Astronomy and Astrophysics – Astrophysics
Scientific paper
Jul 1974
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1974ap%26ss..29..191k&link_type=abstract
Astrophysics and Space Science, Volume 29, Issue 1, pp.191-210
Astronomy and Astrophysics
Astrophysics
3
Scientific paper
Simultaneous observations of hard X-ray and optical emission from Sco X-1 were carried out at Hyderabad, India, on April 16 and 19, 1972. During the first and the second observations Sco X-1 was on the average in a bright phase ofB=12.5 mag. and a slightly darker phase ofB=12.7 mag. respectively. During the first observation the X-ray intensity in the energy range 20 40 keV measured with balloon borne scintillation counters showed an enhancement of a factor of about two in coincidence with an optical flare ofB≅0.2 mag., whereas the apparent temperature derived from the X-ray spectrum observed in the energy range 20 35 keV showed no appreciable change. Both the X-ray intensity and the apparent temperature observed on April 19 are considerably lower than those observed on April 16. Taking into account the effect of radiative transfer in a hot plasma, the electron density and the optical depth for electron scattering of the plasma cloud are derived asn e ≈3×1016 cm-3 and τes ≈ 10 for the quiescent bright phase. The flare is explained by an increase of the plasma mass by about 30% and an increase of τes by τes ≈ 1 without appreciable change of the plasma temperature. The results on April 19 is interpreted as indicating that the quiescent dark phase may be characterized by a decrease of the plasma mass, its contraction and lower temperature.
No associations
LandOfFree
Simultaneous Hard X-Ray and Optical Observations ofScjo X-1 and a Model of Semi-Opaque X-Ray Sources does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Simultaneous Hard X-Ray and Optical Observations ofScjo X-1 and a Model of Semi-Opaque X-Ray Sources, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Simultaneous Hard X-Ray and Optical Observations ofScjo X-1 and a Model of Semi-Opaque X-Ray Sources will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1758449