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.

河外宇宙富含与宇宙中最强大的持久现象相关的来源：吸积超大质量黑洞，形成活动星系核（AGN）。许多活动星系核从其黑洞附近发射相对论性双等离子体射流，当这些射流靠近观察者的视线时，会产生一类称为耀变体的活动星系核。费米卫星和地面成像切伦科夫望远镜的观测表明，许多耀变体是兆电子伏（TeV）能量的巨大伽马射线源。然而，此前人们认为它们对宇宙能量的影响很小，因为它们的发光输出仅占宇宙总辐射功率的一小部分。然而，PI 及其合作者最近的工作表明 TeV 耀变体实际上是非凡的能源。通过研究双光束（TeV 耀变体的光子与河外背景光光子相遇时产生的正负电子对），PI 认为耀变体是红移 2-3 的星系际介质 (IGM) 中的主要热源。这将对宇宙的演化产生重大影响。PI将对TeV耀变体的宇宙学影响进行详细分析，这将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，再到热力学IGM 的形成，以及星系和星团的形成。他将 (1) 研究超相对论对光束的等离子体物理学，(2) 在宇宙学背景下设置耀变体加热，以及 (3) 探索他的工作对宇宙结构形成的影响。PI 将把他的研究传播到以多种方式吸引广泛的受众。首先，他将通过将传统讲座与在线视频课程和练习相结合，重新构想威斯康星大学密尔沃基分校 (UWM) 的物理入门课程。他还将与 UWM 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夏季研究项目。最后，PI 将通过在附近的曼弗雷德·奥尔森天文馆制作和举办 Astrobreak 系列公开讲座来进行公共宣传。