Abstract:
NGC 1313 X-1 is a mysterious ultraluminous X-ray (ULX) source whose X-ray-powering mechanism and bubblelike structure surrounding the source are topics of intense study. Here, we perform an X-ray spectroscopic study of
the source using joint XMM-Newton and NuSTAR observations taken during 2012–2017. The combined spectra
cover the energy band 0.3–20 keV. We use the accretion–ejection-based JeTCAF model for spectral analysis. The
model-fitted disk mass accretion rate varies from 4.6 to 9.6 M Edd and the halo mass accretion rate varies from 4.0 to
6.1 M Edd with a dynamic Comptonizing corona of average size of ∼15 rg. The data fitting is carried out for
different black hole (BH) mass values. The goodness of the fit and uncertainties in model parameters improve
while using higher BH masses, with the most probable mass of the compact object being 133 ± 33 Me. We have
estimated the mass outflow rate, its velocity and power, and the age of the inflated bubble surrounding the source.
Our estimated bubble morphology is in accordance with the observed optical bubble and winds found through
high-resolution X-ray spectroscopy, suggesting that the bubble was expanded by the outflows originating from the
central source. Finally, we conclude that the super-Eddington accretion onto a nearly intermediate-mass BH may
power a ULX when the accretion efficiency is low, though their efficiency increases when the jet/outflow is taken
into account, in agreement with numerical simulations in the literature
