Large-scale Map of Millimeter-wavelength Hydrogen Radio Recombination Lines around a Young Massive Star Cluster

Journal Article · Tue Aug 01 04:00:00 EDT 2017 · Astrophysical Journal Letters

DOI:https://doi.org/10.3847/2041-8213/AA7D48· OSTI ID:22872575

Nguyễn-Lu’o’ng, Q.; Kim, Kee-Tae ^[1]; Anderson, L. D. ^[2]; Motte, F.; Nony, T. ^[3]; Schilke, P.; Carlhoff, P.; Schneider, N.; Simon, R. ^[4]; Beuther, H.; Bihr, S.; Rugel, M.; Soler, J.; Wang, Y. ^[5]; Didelon, P. ^[6]; Kramer, C. ^[7]; Louvet, F.; Bronfman, L. ^[8]; Menten, K. M.; others, and

---

1. Korea Astronomy and Space Science Institute, 776 Daedeok daero, Yuseoung, Daejeon 34055 (Korea, Republic of)
2. Department of Physics and Astronomy, West Virginia University, Morgantown, WV 26506 (United States)
3. University Grenoble Alpes, CNRS, Institut de Planétologie et d’Astrophysique de Grenoble, F-38000 Grenoble (France)
4. I. Physik. Institut, University of Cologne, D-50937 Cologne (Germany)
5. Max Planck Institute for Astronomy, Konigstuhl 17, D-69117 Heidelberg (Germany)
6. AIM Paris-Saclay/Service d’Astrophysique, CEA/IRFU—CNRS/INSU—Univ. Paris Diderot, CEA-Saclay, F-91191 Gif-sur-Yvette Cedex (France)
7. Instituto Radioastronoma Milimtrica (IRAM), Av. Divina Pastora 7, Nucleo Central, E-18012 Granada (Spain)
8. Departamento de Astronomía, Universidad de Chile, Santiago (Chile)

We report the first map of large-scale (10 pc in length) emission of millimeter-wavelength hydrogen recombination lines (mm-RRLs) toward the giant H ii region around the W43-Main young massive star cluster (YMC). Our mm-RRL data come from the IRAM 30 m telescope and are analyzed together with radio continuum and cm-RRL data from the Karl G. Jansky Very Large Array and HCO{sup +} 1–0 line emission data from the IRAM 30 m. The mm-RRLs reveal an expanding wind-blown ionized gas shell with an electron density ∼70–1500 cm{sup −3} driven by the WR/OB cluster, which produces a total Lyα photon flux of 1.5×10{sup 50} s{sup −1}. This shell is interacting with the dense neutral molecular gas in the W43-Main dense cloud. Combining the high spectral and angular resolution mm-RRL and cm-RRL cubes, we derive the two-dimensional relative distributions of dynamical and pressure broadening of the ionized gas emission and find that the RRL line shapes are dominated by pressure broadening (4–55 km s{sup −1}) near the YMC and by dynamical broadening (8–36 km s{sup −1}) near the shell’s edge. Ionized gas clumps hosting ultra-compact H ii regions found at the edge of the shell suggest that large-scale ionized gas motion triggers the formation of new star generation near the periphery of the shell.

• OSTI ID: 22872575
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 844; ISSN 2041-8205
• Country of Publication: United Kingdom
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ELECTRON DENSITY
HYDROGEN
LYMAN LINES
PHOTONS
RADIOWAVE RADIATION
RECOMBINATION
SPATIAL RESOLUTION
STAR CLUSTERS
TELESCOPES
WAVELENGTHS