A NuSTAR view of SS433: Precessional evolution of the jet-disk system

Abstract

SS433 is a Galactic microquasar with powerful outflows (double jet, accretion disk and winds) with well known orbital, precessional and nutational period. In this work we characterise different outflow parameters throughout the precessional cycle of the system. We analyse 10 NuSTAR ($3-70$ keV) observations of $\sim$30~ks that span $\sim$1.5 precessional cycles. We extract averaged spectra and model them using a combination of a double thermal jet model (bjet) and pure neutral and relativistic reflection (xillverCp and relxilllpCp) over an accretion disk. We find an average jet bulk velocity of $\beta =v/c\sim 0.29$ with an opening angle of $\lesssim$6~degrees. Eastern jet kinetic power ranges from 1 to $10^{39}$~erg/s, with base "coronal" temperatures $T_o$ ranging between 14 and 18 keV. Nickel to iron abundances remain constant at $\sim$9 (within 1$\sigma$). The western to eastern jet flux ratio becomes $\sim 1$ on intermediate phases, about 35% of the total precessional orbit. The $3-70$ keV total unabsorbed luminosity of the jet and disk ranges from 2 to 20 $\times$10${}^{37}$~erg/s, with the disk reflection component contributing mainly to the hard $20-30$ keV excess and the stationary 6.7 keV ionized Fe line complex. At low opening angles $\Theta$ we find that the jet expands sideways following an adiabatic expansion of a gas with temperature $T_o$. Finally, the central source and lower parts of the jet could be hidden by an optically thick region of $\tau >0.1$ and size $R\sim N_H/n_{e0}\sim 1.5\times 10^9$~cm$\sim$1700~$r_g$ for $M_{BH}=3M_{\odot }$

12 pages, 7 figures, 2 tables. To be published in A&A

References in corpus (7)

• Gaia Data Release 1: Astrometry - one billion positions, two million proper motions and parallaxes
• The role of the reflection fraction in constraining black hole spin
• The Distance to SS433/W50 and its Interaction with the ISM
• Modeling the light curves of ultraluminous X-ray sources as precession
• Diagnostics of Parameters for the X-ray Jets of SS 433 from High-Resolution Chandra Spectroscopy
• Structure and Magnetic Fields in the Precessing Jet System SS433 III. Evolution of the Intrinsic Brightness of the Jets from a Deep Multi-Epoch VLA Campaign
• Mass flows and their behaviors in the SS433--W50 system

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• X-ray panorama of the SS433/W50 complex by SRG/eROSITA
• Simultaneous NICER and NuSTAR observations of the Ultraluminous source NGC 4190 ULX-1
• Constraints on cyclotron features and accretion regime in the high-mass X-ray binary 4U 1700-37 from NuSTAR