Related papers: Discovery of Multiple Shells Around the Planetary …
We have detected the [S IV] 10.5 micron and [Ne II] 12.8 micron fine-structure lines in the halo population planetary nebula (PN) DdDm 1, and set upper limits on their intensities in the halo PN H 4-1. We also present new measurements of…
We present narrow-band H-alpha, [S II], and [O I] Hubble Space Telescope images of the young planetary nebula GL 618. This object is a compact, bipolar nebula that is currently undergoing the transition from asymptotic giant branch star to…
In this paper we present the results of optical high-resolution imaging and spectroscopy of the complex planetary nebula (PN) NGC~3242. Our study is based on the analysis of the narrowband H$\alpha$ $\lambda$6563\AA , [O III]…
I list the 16 planetary nebulae (PNe) known to contain close-binary nuclei, and show that the nebulae generally have axisymmetric structures, including elliptical, bipolar, or ring morphologies. The orbital periods range from 2.7 hr to 16…
We report the result of a search for the infrared counterparts of 37 planetary nebulae (PNs) and PN candidates in the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire II (GLIMPSE II) survey. The photometry and images of…
Through HST imaging of the inner part of the main-ring of the Helix Nebula together with CTIO 4-m images of the fainter outer parts, we have an unprecedented-quality view of the nearest bright planetary nebula. These images have allowed…
We have identified ten candidate intergalactic planetary nebulae in the Fornax galaxy cluster. These objects were found during observations in 1992 and 1993 in three fields chosen well away from any Fornax galaxy at 15 arcmin, 30 arcmin,…
We investigate the diffuse light in the outer regions of the nearby elliptical galaxy M87 in the Virgo cluster, using planetary nebulas (PNs) as tracers. The surveyed areas (0.43 squared degrees) cover M87 up to a radial distance of 150…
We present an observational study of the planetary nebula (PN) NGC 7354 consisting of narrowband Halpha and [NII]6584 imaging as well as low- and high-dispersion long-slit spectroscopy and VLA-D radio continuum. According to our imaging and…
IC 4406 is a large (about 100'' x 30'') southern bipolar planetary nebula, composed of two elongated lobes extending from a bright central region, where there is evidence for the presence of a large torus of gas and dust. We show new…
As the second step in our investigation of the mass-to-light ratio of spiral disks, we present the results of a spectroscopic survey of planetary nebulae (PNe) in five nearby, low-inclination galaxies: IC 342, M74 (NGC 628), M83 (NGC 5236),…
We present near-infrared (IR) spectra of two planetary nebula (PN) candidates in close lines of sight toward the Galactic center (GC) using the Gemini Near-Infrared Spectrograph (GNIRS) at Gemini North. High-resolution images from radio…
The diffuse extended outer regions of galaxies are hard to study because they are faint, with typical surface brightness of 1% of the dark night sky. We can tackle this problem by using resolved star tracers which remain visible at large…
Radio continuum observations trace thermal emission of ionized plasma in planetary nebulae and bring useful information on nebular geometries. A model of homogeneous sphere or shell cannot fit the nebular spectra and brightness…
We present photometric and kinematic information obtained by measuring 197 planetary nebulae (PNs) discovered in the flattened Fornax elliptical galaxy NGC 1344 (also known as NGC 1340) with an on-band, off-band, grism + on-band filter…
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…
We analyzed the minor axis spectra of the elliptical planetary nebula (PN) NGC 7009 observed with the Keck HIRES with a 0.862$"$ $\times$ 10$"$ slit placed at about $\sim$7.5$"$ and 10$"$ away from the center and a 0.862$"$ $\times$ 14$"$…
Observations of the nebula associated with the WO star in the galaxy IC 1613 are presented. The observations were carried out with a scanning Interferometer Fabry-Perot in H_alpha at the 6m Special Astrophysical Observatory telescope;…
We present observations proving the close binary nature of the central stars belonging to the planetary nebulae (PNe) NGC 6326 and NGC 6778. Photometric monitoring reveals irradiated lightcurves with orbital periods of 0.372 and 0.1534…
Here we present initial results of our search for extensive halos around the planetary nebulae (PNe) in our Galaxy based on imaging data from the Southern H-Alpha Sky Survey Atlas (SHASSA). A threshold surface brightness in H$\alpha$…