Damghan University PressIranian Journal of Astronomy and Astrophysics2322-492412320251222Numerical Modeling of the Solar Wind: Fluid, Kinetic, and Hybrid Approaches209225202310.22128/ijaa.2025.3140.1229ENSomayeh TaranFaculty of Physics, University of Tabriz, PO Box 51666-16471, Tabriz, Iran0000-0001-7101-7449Journal Article20251111This paper provides a comprehensive overview of the numerical methods used to model the solar wind, integrating fluid, kinetic, and hybrid perspectives. Beginning with the foundations of solar wind theory and the development of magnetohydrodynamic (MHD) models, we discuss how fluid-based formulations enable the simulation of global structures such as coronal mass ejections, shocks, and large-scale variations in the heliospheric magnetic field. To address processes that fall outside the scope of MHD, we examine kinetic modeling based on the Vlasov–Maxwell equations, emphasizing its capability to reproduce non-Maxwellian particle distributions, wave–particle interactions, temperature anisotropies, and collisionless heating. Hybrid approaches that merge MHD with kinetic techniques are highlighted as essential tools for capturing the multi-scale nature of the solar wind, particularly in regions where macroscopic flows couple to microphysical dynamics. The paper further reviews major numerical strategies used in solar wind simulations, comparing explicit and implicit time integration, adaptive mesh refinement, Particle-in-Cell (PIC) methods, and semi-Lagrangian approaches. Key stability considerations—including boundary-condition selection, the Courant–Friedrichs–Lewy (CFL) constraint, appropriate spatial and velocity-space resolution, and the targeted use of artificial diffusion—are discussed in relation to their impact on accuracy and robustness. Example simulations demonstrate the ability of advanced models to reproduce observed proton and electron temperature profiles \textbf{from the Sun out to 1AU}. Overall, numerical modeling plays a central role in interpreting solar wind observations and predicting space-weather conditions, and ongoing advances in computational methods continue to strengthen our understanding of heliospheric plasma dynamics.https://ijaa.du.ac.ir/article_2023_c85915c5d14c3c4c5b566aed401a1c95.pdfDamghan University PressIranian Journal of Astronomy and Astrophysics2322-492412320251227Analytical Study of Gravitational Magnetoacoustic Waves in the Solar Corona227239202410.22128/ijaa.2025.3144.1231ENMohammadamin Zeinali SabeghFaculty of Physics, University of Tabriz, Tabriz, IranZahra FazelFaculty of Physics, University of Tabriz, Tabriz, Iran0000-0001-8267-9528Journal Article20251116Coronal loops are one of the important waveguides in the solar atmosphere. Waveguides can be considered as the magnetic flux tubes for the generation and propagation of magnetohydrodynamic waves. In this paper, we have used a cylindrical geometry model to study the behavior of magnetohydrodynamic waves in coronal loops analytically. We considered a plasma structure with gravity acceleration and a uniform magnetic field. Wave equations were derived under specific assumptions and initial conditions. After linearization, perturbations were applied to obtain the dispersion relation. Using the dispersion equation, we obtained the frequency graph in terms of wave number. We investigated the effect of some parameters such as density, Alfvén velocity and gravitational acceleration on the behavior of waves. Our analysis of wave’s behavior across different kL regimes, and the observed convergence of phase speeds toward specific limits, provided valuable information regarding mode stability. The results showed that the sausage and kink modes approach each other at particular values of kL, where their phase speeds act as asymptotes. This convergence behavior demonstrates a fundamental relationship between these two types of wave modes under varying waveguide thickness conditions.https://ijaa.du.ac.ir/article_2024_f7cdf9eb1d5c4dd7931e5d409626f365.pdfDamghan University PressIranian Journal of Astronomy and Astrophysics2322-492412320251201Analyzing the Data of Galaxies in Different Scales Using Wavelet Transform241247202510.22128/ijaa.2025.3193.1240ENAria HemmatianDepartment of Physics, Sharif University of Technology, Tehran, Iran0009-0001-0839-8960Reza RezaeiDepartment of Physics, Sharif University of Technology, Tehran, Iran0000-0002-3267-8946Journal Article20251215One of the methods used to analyze the data obtained from a galaxy is to examine them in different scales. The data usually consists of many different wavelengths, and analyzing the structures of the same size in these images can be insanely insightful. Fortunately, a potent mathematical tool called wavelet exists for this exact purpose. Using wavelet analysis, we can decompose an image into structures of different scales, called the wavelet coefficients. Further investigations can be accomplished using wavelet spectrum and scale cross-correlations, which help us understand the energy distribution in scales. In this paper, we utilize the methods of wavelet scale analysis on the data from the galaxies M74 and DDO 69 to extract valuable information from them.https://ijaa.du.ac.ir/article_2025_5f085815e322a0061603f6791c992c5a.pdfDamghan University PressIranian Journal of Astronomy and Astrophysics2322-492412320260114The Relationship Between Recent and Old Star Formation in Dwarf Irregular Galaxies249266203810.22128/ijaa.2026.3206.1242ENAysan HemmatiortakandDepartment of Physics, Sharif University of Technology, Tehran, Iran0009-0006-8489-3193Reza RezaeiDepartment of Physics, Sharif University of Technology, Tehran, Iran0000-0002-3267-8946Sina Mehdizadeh FardDepartment of Physics, Sharif University of Technology, Tehran, Iran0009-0004-6497-7467Journal Article20251229In this paper, we investigate the structural properties of local dwarf irregular galaxies, including optical scale lengths, position angles, and star formation rates, using data from the LITTLE THINGS survey. Our analysis is based on a sample of 24 dwarf irregular galaxies. Optical structural parameters are derived from $B$ and $V$ band images, while recent star formation rates are estimated using $H_{\alpha}$ data. Our goal is to identify correlations among properties associated with the same epoch, such as relationships between scale lengths measured in different optical bands, as well as to explore connections between different evolutionary stages. In particular, we examine how recent star formation relates to the $B-V$ color index, V-band luminosity and magnitude, and scale lengths as measured in optical wavelengths. We find that (A) there is a strong correlation between scale lengths measured in different optical bands and (B) Recent star formation rates show strong correlations with both galaxy magnitude and scale length in the visible filter, indicating that very recent star formation activity (on timescales of $\sim$1 Myr) is closely linked to older star formation activity (on timescales of $\sim$1 Gyr). The results for our sample are consistent and in good agreement with values reported in literature. https://ijaa.du.ac.ir/article_2038_d9594be3a7e924ef23869d92d3337aab.pdfDamghan University PressIranian Journal of Astronomy and Astrophysics2322-492412320260118A Review of Solar Spectral Analysis267290204110.22128/ijaa.2026.3207.1241ENSomaye Hosseini RadDepartment of Physics, Faculty of Science, University of Zanjan, University Blvd., P.O. Box 45371-38791, Zanjan, IranHasan RezaeiDepartment of Geography, Faculty of Basic Sciences, Imam Ali Nazaja University, P.O. Box 1317893471, Tehran, IranMehdi SimiariDepartment of physics, Faculty of Science, Imam Ali University, P.O. Box 1317893471, Tehran, IranHossein SafariDepartment of Physics, Faculty of Science, University of Zanjan, University Blvd., P.O. Box 45371-38791, Zanjan, Iran0000-0003-2326-3201Journal Article20251228Solar spectral lines are among the most powerful diagnostics of plasma conditions in the solar atmosphere, providing constraints on temperature, density, flows, turbulence, magnetic fields, and energy release processes. High-resolution ultraviolet and X-ray observations reveal that solar line profiles often deviate from idealized symmetric Gaussian shapes, exhibiting excess broadening, asymmetries, and multi-component structures from the chromosphere to the flaring corona. This review presents an overview of the physical mechanisms governing solar spectral line formation, symmetry, asymmetry, and broadening, with emphasis on ultraviolet and extreme-ultraviolet diagnostics. We discuss the roles of thermal and non-thermal Doppler motions, unresolved flows, wave activity, magnetic and Stark effects, opacity-related processes, and instrumental broadening. Particular attention is given to transition-region lines, where multiple plasma components and highly dynamic heating processes produce complex, non-Gaussian profiles. We also review widely used methods for spectral line analysis, including single- and multi-Gaussian fitting, Lorentzian and Voigt representations, and Bayesian Markov Chain Monte Carlo approaches that enable robust parameter estimation and model comparison. Recent IRIS observations show that asymmetric Si\,\textsc{iv} line profiles are widespread in flaring and non-flaring conditions and often require multi-component modeling. Finally, we outline current challenges and emerging directions in solar spectroscopy, including instrumental calibration, cross-instrument consistency, and physics-informed analysis techniques. Future coordinated observations and improved inversion methods are expected to enhance the diagnostic potential of solar spectral lines and advance our understanding of plasma heating, magnetic reconnection, and energy transport in the solar atmosphere.https://ijaa.du.ac.ir/article_2041_2a6eca3116146b6d976c031b757e4a18.pdfDamghan University PressIranian Journal of Astronomy and Astrophysics2322-492412320251201Solar Wind–Geomagnetic Coupling Based on Yearly Averages291297206310.22128/ijaa.2026.3131.1228ENBalveer SinghRathoreGovernment Holkar Science College, Indore, M.P. India0009-0007-3310-4366Nidhi ParmarGovernment Holkar Science College, Indore, M.P. IndiaJournal Article20251110Understanding solar phenomena is essential for predicting and mitigating the effects of solar activity on Earth’s near-space environment. Solar variability influences space weather conditions, impacting satellite operations, communication systems, and even terrestrial climate. Continuous investigation into the dynamic relationship between solar and geomagnetic parameters provides valuable insight into the Sun–Earth connection. Future work in solar phenomena research will likely focus on improving our understanding of the Sun's behaviours, particularly regarding its impact on Earth. This includes refining and investigating the connection between solar activity and terrestrial climate. In the present work, the focus is on examining the relationship between solar wind parameters and geomagnetic indices using yearly averaged data. The electric field and IMF Bz vary noticeably, exhibiting peaks that correspond with sunspot cycles (spanning the years 2014 to 2025). The total magnetic field B increases during solar maxima and shows a strong correlation with the Dst index. The Dst index becomes more negative during periods of high sunspot activity, indicating stronger geomagnetic storms during the observed duration. Bz shows fluctuations between positive and negative values with no clear long-term trend. The negative Bz (southward) component is essential because it couples strongly with Earth’s magnetosphere, enhancing geomagnetic storms.https://ijaa.du.ac.ir/article_2063_d996731b4dc0092bdfb1c448b8549ab9.pdf