arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2005.03303astro-ph.HE
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用ELWA发现B0950 +08附近的脉冲星风星云

Discovery of a Pulsar Wind Nebula around B0950+08 with the ELWA

D. Ruan, G. B. Taylor, J. Dowell, K. Stovall, F. K. Schinzel, P. B. Demorest

摘要:

利用扩展长波天线阵(ELWA)和脉冲星面元技术,对PSR B 0950 +08在76 MHz的非脉冲辐射进行了探测。以前的研究表明,非脉冲发射可能是由于年轻恒星中的脉冲星风星云(PWNe)。其他的研究,如Basu等人(2012年)的研究,提出在较老的类星体中,这种辐射会延伸到某个半径,这个半径大约是光柱半径的数量级,并且起源于磁层。通过成像分析,我们得出结论,这颗自转年龄为1700万年的较老脉冲星周围有一个PWN,这是出乎意料的,因为随着脉冲星年龄的增长,其PWN光谱被认为从同步加速器转变为逆康普顿散射主导。在76 MHz时,截止脉冲发射的平均通量密度为0.59 $\pm$ 0.16 Jy。B 0950 +08的非脉冲辐射的大小为$\sim$ 110 $\pm$ 17弧秒(0.14 $\pm$ 0.02 pc),远远超出了光圆柱的直径,排除了磁层起源。利用我们的观测和VLSSr、TGSS、NVSS、FIRST和VLASS巡天的数据,我们发现B 0950 +08的光谱指数约为-1.36 $\pm$ 0.20,而PWN的光谱指数比-1.85 $\pm$ 0.45更陡。

英文摘要:

With the Expanded Long Wavelength Array (ELWA) and pulsar binning techniques, we searched for off-pulse emission from PSR B0950+08 at 76 MHz. Previous studies suggest that off-pulse emission can be due to pulsar wind nebulae (PWNe) in younger pulsars. Other studies, such as that done by Basu et al. (2012), propose that in older pulsars this emission extends to some radius that is on the order of the light cylinder radius, and is magnetospheric in origin. Through imaging analysis we conclude that this older pulsar with a spin-down age of 17 Myr has a surrounding PWN, which is unexpected since as a pulsar ages its PWN spectrum is thought to shift from being synchrotron to inverse-Compton-scattering dominated. At 76 MHz, the average flux density of the off-pulse emission is 0.59 $\pm$ 0.16 Jy. The off-pulse emission from B0950+08 is $\sim$ 110 $\pm$ 17 arcseconds (0.14 $\pm$ 0.02 pc) in size, extending well-beyond the light cylinder diameter and ruling out a magnetospheric origin. Using data from our observation and the surveys VLSSr, TGSS, NVSS, FIRST, and VLASS, we have found that the spectral index for B0950+08 is about -1.36 $\pm$ 0.20, while the PWN's spectral index is steeper than -1.85 $\pm$ 0.45.

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