On the optical extinction and distance of GRS 1915+105

¹ Service d'Astrophysique, DAPNIA, bâtiment 709, l'Orme des merisiers, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
² Département de physique, bâtiment Buffon, Université de Versailles, 45 avenue des États-Unis, 78035 Versailles Cedex, France
³ Université Paris VII, 2 place Jussieu, 75251 Paris Cedex 05, France

Corresponding author: C. Chapuis, cchapuis@cea.fr

Received: 30 June 2003
Accepted: 21 October 2003

Abstract

Based on new millimeter and radio observations, we reevaluate the total hydrogen column density along the line of sight to the microquasar GRS 1915+105 to cm^-2. Our value is consistent with the one derived from X-ray measurements, namely ( cm^-2 (Ebisawa et al. [CITE]). Using the empirical law between the visual extinction and the total column density of hydrogen, A_v is found to 19.6 ± 1.7 mag. This result is ~mag lower than previously thought, and therefore, a reevaluation of infrared fluxes after derredening is needed. The revisited kinematic study allows to give a lower limit to the distance of GRS 1915+105 , namely 6.0 kpc. Taking into account the most accurate upper limit of distance inferred from radio data ( kpc, Fender et al. [CITE]) as well as this lower limit, this implies a distance of kpc.