ISSI-Beijing International Team

Who are we?

We are a team of black hole accretion disc observers and theorists at various career stages.

We are motivated by the latest advancements in X-ray polarisation and spectral observations, revealing complex, but yet-to-be-fully-understood details of disks and winds in XRBs and ULXs, and high-cadence monitoring of extreme transient events—such as changing-look AGNs and TDEs.

Together, we will

✔ answer the following two questions:

1. Which foundational aspects of the standard accretion disc model remain most consistent with modern observations, and should therefore be retained in the development of next-generation accretion theories?

2. What critical physical processes, revealed by the latest observations but absent in the standard accretion disc model, can be incorporated and explored through modern numerical simulations?

✔explore ways to improve communication between observers and theorists. This effort will serve as a model for future similar collaborations.

We use state-of-the-art observatories!

We use state-of-the-art simulations!

Sub-to-Near Eddington Accretion

Andrew Young* (Uni. of Bristol)

Adam Ingram (Newcastle Uni.)

Sophia Waddell (McGill Uni.)

Jiachen Jiang** (Uni. of Warwick)

Super Eddington Accretion

Ciro Pinto (INAF – IASF Palermo)

Yuhan Yao (UCB)

Sub-to-Near Eddington Accretion

Nicolas Scepi (IPAG)

Andrew Mummery (Uni. of Oxford)

Super Eddington Accretion

James Stone* (Princeton Uni.)

Jane Dai (Uni. of Hong Kong)

Yanfei Jiang (Flatiron)

Brenna Mockler (Carnegie Obs.)

Actions Needed for Core Members

1. Vote for your preferred dates for the first in-person meeting dates here before 10 October 2025.

2. Fill in the kick-off meeting program before 10 November 2025.

(updated on 12 September 2025)

Upcoming Events

Kick-off meetings on 1, 2 and 4 December 2025.

(updated on 12 September 2025)

Event Calendar

Click here for a summary of our events

Travel Information

• Local travel informationLink opens in a new window
• China's 240-hour, visa-free transit policyLink opens in a new window
• Food allergen matrix and dietary requirements in English and Chinese

Code of Conduct

Collaboration is based on mutual respect and equal communication. We follow the code of conductLink opens in a new window of ISSI-Beijing.

Kick-Off Meeting

• Kick-off meeting surveyLink opens in a new window (Deadline: 10 September 2025)
• Kick-off meeting minutes (Internal access onlyLink opens in a new window)
• Dates, time and links to the meetings, and presentation guideline (here)
• Meeting programs (here)
• LIVE! Vote for first in-person meeting dates here (Deadline: 10 November 2025)

First In-Person Meeting

Coming soon!

Second In-Person Meeting

Coming soon!

Open Access

We are fully dedicated to being an open and accountable collaboration team. We aim to break the knowledge barrier between telescope observations and large-scale numerical simulations.

Please visit our open access repository (coming soon).

Publications

• Poster at the New Results in X-ray Astronomy Meeting (Bristol, 2025) Download

Early-Career Researchers

We are proud to support early-career researchers through this collaboration.

Coming soon!