Poster Presentation

Transverse Proximity Effect around a Type 2 Quasar

Author(s): Makoto Sato (Shinshu University), Toru Misawa (Shinshu University), Yusuke Maeda (Shinshu University), Akatoki Noboriguchi (Shinshu University), Rikako Ishimoto (The University of Tokyo)

Presenter: Makoto Sato (Shinshu University)

An intense ultraviolet (UV) radiation from quasars ionizes neutral hydrogen in the inter-galactic medium (IGM) within several Mpc from the quasars, causing a proximity effect. However, this effect may be anisotropic, since there exists more neutral hydrogen in the transverse direction than in the line-of-sight direction around typical Type 1 (i.e., face-on) quasars (Prochaska et al. 2013). The most plausible explanation for this trend is that the UV radiation from quasars is shielded by the dust torus, making the UV radiation anisotropic. Indeed, the opposite trend (i.e., HI gas is deficit in the transverse direction) is seen around BAL quasars whose inclination angle is large (i.e., observing from edge-on), which supports this scenario (Misawa et al. 2022).
In this study, we performed the same analysis around a Type 2 quasar whose large inclination angle is guaranteed more than BAL quasars. We compare our results to those of the past studies around Type 1 and BAL quasars to verify the anisotropic scenario with the dust torus.