Angular diameters, fluxes and extinction of compact planetary nebulae: further evidence for steeper extinction towards the Bulge

Abstract

We present values for angular diameter, flux and extinction for 70 Galactic planetary nebulae observed using narrow band filters. Angular diameters are derived using constant emissivity shell and photoionization line emission models. The mean of the results from these two models are presented as our best estimate. Contour plots of 36 fully resolved objects are included and the low intensity contours often reveal an elliptical structure that is not always apparent from FWHM measurements. Flux densities are determined, and for both H-alpha and O[III] there is little evidence of any systematic differences between observed and catalogued values. Observed H-alpha extinction values are determined using observed H-alpha and catalogued radio fluxes. H-alpha extinction values are also derived from catalogued H-alpha and H-beta flux values by means of an Rv dependent extinction law. Rv is then calculated in terms of observed extinction values and catalogued H-alpha and H-beta flux values. Comparing observed and catalogue extinction values for a subset of Bulge objects, observed values tend to be lower than catalogue values calculated with Rv = 3.1. For the same subset we calculate <Rv> = 2.0, confirming that toward the Bulge interstellar extinction is steeper than Rv = 3.1. For the inner Galaxy a relation with the higher supernova rate is suggested, and that the low-density warm ionized medium is the site of the anomalous extinction. Lowvalues of extinction are also derived using dust models with a turnover radius of 0.08 microns.

arXiv commentAccepted by MNRAS. 17 pages, 9 figures (including 36 contour plots of PNe), 5 Tables (including 2 large tables of angular diameters, fluxes and extinction)

References in corpus (6)

• The Optical Gravitational Lensing Experiment. Is Interstellar Extinction Toward the Galactic Center Anomalous?
• Field Stars and Clusters of the Galactic Bulge: Implications for Galaxy Formation
• Angular dimensions of planetary nebulae
• Clump Distance to the Magellanic Clouds and Anomalous Colors in the Galactic Bulge
• The Distance Scale of Planetary Nebulae
• Measuring angular diameters of extended sources

Cited by in corpus (37)

• The Hα surface brightness - radius relation: a robust statistical distance indicator for planetary nebulae
• Binary Planetary Nebulae Nuclei towards the Galactic Bulge. I. Sample Discovery, Period Distribution and Binary Fraction
• Identification of the OGLE-2003-BLG-235/MOA-2003-BLG-53 Planetary Host Star
• Interstellar Extinction Curve Variations Toward the Inner Milky Way: A Challenge to Observational Cosmology
• Elemental abundances of Galactic bulge planetary nebulae from optical recombination lines
• A catalogue of integrated H-alpha fluxes for 1,258 Galactic planetary nebulae
• Symbiotic stars and other Halpha emission line stars towards the Galactic Bulge
• The Planetary Nebula population of the Sagittarius Dwarf Spheroidal Galaxy
• Chemical Abundances and Dust in Planetary Nebulae in the Galactic Bulge
• IPHAS extinction distances to Planetary Nebulae
• Multi-wavelength diagnostic properties of Galactic Planetary Nebulae detected by GLIMPSE-I
• The Extinction Toward the Galactic Bulge from RR Lyrae Stars
• The enigma of the oldest `nova': the central star and nebula of CK Vul
• An Investigation of Diffuse Interstellar Gas toward a Large, Low Extinction Window into the Inner Galaxy
• Problems for the WELS classification of planetary nebulae central stars: Self-consistent nebular modelling of four candidates
• Flux calibration of the AAO/UKST SuperCOSMOS H-alpha Survey
• New Planetary Nebulae in the Galactic Bulge region with l>0deg - II
• Central stars of planetary nebulae in the Galactic bulge
• Radio Stars: from kHz to THz
• Discovery of Eclipsing Binary Central Stars in the Planetary Nebulae M 3-16, H 2-29 and M 2-19
• The Coordinated Radio and Infrared Survey for High-mass Star Formation. IV: A new radio selected sample of compact Galactic Planetary Nebulae
• Galactic Edge Clouds I: Molecular Line Observations and Chemical Modelling of Edge Cloud 2
• Absolute Spectrophotometry of Northern Compact Planetary Nebulae
• Planetary Nebulae towards the Galactic bulge. I. [OIII] fluxes
• The binary fraction of planetary nebula central stars: the promise of VPHAS+
• Determination of Planetary Nebulae angular diameters from radio continuum Spectral Energy Distribution modeling
• Maser and Infrared Studies of Oxygen-Rich Late/Post-AGB Stars and Water Fountains: Development of a New Identification Method
• New Galactic Planetary Nebulae selected by radio and multi-wavelength characteristics
• New Candidate Planetary Nebulae in Galactic Globular Clusters from the VVV Survey
• Near-infrared photometry of Galactic planetary nebulae with the VVV Survey
• The Interstellar Extinction Toward the Milky Way Bulge with Planetary Nebulae, Red Clump, and RR Lyrae stars
• Dust Properties in the Galactic Bulge
• The Mid-Infrared Colours of Galactic Bulge, Disk and Magellanic Planetary Nebulae
• A pilot study of the radio-continuum emission from MASH planetary nebulae
• A catalogue of 108 extended planetary nebulae observed by GALEX
• The INT Photometric H-alpha Survey of the Northern Galactic Plane (IPHAS)
• Evidence for cold plasma in planetary nebulae from radio observations with the LOw Frequency ARray (LOFAR)