Near-Ultraviolet Radiation toward Molecular Cloud N4 in W 50/SS 433: Evidence for Direct Interaction of the Jet with Molecular Cloud

Abstract

We compared the molecular clouds in the western part of SS 433 with near-ultraviolet radiation data obtained from GALEX. Near-ultraviolet radiation is prominently confirmed toward only N4, while no near-ultraviolet radiation is detected toward N1, N2, and N3. The radiative region of near-ultraviolet radiation is nearly the same as the CO-emitting region in N4, and does not extend beyond the jet seen in X-ray radiation. Near-ultraviolet radiation cannot be explained solely by broadband continuous radiation and may originate from line emissions. The intensity of near-ultraviolet radiation exhibits an anti-correlation with that of 13CO(J=3-2) emission. This anti-correlation, along with strong far-infrared radiation in the region with weaker near-ultraviolet radiation intensity compared to its surroundings, suggests that near-ultraviolet radiation originates from behind the molecular cloud, heating up the interstellar dust in N4. Subsequently, the dust in N4 re-radiates in the far-infrared band. In the same region, a high peak T_MB ratio of 12CO(J=3-2)/12CO(J=1-0) of ~0.9, and a high kinetic temperature of T_k ~56 K in the molecular cloud indicate that CO molecules are highly excited, and the molecular cloud is heated through photoelectric heating. This heating results from electrons released due to the photoelectric effect caused by the phenomenon where interstellar dust absorbs near-ultraviolet radiation. In terms of the timescale of near-ultraviolet radiation originating from line emissions, near-ultraviolet radiation towards N4 cannot be explained by the shock of the blast wave from a supernova that created W 50. These findings also suggest that N4 directly interacts with the jet from SS 433. As a result of this direct interaction, near-ultraviolet radiation is emitted from an interacting layer between the jet and N4.

arXiv comment16 pages, 7 figures, Accepted for publication in PASJ

References in corpus (25)

• Gaia Data Release 2. Summary of the contents and survey properties
• JADES NIRSpec Spectroscopy of GN-z11: Lyman-$\alpha$ emission and possible enhanced nitrogen abundance in a $z=10.60$ luminous galaxy
• Mass models of the Milky Way
• HARP/ACSIS: A submillimetre spectral imaging system on the James Clerk Maxwell Telescope
• The Second Data Release of the INT Photometric H-Alpha Survey of the Northern Galactic Plane (IPHAS DR2)
• Very high energy particle acceleration powered by the jets of the microquasar SS 433
• Symmetry in the changing jets of SS433 and its true distance from us
• On-The-Fly Observing System of the Nobeyama 45-m and ASTE 10-m Telescopes
• The Ultraviolet Sky: An Overview from the GALEX Surveys
• The $AKARI$ Far-Infrared All-Sky Survey Maps
• The Distance to SS433/W50 and its Interaction with the ISM
• The evolution of ultraviolet emission lines from the circumstellar material surrounding SN 1987A
• XMM-Newton observations of the eastern jet of SS433
• A Detailed Analysis of a Cygnus Loop Shock-Cloud Interaction
• The Large-scale ISM of SS433/W50 Revisited
• Aligned Molecular Clouds towards SS433 and L=348.5 degrees; Possible Evidence for Galactic "Vapor Trail" Created by Relativistic Jet
• Jets of SS433 on scales of dozens parsecs
• GeV-TeV Counterparts of SS 433/W50 from Fermi-LAT and HAWC Observations
• Self-generated ultraviolet radiation in molecular shock waves II. CH+ and the interpretation of emission from shock ensembles
• Detection of Optical Synchrotron Emission from the Radio Jet of 3C279
• A Multi-Wavelength Study of the Western Lobe of W50 Powered by the Galactic Microquasar SS 433
• A Small-Scale Investigation of Molecular Emission toward the Tip of the Western Lobe of W50/SS433
• Molecular clouds at the eastern edge of radio nebula W50
• A Cold and Diffuse Giant Molecular Filament in the Region of $l=41^{\circ }$, $b=-1^{\circ }$
• Physical properties of the molecular cloud, N4, in SS433; Evidence for an interaction of molecular cloud with the jet from SS433

Cited by in corpus (1)

• Discovery of CO Clouds Associated with the X-ray Jets of SS 433: Evidence for Shock-Cloud Interaction Enhancing Nonthermal X-ray Emission