Dense CO in Mrk 71-A: Superwind Suppressed in a Young Super Star Cluster

作者：Oey M S^*; Herrera C N; Silich Sergiy; Reiter Megan; James Bethan L; Jaskot A E; Micheva Genoveva

来源：Astrophysical Journal Letters, 2017, 849(1): L1.

DOI：10.3847/2041-8213/aa9215

• galaxies: starburst
• galaxies: star clusters: general
• ISM: bubbles
• ISM: molecules
• stars: formation
• stars: massive

We report the detection of CO(J = 2 - 1) coincident with the super star cluster (SSC) Mrk. 71-A in the nearby Green Pea analog galaxy, NGC. 2366. Our observations with the Northern Extended Millimeter Array reveal a compact, similar to 7 pc, molecular cloud whose mass (10(5) M-circle dot) is similar to that of the SSC, consistent with a high star formation efficiency, on the order of 0.5. There are two spatially distinct components separated by 11 km s(-1). If expanding, these could be due to momentum-driven stellar wind feedback. Alternatively, we may be seeing remnants of the infalling, colliding clouds responsible for triggering the SSC formation. The kinematics are also consistent with a virialized system. These extreme, high-density, star-forming conditions inhibit energy-driven feedback; the co-spatial existence of a massive, molecular cloud with the SSC supports this scenario, and we quantitatively confirm that any wind-driven feedback in Mrk. 71-A is momentum-driven, rather than energy-driven. Since Mrk. 71-A is a candidate Lyman continuum emitter, this implies that energy-driven superwinds may not be a necessary condition for the escape of ionizing radiation. In addition, the detection of nebular continuum emission yields an accurate astrometric position for the Mrk. 71-A. We also detect four other massive molecular clouds in this giant star-forming complex.

• 出版日期2017-11-1