1,637 research outputs found
Electric Character of Strange Stars
Using the Thomas-Fermi model, we investigated the electric characteristics of
a static non-magnetized strange star without crust in this paper. The exact
solutions of electron number density and electric field above the quark surface
are obtained. These results are useful if we are concerned about physical
processes near the quark matter surfaces of strange stars.Comment: 4 pages, 2 figures, LaTeX, Published in Chinese Physics Letters,
Vol.16, p.77
Functional characterization of a short peptidoglycan recognition protein from Chinese giant salamander (Andrias davidianus)
This work was supported by the National Natural Science Foundation of China (Grant no. 31302221, 31172408 and 31272666) and Jiangsu Province (Grant no. BK20171274 and BK2011418), and partially by the Opening Project of Jiangsu Key Laboratory of Biochemistry and Biotechnology of Marine Wetland (Grant no. K2016-08). QZ was supported by the âQinglanâ project of Jiangsu province of China.Peer reviewedPublisher PD
5 GHz TMRT observations of 71 pulsars
We present integrated pulse profiles at 5~GHz for 71 pulsars, including eight
millisecond pulsars (MSPs), obtained using the Shanghai Tian Ma Radio Telescope
(TMRT). Mean flux densities and pulse widths are measured. For 19 normal
pulsars and one MSP, these are the first detections at 5~GHz and for a further
19, including five MPSs, the profiles have a better signal-to-noise ratio than
previous observations. Mean flux density spectra between 400~MHz and 9~GHz are
presented for 27 pulsars and correlations of power-law spectral index are found
with characteristic age, radio pseudo-luminosity and spin-down luminosity. Mode
changing was detected in five pulsars. The separation between the main pulse
and interpulse is shown to be frequency independent for six pulsars but a
frequency dependence of the relative intensity of the main pulse and interpulse
is found. The frequency dependence of component separations is investigated for
20 pulsars and three groups are found: in seven cases the separation between
the outmost leading and trailing components decreases with frequency, roughly
in agreement with radius-to-frequency mapping; in eleven cases the separation
is nearly constant; in the remain two cases the separation between the outmost
components increases with frequency. We obtain the correlations of pulse widths
with pulsar period and estimate the core widths of 23 multi-component profiles
and conal widths of 17 multi-component profiles at 5.0~GHz using Gaussian
fitting and discuss the width-period relationship at 5~GHz compared with the
results at at 1.0~GHz and 8.6~GHz.Comment: 46 pages, 14 figures, 8 Tables, accepted by Ap
The Current Flows in Pulsar Magnetospheres
The global structure of the current flows in pulsar magnetospheres is
investigated, with rough calculations of the elements in the magnetospheric
circuit. It is emphasized that the potential of critical field lines is the
same as that of interstellar medium, and that the pulsars whose rotation axes
and magnetic dipole axes are parallel should be positively charged, in order to
close the pulsar's current flows. The statistical relation between the radio
luminosity and pulsar's electric charge (or the spindown power) may hint that
the millisecond pulsars could be low-mass bare strange stars.Comment: 10 pages, 4 figure
The `bare' strange stars might not be bare
It is proposed that the `bare' strange matter stars might not be bare, and
radio pulsars might be in fact `bare' strange stars. As strange matter stars
being intensely magnetized rotate, the induced unipolar electric fields would
be large enough to construct magnetospheres. This situation is very similar to
that discussed by many authors for rotating neutron stars. Also, the strange
stars with accretion crusts in binaries could act as X-ray pulsars or X-ray
bursters. There are some advantages if radio pulsars are `bare' strange stars.Comment: 11 pages, 1 Postscript figures, LaTeX, Chin. Phys. Lett. 1998,
Vol.15, Nov.12, p.93
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