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91.
Zhao Wen Zhang Xing Liu Xiao-jin Zhang Yang Wang Yun-yong Zhang Fan Zhao Yu-hang Guo Yue-fan Chen Yi-kang Ai Shun-ke Zhu Zong-hong Wang Xiao-ge Lebigot Eric Du Zhi-hui Cao Jun-wei Qian Jin Yin Cong Wang Jian-bo Wen Lin-qing 《Chinese Astronomy and Astrophysics》2018,42(4):487-526
The recent discovery of gravitational-wave burst GW150914 marks the coming of a new era of gravitational-wave astronomy, which provides a new window to study the physics of strong gravitational field, extremely massive stars, extremely high energy processes, and extremely early universe. In this article, we introduce the basic characters of gravitational waves in the Einstein's general relativity, their observational effects and main generation mechanisms, including the rotation of neutron stars, evolution of binary systems, and spontaneous generation in the inflation universe. Different sources produce the gravitational waves at quite different frequencies, which can be detected by different methods. In the lowest frequency range (f < 10?15 Hz), the detection is mainly dependent of the observation of B-mode polarization of cosmic microwave background radiation. In the middle frequency range (10?9 < f < 10?6 Hz), the gravitational waves are detected by analyzing the timing residuals of millisecond pulsars. And in the high frequency range (10 ? 4 < f < 104 Hz), they can be detected by the space-based and ground-based laser interferometers. In particular, we focus on the main features, detection methods, detection status, and the future prospects for several important sources, including the continuous sources (e.g., the spinning neutron stars, and stable binary systems), the burst sources (e.g., the supernovae, and the merge of binary system), and the stochastic backgrounds generated by the astrophysical and cosmological process. In addition, we forecast the potential breakthroughs in gravitational-wave astronomy in the near future, and the Chinese projects which might involve in these discoveries. 相似文献
92.
93.
D. A. Green 《Monthly notices of the Royal Astronomical Society》2009,399(1):177-180
G35.6−0.4 is an extended radio source in the Galactic plane which has previously been identified as either a supernova remnant or an H ii region. Observations from the Very Large Array Galactic Plane Survey at 1.4 GHz with a resolution of 1 arcmin allow the extent of G35.6−0.4 to be defined for the first time. Comparison with other radio survey observations show that this source has a non-thermal spectral index, with S ∝ν−0.47±0.07 . G35.6−0.4 does not have obvious associated infrared emission, so it is identified as a Galactic supernova remnant, not an H ii region. It is ≈15 × 11 arcmin2 in extent, showing partial limb brightening. 相似文献
94.
Data on the positions of gamma-ray bursts (GRBs) in galaxies are used to construct the radial distributions of their surface density. The gradient in GRB surface density is shown to decrease sharply at a galactocentric distance equal to the effective galactic radius. In central galactic regions, the GRB density distribution agrees with the galactic surface-brightness distribution; in outer regions, the GRB density decreases more slowly than does the surface brightness. Based on improved statistics, we analyze the radial distribution of type Ib/c supernovae. We show that it differs insignificantly from the distributions of other types of supernova and exhibits a much closer similarity to the distribution of star-forming regions than do GRBs. Although the statistics for GRBs is poor, the deviation of their distribution from the distribution of active star-forming regions in nearby galaxies seems to have been firmly established. A correlation of GRBs with the distribution of dark matter in outer galactic regions is not ruled out. 相似文献
95.
96.
A radio continuum map of a 1°5 X 1°5 region in the galactic plane nearl = 54° is presented at 49 cm with a resolution of 100 arcsec X 200 arcsec. The shell source G 54.4 - 0.3 has the characteristics
of a supernova remnant while the second large ring structure G 53.9 + 0.3 is a Hn ring consisting of W 52 and several small-diameter
thermal sources. One of the twelve small-diameter sources (G 54.73 + 0.61) has a spectral index⇏ -1.6. 相似文献
97.
We consider the time, angular, and energy distributions of SN 1987A events and discuss the quality of their agreement with
the expectations. A global interpretation is made by considering a simple model based on the standard scenario for the explosion.
Despite the contrasting and confusing indications, a straightforward fit to the data provides a result that does not contradict
but rather supports the expectations. The calculated electron antineutrino flux is applied to predict the relic neutrino signal.
The article was translated by the authors. 相似文献
98.
I. V. Gosachinskii 《Astronomy Letters》2005,31(3):179-185
The well-known shell supernova remnant (SNR) HB3 is part of a feature-rich star-forming region together with the nebulae W3, W4, and W5. We study the HI structure around this SNR using five RATAN-600 drift curves obtained at a wavelength of 21 cm with an angular resolution of 2′ in one coordinate over the radial-velocity range ?183 to +60 km s?1 in a wider region of the sky and with a higher sensitivity than in previous works by other authors. The spatial-kinematic distribution of HI features around the SNR clearly shows two concentric expanding shells of gas that surround the SNR and coincide with it in all three coordinates (α, δ, and V). The outer shell has a radius of 133 pc, a thickness of 24 pc, and an expansion velocity of 48 km s?1. The mass of the gas in it is ≈2.3 × 105M⊙. For the inner shell, these parameters are 78 pc, 36 pc, 24 km s? 1, and 0.9 × 105M⊙, respectively. The inner shell is immediately adjacent to the SNR. Assuming that the outer shell was produced by the stellar wind and the inner shell arose from the shock wave of the SNR proper, we estimated the age of the outer shell, ≈1.7 × 106 yr, and the mechanical luminosity of the stellar wind, 1.5 × 1038 erg s?1. The inner shell has an age of ≈106 yr and corresponds to a total supernova explosion energy of ≈1052 erg. 相似文献
99.
100.