CAREER: The Physics and Cosmology of TeV Blazars

职业：TeV 耀变体的物理学和宇宙学

• 批准号: 1255469
• 负责人: Philip Chang
• 金额: $ 45.61万
• 依托单位: University of Wisconsin-Milwaukee
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1255469&HistoricalAwards=false
• 关键词: CAREER; Physics; Cosmology; TeV; Blazars

The extragalactic universe is abundant with sources that are associated with the most powerful persistent phenomenon in the universe: accreting supermassive black holes that form Active Galactic Nuclei (AGN). Numerous AGN launch relativistic twin jets of plasma from the immediate vicinity of their black holes which, when oriented close to the line of sight to the observer, give rise to a class of AGN named blazars. Observations by the Fermi satellite and ground based imaging Cerenkov telescopes show that many blazars are prodigious sources of gamma-rays at tera-electronvolt (TeV) energies. Their impact on the energetics of the universe, however, has previously been thought to be slim since their luminous output is a minor component of the total radiative power in the universe. However, recent work by the PI and his collaborators suggest that TeV blazars are, in fact, remarkable sources of energy. By studying pair beams (electron-positron pairs that are produced when photons from TeV blazars meet extragalactic background light photons) the PI argues that blazars are the dominant heat source in the intergalactic medium (IGM) at redshifts 2-3. This would have substantial implications for the evolution of the universe.The PI will perform a detailed analysis of the cosmological implications of TeV blazars, which will touch on many different areas of astrophysics: from linear plasma instabilties, to weak turbulence and thermalization, to thermodynamics of the IGM, and to the formation of galaxies and clusters. He will (1) investigate the plasma physics of ultrarelativistic pair beams, (2) set blazar heating in a cosmological context, and (3) explore the implications of his work for the structure formation of the universe.The PI will disseminate his research to a broad audience in numerous ways. First, he will reimagine introductory physics classes at the University of Wisconsin-Milwaukee (UWM), by combining traditional lectures with online video lessons and exercises. He will also work closely with the Astronomy Club at UWM by recruiting undergraduates and high school teachers for semester and summer research projects. Finally, the PI will perform public outreach by producing and giving public lectures through the Astrobreak series at the nearby Manfred Olson planetarium.

河外宇宙有着丰富的来源，这些来源与宇宙中最强大的持续现象有关：吸积超大质量黑洞，形成活动星系核（AGN）。许多活动星系核从它们的黑洞附近发射出相对论性的孪生等离子体喷流，当喷流的方向接近观测者的视线时，就产生了一类名为耀变体的活动星系核。费米卫星和切伦科夫地面成像望远镜的观测表明，许多耀变体是太电子伏（TeV）能量的巨大伽马射线源。然而，它们对宇宙能量的影响以前被认为是微小的，因为它们的发光输出是宇宙中总辐射功率的一个次要组成部分。然而，PI和他的合作者最近的工作表明，TeV耀变体实际上是显着的能源。通过研究对束（电子-正电子对，当TeV耀变体的光子遇到河外背景光子时产生），PI认为耀变体是星系际介质（IGM）中红移2-3的主要热源。PI将对TeV耀变体的宇宙学意义进行详细分析，涉及天体物理学的许多不同领域：从线性等离子体不稳定性到弱湍流和热化，到IGM的热力学，以及星系和星系团的形成。他将（1）研究超相对论对光束的等离子体物理，（2）在宇宙学背景下设置耀变体加热，（3）探索他的工作对宇宙结构形成的影响。PI将以多种方式向广大观众传播他的研究。首先，他将通过将传统讲座与在线视频课程和练习相结合，重新设计威斯康星大学密尔沃基分校（UWM）的入门物理课程。他还将与UWM的天文学俱乐部密切合作，招募本科生和高中教师进行学期和暑期研究项目。最后，PI将通过在附近的Manfred Olson天文馆制作和举办Astrobreak系列公开讲座来进行公众宣传。