10:00 | 0:15 | Welcome | |
10:15 | 0:40 |
Prof. Marat Gilfanov
Prof. Marat Gilfanov
IKI, Moscow; MPA, Garching
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SRG/eROSITA all-sky survey: results on the Eastern Galactic hemisphere |
After more than two years of scanning the sky during 2019--2022 the eROSITA X-ray telescope aboard SRG orbital observatory produced the best ever X-ray maps of the sky and discovered more than three million X-ray sources, of which about 20% are stars with active coronas in the Milky Way, and most of the rest are galaxies with active nuclei, quasars and clusters of galaxies. eROSITA detected over ~10^3 sources that changed their luminosity by more than an order of magnitude, including about a hundred tidal disruption events. SRG/eROSITA samples of quasars and galaxy clusters will make it possible to study the large-scale structure of the Universe at z~1 and measure its cosmological parameters. I will review some of the SRG/eROSITA results in the Eastern Galactic hemisphere and future prospects. | |||
10:15 | 0:40 |
Prof. Marat Gilfanov
Prof. Marat Gilfanov
IKI, Moscow; MPA, Garching
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SRG/eROSITA all-sky survey: results on the Eastern Galactic hemisphere | |||
10:55 | 0:40 |
Prof. Hua Feng
Prof. Hua Feng
Institute of High Energy Physics
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Time domain astronomy with Einstein Probe |
The Einstein Probe is a space mission dedicated to time domain astronomy in the X-ray band. It employs two instruments: a Wide-field X-ray Telescope (WXT) utilizing lobster-eye optics for an unprecedented sensitivity, and a Follow-up X-ray Telescope (FXT) for precise localization. This unique combination enables the detection of relatively faint X-ray transients and has lead to the discovery of new types of X-ray sources that are previously unknown. Furthermore, FXT that features a relatively large field of view and low internal background provides new insights into faint, extended X-ray sources. I will provide an overview of the mission and its current scientific results. | |||
10:55 | 0:40 |
Prof. Hua Feng
Prof. Hua Feng
Institute of High Energy Physics
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Time domain astronomy with Einstein Probe | |||
11:35 | 0:30 | Coffee Break | |
12:05 | 1:00 |
Prof. Luis Ho
Prof. Luis Ho
Kavli Institute for Astronomy and Astrophysics
Peking University
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The Birth of Supermassive Black Holes and their Host Galaxies at Cosmic Dawn |
Supermassive black holes are ubiquitous in the nearby Universe. Their lifecycle is thought to be closely linked with the evolution of galaxies. How and when did these mysterious objects form? What were the first seeds? How did they grow quickly enough to power high-redshift quasars? And how precisely do black holes co-evolve with galaxies? I will summarize the demographics of supermassive and intermediate-mass black holes in the local Universe, their connection to galaxies, and recent discoveries made with the JWST that offer surprising, new insights into the earliest phases of black hole and galaxy formation during the first billion years after the Big Bang. | |||
12:05 | 1:00 |
Prof. Luis Ho
Prof. Luis Ho
Kavli Institute for Astronomy and Astrophysics
Peking University
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The Birth of Supermassive Black Holes and their Host Galaxies at Cosmic Dawn | |||
13:05 | 1:30 | Lunch | |
14:35 | 1:00 |
Prof. Rashid Sunyaev
Prof. Rashid Sunyaev
IKI, Moscow; MPA, Garching
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Clusters of galaxies discovered during microwave (SZ-effect) and SRG/eRosita X-Ray sky surveys: recent results, synergy and competition. |
Clusters of galaxies discovered during microwave (SZ-effect) and SRG/eRosita X-Ray sky surveys: recent results, synergy and competition. | |||
14:35 | 1:00 |
Prof. Rashid Sunyaev
Prof. Rashid Sunyaev
IKI, Moscow; MPA, Garching
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Clusters of galaxies discovered during microwave (SZ-effect) and SRG/eRosita X-Ray sky surveys: recent results, synergy and competition. | |||
15:35 | 0:40 |
Prof. Meicun Hou
Prof. Meicun Hou
Nanjing University
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eROSITA Survey of the Hot Gaseous Halo of the Member Galaxies in Virgo |
The X-ray-emitting hot gas is one of the primary components of the X-ray emission in normal galaxies and is crucial for understanding the evolution of the galactic ecosystem. The Virgo Cluster is the nearest and a rich galaxy cluster at its early evolutionary stage, which offers a great opportunity to study the hot gas content of its member galaxies and the cluster environmental effects. In this talk I will introduce a systematic study of the diffuse hot gas around member galaxies residing in the Virgo cluster, based on eROSITA first all sky survey, to test the X-ray scaling relations and understand the roles of cluster environmental effects and galactic outflows in regulating the hot gas content of galaxies. Our results start to provide fresh and crucial X-ray observational constrains to the modern galaxy cluster simulations. | |||
15:35 | 0:40 |
Prof. Meicun Hou
Prof. Meicun Hou
Nanjing University
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eROSITA Survey of the Hot Gaseous Halo of the Member Galaxies in Virgo | |||
16:15 | 0:30 | Coffee Break | |
16:45 | 0:25 |
Svetlana Voskresenskaia
Svetlana Voskresenskaia
IKI
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ComPACT: A Deep Learning-based ACT+Planck Galaxy Cluster catalogue with redshift and mass characterization |
Galaxy clusters are the most massive gravitationally bound systems in the Universe, making them powerful laboratories for studying galaxy evolution and probing cosmological models. We developed a deep learning model to segment the Sunyaev–Zeldovich (SZ) signal in ACT+Planck intensity maps and built a pipeline for detecting microwave-selected clusters across the ACT footprint. By applying this model to the extended catalogue of Sunyaev-Zeldovich objects from Planck data (SZcat), we improve cluster purity and construct a new catalogue – ComPACT – containing 2,962 SZ sources. We validated 71.3% of the candidates through photometric redshifts derived from DECaLS DR9 and WISE data, and by cross-matching with Compton-y maps from ACT+Planck and Planck. Redshifts were measured for 58.3% of the sample (0.007 < z < 1.7), including 111 new determinations. Masses were estimated for 52% of the clusters, yielding 133 new measurements. The covered mass range spans $M_{500c} = (0.25–13.1) \times 10^{14} M_\odot$ . The catalogue also reveals several new, massive high-redshift clusters (z > 0.8, $M_{500c} > 5.3 \times 10^{14} M_\odot$), expanding the known population of such systems by 20%. Overall, ComPACT demonstrates high completeness (≥90%) across a wide range of masses and redshifts, particularly excelling at high z and in regions not covered by ACT DR5. | |||
16:45 | 0:25 |
Svetlana Voskresenskaia
Svetlana Voskresenskaia
IKI
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ComPACT: A Deep Learning-based ACT+Planck Galaxy Cluster catalogue with redshift and mass characterization | |||
17:10 | 0:25 |
Dr. Natalya Lyskova
Dr. Natalya Lyskova
IKI
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A rare Bullet-like merger at the moment of pericenter passage |
Massive clusters of galaxies are very rare in the observable Universe. Even rarer are mergers of such clusters observed close to pericenter passage. And a massive and hot cluster CL0238.3+2005 at z≈0.42 is one such case. For this cluster, we combine X-ray data from SRG/eROSITA and Chandra, optical images from DESI, and spectroscopy from BTA and RTT-150 telescopes. The X-ray and optical morphologies suggest an ongoing merger with the projected separation of subhalos of ∼200 kpc. The line-of-sight velocity of galaxies tentatively associated with the two merging halos differs by 2000-3000 km/s. We conclude that, most plausibly, the merger axis is neither close to the line of sight nor to the sky plane. We compare CL0238 with two well-known clusters MACS0416 and Bullet, and conclude that CL0238 corresponds to an intermediate phase between the pre-merging MACS0416 cluster and the post-merger Bullet cluster. Namely, this cluster has recently experienced an almost head-on merger. We argue that this "just after" system is a very rare case and an excellent target for lensing, Sunyaev-Zeldovich effect, and X-ray studies that can constrain properties ranging from dynamics of mergers to self-interacting dark matter, and plasma effects in intracluster medium that are associated with shock waves, e.g., electron-ion equilibration efficiency and relativistic particle acceleration. | |||
17:10 | 0:25 |
Dr. Natalya Lyskova
Dr. Natalya Lyskova
IKI
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A rare Bullet-like merger at the moment of pericenter passage | |||
17:35 | 0:25 |
Dr. Vladislav Barinov
Dr. Vladislav Barinov
INR
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Mass Calibrations of Galaxy Clusters: Velocity Dispersion and X-Ray Masses |
This talk will focus on the study of galaxy clusters as cosmological probes for precision cosmology. We will discuss methods for identifying cluster member galaxies as well as interlopers, and explore the velocity dispersion–mass relation derived from both optical and X-ray observations. Special attention will be given to how these methods and relations can be applied to large samples of galaxy clusters to constrain cosmological parameters. | |||
17:35 | 0:25 |
Dr. Vladislav Barinov
Dr. Vladislav Barinov
INR
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Mass Calibrations of Galaxy Clusters: Velocity Dispersion and X-Ray Masses | |||
18:00 | 1:00 | Welcome Reception | |