GeV-TeV Counterparts of SS 433/W50 from Fermi-LAT and HAWC Observations

Abstract

The extended jets of the microquasar SS 433 have been observed in optical, radio, X-ray, and recently very-high-energy (VHE) $\gamma$-rays by HAWC. The detection of HAWC $\gamma$-rays with energies as great as 25 TeV motivates searches for high-energy $\gamma$-ray counterparts in the Fermi-LAT data in the 100 MeV--300 GeV band. In this paper, we report on the first-ever joint analysis of Fermi-LAT and HAWC observations to study the spectrum and location of $\gamma$-ray emission from SS~433. Our analysis finds common emission sites of GeV-to-TeV $\gamma$-rays inside the eastern and western lobes of SS 433. The total flux above 1 GeV is $\sim 1\times 10^{-10}\mathrm{c}{\mathrm{m}}^{-2}{\mathrm{s}}^{-1}$ in both lobes. The $\gamma$-ray spectrum in the eastern lobe is consistent with inverse-Compton emission by an electron population that is accelerated by jets. To explain both the GeV and TeV flux, the electrons need to have a soft intrinsic energy spectrum, or undergo a quick cooling process due to synchrotron radiation in a magnetized environment.

10 pages, 3 figures, 2 tables. To appear in ApJ Letters

References in corpus (4)

• Absorption of Very High Energy Gamma Rays in the Milky Way
• Detection of persistent gamma-ray emission toward SS433/W50
• Gamma-rays from SS433: evidence for periodicity
• Tentative evidence of spatially extended GeV emission from SS433/W50

Cited by in corpus (15)

• Acceleration and transport of relativistic electrons in the jets of the microquasar SS 433
• Deciphering the Origin of the GeV--TeV Gamma-ray Emission from SS 433
• The LHAASO PeVatron bright sky: what we learned
• Gamma-ray observations of MAXI J1820+070 during the 2018 outburst
• Spatially resolved study of the SS 433/W50 west region with Chandra: X-ray structure and spectral variation of non-thermal emission
• Spectral study of very high energy gamma rays from SS 433 with HAWC
• Energy estimation of high energy particles associated with the SS433/W50 system through radio observation at 1.4 GHz
• Physical properties of the molecular cloud, N4, in SS433; Evidence for an interaction of molecular cloud with the jet from SS433
• Deep search for gamma-ray emission from the accreting X-ray pulsar 1A 0535+262
• Multimessenger Emission from Very-High-Energy Black Hole-Jet Systems in the Milky Way
• Multi-messenger Implications of Sub-PeV Diffuse Galactic Gamma-Ray Emission
• Universal Peaks Ratio In The Spectral Energy Density Of Double Hump Blazars, Gamma Ray Bursts, And Microquasars
• Near-Ultraviolet Radiation toward Molecular Cloud N4 in W 50/SS 433: Evidence for Direct Interaction of the Jet with Molecular Cloud
• Investigation of the Microquasar SS 433 with VERITAS
• Hard X-ray emission from the eastern jet of SS 433 powering the W50 `Manatee' nebula: Evidence for particle re-acceleration