Emission line diagnostics to constrain high temperature populations in early-type galaxies

Abstract

Once thought to be devoid of warm and cold interstellar matter, elliptical galaxies are now commonly observed to host extended regions of neutral and ionized gas. Outside of the innermost nuclear regions of these galaxies, the favoured candidate ionizing source remains some component of the stellar population, with mounting evidence suggesting post-asymptotic-giant-branch stars (pAGBs). In a recent paper, we demonstrated that observations of recombination lines of He II (or upper limits thereof) may provide a strong constraint on the presence of any other, higher temperature ionizing sources, in particular nuclear-burning white dwarfs in the context of the single degenerate (SD) scenario for type Ia supernovae. The sensitivity of the HeII test is greatest for WD effective temperatures ~ 2 x 10^5 K. Here we extend our analysis to include predictions for all of the "classical" strong optical lines, as well as UV, optical, and infra-red lines of neutral Oxygen, Nitrogen, and singly-ionized Carbon. This allows us to extend the temperature range over which we can meaningfully constrain the collective luminosity of nuclear-burning WDs to 10^5 K <~ T <~ 10^6 K. We then demonstrate how observations of nearby early-type and post-starburst galaxies can place strong limits on the origin of type Ia supernovae.

15 pages, 13 figures, MNRAS Accepted

References in corpus (2)

• Diagnostics of irradiated dense gas in galaxy nuclei. II. A grid of XDR and PDR models
• The Dearth of UV-Bright Stars in M32: Implications for Stellar Evolution Theory

Cited by in corpus (18)

• Observational clues to the progenitors of Type-Ia supernovae
• On the Progenitors of Type Ia Supernovae
• Self-consistent predictions for LIER-like emission lines from post-AGB stars
• The contribution from stars stripped in binaries to cosmic reionization of hydrogen and helium
• Probing type Ia supernova properties using bolometric light curves from the Carnegie Supernova Project and the CfA Supernova Group
• Comprehensive models of novae at metallicity $Z=0.02$ and $Z=10^{-4}$
• Surviving companions of Type Ia supernovae: theory and observations
• Population synthesis of accreting white dwarfs: II. X-ray and UV emission
• Diffuse Gas in Retired Galaxies: Nebular Emission Templates and Constraints on the Sources of Ionization
• No hot and luminous progenitor for Tycho's supernova
• Why do many early-type galaxies lack emission lines? I. Fossil clues
• Balmer-Dominated Shocks Exclude Hot Progenitors for Many Type Ia Supernovae
• Delayed Photons from Binary Evolution Help Reionize the Universe
• A Comparison of Stellar and Gas-Phase Chemical Abundances in Dusty Early-Type Galaxies
• Populations of super-soft X-ray sources in galaxies of different morphological types
• Constraining the role of novae as progenitors of Type Ia Supernovae
• The Metallicity measurement of Early-type Galaxies
• Measuring the Metallicity of Early-type Galaxies. I. Composite Region