NCTS-TCA Summer Student Program 2024
理論計算天文暑期學校

This research project focuses on understanding the interactions between the Moon's magnetic environment, its exosphere and ionosphere, and the solar wind plasma, drawing upon recent insights into lunar-solar dynamics. We aim to investigate how the solar wind plasma influence Moon's magnetic anomalies, particularly examining proton backscattering, surface sputtering, and mini-magnetosphere formation. By integrating data from recent lunar missions, our study seeks to reveal the dynamic responses of the lunar surface and exosphere to solar wind particles. This research will enhance our understanding of the Moon's environmental conditions, offering vital insights for future lunar exploration including our own Lunar Vector Magnetometer on Lunar Lander (TASA’s space mission).

Pre-requisites: Basic programing such as Fortran, Python or Matlab to solve the ODEs
Keywords: Moon, plasma interaction
Location: NTNU

Io, the innermost of Jupiter's Galilean moons, is known for its active volcanos in our solar system. Both volcanic emissions and surface frost sublimation can contribute to Io’s atmosphere, particularly its sulfur dioxide (SO2). The study aims to develop a radiative transfer model to interpret data obtained from the Submillimeter Array (SMA), enhancing our understanding of Io's atmospheric composition and behavior. By analyzing the SMA observations, we will investigate the thermal and chemical processes governing Io's atmosphere. Our model will provide insights into the interaction of solar radiation with Io's SO2 atmosphere, revealing the impact of volcanic activities on its thermal structure. This research is pivotal in understanding the atmospheric dynamics of celestial bodies with active volcanism and offer a deeper understanding of the complexities of extraterrestrial atmospheres in our solar system.

Pre-requisites: Basic programing such as Fortran, Python and Matlab
Keywords: Radio Astronomy, Radiative Transfer
Location: NTNU

With advances in observational techniques and computing capabilities, we enter an era to investigate detailed mechanisms in high spatial and temporal resolution for processes responsible for forming protoplanetary systems like ours. In particular, we aim to study the active physical processes operating simultaneously with the ongoing formation and evolution of the powerful jets and outflows in the earliest phases of the lifetimes of sun-like stars, which are advanced by ALMA and JWST, revealing their multifaceted views. We employ theoretical, computational, and observational methods to converge critical theoretical and observational features from these systems in vast multi-wavelength parameter space. Specific project aspects will be formulated commensurate with students' academic and technical backgrounds. We look for highly motivated advanced-level students intensely interested in learning numerical methods and tools, code development techniques, data analysis methods, and their applications to star formation problems. The students will have hands-on experiences in various areas, from computation to observation.

Pre-requisites: Good knowledge of Python, C/C++; college-level physics and mathematics; English fluency; visualization software such as Matlab
Keywords: star formation; jets and winds; protostellar outflows; ALMA and JWST
Location: NTU/ASIAA

Planets are formed from dust grains embedded in gaseous protoplanetary disks around young stars. Hydrodynamic instabilities in the gas, which drive turbulence and structure formation, directly impact the dust dynamics. One example is the ""convective overstability"" (COS) --- a form of radial convection --- that may occur in particular regions in the disk. However, the nonlinear evolution of the COS is still not well explored. In this project, the student will carry out numerical simulations of the COS using the Python-based Dedalus spectral code to study 1) the influence of radial boundaries, and 2) the formation and evolution of large-scale zonal flows and vortices. The student will run simulations, analyze and interpret the data, and write results. The student will have access to the Kawas supercomputer at ASIAA, as well as the Taiwania-3 cluster at the National Center for High-Performance Computing. Successful completion of this project is expected to lead to a first-author publication by the student. Past publications from the supervisor's summer students include Chen & Lin (2018); Chen & Lin (2020); Bi, Lin, & Dong (2021); and Wu et al. (2023).

Pre-requisites: Mandatory: Mathematical or physical sciences, basic calculus and partial differential equations, Python or other programming languages, English communication skills Useful: fluid dynamics, high-performance computing
Keywords: Astrophysical Fluid Dynamics, Computational Astrophysics, Hydrodynamic Instabilities, Numerical Simulations, Planet Formation, Protoplanetary Disks, Theoretical Astrophysics
Location: ASIAA (in person)

We develop hydrodynamic and magnetohydrodynamic codes and solvers for astrophysical problems in the ASIAA CompAS project. We invite students to explore and validate state-of-the-art numerical codes and solvers made with fundamental numerical methods and physics under active development. These codes and solvers range from the Newtonian to General Relativistic regimes occurring from young stars to black holes. The students will obtain hands-on experience testing the accuracy and performance of numerical methods for HD, MHD, and particle problems for their validation and benchmarks. We look for highly motivated students interested in numerical methods, code development techniques, their science verifications, potential applications, and explorations of some machine learning approaches. Actual projects will be assigned commensurate with students' interests, experiences, and levels of academic background. The experiences obtained will prove very helpful in future career development in science and engineering, in addition to astronomy and astrophysics.

Pre-requisites: Good knowledge of any of these programming languages: Python, C/C++ or Fortran College-level physics curricula, applied mathematics, or mathematical methods Ability to read, write, and communicate orally in English Knowledge of Python, Matlab, or interactive plotting tools.
Keywords: Black Holes, CompAS, Computational Astrophysics, Computational Fluid Mechanics, Hydrodynamics, Machine Learning, Magnetohydrodynamics, Numerical Astrophysics, Numerical methods, Particle-In-Cell, Plasma Physics, Young Stars
Location: NTU/ASIAA or remote

When a star has consumed most of its nuclear fuel, it eventually reaches a point in its evolution where the outward radiation pressure due to nuclear fusions can no longer support the gravitational pull. Suppose the collapsing stellar core has a mass exceeding (approximately) three solar masses. In that case, the degenerate pressure of neutrons can no longer support its gravitational collapse, leaving a black hole (BH) as an end product of stellar evolution. In addition to these stellar-mass BHs, there are much heavier BHs in the center of galaxies and globular clusters. For example, the Milky Way galaxy has a supermassive BH whose mass attains 4 million solar masses. Depending on the academic and technical backgrounds of the student, she/he may get to learn one active project related to the following areas: how electron-positron pair plasmas are created, accelerated, and radiate emissions in BH magnetospheres, comparisons with the blackhole multiwavelength observations, plasma physics around neutron stars, and pulsars.

Pre-requisites: Solid advanced college-level physics and mathematics, and knowledge of Special Relativity. Basic skills in computer programming in C/C++, Fortran, and Python, and familiarity with visualization packages such as Matlab, ParaView, or Python Scripts
Keywords: Computational Astrophysics, General Relativity, Black Hole, Neutron Stars, Pulsars
Location: NTU/ASIAA

The selected student will learn how to use the stellar evolution code MESA to conduct binary stellar evolution to investigate the progenitors of magnetars and some peculiar core-collapse supernovae.

Pre-requisites: Basic usage of Python and some knowledge of general astronomy or stellar evolution.
Keywords: stellar evolution, stars, binary, magnetar, neutron star, balck hole, core-collapse supernova
Location: NTHU

Jet feedback from supermassive black holes (SMBHs) is believed to be an important heating mechanisms that can significantly influence the evolution of galaxy clusters in the universe. However, the detailed heating mechanism is still debated and sensitively depends on the composition of the SMBH jets, e.g., whether the jets are heavy or light. In this project, we will compare two hydrodynamic simulations of SMBH feedback in galaxy clusters, one with heavy jets and the other with light jets. We will analyze the simulation results using a Python-based software, compare the predictions of the two simulations, and see which jet composition better fits the observational data.

Pre-requisites: General Astronomy; Basic programming (e.g. basic knowledge on Fortran, C, or Python is preferred but not required)
Keywords: hydrodynamics, galaxy clusters, supermassive black holes
Location: NTHU or remote

Observations of galaxy clusters often show existence of long, filamentary distributions of cold gas near the cluster center (e.g., H_alpha filaments in Perseus Cluster). The cold gas is believed to be important fuels for the central supermassive black hole; however, the properties of the cold gas and how it is formed are still not well understood. In particular, recent studies of the cold gas in Perseus have found velocity structures that are hard to explain. In this project, we will use hydrodynamic simulations of cold gas in galaxy clusters, one assuming the cold gas is like bricks, and the other assuming it is more like mists. We will analyze the simulation results using a Python-based software, compare the velocity distributions predicted by these two simulations, and see which model is better aligned with the observational data.

Pre-requisites: General Astronomy; Basic programming (e.g. basic knowledge on Fortran, C, or Python is preferred but not required)
Keywords: hydrodynamics, galaxy clusters
Location: NTHU or remote

Galactic X-ray binaries derive their power from gas accretion onto a black hole. As this gas falls onto the black hole, it forms a hot corona emitting X-rays photons. The advent of X-ray polarization, marked by the launch of IXPE in 2021, provides the first insights into the geometry of black hole accretion flows. This project focuses on the impact of Faraday rotation on polarized X-ray emission from the corona. The student will have the opportunity to explore various projects, including studying polarization boosting due to Faraday rotation, implementing realistic magnetic field structures, creating tools for simulator communities to test their models, or applying Faraday rotation to young stellar objects' accretion flows. IXPE's recent findings challenge existing theoretical models, making this research essential for advancing our understanding of accretion phenomena.

Pre-requisites: Interest in high-energy astrophysics. Familiar with Python.
Keywords: Black Hole, Accretion Flow, Faraday Rotation, Magnetic Fields, X-ray binaries, High Energy Astrophysics
Location: remote

Explore the fascinating realm of Wave/Fuzzy Dark Matter (FDM) during this summer student program. Comprising ultralight bosons with a mass of approximately 1e-22 eV, FDM exhibits intricate wave-like structures, presenting a compelling alternative to conventional cold dark matter. This project delves into the impact of dark matter halo mergers on FDM characteristics, such as halo density profiles, temperature distributions, and soliton-halo relation. Utilizing the state-of-the-art FDM code GAMER-2, students will acquire hands-on experience in cutting-edge dark matter research and high-performance parallel computing.

Pre-requisites: General astronomy, basic knowledge of Python, C, and Linux
Keywords: Dark Matter, Halo Mergers, Numerical Simulations
Location: NTU or remote

GRO J1655-40 is a well-known black hole binary system. However, it has a very complicated X-ray light curve. There is currently no one model that is able to explain the system fully. In this project, the student will analyse archival X-ray data of GRO J1655-40 and characterise its dynamic behaviour using modern time-domain analyses. The student will learn to identify key temporal patterns and use these to quantify the orbital period, accretion disk properties and jet activity. This project will contribute to our broader understanding of black hole accretion processes and the evolution of binary systems.

Pre-requisites: Comfortable to work with data. Familiar with Python. Background in X-ray astronomy is useful but not essential.
Keywords: X-ray binaries, black hole, accretion, time-domain analysis
Location: NTHU or remote

Active galactic nuclei (AGNs) are generally powered by accretion onto supermassive black holes, e.g. Sagittarius A* (Sgr A*), Messier 87 (M87), etc. Relativistic jets and outflows are also ubiquitously observed from AGNs. To understand the mechanism of jets, one needs to explore the accretion process and models around black holes in detail. The general consensus is that a highly magnetized accretion state is capable of producing relativistic jets ( Blandford & Znajek 1977, Tchekhovskoy et al., 2011, Aktar et al., 2024). In brief, our project aim is to (1) Simulation model of highly magnetized accretion-ejection flows around black holes. (2) Possible application of our simulation model to various AGN sources.

Pre-requisites: (1) Basic understanding of accretion process around compact objects (2) Basic understanding black hole astrophysics (3) Basic coding: python, C++,C
Keywords: accretion, accretion discs, black hole physics, (magnetohydrodynamics) MHD, ISM: jets and outflows, quasars: supermassive black holes
Location: NTHU

Understanding how protostellar disks form is crucial for insights into star and planet formation. Recent observations by the Atacama Large Millimeter/submillimeter Array (ALMA) revealed "accretion streamers" connecting the envelope and the disk, believed to accumulate mass onto protostellar disks. This project aims to investigate protostellar disk formation by observing theoretical simulations using advanced radiative transfer codes. The main goal is to determine whether "accretion streamers" are a dominant mechanism for feeding protoplanetary disks or just an observational illusion. The study analyzes simulated data to improve our understanding of mass accumulation processes in protostellar disks and their impact on planetary system formation.

Pre-requisites:Basic programming experience (Python is preferred but not required)
Keywords: star formation, radiative transfer
Location: NTHU

This is an opportunity to learn quantum cosmology, loop quantum gravity (LQG), and the skills to utilize quantum computers. If the students progress well, they will move on to study quantum cosmology or other physics on the IBM quantum computer.

Pre-requisites:Strong motivation and good learning capability
Keywords: Cosmology, quantum computing, quantum cosmology, loop quantum gravity
Location: NTU