【場所】国立天文台・三鷹 中央棟（北）1階 講義室
【発表者（敬称略）】今瀬 佳介（総研大 D1・ハワイ、指導教員 : 児玉 忠恭 & 今西 昌俊）
【タイトル】近赤外線PaαによるMBHの推定(Estimating Black Hole Masses Using Paα emission line)
Active Galactic Nuclei (AGNs) are luminous objects, found in the nuclei of galaxies.
It is believed that they have suppermassive black hole and accretion disk in their central region, surrounded with broad-line region(BLR).
This picture is called “Unified model for AGN” (e.g., Antonucci 1993) Today, masses of black holes of AGNs (MBHs) are mainly estimated with broad optical and UV emission lines (Hα, Hβ, MgII), using their line width and flux.
More than half of AGNs, however, are affected with the foreground gas and dust.
For such AGNs (so-called “dusty AGNs”), it is difficult to use UV/optical lines as estimators of MBHs.
On the other hand, Paα and Paβ lines, two of the strongest lines in near-infrared(NIR) and free of blending, are detectable in “dusty AGNs” and ultra luminous IR galaxy(ULIRG).
We have observed 21 nearby PG QSOs with IRTF/SpeX in order to establish Paα lines, the strongest line in NIR, as a new estimator of MBHs for dusty AGNs.
In the colloquium, we report the present results and our future work.