I propose a model for the formation of slow-massive-wide (SMW) jets by accretion disks around compact objects. This study is motivated by claims for the existence of SMW jets in some astrophysical objects such as in planetary nebulae (PNs) and in some active galactic nuclei in galaxies and in cooling flow clusters. In this model the energy still comes from accretion onto a compact object. The accretion disk launches two opposite jets with velocity of the order of the escape velocity from the accreting object and with mass outflow rate of ~1-20% of the accretion rate as in most popular models for jet launching; in the present model these are termed fast-first-stage (FFS) jets. However, the FFS jets encounter surrounding gas that originates in the mass accretion process, and are terminated by strong shocks close to their origin. Two hot bubbles are formed. These bubbles accelerate the surrounding gas to form two SMW jets that are more massive and slower than the FFS jets. There are two conditions for this mechanism to work. Firstly, the surrounding gas should be massive enough to block the free expansion of the FFS jets. Most efficiently this condition is achieved when the surrounding gas is replenished. Secondly, the radiative energy losses must be small.
Structured jets in TeV BL Lac objects and radiogalaxies
TeV BL Lacertae天体在伽马射线发射区需要极端的相对论性整体运动,但在VLBI尺度下,它们的射电结几乎不移动。同样的来源显示,在无线电中,一种由快速脊柱加慢速层组成的结构的证据。我们建议,这种结构存在,甚至在空间尺度上的区域负责的伽马射线发射。一个组件看到另一个组件产生的(光束)辐射,这增强了两个组件的逆康普顿发射。此外,这允许磁场与发射粒子几乎均分。脊柱的逆康普顿发射在其框架中是各向异性的,可能通过康普顿火箭效应产生脊柱的减速。在这种情况下,慢层也是相对强的高能量发射体,因此放射性镓变得可能被GLAST检测到。
大质量X射线双星是由一个致密的物体从早期类型的施主星的恒星风中吸积物质而形成的。在这些系统中的一些,称为微类星体,相对论喷流从致密物体的周围发射。这样的喷流与伴星的光子场、恒星风相互作用,并且在很远的距离上与星际介质相互作用。在本文中,我将回顾这种相互作用的主要结果,特别强调高能光子和中微子的产生。将详细讨论某些特定系统(如LS I +61 303)的情况。将提出今后在不同波长上观测这类物体的前景。