The detection of gravitational waves (GWs) from the binary neutron star (BNS) has opened a new window on the gravitational wave astronomy. With current sensitivities, detectable signals coming from compact objects like neutron stars turn out to be a crucial ingredient for probing their structure, composition, and evolution. Moreover, the astronomical observations on the pulsars and their...
Pulsars are rapidly rotating and highly magnetized neutron stars that radiate non-thermal radio beams from their poles. The radio emission of pulsars usually remains stable in the averaged intensity of ~1,000 pulses or more, but some pulsars exhibit interesting features in emission variations on short and long timescales. In this research, we report the phase-resolved pulse-to-pulse energy...
Maser flares are spectacular increases in brightness of astrophysical masers over a typical timescale of weeks to months. I consider a number of plausible mechanisms for generating these flares and determine the most likely mechanisms on the basis of timescale, variability index and ability to support periodic flares. The flare mechanisms considered are overlap of clouds in the line of sight,...
Jiangmen Underground Neutrino Observatory (JUNO) has a potential to indirectly detect dark matter (DM), observing neutrino events from annihilations of DM trapped by the gravitational force in the solar core. Weakly interacting massive particle (WIMP) DM candidate with mass $>$ 3-4 GeV has significant solar capture rate. In this work, we simulate JUNO neutrino events from the most dominated...
In this work R-symmetry defined in Wess-Zumino model is determined to be broken spontaneously within broken supersymmetric vacuum according to O'Raifeartaigh potential containing scalar fields of R-charges of 0 or 2. The analysis is done on Coleman-Weinberg effective potential at one-loop level. We find that there can be gauge symmetry breaking and R-symmetry breaking if $m_{X}^2<0$ and scalar...
Nonlinear dynamical systems, such as well-tuned recurrent neural networks, have proved a powerful tool for modeling temporal data. However, tuning such models to achieve the best performance remains an outstanding challenge, not least because of the complex behaviors that emerge from interacting microscopic constituents. Here, we consider a minimal model of two interacting phase oscillators...
We present the results of the most complete up-to-date spectropolarimetric survey of early-type peculiar (CP) stars in the association Orion OB1. The final sample contains 31 magnetic stars or 55% of the whole CP population in Orion OB1. For 14 CP stars, the longitudinal magnetic field exceeding approximately 500 G was detected for the first time. We show that the percentage of the magnetic CP...
The locations of Earthโs auroral initial brightening and maximum poleward expansion are indicated as the magnetic latitudes, when the auroral breakup is expected to occur at magnetic local time between 22:00-1:00. Auroral images taken by the Visible Imaging System (VIS) and the Ultraviolet Imager (UVI) instruments onboard POLAR spacecraft reveal the variation of the locations that different...
The Sun is a well-known source of gamma rays emitted from cosmic rays during solar activity. It exhibits the variations over an approximately 11-year cycle due to the changes in the Sunโs magnetic field. In this work, we studied photons of energy of 0.1 โ 10 GeV from the Sun disk detected by the Large Area Telescope (LAT) onboard of the Fermi Gamma-ray Space Telescope (Fermi), moving in...
Strange and charmed baryon pair productions in proton-antiproton collisions are studied in effective Lagrangian and Regge approaches. Unknown parameters from both models are determined from the comparison with the existing data for strangeness productions. Then, we predict charm production cross sections by extrapolating the amplitudes for strangeness productions to those for charm. From our...
The masses of low-lying S-wave and P-wave charmonium mesons are evaluated in a constituent quark model (CQM) where the Cornell-like potential and Breit-Fermi interaction are employed. All model parameters are imported from the previous work of S-wave meson mass calculation. Two sets of complete bases are constructed by using the harmonic oscillator wave function, and the Sturmian wave...
Fluid-Gravity correspondence is an effective theory of AdS-CFT correspondence in a long-wavelength regime. The correspondence represents the map between Einstein equations in AdS bulk and hydrodynamics on the boundary. In particular, we demonstrate the construction of the energy-momentum tensor of the fluid on the boundary from various types of black holes in the bulk of AdS spacetime up to...
Although the discovery of the 125 GeV Higgs boson has confirmed the Higgs mechanism of the Standard Model (SM), many theories beyond the Standard Model (BSM) has been introduced to solve several phenomena not explained by the SM. One example is the Two Higgs Doublet Models (2HDM), the simplest extension of the SM Higgs sector, that predicted the existence of additional Higgs bosons. In this...
Proton computed tomography (pCT) is a medical scanning technology suitable for treatment planning of proton therapy. Suranaree University of Technology, together with the Bergen pCT collaboration, is currently constructing a pCT prototype for clinical trials. This study aims to reconstruct proton tracks generated from a Monte Carlo simulation which can be applied to 3-dimensional image...
High-mass X-ray binaries (HMXBs) are systems in which a neutron star or black hole accretes material from a massive companion. They can be roughly divided into three main classes: (i) wind-fed compact objects with supergiant donors; (ii) compact objects accreting from the decretion disc of a Be star; (iii) compact objects accreting via a disc from a Roche-lobe filling companion. All HMXBs must...
Starting from June 2022, LHC will start Run-3 with proton collisions at 13.6 TeV. In this talk, highlight results from LHC Run-2 will be presented. The physics plan for Run-3 for both LHC and non-LHC experiments to be discussed. In addition, we will also discuss on the plan for high luminosity LHC which is expected to start in 2029.
The detection of a very extended gamma-ray emission around the Geminga and Monogem pulsars at TeV energies has set a new class of gamma-ray sources called gamma-ray halo. These objects are characterised by the presence of a rather old pulsar (~100 kyr), emitting electrons and positron that are escaping and diffusing away into the interstellar medium, producing a large scale gamma-ray emission...
We present the initial study on the membership determination of the open clusters in Cassiopeia. Proper motion and parallax of stars collected in the Gaia Early Data Release 3 are used to derive the cluster members by employing the Hierarchical Density-Based Spatial Clustering of Applications with Noise (HDBSCAN) algorithm which is further improved upon using a Gaussian Mixture Model. We...
We investigate the impact of a first-order chiral phase transition and critical point on hadron multiplicity ratios. We model the dynamical expansion of the hot and dense matter created in a heavy ion collision with a Bjorken hydrodynamics expansion coupled to the explicit evolution of the chiral order parameter at center-of-mass energies from 2 to 10 GeV. Hereby, the chiral dynamics is...
We investigate scalar field minimally coupled to gravity in the framework of holographic dark energy with apparent horizon cutoff in non flat universe. Dynamics of the model are studied by rewriting the Friedmann equation which modified by holographic effect in the form of autonomous differential equations system. In the model, we consider in pure kinetic $(V(\phi)=0)$, power law potential...
Circumstellar structures, such as inclination and opening angles of outflow/jet cavities, thickness and flaring angle of disk surrounding an central object, and so on, is crucial to understand formation processes of high-mass stars and their evolution more quantitatively by determining a spectral energy distribution (SED) accurately that provides us information of the spectral types and to...
Thailand is involved in the next generation of Cherenkov Telescopes, the Cherenkov Telescope Array (CTA). Amongst the main CTA key science cases is the search for dark matter (DM). With a sensitivity one order of magnitude better than current instruments, CTA will be in a unique position to discover a DM signal in the GeV and TeV energy domain, or, in the absence of it, to significantly...
Abstract. We study the production of charged particles and the kaonic nuclei $K^{-}p$, $K^{+}\overline{p}$ in pp collisions at $\sqrt{s_{NN}}$ = 7 TeV and $K^{-}pp$, $K^{+}\overline{pp}$ in Au + Au collisions at beam energy 130 GeV. The PACIAE model is used to calculate the charged particles, and the DCPC model is used to calculate the kaonic nuclei. Results showed that the yield of charged...
Anisotropic flow in Au + Au collision at 1 A GeV using a quantum molecular dynamics model was concentrated. The direct flow of proton ($v_{1}$) as a function of rapidity ($y_{0}$) at intermediate energy around 1 A GeV and impact parameter from 0.25 to 0.45 fm with the nuclear equation of state (soft and hard equation of state) were computed and compared with FOPI experiment. The results showed...
Galactic-scale outflows driven by active galactic nuclei (AGNs) have been invoked to explain the quenching of star formation in massive galaxies. Large statistical outflow samples are required to study to fully understand their impact on galaxy evolution. The most traditional technique to distinguish the outflowing gas from non-outflowing gas is to detect the blueshifted-wings in the...
We use numerical simulations to study the evolution of merging galaxies. This study focuses on the AGN-driven feedback mechanism which could be responsible for outflow gas on kpc scales observed in Seyfert galaxies. The galaxy's initial conditions were created to mimic observational properties of a galaxy NGC 5252. The object is one of the interesting seyfert galaxies, showing an extended...
The Schamel-Korteweg-de Vries (SKdV) equation is the equation which described weakly ion-acoustic wave in cold plasmas. The soliton solution to the Schamel-Korteweg-de Vries equation can be determined by the shooting method. The spectral method is applied to study the time evolution of this solution. This can experimentally confirm that the solution is stable.
To detect distant, low-mass exoplanets, the microlensing technique has been proven to be one of the most successful techniques. On the other hand, to detect the Earth as a rocky planet in the Solar system, the other technological civilisations could also use the microlensing technique. Assuming that technological civilisations have equal chance to be located around any star anywhere in the...
Cosmic rays are high-energy particles from space, i.e., the sun, the supernova explosion of stars, and other currently unknown sources by processes that are not fully understood. Magnetic fields influence the propagation of these particles in the solar wind and the magnetosphere of the Earth. We can investigate changes in these magnetic fields by recording variations and fluctuations in the...
Interstellar complex molecules can be formed in interstellar molecular clouds during the process of star formation. Those complex molecules can be later delivered to planets to serve the role of the building blocks of life. Therefore, understanding the interaction and formation processes of those complex molecules in interstellar conditions is crucial to the understanding of the origin of...
Understanding the extraterrestrial origin of ribose, as one of the subunits of ribonucleic acid (RNA), is crucial to anticipating the formation of the building blocks of life under interstellar medium conditions. Under ordinary atmospheric conditions, the formation of sugar is suggested to occur through the formose reaction, where formaldehyde is solely used as the precursor in each of the...
This study investigates the enhancements of relativistic electron flux (MeV) in the outer radiation belt that can cause anomalies of geosynchronous satellite systems. The enhancements occurred during High Intensity, Long Duration, Continuous AE Activity (HILDCAA) of 12 events during 2015 - 2017. The relativistic electron (0.8 - 2.0 MeV) flux measured by GOES-13 satellite and low-energy...
The solutions of sine-Gordon equation will be used as the series solution for determining the kink solution of Oskolkov equation. The matching coefficients and choosing the some parameters of the series can provide the suitable solution. The numerical calculation with the kink soliton as the initial condition shows the stable solution can be found by this expansion method.
The National Astronomical Research Institute of Thailand (NARIT) is currently developing new low resolution and high-resolution spectrographs for the Thai National Telescope. These instruments will be used for follow-up observations for spectral type characterisation and exoplanet detections. Such observation typically will need long exposure (> 1 hour) where the target has to stay inside the...
Recent discoveries regarding the existence of the largeโscale structures in the universe, especially on the scales where the Cosmological Principle is expected to be accurate, pose a challenge to the Standard Model of Cosmology (ฮCDM model). These structures extend beyond 200 โ 300 Mpc (Haines, Clowes, and Campusano, 2000; Gott III et al., 2005; Clowes et al., 2013; Horvรกth, Hakkila, and...
I will present the first result of our project on the search for high-degree nonradial pulsations in the very fast rotating bright A-f stars.
These pulsations look like the tsunami waves running over the stellar equator to the direction of rotation (prograde waves).
To search for the pulsating candidates, we used the photometric data from the NASA space telescope TESS and the high- and...
We outline a new model in which generalised uncertainty relations, that govern the behaviour of microscopic world, and dark energy, that determines the large-scale evolution of the Universe, are intrinsically linked via the quantum properties of space-time. In this approach the background is treated as a genuinely quantum object, with an associated state vector, and additional fluctuations of...
The 21-cm neutral hydrogen (HI) survey is an important probe for cold gas and galaxy evolutions in the local and low-redshift universe. One of the key measurements used to study evolution and properties of local star-forming galaxies is the HI mass function (HIMF). Among the interested topics in modern astrophysics, the study could potentially shed more light and offer explanations for the...
A new notion of integrability called the multi-dimensional consistency for the integrable
systems with the 1-form structure is captured in the geometrical language both in classical
and especially quantum realms. A zero-curvature condition, which implies the multi-
dimensional consistency, will be a key relation in context of Hamiltonian operator.
Therefore, the existence of the...
We investigate how the local and temporal variation in the speed of light may help alleviating the Hubble tension problem. The idea is motivated from the observed variation in the fine structure constant from spectra of quasar absorption systems which could potentially be caused by the change in the speed of light. To test the hypothesis, we use the data from Pantheon Supernova which...
It is widely believed that star-forming spiral galaxies stop their star formation activity and eventually evolve into the passively evolved elliptical galaxy. One of the key factors is the gas outflowing process that depletes the star-forming ingredient in the galaxy. In 2017, we reported the systematic search for large-scale outflowing galaxies at $z=0.1-1.5$ covering the past 9 billion years...
Coiling of rope, fed from a height onto a rotating plane, progresses through a sequence of shapes, a hypotrochoid to an epitrochoid to a circle as frequency of plane increases. Feeding velocity controls the rate of length deposition on a plane and frequency of plane controls the rate of length transfer from a contact point, where rope first touches a plane. Formation of secondary loops of a...
Understanding of the dynamics of stars around the black hole is still incomplete. The Hubble Telescope discovered an evidence of the orbits of stars in the galactic centre that do not follow the Keplerโs laws. In this work, we study the classical effects on the periastron shift. We select the Hernquist potential function for the galactic bulge to examine the rate of change of periastron...
The cosmos consists of various elements, which have many different isotopes. Some of those isotopes are stable nuclei, but some of those are radioactive nuclei. However, some radioactive isotopes have exotic properties, and these nuclei cannot be explained by the shell model. In this work, we studied the light neutron-rich nuclei, He-6, by using the halo structure model. We applied the...
Blazars are a class of active galactic nuclei whose jets are aligned with the observerโs line of sight. They are powerful multi-frequency emitters that exhibit rapid and violent variation. Based on optical emission lines, blazars are classified into two subclasses which are BL Lacertae objects (BL Lacs), and flat spectrum radio quasars (FSRQs). Various studies have shown that besides using...
Galaxy haloes evolve through complex structure formation processes. Feedback from active galactic nuclei (AGN) plays an important role on the formation and matter distribution in haloes. We investigate the effect of AGN feedback on the shape of dark haloes formed in the EAGLE simulations and trace the evolution. Haloes from the 50 Mpc box simulation with and without AGN feedback are extracted...
This research aims to study photometric variability and Fourier analysis of High Amplitude Delta Scuti stars (HADS), which are interesting short period variable stars with spectral types between A2 and F0. They are located in the area of the classical cepheid instability strip, which crosses the main-sequence (MS) on the Hertzsprung-Russell (H-R) diagram. The CCD photometric V-magnitude data...
The Evanescent Wave Coronagraph, EvWaCo, is an in-development prototype coronagraph, designed for use on the 2.4m Thai National Telescope (TNT), in the R and I-band filters. This work examines the astronomical capabilities of EvWaCo using the results from Fourier-analysis simulations. The coronagraph mask comprises a spherical lens placed in contact with a prism, utilising the principle of...
The three Jones-Scadron form factors G$_M$ , G$_E$ and G$_C$* for the โN transition
are derived in the dispersion theory and chiral perturbation theory at low Q$^2$
regions. The Q$^2$ dependence of magnetic dipole form factors are compared
to the experimental data of the resonant multipoles ImM$_{1+}$$^{3/2}$. The decay rate
of the Dalitz decay โ-> Ne$^-$e$^+$ is also derived in...
We perform transit timing variation (TTV) and transmission spectroscopy analyses of the planet WASP-43 b, which is a hot Jupiter exoplanet with an ultrashort orbital period 0.81347753ยฑ0.0000007 day. Ninety-three transit light curves are obtained from the VizieR database and the observation from National Astronomical Research Institute of Thailand (NARIT)โs telescopes. We combine the mid...
