Luminous Red Novae: population models and future prospects

Abstract

A class of optical transients known as Luminous Red Novae (LRNe) have recently been associated with mass ejections from binary stars undergoing common-envelope evolution. We use the population synthesis code COMPAS to explore the impact of a range of assumptions about the physics of common-envelope evolution on the properties of LRNe. In particular, we investigate the influence of various models for the energetics of LRNe on the expected event rate and light curve characteristics, and compare with the existing sample. We find that the Galactic rate of LRNe is $\sim 0.2$ yr${}^{-1}$, in agreement with the observed rate. In our models, the luminosity function of Galactic LRNe covers multiple decades in luminosity and is dominated by signals from stellar mergers, consistent with observational constraints from iPTF and the Galactic sample of LRNe. We discuss how observations of the brightest LRNe may provide indirect evidence for the existence of massive ($>40$ M${}_{\odot }$) red supergiants. Such LRNe could be markers along the evolutionary pathway leading to the formation of double compact objects. We make predictions for the population of LRNe observable in future transient surveys with the Large Synoptic Survey Telescope and the Zwicky Transient Facility. In all plausible circumstances, we predict a selection-limited observable population dominated by bright, long-duration events caused by common envelope ejections. We show that the Large Synoptic Survey Telescope will observe $20$--$750$ LRNe per year, quickly constraining the luminosity function of LRNe and probing the physics of common-envelope events.

13 pages, 8 Figures. MNRAS Accepted

References in corpus (20)

• Cosmic Star Formation History
• Binary interaction dominates the evolution of massive stars
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• The Zwicky Transient Facility: Science Objectives
• The 2008 Luminous Optical Transient in the Nearby Galaxy NGC 300
• An Intermediate Luminosity Transient in NGC300: The Eruption of a Dust-Enshrouded Massive Star
• Stellar Mergers Are Common
• Common envelope ejection in massive binary stars - Implications for the progenitors of GW150914 and GW151226
• Shock-powered light curves of luminous red novae as signatures of pre-dynamical mass loss in stellar mergers
• Grids of stellar models with rotation IV. Models from 1.7 to 120 Msun at a metallicity Z = 0.0004
• A very faint core-collapse supernova in M85
• The metallicity dependence of envelope inflation in massive stars
• Episodic mass ejections from common-envelope objects
• A Spitzer/IRS Spectrum of the 2008 Luminous Transient in NGC 300: Connection to Proto-Planetary Nebulae
• A Luminous Red Nova in M31 and its Progenitor System
• Nuclear ashes and outflow in the eruptive star Nova Vul 1670
• The Environment of M85 optical transient 2006-1: constraints on the progenitor age and mass
• The transitional gap transient AT 2018hso: new insights on the luminous red nova phenomenon
• The January 2015 outburst of a red nova in M31
• Luminous Red Nova 2015 in the Galaxy M101

Cited by in corpus (10)

• Modelling Neutron Star-Black Hole Binaries: Future Pulsar Surveys and Gravitational Wave Detectors
• Luminous Red Nova AT 2019zhd, a new merger in M 31
• The luminous red nova variety: AT 2020hat and AT 2020kog
• Observational identification of a sample of likely recent Common-Envelope Events
• The Carnegie Supernova Project II. Observations of the luminous red nova AT 2014ej
• Gap Transients Interacting with Circumstellar Medium
• Simulating a stellar contact binary merger -- I. Stellar models
• A search for cool molecular gas in GK Persei and other classical novae
• Spectropolarimetric follow-up of 8 rapidly rotating, X-ray bright FK Comae candidates
• Hubble Space Telescope Imaging of Luminous Extragalactic Infrared Transients and Variables from the SPIRITS Survey