arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.06223astro-ph.GA
收藏

三维HST/CANDELS中$2<z<3$的致密成星星系核:AGN和非活动星系核的物理性质

The Compact Star-Forming Galaxies at $2<z<3$ in 3D-HST/CANDELS: AGN and Non-AGN Physical Properties

Shiying Lu, Yizhou Gu, Guanwen Fang, Qirong Yuan, Min Bao, Xiaotong Guo

摘要:

在$2<z<3$观测的5个3D-HST/CANDELS场上,研究了有无活动星系核的大质量致密恒星形成星系(cSFG)在恒星星族特性、结构和环境方面的差异.在221个大质量cSFG的样本中,我们构成了迄今为止最完整的活动星系核普查,通过X射线探测,中红外颜色标准和/或SED拟合识别出66个活动星系核,而其余的(155个)是非活动星系核。进一步将这些cSFG分成两个红移仓,即,$2<z<2.5$和$2.5 \leq z<3$的计算结果表明,在每个红移仓中,有活动星系核的cSFG与无活动星系核的cSFG具有相似的恒星质量、比恒星形成率和$L_{\rm IR}$/$L_{\rm UV}$的分布。在对那些具有X射线探测到的活动星系核的cSFG(37)进行二维表面亮度建模以校正中心点状X射线活动星系核对其宿主星系结构参数测量的影响之后,我们发现,在每个红移仓中,具有活动星系核的cSFG具有所有相关结构参数的可比分布,即,Sersic指数、20%光半径、Gini系数和集中指数等。随着可用气体和尘埃的逐渐消耗,由上述结构参数指示的cSFG的结构似乎随着红移的减小而稍微更加集中。在$2<z<3$,有活动星系核和没有活动星系核的cSFG之间类似的环境表明,它们的活动星系核活动可能是由内部长期过程触发的,例如引力不稳定性或/和动力学摩擦。

英文摘要:

We investigate the differences in the stellar population properties, the structure, and the environment between massive compact star-forming galaxies (cSFGs) with or without active galactic nucleus (AGN) at $2<z<3$ in the five 3D-HST/CANDELS fields. In a sample of 221 massive cSFGs, we constitute the most complete AGN census so far, identifying 66 AGNs by the X-ray detection, the mid-infrared color criterion, and/or the SED fitting, while the rest (155) are non-AGNs. Further dividing these cSFGs into two redshift bins, i.e., $2<z<2.5$ and $2.5 \leq z<3$, we find that in each redshift bin the cSFGs with AGNs have similar distributions of the stellar mass, the specific star formation rate, and the ratio of $L_{\rm IR}$ to $L_{\rm UV}$ to those without AGNs. After having performed a two-dimensional surface brightness modeling for those cSFGs with X-ray-detected AGNs (37) to correct for the influence of the central point-like X-ray AGN on measuring the structural parameters of its host galaxy, we find that in each redshift bin the cSFGs with AGNs have comparable distributions of all concerned structural parameters, i.e., the Sersic index, the 20\%-light radius, the Gini coefficient, and the concentration index, to those without AGNs. With a gradual consumption of available gas and dust, the structure of cSFGs, indicated by the above structural parameters, seem to be slightly more concentrated with decreasing redshift. At $2<z<3$, the similar environment between cSFGs with and without AGNs suggests that their AGN activities are potentially triggered by internal secular processes, such as gravitational instabilities or/and dynamical friction.

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。

↑