M. Tiwari, R. Karim, M. W. Pound, M. Wolfire, A. Jacob, C. Buchbender, R. Güsten, C. Guevara, R. D. Higgins, S. Kabanovic, C. Pabst, O. Ricken, N. Schneider, R. Simon, J. Stutzki, and A. G. G. M. Tielens
SOFIA, the Stratospheric Observatory for Infrared Astronomy, is a Boeing 747SP aircraft modified to carry a 2.7-meter (106-inch) reflecting telescope (with an effective diameter of 2.5 meters).
The analysis in the paper shows that a single, expanding bubble of warm gas surrounds the Westerlund 2 star cluster and disproved earlier studies suggesting there may be two bubbles surrounding Westerlund 2. The researchers also identified the source of the bubble and the energy driving its expansion.
Tiwari and her colleagues created a clearer picture of the bubble by measuring radiation emitted from the cluster across the electromagnetic spectrum.
The paper presents, for the first time, large-scale velocity integrated intensity maps of 2P3/2 → 2P1/2 transition of [C II], J = 3 → 2 transitions of 12CO and 13CO toward RCW 49. By analyzing the observed data in different velocity ranges, the researchers successfully decoupled an expanding shell associated with RCW 49 from the entire gas complex.
The Astrophysical Journal（APJ）是享有盛誉的天文和天体物理学研究期刊，由美国天文学学会和IOP合作出版，发表天文学和天体物理学领域的原创性研究、最新进展、新发现和理论等。APJ是20世纪许多经典发现的首发者，同时也是近年来关于类星体、脉冲星、中子星、黑洞、太阳和恒星磁场、X射线和星际物质等重大发现的发表平台。