Multi-wavelength observations of the microquasar XTE J1720-318: a transition from high-soft to low-hard state
| dc.creator | Chaty, Sylvain | |
| dc.date | 2006-11-17 | |
| dc.date.accessioned | 2026-07-07T10:20:53Z | |
| dc.date.available | 2026-07-07T10:20:53Z | |
| dc.description | To gain a better understanding of high-energy Galactic sources, we observed the Galactic X-ray binary and black hole candidate XTE J1720-318 in the optical and near-infrared, just after the onset of its X-ray outburst in January, 2003. These observations were obtained with the ESO/NTT as a Target of Opportunity, in February and April 2003. We performed an accurate astrometry and analysed photometrical observations. We then produced a colour-magnitude diagram, looked at the overall evolution of the multi-wavelength light curve, and analysed the spectral energy distribution. We discovered the optical counterpart in the R-band (R ~ 21.5) and confirmed the near-infrared counterpart. We show that, for an absorption between 6 and 8 magnitudes, XTE J1720-318 is likely to be an intermediate mass X-ray binary located at a distance between 3 and 10 kpc, hosting a main sequence star of spectral type between late B and early G. Our second set of observations took place simultaneously with the third secondary outburst present in X-ray and near-infrared light curves. The evolution of its spectral energy distribution shows that XTE J1720-318 entered a transition from a high-soft to a low-hard state in-between the two observations. We finally discuss the different phases of the outburst of this source in the general scheme of outbursts from microquasars. | |
| dc.description | 12 pages, 5 figures; contributed talk at the VIth Microquasar Workshop: "Microquasars and beyond" (Como, Italy), eds: T. Belloni et al. September 2006 | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0611558 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0611558 | |
| dc.identifier | PoSMQW6:014,2006 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/174993 | |
| dc.subject | Astrophysics | |
| dc.title | Multi-wavelength observations of the microquasar XTE J1720-318: a transition from high-soft to low-hard state | |
| dc.type | text |