Letter to the Editor

Precessing microblazars and unidentified gamma-ray sources

¹ Instituto Argentino de Radioastronomía, C.C.5, (1894) Villa Elisa, Buenos Aires, Argentina
² CEA/DMS/DAPNIA/Service D'Astrophysique, Centre d'Etudes de Saclay, 91191 Gif-sur-Yvette, France
³ Instituto de Astronomía y Física del Espacio/CONICET, C.C. 67, Suc. 28, Buenos Aires, Argentina

Corresponding author: M. M. Kaufman Bernadó, mar@vianw.com.ar

Received: 22 January 2002
Accepted: 13 February 2002

Abstract

The recent discovery by Paredes et al. ([CITE]) of a persistent microquasar that is positionally coincident with an unidentified gamma-ray source has open the possibility that other sources in the Third EGRET Catalog could be interpreted as microquasars as well. In this letter we show that some variable unidentified EGRET sources in the galactic plane could be produced by faint, otherwise undetected microquasars with precessing jets. When the jet points towards the observer, gamma-ray emission resulting from upscattered stellar photons could be detectable yielding a variable source with weak or undetectable counterpart at longer wavelengths. Strategies for detecting these “microblazars” with forthcoming satellites are briefly discussed.