Discovery of CO Clouds Associated with the X-Ray Jets of SS 433: Evidence for Shock–Cloud Interaction Enhancing Nonthermal X-Ray Emission
Authors:
- Haruka SakemiHSHaruka Sakemi
- Hidetoshi SanoHSHidetoshi Sano
- Yasuo FukuiYFYasuo Fukui
- Mami MachidaMMMami Machida
- Shigeo S. KimuraSKShigeo S. Kimura
- Masato I.N. KobayashiMKMasato I.N. Kobayashi
- Kazuho KayamaKKKazuho Kayama
- Hiroaki YamamotoHYHiroaki Yamamoto
- Kengo TachiharaKTKengo Tachihara
- Hiroshi NagaiHNHiroshi Nagai
Open Access
- 9 June 2026
- journal article
- Published by American Astronomical Society in The Astrophysical Journal Letters
- Vol. 1004 (1) , L18
Abstract
We report the first identification of molecular clumps directly associated with the rebrightening regions of the large-scale X-ray jets of SS 433, based on 12 CO ( J = 1–0) observations with the Nobeyama 45 m Radio Telescope. Multiple clumps are detected toward the eastern and western jet heads, showing clear spatial correlation with the X-ray emission. The X-ray emission peaks immediately downstream of the molecular clumps, while the hardness ratio is enhanced at their surfaces, indicating that the observed structures cannot be explained by absorption effects. These results provide direct evidence for shock–cloud interactions between the jets and the surrounding interstellar medium. We suggest that turbulence generated at the jet–cloud interface amplifies magnetic fields, producing the observed nonthermal X-ray emission. Our findings highlight the importance of jet–interstellar medium interactions in shaping the X-ray properties of microquasar jets.Keywords
All Related Versions
Funding Information
- MEXT ∣ Japan Society for the Promotion of Science (22K20386)
- MEXT ∣ Japan Society for the Promotion of Science (22H01272)
- MEXT ∣ Japan Society for the Promotion of Science (23K22543)
- MEXT ∣ Japan Society for the Promotion of Science (24K00672)
- MEXT ∣ Japan Society for the Promotion of Science (22K14080)
- MEXT ∣ Japan Society for the Promotion of Science (23H04899)
This publication has 51 references indexed in Scilit:
- X-ray panorama of the SS 433/W50 complex by SRG/eROSITAAstronomy & Astrophysics, 2026
- Large-scale radio bubbles around the black hole transient V4641 SgrAstronomy & Astrophysics, 2026
- A MeerKAT view of the parsec-scale jets in the black-hole X-ray binary GRS 1758–258Astronomy & Astrophysics, 2025
- Quantifying jet–interstellar medium interactions in Cyg X-1: Insights from dual-frequency bow shock detection with MeerKATAstronomy & Astrophysics, 2025
- MeerKAT discovers a jet-driven bow shock near GRS 1915+105Astronomy & Astrophysics, 2025
- The radio jets of SS 433 at millimetre wavelengthsAstronomy & Astrophysics, 2018
- NRO Legacy Project: M33 all Disk Survey of Giant Molecular Clouds with NRO 45-m and ASTE 10-m telescopesProceedings of the International Astronomical Union, 2010
- Extremely fast acceleration of cosmic rays in a supernova remnantNature, 2007
- A multi-wavelength study of the western lobe of W50 powered by the galactic microquasar SS 433Advances In Space Research, 2005
- A kinematic model for SS433Nature, 1979