• Studying the evolution of the radio luminosity function of galaxies in COSMOS: To understand the role of the galaxy group environment on galaxy evolution, we present a study of radio luminosity functions (RLFs) of group galaxies based on the Karl G. Jansky Very Large Array-COSMOS 3 GHz Large Project. The radio-selected sample of 7826 COSMOS galaxies with robust optical/near-infrared counterparts, excellent photometric coverage, and the COSMOS X-ray galaxy groups (M200c > 1013.3M⊙) enable us to construct the RLF of group galaxies (GGs) and their contribution to the total RLF since z ∼ 2.3. Using the Markov chain Monte Carlo algorithm, we fit a redshift-dependent pure luminosity evolution model and a linear and power-law model to the luminosity functions. We compare it with past RLF studies from VLA-COSMOS on individual populations of radio-selected star-forming galaxies (SFGs) and galaxies hosting active galactic nuclei (AGN). These populations are classified based on the presence or absence of a radio excess concerning the star-formation rates derived from the infrared emission. 

​

• AstroA: AI for Astronomy: Developing Novel Techniques for Big Data Interpretation:  with the development and application of major space- and ground-based telescopes such as James Webb, and ELT, astronomy will experience rapid growth in data size and complexity, and astronomy will enter the era of Big Data. We need highly developed technologies (databases, cloud storage, high-performance computation, machine learning, deep learning, and artificial intelligence). Extracting useful information and knowledge from Big Data is a big challenge. In recent years, deep learning has become popular among astronomers. It is now applied for solving various problems, such as classification, regression, clustering, outlier detection, time series analysis, and association rule. One of the aims of this research program is to broadly benchmark recent genetic programming approaches to symbolic regression in the context of state-of-the-art machine learning approaches. 

​

• BAR-FEED: A Multimodal Study of Baryons and Feedback in Galaxy Groups Using X-Ray, Optical and Radio Observations: The project focuses on studying the impact of feedback and baryonic physics in galaxy evolution and cosmology by determining the baron fraction of well-defined samples of galaxy groups and clusters. This will be achieved by utilizing X-ray observations to determine the total hot gas content of the clusters and groups within R500 and multiband imaging to probe the total stellar mass and intragroup light. The project will develop a baryonic correction model to calibrate feedback processes and accurately predict matter distribution. The research has significant implications for upcoming cosmological surveys, and cosmological simulations will contribute to understanding dark matter and energy and the accelerating expansion of the Universe.'

​

• Euclid is a significant European Space Agency (ESA) medium-class space mission aimed at understanding the origin of the accelerating expansion of the Universe. As a member of the Euclid Consortium since 2014, I have contributed 2.5 years of experience designing and developing algorithms and pipelines essential for the SGS Data Quality Common Tools (DQCT) and various science and infrastructure working groups. My work has focused on developing efficient tools and techniques to ensure the Euclid mission's data quality and improve its scientific output. Through my contributions to the Euclid Consortium, I have been involved in cutting-edge research on the nature and evolution of dark energy, dark matter, and the Universe's large-scale structure.

​

• Planetary systems: As a Ph.D. supervisor to Mahdiyar Mousavi Sadr, my current research project studies planetary systems using machine learning techniques. Our approach involves analyzing all discovered multiple-exoplanet systems to study the presence of additional member planets in these systems. In addition, we recently investigated the Radius-Mass relationship and utilized machine learning techniques to predict exoplanet radius based on observable features. Our research contributes to the broader understanding of exoplanetary systems and provides valuable insights into applying machine learning techniques in astrophysics.

​

• As part of the COSMOS team, I contributed to studying galaxy groups and clusters to understand the formation and evolution of galaxies. I provided a catalog of X-ray-selected groups and clusters based on XMM and deep Chandra observations, published in the paper "Chandra centers for COSMOS X-ray galaxy groups: Differences in stellar properties between central dominant and offset brightest group galaxies" (Gozaliasl et al. 2019). In this project, we investigated the multiband properties of galaxies, including radio sources and their environmental dependence.

​

• Additionally, I worked on the "Evolution and formation of the Brightest Group Galaxies (BGGs)" project, which aimed to understand the formation and evolution of the most massive and brightest central group galaxies in deep surveys. This project involved comparing observations with numerical simulations and investigating the stellar properties (Gozaliasl et al. 2016, 2018), mass assembly, and dynamics of BGGs (Gozaliasl et al. 2020), as well as the local connectivity of groups to cosmic filaments (Darragh Ford, Laigle, Gozaliasl, et al. 2019).

​

• Fossil groups as a tracer of coalescence history in the Universe: As an astrophysicist, I have been involved in various projects studying the properties of galaxy groups and clusters, which are crucial systems for understanding cosmology and galaxy evolution. One of my research focuses on understanding the formation of fossil groups containing isolated, luminous early-type galaxies embedded in an extended X-ray halo. I investigated the evolution of the luminosity function of fossil groups using semi-analytic models based on the Millennium simulation. Through this work, we traced the evolution of the luminosity function of galaxies residing in progenitors of groups classified by the magnitude gap from z=0 to z=1.0. We find that the bright end of the galaxy luminosity function of fossil groups shows a significant evolution with redshift, with changes in M∗ by ~1-2 mag between z ~ 0.5 and z = 0 (for the central 0.5 R200), suggesting that the formation of the most luminous galaxy in a fossil group has had a significant impact on the M∗ galaxies, e.g., it is formed as a result of multiple mergers of M∗ galaxies within the last 5 Gyr. (Gozaliasl et al. 2014b). We also developed an algorithm that optically detects fossil groups in comprehensive surveys without X-ray observations and applied it to identify fossils in the 2dFGRS survey. We then studied their optical and X-ray properties (Khosroshahi, Gozaliasl, et al. 2014).

​

• Additionally, I led a project to detect X-ray groups and clusters using all X-ray observations of the XMM-Newton telescope in the W1 field of CFHTLS in common with the XMM-LSS field. We identified 129 X-ray groups and clusters, including several fossil groups, and studied the magnitude gap distribution to redshift 1.2 (Gozaliasl et al. 2014a).

​

• Furthermore, I was involved in a project to study the evolution of the magnitude gap in X-ray galaxy groups using the 3-square-degree XMM coverage of CFHTLS (Gozaliasl et al. 2014). My research on fossil groups and X-ray-selected groups and clusters provides insights into their coalescence history and evolution in the Universe.

​

• The long-term luminosity variation and the orbital period changes of close active binary stars: In my Master's degree, I conducted photometric observations of some RS CVn binary stars. I analyzed their light and O-C curves, obtaining the absolute parameters of both components and the features of their hot and cool spots. The results of my work were presented in the following articles: "Orbital Period Changes and Long Term Luminosity Variation in Active Binary CG Cyg," "A Period Study of the Eclipsing Binary U Sagittae," and "Orbital period changes and photometric study of contact binary system AK Her." One of the most important aspects of studying binary stars is their use as a distance indicator. We can accurately determine the distances to these eclipsing binaries by studying their light curves. This technique has allowed us to accurately measure the distance to nearby galaxies, such as the Large Magellanic Cloud.