相关论文: A Herschel study of Planetary Nebulae
The dust destruction timescales in the cores of clusters of galaxies are relatively short given their high central gas densities. However, substantial mid-infrared and sub-mm emission has been detected in many brightest cluster galaxies. In…
We analyze the dependence of circumstellar extinction on core mass for the brightest planetary nebulae (PNe) in the Magellanic Clouds and M31. We show that in all three galaxies, a statistically significant correlation exists between the…
We have obtained multi-wavelength observations of compact Galactic planetary nebulae (PNe) to probe post-Asymptotic Giant Branch (AGB) evolution from the onset of nebular ejection. We analyze new observations from HST to derive the masses…
Mid-IR observations of planetary nebulae (PNe) have revealed diffuse emission associated to their main nebular shells and outer envelopes or haloes. The interpretation of this emission is uncertain because the broad-band mid-IR images may…
The study of the chemical composition of Planetary Nebulae in external galaxies is of paramount importance in the fields of stellar evolution and of the chemical enrichment history of galaxies. In the last years a number of spectroscopic…
We characterize the dust in NGC628 and NGC6946, two nearby spiral galaxies in the KINGFISH sample. With data from 3.6um to 500um, dust models are strongly constrained. Using the Draine & Li (2007) dust model, (amorphous silicate and…
The goal of the present study is twofold. First, we employ new HST/STIS spectra and photoionization modeling techniques to determine the progenitor masses of eight planetary nebulae (IC 2165, IC 3568, NGC 2440, NGC 3242, NGC 5315, NGC 5882,…
The Spitzer GLIMPSE and MIPSGAL surveys have revealed a wealth of details of the Galactic plane. We use them to study the energetics and dust properties of M16, one of the best known SFR. We present MIPSGAL observations of M16 at 24 and 70…
Planetary nebulae are now well established as probes of galaxy dynamics and as standard candles in distance determinations. Motivated by the need to improve the efficiency of planetary nebulae searches and the speed with which their radial…
A review of some of the papers that discuss the relevance of the temperature structure present in H II regions and planetary nebulae is presented. Particular attention is given to the determination of the chemical abundances of these…
Dusty debris discs around main sequence stars are thought to be the result of continuous collisional grinding of planetesimals in the system. The majority of these systems are unresolved and analysis of the dust properties is limited by the…
A photoelectric monitoring program has been applied, during the last four years, to five central stars of planetary nebulae (PNNs) with strong O\,VI $\lambda$ 3811--34 \AA \hspace{0.1mm} emission. NGC\,6905 and, marginally, NGC\,2452, show…
New ground-based telescopes and instruments, the return of the NICMOS instrument on the Hubble Space Telescope (HST), and the recent launch of the Spitzer Space Telescope have provided new tools that are being utilized in the study of…
Context: In recent years mid- and far infrared spectra of planetary nebulae have been analysed and lead to more accurate abundances. It may be expected that these better abundances lead to a better understanding of the evolution of these…
The globular cluster (GC) system of our Galaxy contains four planetary nebulae (PNe): K 648 (or Ps 1) in M15, IRAS 18333-2357 in M22, JaFu 1 in Pal 6, and JaFu 2 in NGC 6441. Because single-star evolution at the low stellar mass of…
The optical line and continuum emission in the very high ionization Galactic planetary nebula (PN) NGC 4361 (PN G294.1 +43.6), has been mapped with VLT MUSE Wide Field normal mode (4750-9300A) commissioning observations. The PN is larger…
This paper discusses the location of a sample of planetary nebulae on the HR diagram. We determine the internal velocity fields of 14 planetary nebulae from high-resolution echelle spectroscopy, with the help of photoionization models. The…
The Polaris Flare cloud region contains a great deal of extended emission. It is at high declination and high Galactic latitude. It was previously seen strongly in IRAS Cirrus emission at 100 microns. We have detected it with both PACS and…
We present the first overview of the Herschel observations of the nearby high-mass star-forming region NGC 7538, taken as part of the Herschel imaging study of OB Young Stellar objects (HOBYS) Key Programme. These PACS and SPIRE maps cover…
Planetary Nebulae are the ionised ejected envelopes surrounding the remnant cores of dying stars. Theory predicts that main-sequence stars with one to about eight times the mass of our sun may eventually form planetary nebulae. Until now no…