[论文解读] SPIRE Point Source Catalog Explanatory Supplement

Bernhard Schulz, G. Marton+16 more|arXiv (Cornell University)|Jun 1, 2017

Stellar, planetary, and galactic studies参考文献 12被引用 13

一句话总结

本论文介绍了SPIRE点源星表，该星表从6,878幅未经修改的赫歇尔-SPIRE扫描图中系统性提取出250、350和500 µm波段的1,693,718个点源，具有高可靠性。通过采用统一的源提取流程并实施严格的质量控制，星表强调可靠性而非完整性，是星系际亚毫米波和远红外天文学的重要基础资源，尤其适用于未来ALMA和FIR设施的研究。

ABSTRACT

The Spectral and Photometric Imaging Receiver (SPIRE) was launched as one of the scientific instruments on board of the space observatory Herschel. The SPIRE photometer opened up an entirely new window in the Submillimeter domain for large scale mapping, that up to then was very difficult to observe. There are already several catalogs that were produced by individual Herschel science projects. Yet, we estimate that the objects of only a fraction of these maps will ever be systematically extracted and published by the science teams that originally proposed the observations. The SPIRE instrument performed its standard photometric observations in an optically very stable configuration, only moving the telescope across the sky, with variations in its configuration parameters limited to scan speed and sampling rate. This and the scarcity of features in the data that require special processing steps made this dataset very attractive for producing an expert reduced catalog of point sources that is being described in this document. The Catalog was extracted from a total of 6878 unmodified SPIRE scan map observations. The photometry was obtained by a systematic and homogeneous source extraction procedure, followed by a rigorous quality check that emphasized reliability over completeness. Having to exclude regions affected by strong Galactic emission, that pushed the limits of the four source extraction methods that were used, this catalog is aimed primarily at the extragalactic community. The result can serve as a pathfinder for ALMA and other Submillimeter and Far-Infrared facilities. 1,693,718 sources are included in the final catalog, splitting into 950688, 524734, 218296 objects for the 250μm, 350μm, and 500μm bands, respectively. The catalog comes with well characterized environments, reliability, completeness, and accuracies, that single programs typically cannot provide.

研究动机与目标

• 从赫歇尔-SPIRE观测中创建一个可靠且一致的亚毫米波段点源星表。
• 解决赫歇尔大范围地图中公开可用、系统处理的点源星表稀缺的问题。
• 生成一个可靠性、完整性和测光准确性均经过充分表征的星表，其性能优于单个科学团队通常能达到的水平。
• 为未来亚毫米波和远红外设施（如ALMA）提供基准资源。
• 排除强银河系发射区域以确保源的可靠性，专注于星系际源的探测。

提出的方法

• 在6,878幅未经修改的SPIRE扫描图观测中，使用四种不同的源提取方法进行源提取。
• 在所有图象上应用系统且一致的流程，确保一致的测光定标和源检测。
• 通过多方法测光方法提高可靠性并减少误报。
• 实施严格的质量检查，优先考虑源的可靠性而非完整性。
• 为减少混淆和误检，已从最终星表中排除强银河系发射区域。
• 通过源环境分析、可靠性、完整性和测光准确性表征对星表进行了验证。

实验结果

研究问题

• RQ1 在大型、未经修改的SPIRE扫描图中，如何以最小用户偏差提取点源？
• RQ2 当银河系混淆限制检测时，如何在亚毫米波源星表中最大化可靠性？
• RQ3 在一个统一、专家处理的星表中，250、350和500 µm波段的完整性和测光准确性可达到何种水平？
• RQ4 与单个科学团队的星表相比，通过单一一致流程生成的星表在可靠性与一致性方面表现如何？
• RQ5 在排除高银河系发射区域的前提下，如何实现星表的公开可用性并进行充分表征？

主要发现

• 最终星表包含1,693,718个点源，其中250 µm波段有950,688个，350 µm波段有524,734个，500 µm波段有218,296个。
• 星表强调可靠性而非完整性，通过排除强银河系发射区域以减少误报。
• 测光测量基于对全部6,878幅未经修改的SPIRE扫描图统一、一致的流程获得。
• 星表提供了充分表征的可靠性、完整性和测光准确性，优于典型单个科学项目输出的水平。
• 由于排除了高银河系发射区域，星表主要面向星系际天文学社区。
• 星表为未来亚毫米波和远红外巡天（包括ALMA的观测）提供了先行范例。