A Reanlysis to Extend the Planetary Nebula Luminosity Function into the Hubble Flow
Open Access
- Author:
- Chase, Owen
- Area of Honors:
- Astronomy and Astrophysics
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Robin Bruce Ciardullo, Thesis Supervisor
Steinn Sigurdsson, Thesis Honors Advisor - Keywords:
- distances
planetary nebulae
PNLF
hubble tension
extragalactic - Abstract:
- The [O III] λ5007 planetary nebula luminosity function (PNLF) is a well-established distance indicator for galaxies out to at least ∼10 Mpc. However, systematic discrepancies with other methods emerge at larger distances, and it reaches its effective limit at around 20 Mpc. Thus, the PNLF has recently fallen out of favor compared to methods like tip of the red giant branch (TRGB) and surface brightness fluctuations (SBF). In order to bring the PNLF into the modern era of precision cosmology and make it a competitive method for addressing the Hubble Tension, it is imperative to address the higher order sources of systematic error. A central issue with the PNLF is contamination from “overluminous” planetary nebulae (PNe). These overluminous objects tend to result in smaller implied distances, possibly accounting for the discrepancies seen in PNLF distances greater than 10 Mpc. Contamination of the PNLF by such objects has up to now not been seriously addressed. In this thesis, I explore a potential source of overluminous objects: planetary nebulae superimposed along the line of sight. Here, I present a reanalysis of the PNLF technique from the ground up to address this issue and determine whether blending is the primary source of systematic error observed in past PNLF studies. By analyzing 4 galaxies, I find that line-of-sight blending is very likely responsible for a significant portion of the apparent discrepancy between the PNLF and other methods at large distances.