A SURVEY OF IRRADIATED PILLARS, GLOBULES, AND JETS IN THE CARINA NEBULA

• Published in: The Astronomical journal 2015-03, Vol.149 (3), p.1-31
• Main Authors: Hartigan, P., Reiter, M., Smith, N., Bally, J.
• Format: Article
• Language: English
• Subjects: ASTRONOMY AND ASTROPHYSICS; Clusters; H II regions; Herbig-Haro objects; Irradiation; ISM: bubbles; ISM: jets and outflows; Jets; Molecular clouds; photon-dominated region (PDR); Pillars; regions; Star formation; stars: formation; Ultraviolet radiation
• ISSN: 0004-6256; 1538-3881; 1538-3881
• DOI: 10.1088/0004-6256/149/3/101

ABSTRACT We present wide-field, deep narrowband H2, Brγ, H , [S ii], [O iii], and broadband I- and K-band images of the Carina star formation region. The new images provide a large-scale overview of all the H2 and Brγ emission present in over a square degree centered on this signature star-forming complex. By comparing these images with archival Hubble Space Telescope and Spitzer images we observe how intense UV radiation from O and B stars affects star formation in molecular clouds. We use the images to locate new candidate outflows and identify the principal shock waves and irradiated interfaces within dozens of distinct areas of star-forming activity. Shocked molecular gas in jets traces the parts of the flow that are most shielded from the intense UV radiation. Combining the H2 and optical images gives a more complete view of the jets, which are sometimes only visible in H2. The Carina region hosts several compact young clusters, and the gas within these clusters is affected by radiation from both the cluster stars and the massive stars nearby. The Carina Nebula is ideal for studying the physics of young H ii regions and photodissociation region (PDR), as it contains multiple examples of walls and irradiated pillars at various stages of development. Some of the pillars have detached from their host molecular clouds to form proplyds. Fluorescent H2 outlines the interfaces between the ionized and molecular gas, and after removing continuum, we detect spatial offsets between the Brγ and H2 emission along the irradiated interfaces. These spatial offsets can be used to test current models of PDRs once synthetic maps of these lines become available.