The Origin and Evolution of Extragalactic Radio Sources and their Impact on Galaxy Formation and Evolution

位于星系中心的超大质量黑洞（活动星系核，AGN）可以被气体的吸积所推动，产生极具能量的现象，如吸积气体的发光热盘和相对论性等离子体和磁场的强大流出，称为喷流。观测到的超大质量黑洞与宿主星系的质量关系表明，星系及其中心黑洞必须在一种反馈机制的影响下共同演化，这种反馈机制使它们的质量成比例。最近已经认识到，强大的agn驱动的外流直接影响星系的演化，射流中的动能加热星系的气体并将其从中央凸起区域驱逐出去。这反过来影响星系恒星形成历史，调解宿主星系和中心超大质量黑洞之间的关系，形成星系光度函数的高亮度端。“AGN反馈效应”现在经常被纳入星系演化的数值模拟中。然而，主要的不确定性仍然存在于AGN如何与形成和演化的宿主星系及其环境相互作用，包括反馈的时间尺度和能量学。如果我们要真正理解星系演化与AGN活动之间的联系，从而准确地将AGN反馈效应纳入星系形成和演化模型，那么解决这些不确定性是很重要的。这个问题已经被加拿大和美国最近的十年调查确定为天文学和天体物理学的一个关键问题。我的长期目标是了解由于射电源膨胀导致能量在宿主星系中沉积的物理过程，包括空间尺度、时间尺度和总能量。我们的短期目标是研究紧凑型射电源，以探测亚kpc到kpc尺度上喷流与其星际介质（ISM）之间的相互作用。这些射电源与ISM的大小很好地匹配，应该对宿主星系的恒星形成产生最大的影响，无论是积极的还是消极的。我之前的工作表明，紧凑射电源中的喷流与气体云有强烈的相互作用，在某些情况下可以触发恒星形成，也可以对ISM的热成分产生冲击。因此，CSS源探测了理解射电源反馈所需的时间尺度和能量。这项研究的影响将极大地提高我们对星系的形成和演化如何受到超大质量黑洞的影响的理解。申请的资金将为曼尼托巴大学的两名研究生和一名本科生提供为期5年的暑期研究支持。学生将培养团队合作、独立思考、有效沟通和开展一线科学研究的必要技能。

Supermassive black holes located in the center of a galaxy (an Active Galactic Nucleus, AGN) can be fueled by the accretion of gas, producing extremely energetic phenomenon such as luminous hot disks of accreting gas and powerful outflows of relativistic plasma and magnetic fields, called jets.  The observed relation between mass of the supermassive black hole and the host galaxy  indicates that galaxies and their central black holes must co-evolve under the influence of a feedback mechanism which creates the proportionality in their masses.  It has been recently recognized that powerful AGN-driven outflows directly affect the evolution of galaxies, with the kinetic energy in the jets heating the galaxy's gas and expelling it from the central bulge regions. This in turn influences galaxies star formation histories, mediating the relationship between host galaxy and central supermassive black hole shaping the high luminosity end of the galaxy luminosity function. The "AGN feedback effect" is now routinely incorporated into numerical simulations of galaxy evolution. However, major uncertainties remain about how AGN interact with the forming and evolving host galaxies and their environments, including the time scales and energetics of the feedback. It is important to resolve these uncertainties if we are to truly understand the links between galaxy evolution and AGN activity, and thereby accurately incorporate the AGN feedback effect into galaxy formation and evolution models. This question has been identified as a critical issue for astronomy and astrophysics by the most recent decadal surveys in both Canada and the USA. My long term goals are to understand the physical processes through which energy is deposited in the host galaxy due to the expanding radio source, including the spatial scales, time scales, and total energy. Our short term goals for this proposal are to investigate compact radio sources to probe interactions between jets and their interstellar medium (ISM) on sub-kpc to kpc scales. These radio sources are well matched to the size of the ISM and should have maximum impact on the star formation of the host galaxy in either a positive or negative sense. My previous work has shown that the jets in compact radio sources interact strongly with gas clouds, can trigger star formation in some cases, and can also drive shocks into the hot component of the ISM. Thus, the CSS sources probe the time scales and energetics which are needed to understand radio source feedback. The impact of this research will be to greatly improve our understanding of how the formation and evolution of galaxies is affected by their supermassive black holes. The requested funding will provide support for two graduate students and summer research for an undergraduate at U Manitoba for 5 years. The students will develop the skills necessary to work in teams, think independently, communicate effectively, and carry out front-line scientific research.