The Carina Nebula and Gum 31 molecular complex III: The distribution of the 1-3 GHz radio continuum across the whole nebula

Abstract

We report the most detailed $1-3$ GHz radio continuum emission map of the nearest region of massive star formation, the Carina Nebula. As part of a large program with the Australia Telescope Compact Array, we have covered $\sim$ 12 deg${}^2$, achieving an angular resolution of $\sim$ 16 arcsec, representing the largest and most complete map of the radio continuum to date. Our continuum map shows a spectacular and complex distribution of emission across the nebula, with multiple structures such as filaments, shells, and fronts across a wide range of size scales. The ionization fronts have advanced far into the southern and northern region of the Galactic Plane, as fronts are clearly detected at distances $\sim$ 80 pc from the stellar clusters in the center. We estimated an ionization photon luminosity $Q_{\mathrm{H}}=(7.8\pm 0.8)\times 10^{50}$ s${}^{-1}$ which corresponds to $\sim 85\%$ of the total value obtained from stellar population studies. Thus, approximately $15\%$ of the ionizing flux has escaped from the nebula into the diffuse Galactic Interstellar Medium. Comparison between radio continuum and the hydrogen atomic and molecular gas maps offers a clear view of the bipolar outflow driven by the energy released by the massive stellar clusters that also affects the fraction of molecular gas across the nebula. Comparison between 8$\mu$m and 70$\mu$m emission maps and the radio continuum reveals how the hot gas permeates through the molecular cloud, shapes the material into features such as pillars, small shells and arc-like structures, and ultimately, escapes.

arXiv comment18 pages, 16 Figures, 1 appendix

References in corpus (33)

• Hi-GAL: the Herschel infrared Galactic Plane Survey
• The Millennium Arecibo 21-CM Absorption Line Survey. II. Properties of the Warm and Cold Neutral Media
• The Australia Telescope Compact Array Broadband Backend (CABB)
• Post-correlation radio frequency interference classification methods
• The Molonglo Galactic Plane Survey (MGPS-2): Compact Source Catalogue
• Rotation Measures of Extragalactic Sources Behind the Southern Galactic Plane: New Insights into the Large-Scale Magnetic Field of the Inner Milky Way
• A Census of the Carina Nebula. I: Cumulative Energy Input from Massive Stars
• The Millennium Arecibo 21-cm Absorption Line Survey. I. Techniques and Gaussian Fits
• The 6-GHz Multibeam Maser Survey I. Techniques
• The 6-GHz methanol multibeam maser catalogue IV: Galactic longitudes 186 to 330 including the Orion-Monoceros region
• Cloud-cloud collision as a trigger of the high-mass star formation; a molecular line study in RCW120
• Molecular clouds in the Trifid nebula M20; Possible evidence for a cloud-cloud collision in triggering the formation of the first generation stars
• HST/ACS H-alpha Imaging of the Carina Nebula: Outflow Activity Traced by Irradiated Herbig-Haro Jets
• A Census of the Carina Nebula -- II. Energy Budget and Global Properties of the Nebulosity
• A New 1.4GHz Radio Continuum Map of the Sky South of Declination +25 deg
• S-band Polarization All Sky Survey (S-PASS): survey description and maps
• THOR - The HI, OH, Recombination Line Survey of the Milky Way - The pilot study: HI observations of the giant molecular cloud W43
• Photodissociation regions and star formation in the Carina Nebula
• Spitzer Space Telescope observations of the Carina Nebula: The steady march of feedback-driven star formation
• The Carina Nebula and Gum 31 molecular complex: I. Molecular gas distribution, column densities and dust temperatures
• The Giant Pillars of the Carina Nebula
• Constraining physical conditions for the PDR of Trumpler 14 in the Carina Nebula
• H110alpha recombination-line emission and 4.8-GHz continuum emission in the Carina Nebula
• 1420 MHz Continuum Absorption Towards Extragalactic Sources in the Galactic Plane
• Discovering young stars in the Gum 31 region with infrared observations
• Excited-state hydroxyl maser catalogue from the methanol multibeam survey -- I. Positions and Variability
• Effect of feedback of massive stars in the fragmentation, distribution, and kinematics of the gas in two star forming regions in the Carina Nebula
• Probing ISM Structure in Trumpler 14 & Carina I Using The Stratospheric Terahertz Observatory 2
• Massive star formation in the Carina nebula complex and Gum 31 -- I. The Carina nebula complex
• The Carina Nebula and Gum 31 molecular complex: II. The distribution of the atomic gas revealed in unprecedented detail
• Chandra X-ray observation of the HII region Gum 31 in the Carina Nebula complex
• 870 micron continuum observations of the bubble-shaped nebula Gum 31
• Environmental conditions shaping star formation: The Carina Nebula

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