The gamma-ray bursts hosts (GRBHs) are excellent targets to study the extinction properties of dust and its effects on the global emission of distant galaxies. The dust extinction curve is measured along the GRB afterglow line of sight and the analysis of the spectral energy distribution (SED) of the host galaxy gives access to the global dust attenuation of the stellar light. We selected a sample of 30 GRBs for which the extinction curve along the GRB afterglow line-of-sight (l.o.s) is measured in the rest-frame ultraviolet (UV) up to optical and we analysed the properties of the extinction curve as a function of the host galaxy properties. From these 30 GRBs, we selected seven GRBHs with a good rest-frame UV to near infra-red spectral coverage for the host. The attenuation curve was derived by fitting the SEDs of the GRBH sample with the CIGALE SED fitting code. Different star formation histories were studied to recover the star formation rates (SFR) derived using H$_α$ luminosities. The most extinguished GRBs are preferentially found in the more massive hosts and the UV bump is preferentially found in the most extinguished GRB l.o.s. Five out of seven hosts are best fitted with a recent burst of star formation, leading to lower stellar mass estimates than previously found. The average attenuation in the host galaxies is about 70% of the amount of extinction along the GRB l.o.s. We find a great variety in the derived attenuation curves of GRBHs, the UV slope can be similar, flatter or even steeper than the extinction curve slope. We find that the flatter (steeper) attenuation curves are found in galaxies with the highest (lowest) SFR and stellar masses. The comparison of our results with radiative transfer simulations leads to a uniform distribution of dust and stars in a very clumpy ISM for half the GRBHs and various dust-stars geometries for the second half of the sample.
利用数值N体/流体动力学模拟方法，研究了在高红移的PopII GRBs（GRBIs）观测中，从不同初始质量函数（IMF）、产额和寿命的恒星星族中探测和区分PopIII星富集特征的可能性。PopIII和PopII的恒星形成制度，同时采用头重脚轻和Salpeter-like IMF的原始PopIII恒星形成。我们发现，部分GRBIIs托管在介质中以前丰富的PopIII星（PopIII为主）是模型独立的。典型的丰度比，如[Si/O] vs [C/O]和[Fe/C] vs [Si/C]，可以帮助从大质量和中等质量的PopIII恒星中分离富集，而低质量的第一颗恒星则与常规的PopII世代退化。拥有PopIII主导的GRBII的星系的性质对第一颗恒星质量的特定假设并不十分敏感。
The Koi Pond: A Strongly Lensed Protocluster Core hosting a Diverse Population of DSFGs
Arizona State University（亚利桑那州立大学）；Joint ALMA Observatory（ALMA联合天文台）；National Astronomical Observatory of Japan（日本国立天文台）；European Southern Observatory（欧洲南方天文台）；Universidad Diego Portales（迭戈·波特莱斯大学）；University of Arizona（亚利桑那大学）；Chalmers University of Technology（查尔姆斯理工大学）
Back to basics: Little Red Dots as galaxies and dust-obscured AGNs in a synthetic NIRCam sky simulated with L-GalaxiesBH
Donostia International Physics Centre (DIPC)（多诺斯蒂亚国际物理中心）；University of the Basque Country UPV/EHU（巴斯克国立大学）；Como Lake Center for AstroPhysics, University of Insubria（因斯布鲁克大学科莫湖天体物理中心）；Dipartimento di Fisica “G. Occhialini”, Università degli Studi di Milano-Bicocca（米兰比可卡大学 G. Occhialini 物理系）；INFN, Sezione di Milano-Bicocca（意大利国家核物理研究所米兰比可卡分部）；Key Laboratory for Computational Astrophysics, National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台计算天体物理学重点实验室）；School of Astronomy and Space Sciences, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；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）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所（加泰罗尼亚高等研究学院，西班牙国家科研委员会））
First survey of Wolf-Rayet star populations over the full extension of nearby galaxies observed with CALIFA
在本星系群外存在沃尔夫-拉叶（WR）星的河外区域的搜索是一项具有挑战性的任务，因为难以探测到它们微弱的光谱特征。在这项探索性的工作中，我们开发了一种方法来执行WR签名的自动搜索，通过像素的积分场光谱（IFS）属于卡拉尔阿尔托遗产积分场区域调查，CALIFA的数据的像素分析。这种技术使我们能够建立第一个具有空间分辨信息的Wolf-Rayet丰富区域的目录，从而可以在2D背景下研究这些复合物的性质。探测技术是基于使用逐像素分析来识别蓝色WR凸块（在He II 4686 <$m附近，主要与富氮WR星WN相关）和红色WR凸块（在C IV 5808 <$m附近，与富碳WR星WC相关）。我们确定了44个WR丰富的区域分布在25个星系中的558个蓝色凸起。仅在其中5个地区发现了红色WR凸起。我们发现，在我们的样本中，大多数托管WR人口的星系都参与了某种相互作用过程。一半的宿主星系与伽马射线暴（GRB）的宿主星系具有某些共同的性质，其中WR星是GRB的潜在候选者.我们还将由CALIFA数据得到的WR性质与恒星星族合成模型进行了比较，证实了简单的恒星模型一般不能再现观测结果.我们的结论是，其他的影响，如双星通道（这可能会延长WR阶段高达10万年），快速旋转或其他物理过程，导致观测到的莱曼连续光子的损失，很可能会影响衍生WR属性，因此，应考虑在建模时的大质量恒星的演化。
