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arXiv 2405.03391astro-ph.GA
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200 Mpc以内的蓝莓星系及其光学和红外性质

Blueberry galaxies up to 200 Mpc and their optical and infrared properties

K. Kouroumpatzakis, J. Svoboda, A. Zezas, A. Borkar, E. Kyritsis, P. G. Boorman, C. Daoutis, B. Adamcová, R. Grossová

AI总结:

本研究利用多星表数据识别出48个200 Mpc内的蓝莓星系(含40个新发现),发现其具有可见光更蓝、红外更红、恒星形成更剧烈等独特性质,为研究早期宇宙高恒星形成矮星系提供局域样本。

摘要:

矮星系中高恒星形成率星系(SFGs)主导了早期宇宙,被认为是宇宙再电离的主要驱动因素。然而,对这些遥远星系的直接观测主要局限于静止系紫外和可见光,限制了我们对其完整性质的理解。因此,研究它们的局域对应体——绿豌豆(GP)星系和蓝莓(BB)星系——仍然至关重要。本工作旨在通过识别南天区域更近的新样本,拓展我们对BB星系的认知。除已知的BB星系外,这一新样本将支持对其可见光和红外(IR)波段性质开展具有统计意义的研究。本研究利用提供星系测光与特征表征的HECATE星表,结合Pan-STARSS和SDSS的数据,筛选并分析了一个新的BB星系样本。我们采用光谱能量分布拟合,得到恒星形成率和恒星质量的均匀测量值。此外,我们通过光谱拟合测量了包括$\rm HeII~λ4686$在内的发射线流量。通过这项工作,我们识别出48个BB星系,其中40个为首次发现,最近的距离为19 Mpc。14个BB星系位于南天。这些BB星系的WISE $W1-W2$和$W2-W3$色指数都呈现极红的红外颜色,使其区别于典型SFGs。比恒星形成率更高的矮SFGs往往具有更红的红外颜色。蓝莓星系是局域宇宙中矮星系里恒星形成最剧烈的天体。与典型SFGs和GP星系相比,它们具有独特特征:本征可见光颜色更蓝、红外颜色更红、质量更低,同时拥有更高的比恒星形成率和等值宽度、更低的金属丰度,以及电离程度最强的星际介质。

英文摘要:

Dwarf highly star-forming galaxies (SFGs) dominated the early Universe and are considered the main driver of its reionization. However, direct observations of these distant galaxies are mainly confined to rest-frame ultraviolet and visible light, limiting our understanding of their complete properties. Therefore, it is still paramount to study their local analogs, the green pea (GP) and blueberry (BB) galaxies. This work aims to expand our knowledge of BBs by identifying a new sample that is closer and in the southern sky. In addition to the already known BBs, this new sample will allow for a statistically significant study of their properties probed by visible and infrared (IR) light. By utilizing the HECATE catalog, which provides photometry and characterization of galaxies, along with data from Pan-STARSS and SDSS, this study selects and analyzes a new sample of BBs. We employed spectral energy distribution fitting to derive homogeneous measurements of star-formation rates and stellar masses. Additionally, we measured emission-line fluxes, including $\rm HeII~λ4686$, through spectral fitting. Through this work, we identified 48 BBs, of which 40 were first recognized as such, with the nearest at 19~Mpc. 14 of the BBs are in the south sky. The BBs tend to be extremely IR red in both WISE $W1-W2$ and $W2-W3$ colors, distinguishing them from typical SFGs. Dwarf SFGs with higher specific star-formation rates tend to have redder IR colors. Blueberry galaxies stand out as the most intensely star-forming sources in the local Universe among dwarf galaxies. They exhibit unique characteristics, such as being intrinsically bluer in visible light, redder in the infrared, and less massive. They also have higher specific star-formation rates, equivalent widths, lower metallicities, and the most strongly ionized interstellar medium compared to typical SFGs and GPs.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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