Open AccessOptical spectroscopy of GX 339−4 during the high–soft and low–hard states – I
Author(s) -
Soria Roberto,
Wu Kinwah,
Johnston Helen M.
Publication year - 1999
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 - 10.1046/j.1365-8711.1999.02933.x
Subject(s) - physics , astrophysics , emission spectrum , line (geometry) , spectroscopy , ionization , accretion (finance) , outflow , astronomy , orbital motion , spectral line , low mass , stars , angular momentum , ion , geometry , mathematics , quantum mechanics , meteorology
We carried out spectroscopic observations of the candidate black hole binary GX 339−4 during its low–hard and high–soft X‐ray states. We have found that the spectrum is dominated by emission lines of neutral elements with asymmetric, round‐topped profiles in the low–hard state. In the high–soft state, however, the emission lines from both neutral and ionized elements have unambiguously resolved double‐peaked profiles. The detection of double‐peaked emission lines in the high–soft state, with a larger peak separation for higher ionization lines, indicates the presence of an irradiatively heated accretion disc. The round‐topped lines in the low–hard state are probably caused by a dense matter outflow from an inflated non‐Keplerian accretion disc. Our data do not show velocity modulations of the line centres caused by the orbital motion of the compact object, neither do the line basewidths show substantial variations in each observational epoch. There are no detectable absorption lines from the companion star. All these features are consistent with those of a system with a low‐mass companion star and low orbital inclination.