Spectroscopy of Planetary Nebulae with Herschel: A Beginners Guide

Exter, Katrina

doi:10.3390/galaxies6030073

Cited by 1 publication

(1 citation statement)

References 7 publications

(6 reference statements)

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“…The FWHMs of the circular beam profiles used by PPMAP are 8.5, 13.5, 18.2, 24.9, and 36.3 arcsec, for, respectively, the 70, 160, 250, 350, and 500 μm wavebands (Exter 2017;Valtchanov 2017). In reality, the PACS beams are distorted by the fast scan PACS/SPIRE parallel mode, producing effective non-circular beamsizes of ∼6 arcsec × 12 arcsec for the 70 μm waveband, and ∼12 arcsec × 16 arcsec for the 160 μm waveband, but this is not taken into account in the standard PPMAP procedure.…”

Section: Herschel Observationsmentioning

confidence: 99%

A PPMAP analysis of the filamentary structures in Ophiuchus L1688 and L1689

Howard

Whitworth

Griffin

et al. 2021

Monthly Notices of the Royal Astronomical Society

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We use the Point Process MAPping (PPMAP) algorithm to reanalyse the Herschel and SCUBA-2 observations of the L1688 and L1689 subregions of the Ophiuchus molecular cloud. PPMAP delivers maps with high resolution (here 14 arcsec, corresponding to ${\sim}0.01\, {\rm pc}$ at ${\sim}140\, {\rm pc}$), by using the observations at their native resolutions. PPMAP also delivers more accurate dust optical depths, by distinguishing dust of different types and at different temperatures. The filaments and pre-stellar cores almost all lie in regions with $N_{\rm H_2}\gtrsim 7\times 10^{21}\, {\rm cm}^{-2}$ (corresponding to AV ≳ 7). The dust temperature, T, tends to be correlated with the dust opacity index, β, with low T and low β concentrated in the interiors of filaments. The one exception to this tendency is a section of filament in L1688 that falls – in projection – between the two B stars: S1 and HD147889; here T and β are relatively high, and there is compelling evidence that feedback from these two stars has heated and compressed the filament. Filament fwhms are typically in the range $0.10$ to $0.15\, {\rm pc}$. Most filaments have line-densities in the range $25$ to $65\, {\rm M_{\odot }\, pc^{-1}}$. If their only support is thermal gas pressure, and the gas is at the canonical temperature of $10\, {\rm K}$, the filaments are highly supercritical. However, there is some evidence from ammonia observations that the gas is significantly warmer than this, and we cannot rule out the possibility of additional support from turbulence and/or magnetic fields. On the basis of their spatial distribution, we argue that most of the starless cores are likely to disperse (rather than evolving to become pre-stellar).

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Section: Herschel Observationsmentioning

confidence: 99%