explosion dynamics of a low-mass neutron star
in a binary system that results from the collapse of the rotating iron core of a massive supernova. The numerical solution
has been obtained by the particle method with an adaptive time step that allows the computational accuracy to be controlled
automatically. The constructed numerical models include the proper motion of the massive component in the binary system of
neutron stars, their finite sizes, the graduality of energy release during the explosive disruption of a critical-mass neutron
star, and the nonuniform expansion velocity distribution of iron ejecta. The extent to which each of the listed parameters
affects the explosion characteristics has been determined. The total explosion energy and the pulsar escape velocity have
been estimated. A sizable fraction of the material of the exploded neutron star has been found to remain gravitationally bound
to the massive component of the binary system. A further study of its dynamics is of interest in its own right, because the
captured material can be considered as an additional source of muon neutrinos. 相似文献
20.
I. V. Gosachinskii 《Astronomy Letters》2013,39(3):179-184
The neutral hydrogen emission at 21 cm has been investigated with the RATAN-600 radio telescope in the vicinity of the supernova remnant HB9. A clumpyHI shell with radial motions surrounding the remnant has been detected. Its measured parameters contradict the connection with a shock wave from a supernova explosion. The shell formation under the action of a wind from a star that exploded as a supernova at the end of its evolution seems more realistic. The characteristics of the star obtained from the observed shell parameters are the following: a wind power of 0.5 × 1038 erg s?1, a mass-loss rate of 3.7 × 10?5 M ⊙ yr?1, and an age of 3 × 106 yr. Given the measurement errors, the mass of the star is estimated to be >8M ⊙. 相似文献