A radio and infrared exploration around Cygnus X-3

¹ Departamento de Física, EPS, Universidad de Jaén, Campus Las Lagunillas s/n, Edif. A3, 23071 Jaén, Spain e-mail: [jmarti;dperez;jlg]@ujaen.es
² Grupo de Investigación FQM-322, Universidad de Jaén, Campus Las Lagunillas s/n, Edif. A3, 23071 Jaén, Spain
³ Dpto. de Ing. Mecánica y Minera, EPS, Universidad de Jaén, Campus Las Lagunillas s/n, Edif. A3, 23071 Jaén, Spain e-mail: peter@ujaen.es
⁴ Departament d'Astronomia i Meteorologia, Universitat de Barcelona, Av. Diagonal 647, 08028 Barcelona, Spain e-mail: jmparedes@ub.edu

Received: 9 January 2006
Accepted: 23 January 2006

Abstract

Aims.To investigate the possible hot spot nature of two previously detected radio sources in the vicinity of the Cygnus X-3 microquasar.

Methods.We present the results of a radio and near infrared exploration of the several arc-minute field around the well known galactic relativistic jet source Cygnus X-3 using the Very Large Array and the Calar Alto 3.5 m telescope.

Results.The data on which this paper is based do not support the hot spot hypothesis. Instead, our new observations suggest that these sources are most likely background or foreground objects. None of them appears to be even barely extended, as would be expected if they were part of a bow shock structure. Our near infrared observations also include a search for extended emission in the Bracket γ (2.166 μm) and H₂ (2.122 μm) lines as possible tracers of shocked gas in the Cygnus X-3 surroundings. The results were similarly negative and the corresponding upper limits are reported.