The Distances of SNR W41 and Overlapping H II Regions
Abstract
New H I images from the VLA Galactic Plane Survey show prominent absorption features associated with the supernovae remnant G23.3-0.3 (SNR W41). We highlight the H Iabsorption spectra and the 13CO emission spectra of eight small regions on the face of W41, including four H IIregions, three non-thermal emission regions, and one unclassified region. The maximum velocity of absorption for W41 is 78 +/- 2 km s-1 and the CO cloud at radial velocity 95 +/- 5 km s-1 is behind W41. Because an extended TeV source, a diffuse X-ray enhancement, and a large molecular cloud at radial velocity 77 +/- 5 km s-1 overlap the center of W41, the kinematic distance is 3.9-4.5 kpc for W41. For the H IIregions, our analysis shows that both G23.42-0.21 and G23.07+0.25 are at the far kinematic distances (~9.9 kpc and ~10.6 kpc, respectively) of their recombination-line velocities (103 +/- 0.5 km s-1 and 89.6 +/- 2.1 km s-1, respectively), G23.07-0.37 is at the near kinematic distance (4.4 +/- 0.3 kpc) of its recombination-line velocity (82.7 +/- 2.0 km s-1), and G23.27-0.27 is probably at the near kinematic distance (4.1 +/- 0.3 kpc) of its recombination-line velocity (76.1 +/- 0.6 km s-1).
- Publication:
-
The Astronomical Journal
- Pub Date:
- January 2008
- DOI:
- arXiv:
- arXiv:0708.3377
- Bibcode:
- 2008AJ....135..167L
- Keywords:
-
- H II regions: individual: G23.42–0.21: G23.07–0.25: G23.07–0.37: G23.27–0.27;
- supernova remnants;
- Astrophysics
- E-Print:
- 11 pages, 3 figs., 2 tables, accepted by AJ