2025/09/08 by Lin He, He, Lin, Zhiyuan Li +9 · 1 voice
Physics and Astronomy · #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #Galaxies: Formation, Evolution, Phenomena
paper · pdf · doi:10.3847/1538-4357/ae0722
openalex publication_date 2025/10/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/02
Abstract Based on archival Chandra X-ray observation, optical integral-field spectroscopic data, and radio interferometric data, we report the discovery of a pair of giant bubbles (with a projected radius ∼5 kpc) of ionized gas emerging from a highly inclined starburst galaxy NGC 6286, which is undergoing strong tidal interactions with its close neighbor NGC 6285. The bubbles are manifested by extraplanar soft X-ray emission with an X-shaped morphology, which is tightly cospatial with H α line emission and partially coincident with radio continuum. Low surface brightness diffuse X-ray emission can be traced out to ∼90 kpc from the galactic center, revealing the presence of an extended hot gaseous halo. X-ray spectral analysis of the bubbles yields a gas temperature of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>0.7</mml:mn> <mml:msubsup> <mml:mrow> <mml:mn>0</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.18</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.16</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> keV, a relatively high value among known galactic-scale bubbles in the local Universe. An average energy injection rate of ∼10 43 erg s −1 is required to inflate the bubbles within an estimated dynamical age of ∼6.4 Myr. The multiwavelength properties of the bubbles can be understood with the conventional superwind scenario, in which disk/halo gas is swept up into an expanding, cooling shell by a hot tenuous wind. The current starburst in NGC 6286 is energetically sufficient to launch the superwind, although we cannot rule out the possibility of a more violent active galactic nucleus in the recent past as the driving source. Future high-resolution spectroscopic observations will help to shed light on the origin of the superwind and its role as an important galactic feedback process.