How Robust are the EGRET AGN gamma-ray identifications?

Summary Several AGNs have been proposed as identifications of gamma-ray sources discovered by CGRO. Using the NED database, we show that these AGNs are not the only extragalactic objects within the error boxes of the sources. Therefore, an in-depth study is needed on a case-by-case basis to access the most probable counterparts of the gamma-ray sources. A comparison with the COS-B database is also presented. 28Paper presented at the 6th Cosmic Physics National Conference, Palermo, 3–7 November 1992.     

Dithienylethene-Based Single Molecular Photothermal Linear Actuator

By employing a mechanically controllable break junction technique, we have realized an ideal single molecular linear actuator based on dithienylethene (DTE) based molecular architecture, which undergoes reversible photothermal isomerization when subjected to UV irradiation under ambient conditions. As a result, open form (compressed, UV OFF) and closed form (elongated, UV ON) of dithienylethene-based molecular junctions are achieved. Interestingly, the mechanical actuation is achieved without changing the conductance of the molecular junction around the Fermi level over several cycles, which is an essential property required for an ideal single molecular actuator. Our study demonstrates a unique example of achieving a perfect balance between tunneling width and barrier height change upon photothermal isomerization, resulting in no change in conductance but a change in the molecular length, which results in mechanical actuation at the single molecular level.