Deep spectra of the planetary nebula IC 418 were obtained in the wavelength range 4190-5850 A. The data made it possible to map an extended halo about the...
The Correlations between Planetary Nebula Morphology and Central Star Evolution: Analysis of the Northern Galactic Sample
Northern Galactic planetary nebulae (PNs) are studied to disclose possible correlations between the morphology of the nebulae and the evolution of the central...
The Density, Extinction, and Excitation Characteristics of NGC 6445
We have acquired [O III] lambda5007, H I lambdalambda6563 and 4861, and [S II] lambdalambda6717 and 6731 imaging of the bipolar outflow source NGC 6445. As a...
The Density, Extinction, Temperature, and Excitation Structures of NGC 2440
We have observed the planetary nebula NGC 2440 in the transitions [O II] λ3727, He II λ4686, [O III] λλ(4363+5007), H I λλ(4861+6563), He I λ5876, [N II] λ6584...
The discovery of a supernova type Ia progenitor at the heart of a planetary nebula
I will report on the results of our paper published in Nature this week, outlining the discovery of a super-Chandrasekhar double-degenerate binary system at the...
The Dynamical Evolution of Planetary Nebulae after the Fast Wind
We explore the dynamics of ionization-bounded planetary nebulae after the termination of the fast stellar wind. When the stellar wind becomes negligible, the...
The Dynamical Evolution of the Circumstellar Gas around Low- and Intermediate-Mass Stars. I. The Asymptotic Giant Branch
We have investigated the dynamical interaction of low- and intermediate-mass stars (from 1 to 5 Msolar) with their interstellar medium (ISM). In this first...
The Dynamical Evolution of the Circumstellar Gas around Low- and Intermediate-Mass Stars. II. The Planetary Nebula Formation
We have studied the effect of the mass of the central star (CS) on the gas evolution during the planetary nebula (PN) phase. We have performed numerical...
The edge of the M 87 halo and the kinematics of the diffuse light in the Virgo cluster core
Aims: We study the kinematics and dynamics of the extreme outer halo of M 87, the central galaxy in the Virgo cluster, and its transition to the intracluster...