The Large Early Galaxy Astrophysics Census (LEGA-C) Data Release 2: Dynamical and Stellar Population Properties of z ≲ 1 Galaxies in the COSMOS Field
The Large Early Galaxy Astrophysics Census (LEGA-C) Data Release 2: Dynamical and Stellar Population Properties of z ≲ 1 Galaxies in the COSMOS Field
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DOI：
10.3847/1538-4365/aae37a
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发表时间：
2018-09
期刊：
影响因子：
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通讯作者：
C. Straatman;A. V. D. Wel;R. Bezanson;C. Pacifici;A. Gallazzi;Po-Feng Wu;K. Noeske;I. Barišić;E. Bell;G. Brammer;J. Calhau;Priscilla Chauké;M. Franx;J. V. Houdt;I. Labbé;M. Maseda;J. Muńoz-Mateos;A. Muzzin;J. V. D. Sande;D. Sobral;J. Spilker
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文献类型：
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作者：
C. Straatman;A. V. D. Wel;R. Bezanson;C. Pacifici;A. Gallazzi;Po-Feng Wu;K. Noeske;I. Barišić;E. Bell;G. Brammer;J. Calhau;Priscilla Chauké;M. Franx;J. V. Houdt;I. Labbé;M. Maseda;J. Muńoz-Mateos;A. Muzzin;J. V. D. Sande;D. Sobral;J. Spilker
我们介绍了大型早期星系天体物理普查（LEGA-C）的第二次数据发布，这是ESO 130−夜间使用甚大望远镜上的VIMOS进行的公共光谱调查。我们发布了1988个具有典型连续S/N≃20 Å−1的光谱，每个光谱在0.6≤z≤1.0处观测~ 20 hr，并通过定制的管道完全还原。我们还发布了一个目录，其中包括光谱红移、发射在线通量、Lick/IDS指数，以及观测到的恒星和气体速度色散，这些色散是空间积分量，包括旋转运动和真实色散。为了说明LEGA-C探测到的中间红移区域的新参数空间，我们探讨了动力学和恒星种群性质之间的关系。恒星形成星系通常观测到恒星速度色散为~ 150 km s−1和强Hδ吸收（Hδ a ~ 5 Å），而被动星系观测到的恒星速度色散较高（~ 200 km s−1）和弱Hδ吸收（Hδ a ~ 0 Å）。强[O III]5007/Hβ比值往往主要出现在具有弱HδA或观测到的速度色散较高的星系中。除了这些广泛的趋势之外，我们还发现了休息框架颜色，吸收线强度和发射在线检测的多种可能组合，说明了光谱测量在更准确地理解星系演化方面的效用。通过公开光谱和增值目录，我们鼓励社会利用ESO在望远镜时间上的大量投资。
We present the second data release of the Large Early Galaxy Astrophysics Census (LEGA-C), an ESO 130−night public spectroscopic survey conducted with VIMOS on the Very Large Telescope. We release 1988 spectra with typical continuum S/N ≃ 20 Å−1 of galaxies at 0.6 ≲ z ≲ 1.0, each observed for ∼20 hr and fully reduced with a custom-built pipeline. We also release a catalog with spectroscopic redshifts, emission-line fluxes, Lick/IDS indices, and observed stellar and gas velocity dispersions that are spatially integrated quantities, including both rotational motions and genuine dispersion. To illustrate the new parameter space in the intermediate-redshift regime probed by LEGA-C, we explore relationships between dynamical and stellar population properties. The star-forming galaxies typically have observed stellar velocity dispersions of ∼150 km s−1 and strong Hδ absorption (HδA ∼ 5 Å), while passive galaxies have higher observed stellar velocity dispersions (∼200 km s−1) and weak Hδ absorption (HδA ∼ 0 Å). Strong [O III]5007/Hβ ratios tend to occur mostly for galaxies with weak HδA or galaxies with higher observed velocity dispersion. Beyond these broad trends, we find a diversity of possible combinations of rest-frame colors, absorption-line strengths, and emission-line detections, illustrating the utility of spectroscopic measurements to more accurately understand galaxy evolution. By making the spectra and value-added catalogs publicly available we encourage the community to take advantage of this very substantial investment in telescope time provided by ESO.