Galactic and extragalactic X-ray transients, theory and observational perspectives
Warsaw, Poland, September 9-11, 2024
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Important dates
Important dates
Abstract submission for talks deadline: May 10th, 2024
Notification of accepted talks: middle of June
Registration closing, poster abstracts deadline and conference fee payment deadline: August 20th, 2024
Registration and participants
Registration and participants
The normal registration fee is 150 Euro (650 PLN) and reduced fee for students is 100 Euro (450 PLN). It includes: Coffee break, Lunch, Conference Dinner, Social Event. Daily breakfast, dinners and Hotel accommodation are not included. The payment details are described in the registration form.
Below, the links to registration and participant list are available
Instructions for payments
Instructions for payments
Please do a bank transfer to
Centrum Fizyki Teoretycznej Polskiej Akademii Nauk
addres: aleja Lotników 32/46, 02-668 Warszawa
Bank account No: PL65 1130 1017 0020 1465 1320 0009
IBAN-No: PL65 1130 1017 0020 1465 1320 0009
BIC/SWIFT: GOSKPLPW
Bank Name: Bank Gospodarstwa Krajowego
IMPORTANT: To identify the payment with a particular conference and participant registered, the transfer must include the conference acronym clagn, the participant's name, or the name of the institution sending and financing the participant's attendance.
A copy of the bank transfer receipt has to be sent to cl-agn@cft.edu.pl
The invoice will be generated from the information provided by the participant in the registration form (in the section "Tax invoice request").
Invited Speakers
Invited Speakers
Riccardo Arcodia (MIT)
Marzena Sniegowska (Tel Aviv University)
Federico Vincentelli (IAC, Tenerife)
Fiamma Capitanio (INAF-IAPS Rome)
Dheeraj Pasham (Massachusetts Institute of Technology),
Petra Sukova ( Astronomical Institute, Czech Academy of Sciences, Prague)
Key topics
Key topics
1. Quasi periodic eruptions in accreting black holes
2. Tidal disruption events
3. Changing activity of supermassive black holes
4. Fast variability of Galactic X-ray sources
5. Accretion instabilities and gravitational waves from black hole and neutron star binaries
6. Testing General Relativity with supermassive black holes
Scientific Rationale
Scientific Rationale
Theoretical studies have shown that the multi-wavelength emission of the nuclei of active galaxies, stellar mass black hole and neutron star binaries is fueled by their accretion disks. The accretion process may be not stationary, and the accretion history as well as geometric structure of the infalling matter are not well understood. Importantly, the magnetic fields must play a key role in sustaining the accretion flows. While we have progressed in understanding many of these phenomena, there are recent observations and new models that drive our understanding in new directions. They are related either to the instabilities in the innermost part of the disk or to the sudden interaction of circumnuclear stars with the central black hole and the disk. Processes close to the black hole also allow testing of General Relativity in a strong field regime.
Regular quasi-periodic outbursts (QPO) with a period that depends on the mean flux were observed in Galactic microquasars, and have also been suggested to explain intermediate- and supermassive black holes duty cycles. This regular variability can be well modeled by the radiation pressure instability in the central parts of the accretion disk or alternatively, by orbiting bodies that regularly perturb the accretion flow.
Quasi-periodic eruptions (QPEs) form a novel class of extragalactic X-ray transients that are known to repeat at roughly regular intervals of a few hours to days. Their underlying physical mechanism is a topic of heated debate, with most models proposing that they originate either from instabilities within the inner accretion flow or from orbiting objects. In case orbiting stars or compact objects are behind the quasiperiodic variability of at least some QPEs, they would provide a unique opportunity to study precursors of future gravitational-wave detections of extreme-mass ratio inspirals by LISA.
Changing-Look Active Galactic Nuclei (CL-AGN) forms a special and interesting class of objects. There, the change of the spectral type of an AGN happens on timescales of a few years, with extreme luminosity variations that considerably exceed the usual stochastic variability. These changes may or may not be related to the radiation pressure instability. Tidal disruption events (TDE) traditionally form a separate class, and they were searched for and found in otherwise inactive galaxies. When a TDE event occurs in an active or weak nucleus, however, it can also lead to a CL AGN.
From the theoretical side, an accretion disk formed around a supermassive black hole, after it disrupts a star, is expected to be initially misaligned with respect to the black hole’s equatorial plane. This misalignment induces relativistic torques on the disk, causing the disk to precess at early times, while at later times, the disk aligns with the black hole and precession terminates. The resulting Lense-Thirring precession in the disk can produce X-ray variability consistent with observations, but other physical mechanisms, such as the radiation-pressure instability, are also possible.
Supermassive black holes also offer a unique way to test GR in a strong field regime when we can follow the motion of gas or stars in its vicinity. For example, high-resolution observations of the Sgr A* region offer such opportunities.
Conference Venue
Conference Venue
Warsaw, Poland
Warsaw is one of the most rapidly developing cities in Europe with huge potential and extraordinary energy, its residents like to look back on its history and are able to skilfully combine tradition and modernity. Warsaw has a rich calendar of musical, cultural and sports events. Festivals, star concerts and outdoor exhibitions take place throughout the year.Interactive museums will help you understand the history of the city.
Each city has a place that is its showcase and a must-see on any trip. In Warsaw, it’s the Old Town, entered on the UNESCO World Heritage List – it’s where the city’s heart has been beating for centuries. However, when you cross the Vistula River and look at the Old Town from a distance, you are struck by how unusual the panorama of the city is – skyscrapers rise above the red roofs of the Old Town. Historical buildings blend in harmoniously with modern architecture, and the city surprises us by revealing its second face.
Hotel and Conference hall
The event will take place in the conference hall at 03Hotel Warsaw, located at Mangalia 1, 02-758 Warsaw, Poland. To reserve a room, please visit the following the following link. The hotel is roughly 30 min from the old Town by public transport. In the section on logistics, we included links with detailed routes from the main international arrival points.
SOC
SOC
Bozena Czerny (CFT PAN) Co-Chair website
Agnieszka Janiuk (CFT PAN) - Co-Chair website
Szymon Kozłowski (University of Warsaw)
Vladimir Karas (Astronomical Institute, Prague)
Mikołaj Korzyński (CFT PAN)
Alex Markowitz (CAMK PAN, Warsaw)
Benny Trakhtenbrot (Tel Aviv University)
Michal Zajacek (Masaryk University, Brno)
LOC
LOC
Sponsors
Sponsors
Design and updates: Gerardo Urrutia
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