Detecting Population III Stars through Tidal Disruption Events in the Era of JWST and Roman (2401.12752v2)

Abstract: The first generation metal-free stars, referred to as population III (Pop III) stars, are believed to be the first objects to form out of the pristine gas in the very early Universe. Pop III stars have different structures from current generation of stars and are important for generating heavy elements and shaping subsequent star formation. However, it is very challenging to directly detect Pop III stars given their high redshifts and short life-times. In this paper, we propose a novel method for detecting Pop III stars through their tidal disruption events (TDEs) by massive black holes. We model the emission properties and calculate the expected rates for these unique TDEs in the early Universe at z ~ 10. We find that Pop III star TDEs have much higher mass fallback rates and longer evolution timescales compared to solar-type star TDEs in the local universe, which enhances the feasibility of their detection, although a good survey strategy will be needed for categorizing these sources as transients. We further demonstrate that a large fraction of the flare emissions are redshifted to infrared wavelengths, which can be detected by the James Webb Space Telescope and the Nancy Grace Roman Space Telescope. Last but not least, we find a promising Pop III star TDE detection rate of up to a few tens per year using the Nancy Grace Roman Space Telescope, based on our current understanding of the black hole mass function in the early Universe.

• The paper introduces a novel model for tidal disruptions of Pop III stars, quantifying extreme fallback rates that can exceed Eddington limits by up to 10^6.
• It utilizes advanced hydrodynamic simulations and modified analytical frameworks to estimate prolonged infrared emissions at redshift ~10.
• The results suggest that JWST and Roman may detect several tens of these events annually, advancing our understanding of early universe black holes.

Assessing Population III Stars through Tidal Disruption Events with JWST and Nancy Grace Roman Telescope

The paper of Population III (Pop III) stars, primordial stars theorized to have formed from metal-free gas in the early universe, presents significant challenges due to their high redshifts and ephemeral nature. The paper "Detecting Population III Stars through Tidal Disruption Events in the Era of JWST and Roman" explores the potential for observing these stars via the tidal disruption events (TDEs) they experience when interacting with massive black holes (MBHs).

This research introduces a novel approach by modeling the emissions and fallback rates from TDEs of Pop III stars, estimating these occurrences at redshift $z \sim 10$. It establishes that TDEs from Pop III stars exhibit significantly higher mass fallback rates and elongated evolutionary timelines compared to Solar-type stars in the local universe. The estimated rates highlight the practical potential for detection, contingent on adept survey strategies.

Pop III stars, potentially more massive than their successors with masses ranging from 30 to 300 solar masses, are pivotal in early universe chemical enrichment and structure formation. However, their direct empirical paper remains elusive. By analyzing the fallback rate and resultant emissions, the authors indicate that despite rapid initial mass fallback surpassing the Eddington limit by a substantial margin (by factors as high as $10^4 - 10^6$ for black holes of $10^6 M_\odot$), TDE detection is feasible in the infrared spectrum due to the extensive temporal scales and significant redshifting of emissions attributable to these high-redshift environments.

Methodologically, the paper applies recent hydrodynamic simulation insights to derive mass fallback rates and accretion processes under high stellar disruption scenarios. The authors utilize Strubbe and Quataert's (2009) analytical approach for estimating TDE emission traits while evolving this framework to suit Pop III stellar attributes.

The extend of observational prospects hinges on instrument capabilities, notably those of the James Webb Space Telescope (JWST) and the forthcoming Nancy Grace Roman Telescope. Given the prominence of infrared emissions in these transient events, these instruments are crucial to their detection. Model calculations predict a promising detection rate of up to several tens per year using the Roman space telescope, assuming an effective observational strategy informed by the underlying black hole mass function in the early universe.

The theoretical implications of this work are substantial. Accurately attributing TDEs to Pop III interactions will enhance our understanding of early massive black hole formation and accretion processes, providing an enriched picture of early cosmic events. Furthermore, the potential confirmation of such a detection channel could cement theories about the contribution of Pop III stars to early chemical enrichment and the ionization history of the universe.

Future developments could consider the nuanced physical details of Pop III stars, potentially affecting fallback dynamics and emission characteristics. Additionally, more comprehensive models might explore the impact of stellar multiplicity and dynamics within proto-galactic environments on TDE rates.

In conclusion, this paper provides a critical step toward leveraging advanced observational platforms to paper relics of the early universe, connecting theoretical models with empirical exploration in the quest to understand the universe's formative epochs.