Connecting Eruptive Transients and Their Supernovae

连接爆发瞬变及其超新星

• 批准号: 1515559
• 负责人: Nathan Smith
• 金额: $ 38.24万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1515559&HistoricalAwards=false
• 关键词: Connecting; Eruptive; Transients; Their; Supernovae

The investigators will study an important class of massive stars, which have bright eruptions of material from their surface. These stars are in the last stages of their stellar life cycle, sometimes just before stellar explosions as supernovae (SNe). The investigators will use telescopes of the University of Arizona to study Luminous Blue Variable (LBV) stars. They will study the material ejected around nearby LBVs and the connection between SNe brightnesses. The material from the LBVs appears as bright rings of gas surrounding the stars. The material is visible in observations with optical telescopes and sensitive cameras. These observations provide the only way to measure the ejected mass and speed, as well as the typical time period between large eruptions. The investigators will study the environments of LBVs in the Milky Way and nearby galaxies. The investigator will mentor in CAMPARE, a program that fosters diversity in science by recruiting minorities and statistically underrepresented groups for a summer undergraduate research experience at Steward Observatory. The investigator will continue as a Sky Ambassador, working with Tucson elementary and high-school science teachers. As part of this program, they will develop instructional materials concerning the Sun and stars, supernovae, and the origin of the elements. There research program will also fund one Ph.D. thesis and several undergraduate researchers, providing them with experience with complex multi-wavelength observational data and time-variable phenomena. The investigators focus on observations to understand the stellar life cycle and explosive deaths of massive stars, since SNe dominate feedback in galaxies. SNe enrich the interstellar medium with elements, and they can be used probe conditions in the distant universe. The use of SNe to estimate of distances to galaxies hinges upon understanding the connection between massive stars and the various types of SNe they produce. Eruptive mass loss is influential in stellar evolution, and violent eruptions preceding core collapse can lead to some of the most luminous SNe known. This LBV/SNe connection was initially controversial because stellar models place massive LBVs in an earlier phase, but recently a dramatic confirmation of the connection between LBV stars and SNe was observed. In 2009 an LBV star was noted in a survey of massive stars, and then in 2012 this star became a core-collapse SNe. LBV-like eruptions may hold critical clues about stellar instability during the final phases of nuclear burning, vital to understanding core collapse. During these studies, the investigators will detect a large number of extragalactic transients, and constrain the luminosity, mass-loss rates, duration, and outflow speed of the eruptions. Some of these eruptive transients will soon explode as SNe, so the observations will have tremendous value for understanding the prelude to core collapse of massive stars.

研究人员将研究一类重要的大质量恒星，它们的表面有明亮的物质喷发。这些恒星处于恒星生命周期的最后阶段，有时就在恒星爆炸成为超新星（SNe）之前。研究人员将使用亚利桑那大学的望远镜来研究发光蓝色变星（LBV）。他们将研究lbv附近抛射出来的物质以及SNe亮度之间的联系。来自lbv的物质呈现为围绕恒星的明亮气体环。这种物质在光学望远镜和敏感相机的观测中是可见的。这些观测提供了唯一的方法来测量喷发的质量和速度，以及大喷发之间的典型时间间隔。研究人员将研究银河系和附近星系中lbv的环境。该研究员将指导CAMPARE项目，该项目通过招募少数民族和统计上代表性不足的群体来促进科学多样性，让本科生在斯图尔特天文台进行暑期研究。这位调查员将继续担任天空大使，与图森市的小学和高中科学教师一起工作。作为该计划的一部分，他们将编写有关太阳和恒星、超新星以及元素起源的教学材料。该研究项目还将资助一篇博士论文和几名本科生研究人员，为他们提供复杂的多波长观测数据和时变现象的经验。研究人员专注于观测，以了解恒星的生命周期和大质量恒星的爆炸死亡，因为SNe主导着星系的反馈。SNe丰富了星际介质中的元素，它们可以用来探测遥远宇宙的条件。利用SNe来估计到星系的距离取决于理解大质量恒星和它们产生的各种类型的SNe之间的联系。喷发的质量损失对恒星演化有影响，在核心坍缩之前的剧烈喷发可以产生一些已知最明亮的超新星。这种LBV/SNe之间的联系最初是有争议的，因为恒星模型将大质量LBV置于早期阶段，但最近观测到LBV恒星和SNe之间的联系得到了戏剧性的证实。2009年，在对大质量恒星的调查中发现了一颗LBV恒星，然后在2012年，这颗恒星变成了一颗核心坍缩的超新星。类似lbv的喷发可能提供了关于核燃烧最后阶段恒星不稳定性的关键线索，这对理解核心坍塌至关重要。在这些研究中，研究人员将探测到大量的河外瞬变，并限制亮度、质量损失率、持续时间和喷发的流出速度。其中一些短暂的爆发将很快以超新星的形式爆发，因此这些观测对于理解大质量恒星核心坍缩的前奏具有巨大的价值。