background: miniature neutron sources with high neutron flux have abundant applications in medicine, industry and researches. the most important general characteristic of miniature neutron sources is their diameter which is 3mm in average. in this research, we have surveyed and designed an am-be miniature neutron source fabrication. materials and methods: this investigation resulted in creation...

We report the detection of the double neutron star binary (DNSB) B1534+12 (= J1537+1155) with the Chandra X-ray Observatory. This DNSB (Porb = 10.1 hr) consists of the millisecond (recycled) pulsar J1537+1155A (PA = 37.9 ms) and a neutron star not detected in the radio. After the remarkable double pulsar binary J0737−3039, it is the only other DNSB detected in X-rays. We measured the flux of (2...

We present a comprehensive study of the relation between radio and X-ray emission in neutron star X-ray binaries, use this to infer the general properties of the disc–jet coupling in such systems, and compare the results quantitatively with those already established for black hole systems. There are clear qualitative similarities between the two classes of object: hard states below about 1% of ...

Until now, solar γ-ray and neutron emissions have only been detected during times of intense solar activity, specifically, during solar flares. These emissions arise from the interaction of accelerated solar particles (both electrons and ions) with the ambient solar material. However, there are several reasons to expect that γ-ray emission might also be detectable at times when there is no sign...

We consider gamma-ray burst outflows with a substantial neutron component that are either dominated by thermal energy (fireballs) or by magnetic energy. In the latter case, we focus on the recently introduced ‘AC’ model which relies on magnetic reconnection to accelerate the flow and power the prompt emission. For both the fireball and the AC model, we investigate the dynamical importance of ne...

We discuss how detection of gamma-ray emission from the decay of r-process nuclei can improve our understanding of r-process nucleosynthesis. We find that a gamma-ray detector with a sensitivity of ∼ 10 −7 γ cm −2 s −1 at E γ ≈ 100–700 keV may detect the emission from the decay of 194 Os produced in a future Galactic supernova. In addition, such a detector may detect the emission from the decay...

Numerical simulations for the merger of binary neutron stars are performed in full general relativity incorporating both nucleonic and hyperonic finite-temperature equations of state (EOS) and neutrino cooling. It is found that even for the hyperonic EOS, a hypermassive neutron star is first formed after the merger for the typical total mass ≈2.7M(⊙), and subsequently collapses to a black hole ...

Recent observations by XMM-Newton detected rotational pulsations in the total brightness and spectrum of several neutron stars. To properly interpret the data, accurate modeling of neutron star emission is necessary. Detailed analysis of the shape and strength of the rotational variations allows a measurement of the surface composition and magnetic field, as well as constrains the nuclear equat...

We present the result of astrometric observations of the radio pulsar PSR B0656+14, made using the Very Long Baseline Array. The parallax of the pulsar is π = 3.47± 0.36 mas, yielding a distance 288 −27 pc. This independent distance estimate has been used to constrain existing models of thermal x-ray emission from the neutron star’s photosphere. Simple blackbody fits to the x-ray data formally ...

The contribution of weakly–magnetized (B ∼ 10 G) neutron stars accreting the interstellar medium to the diffuse X–ray emission observed in the Galactic Center is investigated. It is shown that, under rather conservative assumptions about the neutron stars and gas distributions, the accretion luminosity can account for a sizable fraction, possibly most, of the detected X–ray flux in the 2.5–7 ke...