SOFIA FEEDBACK Survey: PDR Diagnostics of Stellar Feedback in Different Regions of RCW 49

The Astronomical Journal, vol. 164, pp. 150

Abstract

Abstract We quantified the effects of stellar feedback in RCW 49 by determining the physical conditions in different regions using the [C ii] 158 μm and [O i] 63 μm observations from SOFIA, the 12CO (3–2) observations from APEX, and the H2 line observations from Spitzer telescopes. Large maps of RCW 49 were observed with the SOFIA and APEX telescopes, while the Spitzer observations were only available toward three small areas. From our qualitative analysis, we found that the H2 0–0 S(2) emission line probes denser gas compared to the H2 0–0 S(1) line. In four regions (“northern cloud,” “pillar,” “ridge,” and “shell”), we compared our observations with the updated PDR Toolbox models and derived the integrated far-ultraviolet flux between 6 and 13.6 eV (G 0), H nucleus density (n), temperatures, and pressures. We found the ridge to have the highest G 0 (2.4 × 103 Habing units), while the northern cloud has the lowest G 0 (5 × 102 Habing units). This is a direct consequence of the location of these regions with respect to the Wd2 cluster. The ridge also has a high density (6.4 × 103 cm−3), which is consistent with its ongoing star formation. Among the Spitzer positions, we found the one closest to the Wd2 cluster to be the densest, suggesting an early phase of star formation. Furthermore, the Spitzer position that overlaps with the shell was found to have the highest G 0, and we expect this to be a result of its proximity to an O9V star.

Authors 15

1. M. Tiwari corresponding

   Max Planck Institute for Radio Astronomy · University of Maryland, College Park

   Affiliation as printed

   Max-Planck Institute for Radioastronomy, Auf dem Hügel, D-53121 Bonn, Germany

   University of Maryland, Department of Astronomy, College Park, MD 20742-2421, USA; mtiwari@umd.edu

   University of Maryland, Department of Astronomy, College Park, MD 20742-2421, USA

2. M. G. Wolfire

   University of Maryland, College Park

   Affiliation as printed

   University of Maryland, Department of Astronomy, College Park, MD 20742-2421, USA; mtiwari@umd.edu

   University of Maryland, Department of Astronomy, College Park, MD 20742-2421, USA

3. Marc W. Pound

   University of Maryland, College Park

   Affiliation as printed

   University of Maryland, Department of Astronomy, College Park, MD 20742-2421, USA; mtiwari@umd.edu

   University of Maryland, Department of Astronomy, College Park, MD 20742-2421, USA

4. Elizabeth Tarantino

   University of Maryland, College Park

   Affiliation as printed

   University of Maryland, Department of Astronomy, College Park, MD 20742-2421, USA; mtiwari@umd.edu

   University of Maryland, Department of Astronomy, College Park, MD 20742-2421, USA

5. R. Karim

   University of Maryland, College Park

   Affiliation as printed

   University of Maryland, Department of Astronomy, College Park, MD 20742-2421, USA; mtiwari@umd.edu

   University of Maryland, Department of Astronomy, College Park, MD 20742-2421, USA

6. Lars Bonne

   Ames Research Center

   Affiliation as printed

   SOFIA Science Center, USRA, NASA Ames Research Center, M.S. N232-12, Moffett Field, CA 94035, USA

7. C. Buchbender

   University of Cologne

   Affiliation as printed

   I. Physik. Institut, University of Cologne, Zülpicher Str. 77, D-50937 Cologne, Germany

8. R. Güsten

   Max Planck Institute for Radio Astronomy

   Affiliation as printed

   Max-Planck Institute for Radioastronomy, Auf dem Hügel, D-53121 Bonn, Germany

9. C. Guevara

   University of Cologne

   Affiliation as printed

   I. Physik. Institut, University of Cologne, Zülpicher Str. 77, D-50937 Cologne, Germany

10. S. Kabanovic

    University of Cologne

    Affiliation as printed

    I. Physik. Institut, University of Cologne, Zülpicher Str. 77, D-50937 Cologne, Germany

11. Ü. Kavak

    Ames Research Center

    Affiliation as printed

    SOFIA Science Center, USRA, NASA Ames Research Center, M.S. N232-12, Moffett Field, CA 94035, USA

12. Nicola Schneider

    University of Cologne

    Affiliation as printed

    I. Physik. Institut, University of Cologne, Zülpicher Str. 77, D-50937 Cologne, Germany

13. Robert Simon

    University of Cologne

    Affiliation as printed

    I. Physik. Institut, University of Cologne, Zülpicher Str. 77, D-50937 Cologne, Germany

14. JÜRGEN STUTZKI

    University of Cologne

    Affiliation as printed

    I. Physik. Institut, University of Cologne, Zülpicher Str. 77, D-50937 Cologne, Germany

15. Alexander G. G. M. Tielens Aachen Leiden Observatory

    Leiden University · Leiden Observatory · University of Maryland, College Park

    Affiliation as printed

    Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands

    University of Maryland, Department of Astronomy, College Park, MD 20742-2421, USA; mtiwari@umd.edu

    University of Maryland, Department of Astronomy, College Park, MD 20742-2421, USA