The Gaia Data Release 1 parallaxes and the distance scale of Galactic planetary nebulae

TL;DR

This paper evaluates Gaia DR1 parallaxes for calibrating the distance scale of Galactic planetary nebulae, demonstrating increased sample size and potential for improved understanding of PNe physics with future Gaia data.

Contribution

It introduces a new calibration of the PNe distance scale using Gaia DR1 parallaxes, expanding the sample and probing a wider parameter space.

Findings

Gaia DR1 parallaxes double existing PNe trigonometric measurements.

The study extends the physical parameter domain by two orders of magnitude.

Preliminary distance scale calibration shows promising statistical robustness.

Abstract

In this paper we gauge the potentiality of Gaia in the distance scale calibration of planetary nebulae (PNe) by assessing the impact of DR1 parallaxes of central stars of Galactic PNe (CSPNe) against known physical relations. For selected PNe targets with state-of-the-art data on angular sizes and fluxes, we derive the distance-dependent parameters of the classical distance scales, i.e., physical radii and ionized masses, from DR1 parallaxes; we propagate the uncertainties in the estimated quantities and evaluate their statistical properties in the presence of large relative parallax errors; we populate the statistical distance scale diagrams with this sample and discuss its significance in light of existing data and current calibrations. We glean from DR1 parallaxes 8 CSPNe with S/N$>$1. We show that this set of potential calibrators doubles the number of extant trigonometric parallaxes (from HST and ground-based), and increases by two orders of magnitude the domain of physical parameters probed previously. We then use the combined sample of suitable trigonometric parallaxes to fit the physical-radius-to-surface-brightness relation. This distance scale calibration, although preliminary, appears solid on statistical grounds, and suggestive of new PNe physics. With the tenfold improvement in PNe number statistics and astrometric accuracy expected from future Gaia releases the new distance scale, already very intriguing, will be definitively constrained.