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The annual IPARCOS Congress brings together all members of the institute, including students and researchers, to discuss the scientific advancements achieved over the past year.
Satellite galaxies experience multiple physical processes when interacting with their host halos, often leading to the quenching of star formation. In the Local Group, satellite quenching has been shown to be highly efficient, affecting most satellites except the most massive ones. While recent surveys are studying Milky Way analogs to assess how representative our Local Group is, the dominant physical mechanisms behind satellite quenching in Milky Way-mass halos remain under debate. We analyze satellite quenching within the same Milky Way-mass halo, simulated using various widely-used astrophysical codes, each using different code architecture and implementing different supernovae feedback recipes. The goal is to determine whether quenched fractions, quenching timescales and the dominant quenching mechanisms are consistent across codes or if they show sensitivity to the specific hydrodynamic method and supernovae feedback physics employed. We use a suite of high-resolution cosmological zoom-in simulations of a Milky Way-mass halo from the multiple-code AGORA CosmoRun simulations. Our analysis focuses on comparing satellite quenching across the different models and against observational data. We also analyze the dominant mechanisms driving satellite quenching in each model by examining the contributions of various processes commonly proposed in the literature: ram pressure stripping, tidal stripping, galaxy harassment and strangulation.
The ALICE collaboration has recently reported pi+-K_S femtoscopic correlations in pp collisions[1]. Here we show [2] how they can be well described using existing realistic pi-K interactions obtained from a dispersive analysis of scattering data [3], containing an accurate description of the kappa/K0*(700) resonance pole. [1] . Acharya et al. (ALICE), Phys. Lett. B 856, 138915 (2024), arXiv:2312.12830 [hep-ex] [2] in progress: M. Albaladejo, A. Canoa, J.M. Nieves, J.R.Pelaez and E.Ruiz-Arriola [3] J.R.Pelaez, A. Rodas,Phys.Rept. 969 (2022) 1-126
The study of the first galaxies which contributed to the ionization of the universe will become possible with an integral field and multi-object spectrograph like MOSAIC (significant contribution from GUAIX), set to be installed on the 39m Extremely Large Telescope (ELT), currently under construction. As a pilot study for that, a detailed two-dimensional study of the physical properties of a sample of low-mass (dwarf) star-forming galaxies at low redshift is being conducted. This project is part of the ITP Dwarfs4MOSAIC program (IP Jesus Gallego), which was selected through a competitive process in the spring of 2023 and extended in spring of 2024. We will present the first results from the reduction and analysis of high-spectral-resolution, two-dimensional integral field spectroscopy data obtained with MEGARA on the Gran Telescopio Canarias (GTC). The galaxies studied include SBS 0335-052 W, Mrk 1486, and J1105+4444, for which we have analyzed two-dimensional maps of physical properties, spatial structures, kinematic properties of ionized gas, and advancements in the data reduction process.
The CIEMAT Gamma-Ray Astronomy group works within the MAGIC and CTA-LST collaborations, covering a wide range of activities from hardware development and testing to data analysis and scientific research. This talk will summarize our main contributions and their role in advancing gamma-ray astrophysics.
Most of the ‘missing’ baryons in the local Universe are expected to reside in some diffuse gas phase of the intergalactic medium. In fact, recent results from X-ray absorption studies and Fast Radio Bursts indicate that all the baryons are essentially accounted for, but it remains to be determined exactly where they lie. Studies that cross-correlate galaxies with the thermal Sunyaev-Zel’dovich (tSZ) maps from Planck indicate that up to 50% of the baryons may be spread throughout filamentary structures in superclusters at low redshift. A wide-area rotation measure (RM) Grid is able to reveal ionised and magnetised gas in the outskirts of a galaxy cluster beyond that typically probed by X-rays. We use the RM catalog from the POSSUM Pilot 2 survey of the Shapley supercluster, from both Band 1 and 2, as well as Planck maps of the tSZ effect, in an attempt to map the diffuse magneto-ionic material extending from the individual galaxy clusters and into the connecting filamentary structures. The Shapley supercluster (z~0.05) contains the largest concentration of Abell clusters (~25) in the local Universe, spread over 100’s of Mpc and 10’s of degrees on the sky. The distribution of clusters displays a complex morphology, with walls and filaments of galaxies extending from the three main interacting Abell clusters (A3556-A3558-A3562). It provides an ideal laboratory to study the diffuse gas expected to permeate these structures. In particular, we are able to probe the magnetic field in the region between the two most massive clusters of the supercluster, namely, A3562 and A3558.
In order to find Earth-like planets in the habitable zone of M dwarfs, it becomes essential to quantify the stellar noise in the radial velocity (RV) data in order to measure planetary signals. This is why the use of multidimensional Gaussian processes can be a clear evolution towards the study and characterisation of exoplanets and their host stars, this will be done using the pyaneti software. To do so, we will use RV data and spectroscopic activity indicators (FWHM, Hα) from CARMENES and ESPRESSO simultaneously for three already studied planetary systems: GJ 338 B and GJ 1002. With our spectroscopic analysis we could model the stellar activity by determining the stellar rotation period and also obtain the planetary parameters of the exoplanets.
We consider a Bubble Expansion mechanism for the production of scalar dark matter during a first-order phase transition in the early Universe. Seeking for a dark matter energy density in agreement with observations, we study different renormalizable and non-renormalizable interactions between the dark matter species and the field undergoing the transition, considering all the possible regimes for the Lorentz boost factor associated to the bubble wall motion. It is shown that is possible to have a sufficient DM production in the so far unexplored low-velocities regime, enlarging the parameter space and the possibilities for the BE mechanism. Additionally, it is found that non-renormalizable interactions exhibit a behavior very similar to the renormalizable case, even for low values of the Lorentz factor. Furthermore, for a transition around the electroweak scale, the associated gravitational wave spectrum is also within the reach of future detectors.
We reflect on the possibility of breaking the diffeomorphism (Diff) invariance in the gravitational couplings of matter down to only transverse diffeomorphisms (TDiff), and study the consequences on scalar field theories. We begin by analyzing the general implications of this restricted symmetry for a single scalar field within a general setting. Afterwards, we study the cosmological scenario by considering shift-symmetric multi-field TDiff theories (with the cosmological dark sector in mind), finding that there is an effective interaction between dark sector components as a result of the broken symmetry. The theoretical predictions of our cosmological models are contrasted with observational data from the CMB and Type Ia supernovae.
Isotopes close to the doubly-magic nuclei 132Sn are of strong interest from the point of view
of nuclear structure. Spectroscopic studies are performed with the aim of obtaining a better un-
derstanding of the evolution of shell orbits in nuclei with large N/Z ratios, and providing critical
tests of theoretical models. The information on the nuclear structure and decay properties of n-rich
nuclei in this region may also provide input to calculations for astrophysical r-process.
A new experimental camping was carried out at the ISOLDE facility to study the β-decay
of neutron-rich cadmium isotopes. High intensity Cd (Z = 48) beams were produced after the
fission of a thick UCx target, selectively ionized by the ISOLDE Resonance Ionization Laser Ion
Source (RILIS) and separated in mass using the General Purpose Separator (GPS) ISOLDE mass
separator. A temperature-controlled quartz transfer line was used to ensure purity of the cadmiun
beams [1].The experiment exploited the excellent spectroscopic capabilities of the ISOLDE Decay
Station (IDS). The fast-timing configuration was employed, which included 6 highly efficient clover-
type HPGe detectors, altogether with 2 LaBr3(Ce) and 3 ultra-fast β-plastic detectors arranged in
close geometry.
Direct observation of γ-ray de-excitations and γ-γ coincidences in 132In has been achieved fo-
llowing the β-decay of the 132Cd 0+ ground state (g.s.). The 132In nuclear structure information
is complemented by the β-n decay of 133Cd, providing enhanced statistics. These results expand
those from experiments at RIKEN facility [2,3].
The significantly higher statistics and the possibility of using coincident γ-γ measurements enable
an expanded level scheme and more detailed comparison with shell-model calculations. An inter-
pretation of the level structure is given based on the experimental findings and the particle-hole
configurations arising from core excitations both from the N < 82 and Z < 50 shells, leading to
positive- and negative-parity particle-hole multiplets [2,3].
These past years the theoretical particle physics community has been, once more, gradually shifting their attention to the phenomenology of highly energetic processes. And rightfully so, as the next big project in the particle physics landscape, the EIC (Electron-Ion Collider), while still undergoing construction, is expected to enter commission with the coming of the new decade. The EIC will give us novel insights on the structure of hadronic matter, and, consequently, on the strong force as a whole by studying such scattering processes as DIS (Deep Inelastic Scattering). This talk is aimed to a general public as an introduction to the concept of "Twist" and its implication in the theoretical framework of DIS, as well as a presentation of a novel technique regarding the numerical implementation of such theoretical models via the software "Snowflake".
This work explores cosmological particle production within Quantum Field Theory in Curved Spacetimes, focusing on its potential as a dark matter production mechanism. It also investigates the use of Bose-Einstein condensates to simulate this process. The study examines how particles are generated from the vacuum due to spacetime dynamics, especially during periods of inflation in the early Universe. Our work suggests that cosmological particle production could explain dark matter abundance and presents experimental results supporting analog gravity as a tool for understanding quantum field effects in curved spacetime. Future research will explore Higgs inflation and further aspects of entanglement and curvature in these contexts.
General Relativity theoretically allows the formation of black holes through the gravitational collapse of purely electromagnetic radiation. However, this scenario would involve electromagnetic strengths surpassing the critical Schwinger limit, resulting in the generation of electron-positron pairs. This quantum phenomenon counteracts the collapse, with the created particles scattering out of the collapsing region, carrying their energy. Here, we show that this dissipative effect alone is enough to prevent the formation of black holes from light in the non-classical regime.
LHCb has observed giant CP violation in localized regions of the Dalitz plots of B to three charmless light mesons. This has been interpreted as an enhancement due to strong two-body final state interactions. In this talk, we show how such interactions, described with dispersive analyses of data, can be implemented beyond the leading order expansion in the two-body re-scattering amplitude.
Gamma rays are key when it comes to studying topics such as dark matter from an indirect perspective or the Lorentz invariance, as well as probing a wide range of astrophysical phenomena that provide a deeper understanding of the most energetic events in the universe. They can be detected through Imaging Atmospheric Cherenkov Telescopes (IACTs), which capture images of extensive air showers generated by gamma rays and cosmic rays (high-energy particles of astrophysical origin) when they interact with the atmosphere. One of the main challenges about these images is the reconstruction of the event’s properties, i.e., obtaining the direction of arrival, energy and type (gamma ray, proton, electron, etc.) of the particles that triggered the shower. AI techniques, such as deep learning methods, have been demonstrated to be suitable for the reconstruction of these events since they are used to analyze and exploit loads of data for carrying out classification and characterization tasks. This presentation provides a brief introduction to gamma-ray astronomy and IACTs, followed by a focus on enhancing IACT event reconstruction using deep learning techniques through the CTLearn package, within the framework of the Cherenkov Telescope Array Observatory (CTAO).
Understanding the mechanisms governing star formation in galaxies is key to unravel their evolution. This work employs Bayesian statistics and data mining techniques to analyze metallicity gradients, which provide valuable insights into the processing and enrichment of gas in galaxies. A notable trend is the manifestation of the downsizing effect the in resolved properties of galaxies, where massive galaxies form stars more rapidly than their lower-mass counterparts. Additionally, the use of Machine Learning techniques will be used to identify HI holes in these galaxies, with the goal of achieving a deeper understanding on how different processes influence galactic evolution.
Imaging Atmospheric Cherenkov Telescopes (IACT) use combined analog and digital electronics for their trigger systems, implementing simple but fast algorithms. Such trigger techniques are forced by the extremely high data rates and strict timing requirements. In recent years, in the context of a new camera design for the Large-Sized Telescopes (LSTs) of the Cherenkov Telescope Array (CTA) based on Silicon PhotoMultipliers (SiPM), a new fully digital trigger system incorporating Artificial Intelligence (AI) algorithms is being developed. The critical improvement relies on implementing those algorithms in Field Programmable Gate Arrays (FPGAs), to increase the sensitivity and efficiency of real-time decision-making while fulfilling timing constraints. In addition, building on our prior experience in IACT event reconstruction using Deep Learning (DL), we are currently engaged in applying analogous algorithms to address the challenge of offline reducing the CTA data volume. We are currently developing all the elements of an AI-based IACT trigger system, including a PCB prototype to test multi-gigabit optical transceivers and using development boards as an AI-algorithm testbench. We also aim to integrate DL capabilities into the CTA offline analysis pipeline, seeking a more efficient processing chain in both computational and storage aspects.
According to numerical models, feedback from accreting supermassive black holes plays a central role in the evolution of galaxies. Kinetic feedback (or radio/jet-mode) is the most important form of AGN feedback in low accretion rate AGNs (i.e., the majority of AGN) and, therefore, it has a major impact on the evolution of most galaxies. Stephan’s Quintet was targeted by JWST Early Release Observations and JWST/MIRI mid-IR spectroscopy was obtained for NGC 7319, the largest spiral in the group, which hosts a type 2 Seyfert AGN with a low-power radio jet. The JWST data analysis reveals a clear jet-ISM interac- tion, which is decelerating the relativistic jet and producing strong hot/warm molecular H_2 emission. We present preliminary results obtained using MEGARA/GTC to characterize the kinematics and physical conditions of the ionized phase of this textbook example of a jet-ISM interaction. The study of optical emission lines in several bands covering several ionization states and sensitive to different physical conditions allows us to characterize the shocked regions, the so-called N2 and S2 spots previously found. A multi-component approach is taken to properly characterize the systemic and the ionized gas outflow components and to derive the velocity and the size of the outflow as well as its mass, momentum and kinetic energy.