Cambridge Astrophysics Joint Colloquia
Thu 30 Jan 16:00: AGN Feedback to Cosmology: eROSITA's Distinct Perspective on Large-Scale Structure
Abstract: Galaxy clusters, representing the peaks in the cosmic density field, serve as an independent and powerful tool for investigating the evolution of cosmic structures. The strategic identification of these clusters through multi-wavelength surveys is essential for advancing our understanding of gravitational theory, general relativity, and cosmological models. A significant milestone was achieved with the successful launch of eROSITA in July 2019. The German-built eROSITA X-ray telescope, on board the Russian-German Spectrum-RG (SRG) mission, operates within the 0.2-8 keV range and has produced the largest ICM -detected catalogs of galaxy clusters and groups through its first All-Sky Survey. With over 10,000 confirmed clusters, the survey is pivotal in refining cosmological parameters when combined with the data from optical surveys like DESI Legacy, DES , HSC, and KIDS . These parameters are constrained at a percentage level through the evolution of the cluster mass function, representing a significant leap forward, exhibiting a 5-9 times improvement compared to previous cluster surveys. In this talk, I will outline the constraints on fundamental cosmological parameters, neutrino masses, and general relativity derived from the first eROSITA All-Sky Survey. Additionally, I will present eROSITA’s significant detection of warm baryons within cosmic filaments identified by optical surveys and the implications for our understanding of AGN feedback in group-size haloes. I will summarize the value-added products made available to the science community by the eROSITA consortium’s data release.
- Speaker: Esra Bulbul
- Thursday 30 January 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Matthew Grayling.
Thu 20 Mar 16:00: Title to be confirmed
Title to be confirmed
- Speaker: Hannah Wakeford
- Thursday 20 March 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Matthew Grayling.
Thu 06 Mar 16:00: Title to be confirmed
Title to be confirmed
- Speaker: Evan O'Connor
- Thursday 06 March 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Matthew Grayling.
Thu 27 Feb 16:00: Title to be confirmed
Title to be confirmed
- Speaker: Ravit Helled
- Thursday 27 February 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Matthew Grayling.
Thu 20 Feb 16:00: Title to be confirmed
Title to be confirmed
- Speaker: Hagai Perets
- Thursday 20 February 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Matthew Grayling.
Thu 06 Feb 16:00: Title to be confirmed
Title to be confirmed
- Speaker: Natascha M. Foerster Schreiber
- Thursday 06 February 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Jan Scholtz.
Thu 23 Jan 16:00: Title to be confirmed
Title to be Confirmed
- Speaker: Mickael Rigault
- Thursday 23 January 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Matthew Grayling.
Thu 30 Jan 16:00: Title to be confirmed
Title to be confirmed
- Speaker: Esra Bulbul
- Thursday 30 January 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Matthew Grayling.
Thu 20 Mar 16:00: Dr
Title to be confirmed
- Speaker: Hannah Wakeford
- Thursday 20 March 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Matthew Grayling.
Thu 06 Mar 16:00: Prof
Title to be confirmed
- Speaker: Evan O'Connor
- Thursday 06 March 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Matthew Grayling.
Thu 27 Feb 16:00: Prof
Title to be confirmed
- Speaker: Ravit Helled
- Thursday 27 February 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Matthew Grayling.
Thu 20 Feb 16:00: Prof
Title to be confirmed
- Speaker: Hagai Perets
- Thursday 20 February 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Matthew Grayling.
Thu 06 Feb 16:00: Dr
Title to be confirmed
- Speaker: Natascha M. Foerster Schreiber
- Thursday 06 February 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Jan Scholtz.
Thu 30 Jan 16:00: Dr
Title to be confirmed
- Speaker: Esra Bulbul
- Thursday 30 January 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Matthew Grayling.
Thu 23 Jan 16:00: Dr
Title to be Confirmed
- Speaker: Mickael Rigault
- Thursday 23 January 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Matthew Grayling.
Thu 05 Dec 16:00: Should we observe spirals in young planet-forming discs?
We live in exciting times where new observations are hinting to us that planets may form early on in planet-forming discs. Young discs are expected to exhibit spiral structures, yet only few observations actually show spirals that are indicative of young discs. In this colloquium I will explore some of the possible reasons why this might be, and in particular I will look at processes that occur in discs which might act to erase the spiral structures.
- Speaker: Farzana Meru University of Warwick
- Thursday 05 December 2024, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: eb694.
Thu 05 Dec 16:00: Should we observe spirals in young planet-forming discs?
Abstract not available
- Speaker: Farzana Meru University of Warwick
- Thursday 05 December 2024, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: eb694.
Thu 05 Dec 16:00: TBC
Abstract not available
- Speaker: Farzana Meru University of Warwick
- Thursday 05 December 2024, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: eb694.
Thu 28 Nov 16:00: Small-scale structure in cold dark matter: from ultra-faint dwarfs to prompt cusps
In our present paradigm of galaxy formation, the onset of structure is brought about via the gravitational collapse of (cold) dark matter, which subsequently acts as the scaffolding for the visible universe. A vigorous programme of numerical simulations has established several features of the dark matter model: the formation of haloes, and how their structure and abundance is influenced by the particle physics of the underlying model. The smallest visible galaxies—so-called “ultra-faint dwarfs”—are fossil records of an early phase of galaxy formation in the Universe and their assembly provides strong clues into the Epoch of Reionisation, galactic feedback, and the nature of the dark matter particle. Yet, the cold dark matter model predicts the formation of structure many orders-of-magnitude below the scale where galaxy formation ends, where individual dark matter haloes have masses comparable to that of the Earth. In this talk, I will discuss some of the progress we have made in understanding this regime using numerical simulations, and what their implications are for understanding the physics of galaxy formation, the nature of dark matter, and our prospects for detecting dark matter in the future.
- Speaker: Sownak Bose Durham University
- Thursday 28 November 2024, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Jan Scholtz.
Thu 21 Nov 16:00: Ways of Probing the Assembly Mechanism of Individual Black Hole Binary Mergers
I will illustrate how different binary black hole (BBH) merger formation channels give rise to phase shifts, or modulations, in the GW signal that can be used to infer the origin of individual BBH mergers. I will in particular describe the case of GW phase shifts arising from chaotic triple BH scatterings that are known to take place in stellar clusters. New ideas on GW phase shifts in strong lensing events will also be presented. Modeling, quantifying and looking for GW modulations will start to play a key-role in the coming years when the GW sensitivity goes up and might be the only way of determining the origin of GW events case-by-case.
- Speaker: Prof. Johan Samsing
- Thursday 21 November 2024, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Mor Rozner.