Towards an understanding of long gamma-ray burst environments through circumstellar medium population synthesis predictions

Abstract

The temporal and spectral evolution of gamma-ray burst (GRB) afterglows can be used to infer the density and density profile of the medium through which the shock is propagating. In long-duration (core-collapse) GRBs, the circumstellar medium (CSM) is expected to resemble a wind-blown bubble, with a termination shock separating the stellar wind and the interstellar medium (ISM). A long standing problem is that flat density profiles, indicative of the ISM, are often found at lower radii than expected for a massive star progenitor. Furthermore, the presence of both wind-like environments at high radii and ISM-like environments at low radii remains a mystery. In this paper, we perform a 'CSM population synthesis' with long GRB progenitor stellar evolution models. Analytic results for the evolution of wind blown bubbles are adjusted through comparison with a grid of 2D hydrodynamical simulations. Predictions for the emission radii, ratio of ISM to wind-like environments, wind and ISM densities are compared with the largest sample of afterglow-derived parameters yet compiled, which we make available for the community. We find that high ISM densities around 1000/cm3 best reproduce observations. If long GRBs instead occur in typical ISM densities of approximately 1/cm3, then the discrepancy between theory and observations is shown to persist at a population level. We discuss possible explanations for the origin of variety in long GRB afterglows, and for the overall trend of CSM modelling to over-predict the termination shock radius.

22 pages, 15 figures, 4 tables. Accepted for publication in MNRAS

References in corpus (36)

• Array Programming with NumPy
• PLUTO: a Numerical Code for Computational Astrophysics
• Binary Population and Spectral Synthesis Version 2.1: construction, observational verification and new results
• An online repository of Swift/XRT light curves of GRBs
• Long gamma-ray bursts and core-collapse supernovae have different environments
• The effect of massive binaries on stellar populations and supernova progenitors
• A giant outburst two years before the core-collapse of a massive star
• The 1% Concordance Hubble Constant
• The Galaxy Population Hosting Gamma-Ray Bursts
• Teraelectronvolt emission from the $\gamma$-ray burst GRB 190114C
• Binary star progenitors of long gamma-ray bursts
• Observation of inverse Compton emission from a long $\gamma$-ray burst
• Swift Identification of Dark Gamma-Ray Bursts
• An Exact Integration Scheme for Radiative Cooling in Hydrodynamical Simulations
• Correlations of Prompt and Afterglow Emission in Swift Long and Short Gamma Ray Bursts
• Gamma-Ray Bursts from tidally spun-up Wolf-Rayet stars?
• Why binary interaction does not necessarily dominate the formation of Wolf-Rayet stars at low metallicity
• Radiative cooling rates, ion fractions, molecule abundances and line emissivities including self-shielding and both local and metagalactic radiation fields
• Are LGRBs biased tracers of star formation? Clues from the host galaxies of the $Swift$/BAT6 complete sample of bright LGRBs III: Stellar masses, star formation rates and metallicities at $z>1$
• A Survey for NV Absorption at z~z_GRB in GRB Afterglow Spectra: Clues to Gas Near the Progenitor Star
• The nature of the dwarf starforming galaxy associated with GRB 060218 / SN2006aj
• Electrons' energy in GRB afterglows implied by radio peaks
• Gamma-Ray Burst Afterglows as Probes of Environment and Blastwave Physics II: the Distribution of p and Structure of the Circumburst Medium
• Forming a constant density medium close to long gamma-ray bursts
• Driving classical Wolf-Rayet winds: A Γ- and Z-dependent mass-loss
• Dependence of Gravitational Wave Transient Rates on Cosmic Star Formation and Metallicity Evolution History
• Binary population synthesis models for core-collapse gamma-ray burst progenitors
• Constraints on the circumburst environments of short gamma-ray bursts
• Multi-dimensional models of circumstellar shells around evolved massive stars
• The circumstellar medium around a rapidly rotating, chemically homogeneously evolving, possible gamma-ray burst progenitor
• Probing the progenitors of spinning binary black-hole mergers with long gamma-ray bursts
• Wind nebulae and supernova remnants of very massive stars
• Unusually High Metallicity Host Of The Dark LGRB 051022
• Where are the magnetar binary companions? Candidates from a comparison with binary population synthesis predictions
• Asymmetric Wolf-Rayet winds: implications for GRB afterglows
• Diagnosing Circumburst Environment with Multiband Gamma-Ray Burst Radio Afterglows

Cited by in corpus (9)

• Extragalactic FXT Candidates Discovered by Chandra (2014-2022)
• Multi-wavelength observations of the Luminous Fast Blue Optical Transient AT2023fhn
• Time Evolving Photo Ionisation Device (TEPID): a novel code for out-of-equilibrium gas ionisation
• VFTS 243 as predicted by the BPASS fiducial models
• Searching for Radio Transients with Inverted Spectra in Epoch 1 of VLASS and VCSS, and Identification of a Sample of Candidate Relativistic Nuclear Transients
• Two-component jet model for the afterglow emission of GRB 201216C and GRB 221009A and implications for jet structure of very-high-energy gamma-ray bursts
• Discovery and Analysis of Afterglows from Poorly Localised GRBs with the Gravitational-wave Optical Transient Observer (GOTO) All-sky Survey
• Dense gas linked to star-forming regions photoionised by embedded gamma-ray bursts
• Revisiting early afterglows of gamma-ray bursts with finite-thickness ejecta: Implications from XRF 080330 and GRB 080710