论文标题
NGC 4869在昏迷集群中：扭曲，包裹，重叠和弯曲
NGC 4869 in the Coma cluster: twist, wrap, overlap and bend
论文作者
论文摘要
升级后的巨型内阁射电望远镜（GMRT）已用于在昏迷群集中对头尾射电射电射击望远镜（GMRT）进行成像，其角度分辨率为6.26 ARCSEC，当时为250-500 MHz，在1050-1450 MHz频段下为250-500 MHz和2.18 ARCSEC。档案遗产GMRT数据也已用于以610 MHz，325 MHz，240 MHz和150 MHz为610 MHz，325 MHz，325 MHz，325 MHz，325 MHz和150 MHz的角度分辨率对源成像。我们发现，〜200 kpc量表无线电形态由五个不同的区域组成，在〜1.4 arcmin（= 38.8 kpc）和〜3.4 arcmin（= 94.2 kpc）的山脊上明显存在捏合。从头部急剧弯曲〜3.5 arcmin（= 97 kpc）的急剧弯曲可能是由于投影效应所致。无线电光谱显示出渐进的光谱陡峭，这是距头部距离的函数，并且可能会重新加速同步器电子，也许在6-208 ARCSEC（= 2.8-96.1 kpc）区域中的磁场重新生成。我们报告了陡峭的鞘层膜，上面包裹着平坦的脊柱，暗示了横向速度结构，并带有速度快速移动的脊柱，周围是缓慢移动的护套层。我们还得出了辐射电子和均衡参数的寿命。特征特征的合理解释是，垂直于尾部方向的发射山脊是直接，准直的无线电射流的张开，因为它越过了kelvin-helmholtz的不稳定性，因此它越过表面亮度边缘。
The upgraded Giant Metrewave Radio Telescope (GMRT) has been used to image the head-tail radio galaxy NGC 4869 in the Coma cluster with an angular resolution of 6.26 arcsec at 250-500 MHz and 2.18 arcsec at the 1050-1450 MHz bands. The archival legacy GMRT data have also been used to image the source with angular resolutions from 4.9 to 21.8 arcsec at 610 MHz, 325 MHz, 240 MHz, and 150 MHz. We find that the ~200 kpc scale radio morphology consists of five distinct regions with the clear presence of a pinch at ~1.4 arcmin (= 38.8 kpc) and a ridge at ~3.4 arcmin (= 94.2 kpc) from the head. The sharp bend by ~70 deg at ~3.5 arcmin (= 97 kpc) from the head is possibly due to projection effects. The radio spectra show progressive spectral steepening as a function of distance from the head and there is possibly re-acceleration of the synchrotron electrons and perhaps also magnetic field re-generation in the 6-208 arcsec (= 2.8-96.1 kpc) region of the jet. We report a steep spectrum sheath layer enveloping a flat spectrum spine, hinting at a transverse velocity structure with a fast-moving spine surrounded by a slow-moving sheath layer. We also derive the lifetimes of the radiating electrons and equipartition parameters. A plausible explanation for the characteristic feature, a ridge of emission perpendicular to the direction of tail is the flaring of a straight, collimated radio jet as it crosses a surface brightness edge due to Kelvin-Helmholtz instabilities.
