A Small-Scale Investigation of Molecular Emission toward the Tip of the Western Lobe of W50/SS433

Abstract

We perform a molecular (CO and CN) line observation using IRAM 30m telescope toward two small regions near the western edge of supernova remnant (SNR) W50/SS433. CO observation reveals spatial correspondence of two molecular clumps at the local-standard-of-rest (LSR) velocity around +53 km s${}^{-1}$ with multiwavelength local features of W50/SS433 system. One of the two clumps appears to be embedded in a void of diffuse radio and X-ray emission. Toward the two clumps, asymmetric broad line profiles of the ${}^{12}$CO lines are obtained, which provide kinematic evidence of the association between the clumps and the jet-related gas. The ${}^{12}$CO $J=2-1$/$J=1-0$ line ratios ($>0.9$) and the kinetic temperatures ($\sim 30$ K) of the clumps are distinctively higher than all those of the clumps at other LSR velocities along the same line of sight, which may be physical signatures of the association. We show that the clump coincident with the void can survive the thermal heating if it is surrounded by hot gas, with an evaporation timescale much larger than the age of SNR W50. We also show that the thermal equilibrium in the high temperature clumps can be maintained by the heating of the penetrating environmental CRs. CN ($J=3/1-1/2$) line emission is detected in the two clumps, and the CN abundances derived are much higher than that in the interstellar molecular clouds (MCs) and that in the SNR-interacting MCs.

15 pages, 12 figures, 3 tables. Published to the Astrophysical Journal

References in corpus (10)

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• The Distance to SS433/W50 and its Interaction with the ISM
• Production of gamma rays and neutrinos in the dark jets of the microquasar SS433
• Spectral Line Survey toward Spiral Arm of M51 in the 3 mm and 2 mm Bands
• Detection of persistent gamma-ray emission toward SS433/W50
• Deep optical observations of the interaction of the SS 433 microquasar jet with the W 50 radio continuum shell
• Multi-wavelength study of the supernova remnant Kes 79 (G33.6+0.1): On its supernova properties and expansion into a molecular environment
• Jets of SS433 on scales of dozens parsecs
• Magneto-hydrodynamic Simulations of a Jet Drilling an HI Cloud: Shock Induced Formation of Molecular Clouds and Jet Breakup
• Magnetohydrodynamic Simulations of the Formation of Molecular Clouds toward the Stellar Cluster Westerlund 2: Interaction of a Jet with Clumpy Interstellar Medium

Cited by in corpus (11)

• Acceleration and transport of relativistic electrons in the jets of the microquasar SS 433
• Investigating the nature of MGRO J1908+06 with multiwavelength observations
• Continuous Jets and Backflow Models for the Formation of W50/SS433 in Magnetohydrodynamics Simulations
• Spatially resolved study of the SS 433/W50 west region with Chandra: X-ray structure and spectral variation of non-thermal emission
• Energy estimation of high energy particles associated with the SS433/W50 system through radio observation at 1.4 GHz
• Molecular clouds at the eastern edge of radio nebula W50
• Physical properties of the molecular cloud, N4, in SS433; Evidence for an interaction of molecular cloud with the jet from SS433
• Near-Ultraviolet Radiation toward Molecular Cloud N4 in W 50/SS 433: Evidence for Direct Interaction of the Jet with Molecular Cloud
• Discovery of CO Clouds Associated with the X-ray Jets of SS 433: Evidence for Shock-Cloud Interaction Enhancing Nonthermal X-ray Emission
• Fermi-LAT detection of extended gamma-ray emission in the vicinity of SNR G045.7$-$00.4: evidence for escaping cosmic rays interacting with the surrounding molecular clouds
• IRAM 30 m CO-line Observation toward PeVatron Candidate G106.3+2.7: Direct Interaction between the Shock and the Molecular Cloud Remains Uncertain