Skip to main content

Self-consistent model incorporates gas self-gravity effects to address accretion across cosmic scales




A research team led by Prof. Jiao Chengliang at the Yunnan Observatories of the Chinese Academy of Sciences, along with collaborators, has introduced a self-consistent model that addresses long-unresolved theoretical gaps in the study of self-gravitating spherical accretion.

Accretion, the fundamental astrophysical process by which matter is drawn onto a central celestial object (such as a black hole or star), underpins our understanding of phenomena ranging from star formation to black hole growth. For decades, the classical Bondi model developed in the 1950s and still widely used today has served as the backbone of accretion research.

However, this foundational framework overlooks a critical factor: the self-gravity of the gas being accreted. This omission, the researchers note, can drastically alter flow structures and accretion rates in high-density astrophysical environments, limiting the model's accuracy in key scenarios.

To address this challenge, the team developed a comprehensive mathematical framework: a three-point boundary value problem tailored to spherically symmetric accretion that fully incorporates the self-gravity of the accreted gas.

The researchers used a relaxation method, a numerical technique ideal for refining solutions to nonlinear systems, and derived simplified analytical formulas, enabling astronomers to quickly estimate the impact of self-gravity without intensive computational work.

At the core of the new model is a dimensionless parameter, denoted as β, which quantifies self-gravity effects based on four measurable properties of the surrounding medium: density, sound speed, outer radius, and adiabatic index (a measure of how a gas responds to temperature and pressure changes).

These findings reveal key insights into how self-gravity shapes accretion:

As β increases (indicating stronger self-gravity), the "sonic point" of the accretion flow where the gas transitions from subsonic to supersonic speed shifts inward toward the central object.

For adiabatic indices (γ) between 1 and 5/3 (a range encompassing most astrophysical gases), higher β values also lead to a significant increase in accretion rate.

A critical exception emerges at γ = 5/3: Here, the gas's high "stiffness" (resistance to compression) negates self-gravity's effect, and no further increase in accretion rate is observed.

The study also identifies an upper limit for β: Exceeding this threshold makes steady accretion impossible a result that aligns closely with classical gravitational instability theory, including the well-known Bonnor-Ebert threshold (which defines when a gas cloud collapses under its own weight).

To validate the model's real-world utility, the researchers applied it to two iconic astrophysical scenarios:

Hyper-Eddington accretion onto supermassive black hole seeds in the early universe: This extreme process, where accretion occurs far faster than the rate predicted by the Eddington limit (a traditional upper bound), depends heavily on self-gravity making the new model critical for understanding how the first supermassive black holes formed.

Accretion onto stellar-mass objects in active galactic nucleus (AGN) disks: AGNs luminous cores of galaxies powered by supermassive black holes host disks of gas and dust where stars and compact objects (e.g., neutron stars) form. The study shows self-gravity becomes non-negligible in these disks under certain conditions, and β provides a reliable tool to assess its influence.

This study offers a novel framework to study accretion across cosmic scales from stellar formation to the evolution of the earliest black holes.

#HighEnergyPhysics#ParticlePhysics#QuantumPhysics#AstroparticlePhysics#ColliderPhysics#HiggsBoson#LHC#QuantumFieldTheory#NeutrinoPhysics#PhysicsResearch#ComputationalScience#DataScience#ScientificComputing#NumericalMethods#HighPerformanceComputing#MachineLearningInScience#BigData#AlgorithmDevelopment#SimulationScience#ParallelComputing

Visit Our Website : hep-conferences.sciencefather.com
Nomination Link :hep-conferences.sciencefather.com/award-nomination/?ecategory=Awards&rcategory=Awardee
Registration Link : hep-conferences.sciencefather.com/award-registration/
Member Link : hep-conferences.sciencefather.com/conference-membership/?ecategory=Membership&rcategory=Member
Awards-Winners : hep-conferences.sciencefather.com/awards-winners/
For Enquiries: supportteam@sciencefather.com

Get Connected Here:
==================
Social Media Link
Twitter : x.com/Psciencefather
Pinterest : in.pinterest.com/physicsresearchorganisation
Blog : physicscience23.blogspot.com
Instagram : www.instagram.com/victoriaanisa1
YouTube :www.youtube.com/channel/UCzqmZ9z40uRjiPSr9XdEwMA
Tumblr : https://www.tumblr.com/blog/hepcs

Comments

Post a Comment

Popular posts from this blog

Physicists observe a new form of magnetism for the first time

MIT physicists have demonstrated a new form of magnetism that could one day be harnessed to build faster, denser, and less power-hungry " spintronic " memory chips. The new magnetic state is a mash-up of two main forms of magnetism: the ferromagnetism of everyday fridge magnets and compass needles, and antiferromagnetism, in which materials have magnetic properties at the microscale yet are not macroscopically magnetized. Now, the MIT team has demonstrated a new form of magnetism , termed "p-wave magnetism." Physicists have long observed that electrons of atoms in regular ferromagnets share the same orientation of "spin," like so many tiny compasses pointing in the same direction. This spin alignment generates a magnetic field, which gives a ferromagnet its inherent magnetism. Electrons belonging to magnetic atoms in an antiferromagnet also have spin, although these spins alternate, with electrons orbiting neighboring atoms aligning their spins antiparalle...
Post a Comment
Read more

Physicists Catch Light in 'Imaginary Time' in Scientific First

For the first time, researchers have seen how light behaves during a mysterious phenomenon called 'imaginary time '. When you shine light through almost any transparent material, the gridlock of electromagnetic fields that make up the atomic alleys and side streets will add a significant amount of time to each photon's commute. This delay can tell physicists a lot about how light scatters, revealing details about the matrix of material the photons must navigate. Yet until now, one trick up the theorist's sleeve for measuring light's journey invoking imaginary time has not been fully understood in practical terms. An experiment conducted by University of Maryland physicists Isabella Giovannelli and Steven Anlage has now revealed precisely what pulses of microwave radiation (a type of light that exists outside the visible spectrum) do while experiencing imaginary time inside a roundabout of cables. Their work also demonstrates how imaginary numbers can describe a ver...
Post a Comment
Read more

new research in qauntum physics

         VISIT:https: //hep-conferences.sciencefather.com/          N ew research in  qauntum physics.                                                    Alphabet Has a Second, Secretive Quantum Computing Team Recent research in quantum physics includes the development of quantum computers, which are expected to be much more powerful than conventional computers and could revolutionize many aspects of technology, such as artificial intelligence and cryptography. Other research includes the development of quantum sensors for a variety of applications, including medical diagnostics, and the study of quantum entanglement and its potential to enable quantum computing and secure communication. Additionally, research is being conducted into the applications of quantum mechanics in materials science, such as unde...
Post a Comment
Read more