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Title: Multi-frequency observations of a superbubble in the LMC: The case of LHA 120-N 70

We present a detailed study of new Australia Telescope Compact Array and XMM-Newton observations of LHA 120-N 70 (hereafter N 70), a spherically shaped object in the Large Magellanic Cloud, classified as a superbubble. Both archival and new observations were used to produce high quality radio continuum, X-ray, and optical images. The radio spectral index of N 70 is estimated to be α = –0.12 ± 0.06, indicating that while a supernova (SN) or supernovae have occurred in the region at some time in the distant past, N 70 is not the remnant of a single specific SN. N 70 exhibits limited polarization with a maximum fractional polarization of 9% in a small area of the northwest limb. We estimate the size of N 70 to have a diameter of 104 pc (±1 pc). The morphology of N 70 in X-rays closely follows that in radio and optical, with most X-ray emission confined within the bright shell seen at longer wavelengths. Purely thermal models adequately fit the soft X-ray spectrum which lacks harder emission (above 1 keV). We also examine the pressure output of N 70 where the values for the hot (P {sub X}) and warm (P{sub H} {submore » II}) phases are consistent with other studied H II regions. However, the dust-processed radiation pressure (P {sub IR}) is significantly smaller than in any other object studied in Lopez et al. N 70 is a very complex region that is likely to have had multiple factors contributing to both the origin and evolution of the entire region.« less
Authors:
; ; ; ; ; ; ; ;  [1] ; ;  [2]
  1. University of Western Sydney, Locked Bag 1797, Penrith South DC, NSW 1797 (Australia)
  2. Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, D-85741 Garching (Germany)
Publication Date:
OSTI Identifier:
22340215
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (New York, N.Y. Online); Journal Volume: 147; Journal Issue: 6; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPACTS; DUSTS; EMISSION; EVOLUTION; IMAGES; MAGELLANIC CLOUDS; POLARIZATION; RADIATION PRESSURE; SOFT X RADIATION; SPECTRA; SPHERICAL CONFIGURATION; SUPERNOVA REMNANTS; SUPERNOVAE; TELESCOPES; WAVELENGTHS