The kinematics and structure of N63A and associated H II regions

Shull, Peter

doi:10.1086/161558

Cited by 13 publications

(15 citation statements)

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“…This is also supported by the presence of only blueshifted velocity structure in the optical remnant (Shull 1983). It has been noted by previous authors (e.g., Shull 1983) that the western lobe of the bright optical SNR knot appears to be only photoionized, as opposed to the adjacent lobes, which show the strong shock signatures. This is also consistent with the blastwave impacting the region from behind, or with the SNR being a background object altogether.…”

Section: The Snrsupporting

confidence: 75%

“…Since the massive stars that ionize these nebulae expire as core-collapse supernovae, we do expect such associated SNRs to occasionally be found in H ii regions. DEM L243 encompasses a wellknown SNR (e.g., Shull 1983;Westerlund & Mathewson 1966), whose spatial area is delineated by the black circle in Figure 2. This nebula will be used to study the effect of an SNR on the emission-line properties of the surrounding H ii region.…”

Section: Observationsmentioning

confidence: 99%

“…The SNR in DEM L243 (N63 A in the Henize 1956 catalog) has been the subject of previous detailed studies (e.g., Shull 1983;Dickel et al 1993;Levenson et al 1995). As noted by several authors, the bright optical remnant is offset to the west side of the circular region of X-ray and radio emission, which is delineated by the black circle in Figure 2.…”

Section: The Snrmentioning

confidence: 99%

“…The 'S' track in Figure 9 shows the range of values for shock velocities between 100 and 200 km s −1 , with the 'S' symbol denoting the locus of the 200 km s −1 end. Estimates for the expansion velocity of the optical remnant range from 110 km s −1 (Dopita 1979) to 350 km s −1 (Shull 1983); additional estimates have been obtained and compiled by Chu & Kennicutt (1988). The presence of at least some radiative shocks with velocities above 200 km s −1 is indicated by the presence of the photoionized precursor mentioned above, and seen in Figure 2b.…”

Section: The Snrmentioning

confidence: 99%

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Calibration of Nebular Emission‐Line Diagnostics. I. Stellar Effective Temperatures

Oey

Dopita

Shields

et al. 2000

ASTROPHYS J SUPPL S

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We present a detailed comparison of optical H ii region spectra to photoionization models based on modern stellar atmosphere models. We examine both spatially resolved and integrated emission-line spectra of the H ii regions DEM L323, DEM L243, DEM L199, and DEM L301 in the Large Magellanic Cloud. The published spectral classifications of the dominant stars range from O7 to WN3, and morphologies range from Strömgren sphere to shell structure. Two of the objects include SNR contamination. The overall agreement with the predictions is generally within 0.2 dex for major diagnostic line ratios. An apparent pattern in the remaining discrepancies is that the predicted electron temperature is ∼ 1000 K hotter than observed. [Ne III] intensities are also slightly overpredicted, which may or may not be related. We model the shock emission for the SNR-contaminated objects, and find excellent agreement with the observations for composite shock and photoionized spectra. DEM L301's emission apparently results from both shocks and density-bounded photoionization. The existence of contaminating shocks can be difficult to ascertain in the spatially integrated spectra.Our analysis of the complex DEM L199 allows a nebular emission-line test of unprecedented detail for WR atmospheres. Surprisingly, we find no nebular He II λ4686 emission, despite the fact that both of the dominant WN3 stars should be hot enough to fully ionize He I in their atmospheres. The nebular diagnostics are again in excellent agreement with the data, for stellar models not producing He + -ionizing photons. The optical diagnostics are furthermore quite insensitive to the ionizing energy distribution for these early WR stars.We confirm that the η ′ emission-line parameter is not as useful as hoped for determining the ionizing stellar effective temperature, T ⋆ . Both empirically and theoretically, we find that it is insensitive for T ⋆ ∼ > 40 kK, and that it also varies spatially. The shock-contaminated objects show that η ′ will also yield a spuriously high T ⋆ in the presence of shocks. It is furthermore sensitive to shell morphology. We suggest [Ne III]/Hβ as an additional probe of T ⋆ . Although it is abundance-dependent, [Ne III]/Hβ has higher sensitivity to T ⋆ , is independent of morphology, and is insensitive to shocks in our objects. These observations should be useful data points for a first empirical calibration of nebular diagnostics of T ⋆ , which we attempt for LMC metallicity.

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Section: The Snrsupporting

confidence: 75%

Section: Observationsmentioning

confidence: 99%

Section: The Snrmentioning

confidence: 99%

Section: The Snrmentioning

confidence: 99%

See 2 more Smart Citations

Calibration of Nebular Emission‐Line Diagnostics. I. Stellar Effective Temperatures

Oey

Dopita

Shields

et al. 2000

ASTROPHYS J SUPPL S

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“…N63A N63A (SNR 0535À66.0) lies within the N63 H ii region (Shull 1983). It was noted as an IRAS source by Graham et al (1987a).…”

Section: N49mentioning

confidence: 98%

Supernova Remnants in the Magellanic Clouds. VII. Infrared Emission from Supernova Remnants

2006

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We have used the instruments on the Spitzer Space Telescope to study the Large Magellanic Cloud supernova remnants (SNRs) N11L, N44, N49, N206, N63A, and N157B. The two large SNRs N44 and N206 were not detected in any Spitzer IRAC or MIPS wave bands; the remainder were detected at one or more wavelengths. In particular, the SNRs N49 and N63A each had features that were evident in all available IRAC and MIPS bands. Each of these two also displayed faint limb emission in the MIPS 24 m band only. Spitzer IRS spectra obtained for the N49 SNR showed a number of prominent lines, with little continuum contribution. We therefore suggest that N49, and possibly N63A, are dominated by line emission, with thermal emission from hot dust being at most a secondary component.

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