Formation of metal-free binaries: Impact of H2 line cooling and CIE cooling

Riaz, R.; Schleicher, Dominik R. G.; Bovino, S.; Vanaverbeke, Sigfried; Klessen, Ralf S.

doi:10.1093/mnras/stac3310

Cited by 3 publications

(2 citation statements)

References 131 publications

(157 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The simulations discussed in this paper were originally published in Riaz et al (2023) addressing the phenomenon of fragmentation in metal-free gas (see Table 1). Here the same calculations are used to address characteristics of circumstellar disks that are found associated with the protostars, which are formed in the models.…”

Section: Methods and Initial Conditionsmentioning

confidence: 99%

“…For each model, the initial radius of the cloud, the total mass inside the cloud, the ratio of kinetic energy to the gravitational potential energy of the gas cloud (𝛼 th ), the initial average number density of the cloud, and the initial temperature of the gas are given by the constant values 2.169 pc, 1.3041 × 10 4 M ⊙ , 0.196, 8.650 × 10 4 cm −3 and 300 K, respectively. See also Riaz et al (2023).…”

Section: Methods and Initial Conditionsmentioning

confidence: 99%

See 1 more Smart Citation

Circumstellar disk and the first generation of stars

Riaz

2023

Astron Nachr

Self Cite

View full text Add to dashboard Cite

Circumstellar disk (CD) around the first generation of stars have been numerically investigated here to see if the cooling regimes also play a role in the formation and evolution of the disk associated with the most massive protostars (MMPS). Also, an emphasis is given to exploring the effect of the initial turbulent motion of the metal‐free gas on the resulting morphology of the CD. For this, a systematic range of Mach number has been examined. It has been found that the disk‐to‐star mass ratio / is larger when the model evolution is based on the first H line cooling followed by subsequent cooling via collision‐induced emission than in the model where only H line cooling remains operative. Also, irrespective of the initial turbulence in the cloud, the former type of model yields a CD as massive as 7.66 M while the latter type produces a disk as massive as 1.29 M. Moreover, the inner part of the CD is found dominated by higher subsonic turbulent motions in the case of the former type of models than in the latter type. CDs around MMPS in both types of models show stable disk structures.

show abstract

Section: Methods and Initial Conditionsmentioning

confidence: 99%

Section: Methods and Initial Conditionsmentioning

confidence: 99%

Circumstellar disk and the first generation of stars

Riaz

2023

Astron Nachr

Self Cite

View full text Add to dashboard Cite

show abstract

Towards a universal analytical model for Population III star formation: interplay between feedback and fragmentation

Liu,

Gurian,

Inayoshi

et al. 2024

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

JWST has brought us new insights into Cosmic Dawn with tentative detection of the unique signatures of metal-free Population III (Pop III) stars, such as strong HeII emission, extremely blue UV spectrum, and enhanced nitrogen abundance. Self-consistent theoretical predictions of the formation rates, sites, and masses of Pop III stars are crucial for interpreting the observations, but are challenging due to complex physical processes operating over the large range of length scales involved. One solution is to combine analytical models for the small-scale star formation process with cosmological simulations that capture the large-scale physics such as structure formation, radiation backgrounds, and baryon-dark matter streaming motion that regulate the conditions of Pop III star formation. We build an analytical model to predict the final masses of Pop III stars/clusters from the properties of star-forming clouds, based on the key results of small-scale star formation simulations and stellar evolution models. Our model for the first time considers the interplay between feedback and fragmentation and covers different modes of Pop III star formation ranging from ordinary small ($\sim 10-2000\ \rm M_\odot$) clusters in molecular-cooling clouds to massive ($\gtrsim 10^{4}\ \rm M_\odot$) clusters containing supermassive ($\sim 10^{4}-3\times 10^{5}\ \rm M_\odot$) stars under violent collapse of atomic-cooling clouds with large gas accretion rates of $\gtrsim 0.1\ \rm M_\odot \ yr^{-1}$. As an example, the model is applied to the Pop III star-forming clouds in the progenitors of typical haloes hosting high-z luminous quasars ($M_{\rm h}\sim 10^{12}\ \rm M_\odot$ at z ∼ 6), which shows that formation of Pop III massive clusters is common ($\sim 20-70{{\%}}$) in such biased (∼4σ) regions, and the resulting heavy black hole seeds from supermassive stars can account for a significant fraction of observed luminous ($\gtrsim 10^{46}\ \rm erg\ s^{-1}$) quasars at z ∼ 6.

show abstract

Gravitational waves from mergers of Population III binary black holes: roles played by two evolution channels

Liu,

Hartwig,

Sartorio

et al. 2024

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

The gravitational wave (GW) signal from binary black hole (BBH) mergers is a promising probe of Population III (Pop III) stars. To fully unleash the power of the GW probe, one important step is to understand the relative importance and features of different BBH evolution channels. We model two channels, isolated binary stellar evolution (IBSE) and nuclear star cluster-dynamical hardening (NSC-DH), in one theoretical framework based on the semi-analytical code a-sloth, under various assumptions on Pop III initial mass function (IMF), initial binary statistics and high-z nuclear star clusters (NSCs). The NSC-DH channel contributes $\sim 8-95{{\%}}$ of Pop III BBH mergers across cosmic history, with higher contributions achieved by initially wider binary stars, more top-heavy IMFs, and more abundant high-z NSCs. The dimensionless stochastic GW background (SGWB) produced by Pop III BBH mergers has peak values $\Omega ^{\rm peak}_{\rm GW}\sim 10^{-11}-8\times 10^{-11}$ around observer-frame frequencies $\nu \sim 10-100\ \rm Hz$. The Pop III contribution can be a non-negligible ($\sim 2-32{{\%}}$) component in the total SGWB at $\nu \lesssim 10\ \rm Hz$. The estimated detection rates of Pop III BBH mergers by the Einstein Telescope are $\sim 6-230\ \rm yr^{-1}$ and $\sim 30-1230\ \rm yr^{-1}$ for the NSC-DH and IBSE channels, respectively. Pop III BBH mergers in NSCs are more massive than those from IBSE, so they dominate the Pop III SGWB below 20 Hz in most cases. Besides, the detection rate of Pop III BBH mergers involving at least one intermediate-mass BH above $100\ \rm M_\odot$ by the Einstein Telescope is $\sim 0.5-200\ \rm yr^{-1}$ in NSCs but remains below $0.1\ \rm yr^{-1}$ for IBSE.

show abstract

Formation of metal-free binaries: Impact of H2 line cooling and CIE cooling

Cited by 3 publications

References 131 publications

Circumstellar disk and the first generation of stars

Circumstellar disk and the first generation of stars

Towards a universal analytical model for Population III star formation: interplay between feedback and fragmentation

Gravitational waves from mergers of Population III binary black holes: roles played by two evolution channels

Contact Info

Product

Resources

About