English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Strong mass loss off stars at the tip of the asymptotic giant branch (AGB)profoundly affects properties of these stars and their surroundings, includingthe subsequent planetary nebula (PN) stage. With this study we wanted todetermine physical properties of mass loss by studying weakly emitting halos,focusing on objects in the galactic disk. Halos surround the, up to severalthousand times, brighter central regions of PNe. Young halos, specifically,still contain information of the preceeding final mass loss stage on the AGB.In the observations we used the method of integral field spectroscopy with thePMAS instrument. This is the first committed study of halos of PNe that usesthis technique. We improved our data analysis by a number of steps. In a studyof the influence of scattered light we found that a moderate fraction ofintensities in the inner halo originate in adjacent regions. As we combine lineintensities of distant wavelengths, and because radial intensity gradients aresteep, we corrected for effects of differential atmospheric refraction. Inorder to increase the signal-to-noise of weak emission lines we introduced adedicated method to bin spectra of individual spatial elements. We alsodeveloped a general technique to subtract telluric lines - without usingseparate sky exposures. By these steps we avoided introducing errors of severalthousand Kelvin to our temperature measurements in the halo. For IC3568 wedetected a halo. For M2-2 we found a halo radius that is 2.5 times larger...(abridged)

Spatially resolved spectroscopy of planetary nebulae and their halos I. Five galactic disk objects