We present an overview of a new integral field spectroscopic survey called MaNGA (Mapping Nearby Galaxies at Apache Point Observatory), one of three core programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV) that began on 2014 July 1. MaNGA will investigate the internal kinematic structure and composition of gas and stars in an unprecedented sample of 10,000 nearby galaxies. We summarize essential characteristics of the instrument and survey design in the context of MaNGA's key science goals and present prototype observations to demonstrate MaNGA's scientific potential. MaNGA employs dithered observations with 17 fiber-bundle integral field units that vary in diameter from 12'' (19 fibers) to 32'' (127 fibers). Two dual-channel spectrographs provide simultaneous wavelength coverage over 3600-10300 ? at R ~ 2000. With a typical integration time of 3 hr, MaNGA reaches a target r-band signal-to-noise ratio of 4-8 (?–1 per 2'' fiber) at 23 AB mag arcsec–2, which is typical for the outskirts of MaNGA galaxies. Targets are selected with M * 109 M ☉ using SDSS-I redshifts and i-band luminosity to achieve uniform radial coverage in terms of the effective radius, an approximately flat distribution in stellar mass, and a sample spanning a wide range of environments. Analysis of our prototype observations demonstrates MaNGA's ability to probe gas ionization, shed light on recent star formation and quenching, enable dynamical modeling, decompose constituent components, and map the composition of stellar populations. MaNGA's spatially resolved spectra will enable an unprecedented study of the astrophysics of nearby galaxies in the coming 6?yr.
展开▼
机译：我们概述了一项新的整体场光谱调查，称为MaNGA（在Apache Point天文台测绘附近的星系），这是自2014年7月1日开始的第四代斯隆数字天空调查（SDSS-IV）的三个核心程序之一。MaNGA将研究10,000个附近星系的空前样本中气体和恒星的内部运动学结构和组成。我们在MaNGA的关键科学目标的背景下总结了仪器的基本特征和调查设计，并提出了原型观测结果以展示MaNGA的科学潜力。 MaNGA采用抖动观测技术，具有17个纤维束积分场单元，其直径从12英寸（19根纤维）到32英寸（127根纤维）不等。两个双通道光谱仪可同时提供3600-10300？在R〜2000。典型的积分时间为3小时，MaNGA在23 AB mag arcsec-2时达到4-8的目标r波段信噪比（每2英寸光纤？-1）。是MaNGA星系郊区的典型代表。使用SDSS-I红移和i波段光度，以M * 109 M selected选择目标，以在有效半径，恒星质量大致平坦的分布以及跨大范围环境的样本方面实现均匀的径向覆盖。对我们的原型观测结果的分析表明，MaNGA能够探测气体电离，阐明最近的恒星形成和淬灭，启用动力学建模，分解组成成分以及绘制恒星种群的组成图。 MaNGA的空间分辨光谱将使未来6年内对附近星系的天体物理学进行前所未有的研究。
展开▼
