Conveners
Latest results from Galactic center observations: Thursday block 1
- Anna Ciurlo (University of California Los Angeles)
- Florian Peißker (Ph1, University of Cologne, Germany)
- Maria Melamed (University of Cologne)
Latest results from Galactic center observations: Thursday block 2
- Maria Melamed (University of Cologne)
- Anna Ciurlo (University of California Los Angeles)
- Florian Peißker (Ph1, University of Cologne, Germany)
Latest results from Galactic center observations: Friday block 1
- Maria Melamed (University of Cologne)
- Florian Peißker (Ph1, University of Cologne, Germany)
- Anna Ciurlo (University of California Los Angeles)
Latest results from Galactic center observations: Friday block 2
- Anna Ciurlo (University of California Los Angeles)
- Florian Peißker (Ph1, University of Cologne, Germany)
- Maria Melamed (University of Cologne)
Description
The Galactic Center with its central supermassive black hole (SMBH) provides a unique opportunity to study the interplay between accretion processes, and various star formation channels in special conditions. Comprehensive simulations, observations, and a detailed analysis of the composition of the inner few parsecs throughout all available wavebands help understanding the evolution of this peculiar region. In the Galactic Center, we have the unique opportunity to provide a blueprint for the composition of other galaxy cores, and deepen our astrophysical knowledge of the mechanisms at play in these regions, which we know ultimately are connected to the way galaxies evolve. In this session, new observations, analysis and models of this region should be presented. We especially want to discuss stellar dynamics, star formation, objects of unknown/debated nature, as well as other sources and phenomena and more general aspects on the Galactic Center.
The galactic black hole is not very active at present, but at about 1 pc there is a large reservoir of material that will eventually trigger a more intense phase of activity. Smaller-scale processes can also accrete material onto the black hole producing short peaks in activity. Here, I present the structure and dynamics of the interstellar medium from the parsec to sub-parsec scale and how...
We study the periapsis shift of a quasi-circular orbit in general static spherically symmetric spacetimes. We derive two formulae in full order with respect to the gravitational field, one in terms of the gravitational mass m and the Einstein tensor and the other in terms of the orbital angular velocity and the Einstein tensor. These formulae reproduce the well-known ones for the forward shift...
The observations of the so-called S-stars together with the dust-enshrouded objects, the G-stars, can help to further corroborate Einstein’s General Relativity theory and to better constrain the nature of the supermassive black hole (SMBH) candidate, SgrA*. In recent years, a novel dark matter (DM) model for galaxy haloes has been developed, the Ruffini-Argüelles-Rueda (RAR) model. It consists...
I will present an overview of temporal variability studies of Sgr A, discussing several observables, such as the flux distribution, the SED, the PSD and (higher order) structure functions, and will give an overview of how these are typically modelled in observational studies. A particular focus will be put on the temporal symmetry of Sgr A, which as a new and useful observable for the study...
I will present a review on the X-ray emission coming from the Galactic Center (GC), and in particular from the Central Molecular Zone, established from the results that have been obtained in the last 20 years with Chandra, XMM-Newton, INTEGRAL and other space observatories operating in the range 1-200 keV.
I will focus in particular on the emission that the GC super Massive Black Hole, Sgr...
Molecular clouds in the Galactic Center reprocess radiation from past outbursts, generating a strong Fe K$\alpha$ fluorescent line (6.4 keV). Reflecting the radiation that reaches them as mirrors, these clouds retain the historical activity of their illuminating sources. Studying this echo radiation provides crucial information about the source, the clouds' properties, and the relative...
The large-scale structures such as Fermi Bubbles and eROSITA Bubbles provide a unique opportunity to study our Milky Way. However, the nature and origin of these large structures are still under debate. In this talk, I will present the identification of several kpc-scale magnetised structures based on their polarized radio emission and their gamma-ray counterparts, which can be interpreted as...
The Galactic centre region consists of the nuclear stellar disk (NSD), a flat, rotating stellar structure, and the nuclear star cluster (NSC), the densest concentration of stars in the Galaxy.
The NSC and NSD are distinct structures of the Milky Way, but also connected to the larger Milky Way structures, e.g. via the inflow and outflow of gas, and the infall of star clusters.
Our knowledge...
The Galactic Center provides a unique opportunity to observe galactic cores, objects in the close proximity to a supermassive black hole (SMBH), and star formation channels that exhibit imprints of this peculiar environment. This habitat hosts, in addition to the SMBH Sgr A * , a surprisingly young cluster with the so-called S-stars. These stars orbit the SMBH on timescales of a few years with...
In this talk, I revisited the model of a dust-enshrouded star orbiting a low-luminosity galactic nucleus (Zajacek et al., 2014, 2016, 2017). Although it is quite challenging for dust to survive in hot X-ray-emitting plasma surrounding supermassive black holes (SMBHs), now we have an observational evidence that compact dusty objects or G objects can approach the SMBH in the Galactic center (Sgr...
Prior studies have revealed the presence of young massive stars in the central 0.5 pc of the Galactic Centre, prompting questions about their properties and formation in the immediate vicinity of the massive black hole Sagittarius A*. Intriguingly, the shape of the initial mass function (IMF) in this region appears to deviate from the standard Salpeter/Kroupa law. However, our knowledge of the...
This work investigates the long-term evolution of two bodies in nearby initially coplanar orbits around a central dominant body, perturbed by a fourth body on a distant Keplerian orbit. Previous works on this setup enforced circular orbits by adding a spherical potential of extended mass. This results in a long-term coherent evolution with nearly coplanar orbits experiencing only small...
The discovery of a cold (~10,000 K) disc-like structure around the super-massive black hole at the centre of the Milk Way, Sagittarius A (Sgr A), has challenged our understanding of the gas dynamics and thermodynamic state of the plasma in its immediate vicinity. State-of-the-art simulations do not agree whether or not such a disc can indeed be a product of the multiple stellar wind...
The innermost regions of most galaxies are characterised by the presence of extremely dense nuclear star clusters, which sometimes appear alongside larger stellar structures known as nuclear stellar discs. Understanding the relationship between nuclear star clusters and nuclear stellar discs is challenging due to the large distances to other galaxies, which limits their analysis to integrated...
Our Galactic Center (GC) is the closest and most accessible galactic nucleus, which provides us with the unique opportunity to conduct resolved star formation studies in extreme environments. Despite the need for very high gas densities to overcome the tidal field of the supermassive black hole Sgr A*, and induce gravitational collapse, there is evidence for star formation taking place at the...
This talk presents a summary of both sessions on the Galactic Center.
The large-scale structures such as Fermi Bubbles and eROSITA Bubbles provide a unique opportunity to study our Milky Way. However, the nature and origin of these large structures are still under debate. In this talk, I will present the identification of several kpc-scale magnetised structures based on their polarized radio emission and their gamma-ray counterparts, which can be interpreted as...
