arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 2002.12922astro-ph.GA
收藏

利用Kilo Degree Survey建立超紧凑大质量星系的最大光谱样本

Building the largest spectroscopic sample of ultra-compact massive galaxies with the Kilo Degree Survey

Diana Scognamiglio, Crescenzo Tortora, Marilena Spavone, Chiara Spiniello, Nicola R. Napolitano, Giuseppe D'Ago, Francesco La Barbera, Fedor Getman, Nivya Roy, … 展开作者

Diana Scognamiglio, Crescenzo Tortora, Marilena Spavone, Chiara Spiniello, Nicola R. Napolitano, Giuseppe D'Ago, Francesco La Barbera, Fedor Getman, Nivya Roy, Maria Angela Raj, Mario Radovich, Massimo Brescia, Stefano Cavuoti, Leon V. E. Koopmans, Koen H. Kuijken, Giuseppe Longo, Carlo Enrico Petrillo

摘要:

超致密大质量星系UCMG,即具有恒星质量$M_{*} > 8 \times 10^{10} M_{\odot}$和有效半径$R_{e} < 1.5$ kpc的星系,是非常罕见的系统,特别是在低和中等红移的星系。它们的起源以及它们在宇宙时间内的数量密度仍在仔细研究中,特别是因为光谱证实的样品很少。我们已经开始在ESO Kilo Degree Survey中对UCMG候选人进行系统的普查,以及一个大型的光谱跟踪活动,以建立最大可能的确认UCMG样本。这是该系列的第三篇论文,也是基于光谱后续计划的第二篇论文。在这里,我们提出了33个新的候选人在红移$0.15 \lesssim z \lesssim 0.5$的光度和结构参数,并确认其中19个UCMG,根据他们的名义光谱推断$M_{*}$和$R_{e}$。这对应于$\sim 58\%$的成功率,与我们之前的发现非常一致。这19个新确认的天体的加入,使我们能够充分评估系统选择上的系统学,并最终减少数量密度的不确定性。此外,把我们现在和过去的观测活动和一些文献数据的结果,我们建立了有史以来收集的最大的UCMG样本,包括92光谱确认的对象在$0.1 \lesssim z \lesssim 0.5$。此数字增加到116,允许UCMG定义的$M_{*}$和$R_{e}$阈值上的$3σ$容差。对于所有这些星系,我们已经估计的速度色散值的有效半径已被用来获得初步的质量-速度色散相关。

英文摘要:

Ultra-compact massive galaxies UCMGs, i.e. galaxies with stellar masses $M_{*} > 8 \times 10^{10} M_{\odot}$ and effective radii $R_{e} < 1.5$ kpc, are very rare systems, in particular at low and intermediate redshifts. Their origin as well as their number density across cosmic time are still under scrutiny, especially because of the paucity of spectroscopically confirmed samples. We have started a systematic census of UCMG candidates within the ESO Kilo Degree Survey, together with a large spectroscopic follow-up campaign to build the largest possible sample of confirmed UCMGs. This is the third paper of the series and the second based on the spectroscopic follow-up program. Here, we present photometrical and structural parameters of 33 new candidates at redshifts $0.15 \lesssim z \lesssim 0.5$ and confirm 19 of them as UCMGs, based on their nominal spectroscopically inferred $M_{*}$ and $R_{e}$. This corresponds to a success rate of $\sim 58\%$, nicely consistent with our previous findings. The addition of these 19 newly confirmed objects, allows us to fully assess the systematics on the system selection, and finally reduce the number density uncertainties. Moreover, putting together the results from our current and past observational campaigns and some literature data, we build the largest sample of UCMGs ever collected, comprising 92 spectroscopically confirmed objects at $0.1 \lesssim z \lesssim 0.5$. This number raises to 116, allowing for a $3σ$ tolerance on the $M_{*}$ and $R_{e}$ thresholds for the UCMG definition. For all these galaxies we have estimated the velocity dispersion values at the effective radii which have been used to derive a preliminary mass-velocity dispersion correlation.

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。

↑