A Study of Classical Novae Across Differing Stellar Populations

该项目旨在更好地了解基本恒星人口对一般双星系统和特别是新星的形成，演化和物理性质的影响。为此，将开展一项观测方案，研究邻近星系中新星的空间分布和爆发特性。虽然恒星人口模型预测，晚型星系的盘组件应产生更多的新星比螺旋凸起和早期类型的星系（因为磁盘包含一个年轻的人口），观测证据表明，一个平等的，如果不是更大的新星率在凸起和椭圆星系。如果得到证实，这些结果将表明人口合成模型的失败，以及目前流行的Ia型超新星模型的问题，其中大质量白色矮星上的吸积引发热核失控-Ia型超新星被观察到在磁盘中更常见，即，这与新星的情况可能相反。观测工作将集中在沿着三个策略上。首先，使用Steward 90英寸反射镜上的宽视场成像仪，将在整个星系空间范围内确定螺旋星系M31中新星的真实膨胀盘比和晚型螺旋星系M101中的总体新星率。第二，将比较M31新星的最大亮度和下降速率（无论是在磁盘和凸起），以确定是否存在速度类的径向梯度，这将意味着两种类型的新星与相关的基本恒星种群的属性。必要的光变曲线将从拉古纳山天文台对在宽视场搜索中发现的新星的后续观测中获得，再加上从利克天文台超新星搜索M31档案和机器人光学凌日搜索实验中获得的光度测定。 第三、M13核球和M87的高新星率（一个巨大的椭圆星系）是由于球状星团中产生的新星双星造成的，我们将通过比较M49和M87中的新星率来检验。M49和M87是两个巨大的室女座椭圆星系，它们的球状星团数量非常不同。这里的工作与广泛的天文学主题有关-从双星形成到Ia型超新星的起源。来自SDSU REU暑期项目的学生将直接参与这项工作，其中包括一个令人兴奋的“发现”部分。具体任务包括发现新星和测量其光学光变曲线的演变。SDSU拥有庞大且多元化的学生群体，该项目将增加他们可用的研究机会。

This project seeks a better understanding of the effects of the underlying stellar population on the formation, evolution, and physical properties of binary systems in general and novae in particular. Towards this end, an observational program will be undertaken to study the spatial distributions and outburst properties of novae in nearby galaxies. While stellar population models predict that the disk components of late-type galaxies should produce more novae than spiral bulges and early type-galaxies (as the disks contain a younger population), observational evidence suggests an equal if not greater novae rate among bulges and elliptical galaxies. If confirmed, these results would be indicative of a failure of population synthesis models as well as a problem with the currently favored model for Type Ia supernovae in which accretion onto massive white dwarfs triggers a thermonuclear runaway - Type Ia supernovae are observed to be more common in disks, i.e., the reverse of what may be true for novae.The observational efforts will be focused along three strategies. First, the true bulge-to-disk ratio of novae in the spiral galaxy M31 and the overall novae rate in the late-type spiral M101 will be determined over the entire spatial extent of the galaxies using the wide field imager on the Steward 90-inch reflector. Second, the maximum brightness and rate of decline of the M31 novae (both in the disk and bulge) will be compared to determine if a radial gradient in speed class exists which would imply two types of novae with properties related to the underlying stellar populations. The necessary light curves will be obtained from follow-up observations at the Mount Laguna Observatory of novae discovered in the wide-field search plus photometry from the Lick Observatory Supernova Search M31 archive and the Robotic Optical Transit Search Experiments. Third, the possibility that the high nova rates for the M13 bulge and M87 (a giant elliptical) are due to nova binaries being generated in globular clusters will be tested by a comparison of nova rates in M49 and M87 - two giant Virgo elliptical galaxies with very different globular cluster populations.The work here is of the relevance to a broad range of astronomy topics - from binary formation to the origins of Type Ia supernovae. Students from the SDSU REU summer program will be directly involved in the work which includes an exciting "discovery" component. Specific tasks include the discovery of novae and measuring the evolution of their optical light curves. SDSU has a large and diverse student population and this project will enhance the research opportunities available to them.