A. E. Watkins, J. C. Mihos, P. Harding, J. J. Feldmeier
备注：
20 pages, 10 figures. Accepted to ApJ. A revision was posted June 29, 2016 to correct Figures 6, 8, 9, and 10. A coding error had induced a uniform ~0.5 magnitude offset in all of the surface brightness profiles found in these figures. This error affects none of the scientific conclusions in the paper
We present deep, wide-field imaging of the M96 galaxy group (also known as the Leo I Group). Down to surface brightness limits of $μ_{B}=30.1$ and $μ_{V}=29.5$, we find no diffuse, large-scale optical counterpart to the "Leo Ring", an extended HI ring surrounding the central elliptical M105 (NGC 3379). However, we do find a number of extremely low surface-brightness ($μ_{B} \gtrsim 29$) small-scale streamlike features, possibly tidal in origin, two of which may be associated with the Ring. In addition we present detailed surface photometry of each of the group's most massive members -- M105, NGC 3384, M96 (NGC 3368), and M95 (NGC 3351) -- out to large radius and low surface brightness, where we search for signatures of interaction and accretion events. We find that the outer isophotes of both M105 and M95 appear almost completely undisturbed, in contrast to NGC 3384 which shows a system of diffuse shells indicative of a recent minor merger. We also find photometric evidence that M96 is accreting gas from the HI ring, in agreement with HI data. In general, however, interaction signatures in the M96 Group are extremely subtle for a group environment, and provide some tension with interaction scenarios for the formation of the Leo HI Ring. The lack of a significant component of diffuse intragroup starlight in the M96 Group is consistent with its status as a loose galaxy group in which encounters are relatively mild and infrequent.
Searching for low-surface-brightness galaxies with compact neural networks A parameter-efficient approach to first-pass selection of diffuse galaxy in HSC-SSP imaging
Edge-on HI-bearing ultra diffuse galaxy candidates in the 40% ALFALFA catalog
超漫射星系是一种具有非常扩展的形态和微弱的中心表面亮度的天体。大多数UDG都是在星系团和星系群中发现的，但也有一些是在低密度环境中发现的。漫射形态和微弱的表面亮度使它们难以从天空背景中区分出来。之前的一些研究表明，至少有一些UDG与指数表面亮度分布（Sérsic n ~ 1）一致。指数盘的表面亮度在边缘上系统中增强，因此搜索边缘上系统可能是选择UDG的有效方式。在本文中，我们专注于寻找边缘上HI轴承超漫射源（HUDS）从40%ALCARFA目录，SDSS的G-和R-波段图像的基础上。在将观察到的中心表面亮度校正为正面视角后，我们发现了11个边缘上的HUD候选者。这些新发现的HUDS候选者都是蓝色的，带有HI，与70%ALOFA星表中的其他HUDS相似，而与星团中的UDG不同。
Modelling and Subtracting Diffuse Cluster Light in JWST Images: A Relation between the Spatial Distribution of Globular Clusters, Dwarf Galaxies, and Intracluster Light in the Lensing Cluster SMACS 0723
Light from the Darkness: Detecting Ultra-Diffuse Galaxies in the Perseus Cluster through Over-densities of Globular Clusters with a Log-Gaussian Cox Process
介绍了一种通过寻找星系际球状星团中的过密度来探测超弥散星系的新方法。我们的方法是基于对数高斯考克斯过程，这是一个常用的模型在空间统计文献中，但很少用于天文学的应用。该方法适用于从PIPER调查，一个\textit{Hubble Space Telescope}成像程序针对英仙座集群获得的球状星团数据。我们成功地发现了所有已确认的超扩散星系与已知的球状星团人口的调查。我们还确定了一个潜在的星系，没有检测到弥漫恒星的内容。初步分析表明，它不太可能仅仅是一个偶然的球状星团或其他物体。如果得到证实，这将是第一个此类系统。模拟被用来评估超漫射星系内的球状星团系统的物理参数如何影响他们的可探测性使用我们的方法。我们量化了探测概率与星系中球状星团总数的相关性以及与球状星团系统半数半径增加的反相关性。球状星团分布的Sérsic指数对可探测性的影响很小。
Is diffuse intracluster light a good tracer of the galaxy cluster matter distribution?
我们利用暗能量巡天（DES）第一年数据中发现的528个$0.2\leq z \leq 0.35$星系团的样本，探讨了团内漫射光（包括中央星系）和星系团（重子和暗）物质分布之间的关系。漫射光的表面亮度在较大的半径上表现出对团簇总质量的依赖性，并且在按团簇半径缩放后表现出具有普遍径向依赖性的自相似性。我们还比较了通过弱透镜测量的集群（重子和暗）物质分布的漫射光径向配置文件，并发现它们是可比的。IllustrisTNG星系形成模拟，TNG 300，提供了进一步的洞察扩散恒星质量和集群物质分布之间的联系-扩散恒星成分的模拟径向轮廓没有与总集群物质含量类似的斜率，虽然集群卫星星系的斜率。无论径向趋势如何，扩散恒星质量的数量与模拟中的星系团总质量具有低散射标度关系，优于星系团卫星星系的总恒星质量。我们的结论是，目前还没有一致的证据，是否漫射光是一个忠实的径向示踪剂的集群物质分布。然而，观测和模拟结果都表明，漫射光是星团总质量的一个很好的指标。
