报告人：范璐璐 教授(山东大学)

时间：2016年4月27日下午4：00

地点：东区理化大楼18层天文台报告厅

报告摘要： We will present our recent works on IR SED decomposition and host galaxy morphology analysis of WISE-selected, hyperluminous dust-obscured galaxies(Hot DOGs). We find that they are hyperluminous ($L_{IR}\geq10^{13}L_\odot$), with torus emission dominating the IR energy output (>75\%). Hot DOGs have both high IR luminosity of cold dust and high dust temperatures (~73K). As a result, they have relatively low dust mass. The hyperluminous Hot DOGs have high dust covering factors, which deviate the previously proposed trend of the dust covering factor decreasing with increasing bolometric luminosity. The torus luminosity has been found to be well correlated with that of cold dust, which is consistent with the model predictions of AGN-dominated systems. We investigate the possible evolutionary path of Hot DOGs by employing a simple physical model. By comparing the model predictions and the observed properties, we suggest that Hot DOGs may lie at or close to both peaks of star formation and black hole growth histories, and represent a transit phase during the evolution of massive galaxies, transforming from the dusty starburst dominated phase to the optically bright QSO phase. Thanks to heavy obscuration, host galaxy morphology of Hot DOGs can be revealed directly with HST WFC3 H band imaging. Using visual classification on a small sample of Hot DOGs, we find that ~62% of them show the merger signal, suggesting that both intense AGN and starburst activities are likely merger-driven. According to fitting the surface brightness profiles, we find that the distribution of Sérsic indices of Hot DOGs peaks around 2, which suggests that most of Hot DOGs have transforming morphologies. From the point of view of morphology, our result suggests again that Hot DOGs may represent a transit phase during massive galaxy evolution.