Open AccessA closer look at the X‐ray transient XTE J1908+094: identification of two new near‐infrared candidate counterparts
Author(s) -
Chaty S.,
Mignani R. P.,
Israel G. L.
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.09838.x
Subject(s) - physics , astrophysics , telescope , flux (metallurgy) , observatory , astronomy , adaptive optics , very large telescope , binary number , star (game theory) , infrared , position (finance) , galaxy , finance , economics , materials science , arithmetic , mathematics , metallurgy
We have reported, in our previous paper, on the near‐infrared (NIR) identification of a possible counterpart to the black hole candidate XTE J1908+094 obtained with the European Southern Observatory/New Technology Telescope. Here, we present new, follow‐up, Canada–France–Hawaii Telescope adaptive optics observations of the XTE J1908+094 field, which resolved the previously proposed counterpart in two objects separated by about 0.8 arcsec. Assuming that both objects are potential candidate counterparts, we derive that the binary system is a low‐mass system with a companion star which could be either an intermediate/late type (A–K) main‐sequence star at a distance of 3–10 kpc or a late‐type (>K) main‐sequence star at a distance of 1–3 kpc. However, we show that the brighter of the two objects ( J ∼ 20.1, H ∼ 18.7, K ′∼ 17.8) is more likely to be the real counterpart of the X‐ray source. Its position is more compatible with our astrometric solution, and colours and magnitudes of the other object are not consistent with the lower limit of 3 kpc derived independently from the peak bolometric flux of XTE J1908+094. Further multiwavelength observations of both candidate counterparts are crucial in order to solve the pending identification.