Descendants of the first stars: the distinct chemical signature of second generation stars
Tilman Hartwig, Naoki Yoshida, Mattis Magg, Anna Frebel, Simon C. O. Glover, Facundo A. Gómez, Brendan Griffen, Miho N. Ishigaki, Alexander P. Ji, Ralf S. Kless… 展开作者
Tilman Hartwig, Naoki Yoshida, Mattis Magg, Anna Frebel, Simon C. O. Glover, Facundo A. Gómez, Brendan Griffen, Miho N. Ishigaki, Alexander P. Ji, Ralf S. Klessen, Brian W. O'Shea, Nozomu Tominaga
Extremely metal-poor (EMP) stars in the Milky Way (MW) allow us to infer the properties of their progenitors by comparing their chemical composition to the metal yields of the first supernovae. This method is most powerful when applied to mono-enriched stars, i.e. stars that formed from gas that was enriched by only one previous supernova. We present a novel diagnostic to identify this subclass of EMP stars. We model the first generations of star formation semi-analytically, based on dark matter halo merger trees that yield MW-like halos at the present day. Radiative and chemical feedback are included self-consistently and we trace all elements up to zinc. Mono-enriched stars account for only $\sim 1\%$ of second generation stars in our fiducial model and we provide an analytical formula for this probability. We also present a novel analytical diagnostic to identify mono-enriched stars, based on the metal yields of the first supernovae. This new diagnostic allows us to derive our main results independently from the specific assumptions made regarding Pop III star formation, and we apply it to a set of observed EMP stars to demonstrate its strengths and limitations. Our results may provide selection criteria for current and future surveys and therefore contribute to a deeper understanding of EMP stars and their progenitors.
The very massive first stars ($m>100\rm M_{\odot}$) were fundamental to the early phases of reionization, metal enrichment, and super-massive black hole formation. Among them, those with $140\leq\rm m/\rm M_{\odot}\leq260$ are predicted to evolve as Pair Instability Supernovae (PISN) leaving a unique chemical signature in their chemical yields. Still, despite long searches, the stellar descendants of PISN remain elusive. Here we propose a new methodology, the PISN-explorer, to identify candidates for stars with a dominant PISN enrichment. The PISN-explorer is based on a combination of physical…
In this study, we report a probabilistic insight into the stellar mass and supernovae (SNe) explosion energy of the possible progenitors of five CEMP-no stars. This was done by a direct comparison between the abundance ratios [X/Fe] of the light-elements and the predicted nucleosynthetic yields of SN of high-mass metal-free stars. This comparison suggests possible progenitors with stellar mass range of 11 - 22\,M$_{\odot}$ and explosion energies of $0.3 - 1.8 \times 10^{51}$\,erg. The coupling of the chemical abundances with kinematics derived from $Gaia$ DR2 suggests that our sample do not en…
Taking advantage of the recent Gaia Data Release 3 (DR3), we map chemical inhomogeneities in the Milky Way's disc out to a distance of $\sim$ 4 kpc from the Sun, using different samples of bright giant stars. The samples are selected using effective temperatures and surface gravities from the GSP-Spec module, and are expected to trace stellar populations of different typical age. The cool (old) giants exhibit a relatively smooth radial metallicity gradient with an azimuthal dependence. Binning in Galactic azimuth $ϕ$, the slope gradually varies from $d$[M/H]$/dR \sim -0.054$ dex kpc$^{-1}$ at …
Chemical Signatures of AGB Mass Transfer in Gaia White Dwarf Companions
California Institute of Technology（加州理工学院）；Gemini Observatory, NSF’s NOIRLab（双子座天文台，美国国家光学-红外天文研究实验室）；Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）
The recently discovered Indus stellar stream exhibits a diverse chemical signature compared to what is found for most other streams due to the abundances of two outlier stars, Indus$\_$0 and Indus$\_$13. Indus$\_$13, exhibits an extreme enhancement in rapid neutron-capture ($r$-)process elements with $\mathrm{[Eu/Fe]} = +1.81$. It thus provides direct evidence of the accreted nature of $r$-process enhanced stars. In this paper we present a detailed chemical analysis of the neutron-capture elements in Indus$\_$13, revealing the star to be slightly actinide poor. The other outlier, Indus$\_0$, d…
We present observations toward HOPS 383, the first known outbursting Class 0 protostar located within the Orion molecular cloud using ALMA, VLA, and SMA. The SMA observations reveal envelope scale continuum and molecular line emission surrounding HOPS 383 at 0.85 mm, 1.1 mm, and 1.3 mm. The images show that HCO$^+$ and H$^{13}$CO$^+$ peaks on or near the continuum, while N$_2$H$^+$ is reduced at the same position. This reflects the underlying chemistry where CO evaporating close to the protostar destroys N$_2$H$^+$ while forming HCO$^+$. We also observe the molecular outflow traced by $^{12}$C…
Chemical signatures from the first stars embedded in metal-poor gas in galaxies at cosmic dawn
Cosmic Dawn Center (DAWN)（宇宙黎明中心）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；DTU Space, Technical University of Denmark（丹麦技术大学空间部）；Dipartimento di Fisica e Astronomia, Università degli Studi di Firenze（佛罗伦萨大学物理与天文学系）；INAF/Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切特里天文台）；Department of Astronomy, University of Geneva（日内瓦大学天文学系）；Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM（巴黎综合理工学院、巴黎西岱大学、法国原子能和替代能源委员会、法国国家科学研究中心、天体物理学信息与方法实验室）；Centre national d’études spatiales (CNES)（法国国家空间研究中心）
Chemical Analysis of the Ultra-Faint Dwarf Galaxy Grus~II. Signature of high-mass stellar nucleosynthesis
我们对超暗矮星系Grus~II巨星系分支顶部的三颗最亮的成员星进行了详细的丰度分析。与其他超暗矮星系和银河系晕中的贫金属恒星相比，所有恒星都表现出高于预期的$\mathrm{[Mg/Ca]}$比率。高质量（$\geqslant 20$ M $_\odot$）核心坍缩超新星的核合成已经被证明可以产生这种特征。这个小样本（3）星的丰度表明，天鹤座~II的化学富集可能是通过大量的高质量恒星演化发生的，并且与头重脚轻的初始质量函数框架相一致。然而，由于只有三颗恒星，不能排除丰度模式是星系早期随机化学富集的结果。这三颗恒星中最富金属的一颗，其快速中子俘获（$r$ -process）元素也有小幅增强。这颗恒星中的$r$过程元素的丰度模式与太阳系的比例$r$过程模式以及其他矮星系和银河系晕中的$r$过程增强型恒星相匹配，暗示了这些元素在一系列环境中的共同起源。所有目前提出的天体物理学站点的$r$过程元素的生产都与高质量的恒星，因此可能头重脚轻的初始质量功能的天鹤座~II将增加任何这些事件发生的可能性。银河系的$α$和$r$过程元素富集之间的时间延迟有利于中子星并合作为Grus~II中$r$过程元素的起源。
The possibility of identifying co-natal stars that have dispersed into the Galactic disc based on chemistry only is called strong chemical tagging. Its feasibility has been debated for a long time, with the promise of reconstructing the detailed star-formation history of a large fraction of stars in the Galactic disc. We investigate the feasibility of strong chemical tagging using known member stars of open clusters. We analysed the largest sample of cluster members that have been homogeneously characterised with high-resolution differential abundances for 16 different elements. We also invest…
EDGE-INFERNO: The chemical signatures of assembly history in reionization fossils
American Museum of Natural History（美国自然历史博物馆）；University of Bath（巴斯大学）；University of Chicago（芝加哥大学）；Kavli Institute for Cosmological Physics, University of Chicago（芝加哥大学卡弗里宇宙学物理研究所）；NSF-Simons AI Institute for the Sky (SkAI)（NSF-Simons 天空人工智能研究所 (SkAI)）；University of Surrey（萨里大学）；Lund University（隆德大学）；Carnegie Observatories（卡内基观测站）；Carnegie Theoretical Astrophysics Center, Carnegie Observatories（卡内基观测站卡内基理论天体物理学中心）；Columbia University（哥伦比亚大学）；Center for Astrophysics | Harvard & Smithsonian（哈佛-史密森尼天体物理中心）
We test the hypothesis that the observed first-peak (Sr, Y, Zr) and second-peak (Ba) s-process elemental abundances in low-metallicity Milky Way stars, and the abundances of the elements Mo and Ru, can be explained by a pervasive r-process contribution originating in neutrino-driven winds from highly-magnetic and rapidly rotating proto-neutron stars (proto-NSs). We construct chemical evolution models that incorporate recent calculations of proto-NS yields in addition to contributions from AGB stars, Type Ia supernovae, and two alternative sets of yields for massive star winds and core-collapse…
One way the AGN are expected to influence the evolution of their host galaxies is by removing metal content via outflows. In this article we present results that show that AGN can have an effect on the chemical enrichment of their host galaxies using the fossil record technique on CALIFA galaxies. We classified the chemical enrichment histories of all galaxies in our sample regarding whether they show a drop in the value of their metallicity. We find that galaxies currently hosting an AGN are more likely to show this drop in their metal content compared to the quiescent sample. Once we separat…
Signatures of planets and Galactic subpopulations in solar analogs. Precise chemical abundances with neural networks
Max-Planck-Institut für Astronomie（马克斯·普朗克天文研究所）；Fakultät für Physik und Astronomie, Universität Heidelberg（海德堡大学物理与天文学系）；Department of Astronomy, Universidade de São Paulo（圣保罗大学天文系）；INAF-Osservatorio Astronomico di Padova（意大利帕多瓦天文台）；INAF-Osservatorio Astrofisico di Arcetri（意大利阿雷特里天文台）
The chemical composition of gas in galaxies can be measured in detail from absorption spectroscopy. By studying gas in galaxies in this way, it is possible to investigate the small and faint galaxies, which are the most numerous in the universe. In particular, the chemical distribution of gas in absorbing systems gives us insight into cycles of gas in and around galaxies. Here we study chemical enrichment within 64 Damped Lyman-alpha Absorption (DLA) systems between $1.7 < z < 4.2$. We use high-resolution spectra from VLT/UVES to infer dust depletion from relative abundances of several metals.…
