Juan Miro-Carretero, Maria A. Gomez-Flechoso, David Martinez-Delgado, Andrew P. Cooper, Santi Roca-Fabrega, Mohammad Akhlaghi, Annalisa Pillepich, Konrad Kuijke… 展开作者
Juan Miro-Carretero, Maria A. Gomez-Flechoso, David Martinez-Delgado, Andrew P. Cooper, Santi Roca-Fabrega, Mohammad Akhlaghi, Annalisa Pillepich, Konrad Kuijken, Denis Erkal, Tobias Buck, Wojciech A. Hellwing, Sownak Bose, Giuseppe Donatiello, Carlos S. Frenk
According to the well established hierarchical framework for galaxy evolution, galaxies grow through mergers with other galaxies and the LambdaCDM cosmological model predicts that the stellar halos of massive galaxies are rich in remnants from minor mergers. The Stellar Streams Legacy Survey (SSLS) has provided a first release of a catalogue with a statistically significant sample of stellar streams in the Local Universe, detected in deep images from DESI Legacy Surveys and the Dark Energy Survey (DES). The main objective is to compare the results of the observations of stellar tidal streams with predictions from state-of-the-art cosmological simulations regarding their abundance, up to a redshift z < 0.02, according to the LambdaCDM model. We use the predictions of the cosmological simulations Copernicus Complexio, TNG50 of the IllustrisTNG project, and Auriga to generate mock-images of nearby halos and search for stellar streams. We compare the stream frequency, characteristics and photometry in these images with DES observations. We find generally good agreement between the real images and the simulated ones regarding frequency, characteristics and photometry of the streams, while the stream morphology is somewhat different between observations and simulations, and between simulations themselves. By varying the sky background of the synthetic images to emulate different surface brightness limit levels, we also obtain predictions for the detection rate of stellar tidal streams up to a surface brightness limit of 35 mag arcsec^-2. The cosmological simulations predict that with an instrument such as the one used in the DES, it would be necessary to reach a surface brightness limit of 32 mag arcsec^-2 in the r-band to achieve a frequency of up to around 70% in the detection of stellar tidal streams around galaxies in the redshift range considered here.
Exploring the formation mechanisms of tidal structures in globular clusters of extragalactic origin
Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学前沿天文与天体物理研究所）；School of Physics and Astronomy, Beijing Normal University（北京师范大学物理与天文学院）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；School of Astronomy and Space Science, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）
Contrastive learning of extragalactic stellar streams. Sculpting a latent space of representations with DES DR2 photometry
Kapteyn Astronomical Institute, University of Groningen（格罗宁根大学卡普坦天文研究所）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）；Departamento de Física de la Tierra y Astrofísica, Universidad Complutense de Madrid（马德里康普顿斯大学地球与天体物理系）
Extragalactic magnetism with SOFIA (SALSA Legacy Program). VI. The magnetic fields in the multi-phase interstellar medium of the Antennae galaxies
合并被认为是星系生长的一个基本通道，扰动了星际介质（ISM）中的气体动力学和磁场（B场）。然而，在合并过程中放大和消散B场的机制仍不清楚。本文描述了最近的两个旋涡星系合并的多相ISM中有序B场的形态。我们比较推断的B-字段使用$154~μ$ m热尘埃和$11$厘米无线电同步辐射偏振观测。我们发现，$154~μ$ m的B-场是更有序的跨星系比$11$ cm的B-场。顺序$154~μ$ m B场在星系核心和恒星形成区增加。残余螺旋臂具有有序的螺旋$154~μ$ m B场，而$11$ cm B场是径向的。$154~μ$ m B场可能是由恒星形成区驱动的具有高$^{12}$ CO（1-0）速度色散的湍流发电机主导的，而$11$ cm B场是由星系相互作用驱动的具有高HI速度色散的共空间。这一结果表明，星系中的暖气体主要受到合并的扰动，而稠密气体仍然遵循残余旋臂的动力学过程，我们发现连接两个星系的是一个$\sim8.9$ kpc尺度的有序B场。潮汐尾的底部与HI和$^{12}$ CO（1-0）辐射是同空间的，并具有由合并驱动的压缩和/或剪切的$154~μ$ m和$11$ cm B场。我们认为，相对于系统的其余部分和其他螺旋星系，放大的B场可能支持两个星系和潮汐尾之间的气体流动。
Extragalactic Stellar Streams in Time-Dependent Cosmological Halos
DTU Space, Technical University of Denmark（丹麦技术大学空间中心）；DARK, Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所DARK研究中心）；Department of Astrophysical Sciences, Princeton University（普林斯顿大学天体物理学系）；Department of Astronomy, Boston University（波士顿大学天文系）；Center for Computational Astrophysics, Flatiron Institute（平顿研究所计算天体物理中心）；Department of Physics and Astronomy, University of Pennsylvania（宾夕法尼亚大学物理与天文学系）；Department of Astronomy and DiRAC Institute, University of Washington（华盛顿大学天文系及DiRAC研究所）
Warm Ionized Gas Revealed in the Magellanic Bridge Tidal Remnant: Constraining the Baryon Content and the Escaping Ionizing Photons around Dwarf Galaxies
Evidence for the First Globular Cluster Stellar Stream beyond the Milky Way
University of Copenhagen（哥本哈根大学）；DTU Space, Technical University of Denmark（丹麦技术大学空间中心）；Princeton University（普林斯顿大学）；University of Arizona（亚利桑那大学）；Flatiron Institute（平顿研究所）；Northwestern University（西北大学）
