Related papers: Angular Diameters of Compact Planetary Nebulae
Powerful new, high resolution, high sensitivity, multi-frequency, wide-field radio surveys such as the Australian Square Kilometre Array Pathfinder (ASKAP) Evolutionary Map of the Universe (EMU) are emerging. They will offer fresh…
We report the discovery of 34 new open clusters and candidates as a result of a systematic search carried out in 200 adjacent fields of 1x1 square degrees area projected towards the Galactic bulge, using Gaia DR2 data. The objects were…
Using a slitless spectroscopy method with the 8.2 m Subaru telescope and its FOCAS Cassegrain spectrograph, we have increased the number of planetary nebula (PN) detections and PN velocity measurements in the flattened elliptical galaxy NGC…
We have obtained 24 {\mu}m imaging, profiles and fluxes for 224 planetary nebulae (PNe) lying within the limits of the Spitzer MIPSGAL survey. It is noted that most of the PNe having extended 24 {\mu}m emission also possess circular…
This article summarizes the structural parameters of the Galactic bulge and disk, and discusses the interpretation of the bulge microlensing observations and the determination of the Milky Way's luminous mass from the terminal velocity…
The planetary nebula luminosity function (PNLF) technique for determining distances to galaxies now has been applied to 34 galaxies, including 6 in the Virgo cluster and 3 in the Fornax cluster. Of these, 16 galaxies are late-type or…
We present a study of the properties of the star-cluster systems around pseudo-bulges of late-type spiral galaxies using a sample of 11 galaxies with distances from 17 to 37 Mpc. Star clusters are identified from multiband HST ACS and WFPC2…
We determine the distance to 38 clusters of galaxies in the redshift range 0.14 < z < 0.89 using X-ray data from Chandra and Sunyaev-Zeldovich Effect data from the Owens Valley Radio Observatory and the Berkeley-Illinois-Maryland…
Binarity has been hypothesised to play an important, if not ubiquitous, role in the formation of planetary nebulae (PNe). Yet there remains a severe paucity of known binary central stars required to test the binary hypothesis and to place…
We estimate distances to the spherical planetary nebula Abell 39 and the bipolar planetary nebula NGC 7027 by interpolating from a wide grid of photoionization models using the 3-D code, MOCASSIN. We find preliminary distances of 1.5 kpc…
We have conducted a spectroscopic analysis of the bulges of a sample of 31 spiral galaxies, spanning the Hubble sequence from S0 to Scd type, in order to study the radial distribution of their stellar population properties.
Three colour photometry on CCD frames in the Special Area SpA23 provides a deep probe of the galactic disc in a low absorption window towards the anticenter. Magnitudes to better than 10% at V = 25 and B-V colour down to V = 23 have been…
This paper presents a homogeneous study of abundances in a sample of 79 northern galactic planetary nebulae whose morphological classes have been uniformly determined. Ionic abundances and plasma diagnostics were derived from selected…
To study the distribution of star formation and dust emission within nearby galaxies, we measured five morphological parameters in the 3.6 and 24 micron wave bands for 65 galaxies in the Spitzer Infrared Nearby Galaxies Survey (SINGS) and 8…
We identify different dust features in our compilation of infrared spectra for 267 planetary nebulae (PNe) from the Spitzer, ISO, and IRAS telescopes. We classify 209 objects according to their dust type: mixed dust (MD), oxygen-rich dust…
We present the identification of 34 likely binary central stars (CSs) of planetary nebulae (PNe) from {\it Kepler/K2} data, seven of which show eclipses. Of these, 29 are new discoveries. Two additional CSs with more complicated variability…
Combined with X-ray imaging and spectral data, observations of the Sunyaev-Zel'dovich effect (SZE) can be used to determine direct distances to galaxy clusters. These distances are independent of the extragalactic distance ladder and do not…
From a diameter-limited sample of 86 `face-on' spiral galaxies, the bulge-to-disk size and luminosity ratios, and other quantitative measurements for the prominence of the bulge are derived. The bulge and disk parameters have been estimated…
We present preliminary results from spectral observations of four candidate radio sources co-identified with known planetary nebulae (PNe) in the Small Magellanic Cloud (SMC). These were made using the Radcliffe 1.9-meter telescope in…
We derive the stellar and circumstellar parameters of the Galactic compact planetary nebula Hen 2-90 with two models: the classical constant density nebula model where the emission (especially of the forbiden lines) is formed in a sphere or…