A5023649463- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Pulsars and Gravitational Waves Research
- Scientific Research and Discoveries
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Particle physics theoretical and experimental studies
- Earth Systems and Cosmic Evolution
- Astrophysical Phenomena and Observations
- Black Holes and Theoretical Physics
- Statistical Mechanics and Entropy
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Computational Physics and Python Applications
- Relativity and Gravitational Theory
- Diverse Scientific and Engineering Research
- Advanced Measurement and Metrology Techniques
- Leaf Properties and Growth Measurement
University of Science and Technology of China
2014-2024
Hefei University
2019
University of St Andrews
2008-2017
Optica
2014
Max Planck Society
2014
Max Planck Institute for Extraterrestrial Physics
2012-2014
University of Bonn
2013
Scottish Universities Physics Alliance
2007
We study the dark and luminous mass distributions, circular velocity curves (CVC), line-of-sight kinematics, angular momenta for a sample of 42 cosmological zoom simulations massive galaxies. Using temporal smoothing technique, we are able to reach large radii. find that: (i)The matter halo density profiles outside few kpc follow simple power-law models, with flat CVCs lower-mass systems, rising high-mass haloes. The projected stellar distributions at radii can be fitted by Sersic functions...
Low-acceleration space-time scale invariant dynamics (SID, Milgrom 2009a) predicts two fundamental correlations known from observational galactic dynamics: the baryonic Tully-Fisher relation (BTFR) and a correlation between observed mass discrepancy acceleration (MDA) in low regime for disc galaxies. SID corresponds to deep MOdified Newtonian Dynamics (MOND) limit. The MDA data emerging cold/warm dark matter (C/WDM) cosmological simulations disagree significantly with tight of Therefore,...
After their birth a significant fraction of all stars pass through the tidal threshold (prah) cluster origin into classical tails. The asymmetry between number in leading and trailing tails tests gravitational theory. All five open clusters with tail data (Hyades, Praesepe, Coma Berenices, COIN-Gaia 13, NGC 752) have visibly more within dcl = 50 pc centre than tail. Using Jerabkova-compact-convergent-point (CCP) method, extended been mapped out for four nearby 600-2000 Myr old to dcl>50 pc....
The ultra-diffuse dwarf galaxy NGC 1052-DF2 (DF2) has ten (eleven) measured globular clusters (GCs) with a line-of-sight velocity dispersion of $\sigma=7.8^{+5.2}_{-2.2}\,$km/s ($\sigma=10.6^{+3.9}_{-2.3}\,$km/s). Our conventional statistical analysis the original GCs gives $\sigma=8.0^{+4.3}_{-3.0}\,$km/s. overall distribution velocities agrees well Gaussian this width. Due to non-linear Poisson equation in MOND, weaker self-gravity when close proximity massive host. This external field...
We compute the Milky Way potential in different cold dark matter (CDM) based models, and compare these with modified Newtonian dynamics (MOND) framework.We calculate axis ratio of various find that isopotentials are less spherical MOND than CDM potentials.As an application we predict escape velocity as a function position Galaxy.This could be useful comparing future data from planned or alreadyunderway kinematic surveys (RAVE, SDSS, SEGUE, SIM, GAIA hypervelocity stars survey).In addition,...
The self-binding energy and stability of a galaxy in MOND-based gravity are curiously decreasing functions its center mass acceleration towards neighbouring concentrations. A tentative indication this breaking the Strong Equivalence Principle field galaxies is RAVE-observed escape speed Milky Way. Another consequence that satellites will move on nearly Keplerian orbits at large radii (100 - 500 kpc), with declining below asymptotically constant naive MOND prediction. But consequences an...
We look for observational signatures that could discriminate between Newtonian and modified (MOND) dynamics in the Milky Way, view of advent large astrometric spectroscopic surveys. Indeed, a typical signature MOND is an apparent disk "phantom" dark matter, which uniquely correlated with visible disk-density distribution. Due to this phantom disk, models spherical halo have different from close Galactic plane. The can thus be differentiated by measuring dynamically (within dynamics) surface...
External fields in Migromian dynamics (MD or MOND, Milgrom 1983) break the Strong Equivalence Principle (SEP) and change of self-bound stellar systems moving space-varying background gravitational fields. We study two kinds re-virialisation systems: violent phase transition adiabatic for on radial orbits, where external field evolves from strong to weak whose corresponding changes Newtonian Milgromian. find that time scale tranformation Milgromian gravity lies only within one a few crossing...
We point out an interesting theoretical prediction for elliptical galaxies residing inside galaxy clusters in the framework of modified Newtonian dynamics (MOND), that could be used to test this paradigm. Apart from central brightest cluster galaxy, other close enough centre experience a strong gravitational influence cluster. This manifests itself only as tides standard gravity, meaning systematic acceleration mass has no consequence. However, context MOND, consequence breaking equivalence...
In recent years several hypervelocity stars (HVSs) have been observed in the halo of our Galaxy. Such HVSs possibly ejected from Galactic center and then propagated potential up to their current position. The survey for candidate show an asymmetry kinematics (position velocity vectors), where more outgoing than ingoing (i.e. positive Galactocentric velocities vs. negative ones) are observed. We that such kinematic asymmetry, which is likely due finite lifetime structure, could be used a...
Adopting Schwarzschild's orbit-superposition technique, we construct a series of self-consistent galaxy models, embedded in the external field clusters framework Milgrom's MOdified Newtonian Dynamics (MOND). These models represent relatively massive ellipticals with Hernquist radial profile at various distances from cluster center. Using N-body simulations, perform first analysis these and their evolution. We find that self-gravitating axisymmetric density even under weak field, lose...
SDSS J1634+2049 is a local (z = 0.1293) infrared-luminous quasar with LIR= 10^11.91 Lsun. We present detailed multiwavelength study of both the host galaxy and nucleus. The demonstrates violent, obscured star formation activities SFR ~ 140 Msun yr^-1, estimated from either PAH emission or IR luminosity. optical to NIR spectra exhibit blueshifted narrow cuspy component in Hb, HeI5876,10830 other lines consistently an offset velocity ~900 km/s, as well additional blueshifting phenomena...
We perform a stability test of triaxial models in MOdified Newtonian Dynamics (MOND) using N-body simulations. The considered here have densities that vary with $r^{-1}$ the center and $r^{-4}$ at large radii. total mass model varies from $10^8\Msun$ to $10^{10}\Msun$, representing scale dwarfs medium-mass elliptical galaxies, respectively, deep MOND quasi-Newtonian gravity. build galaxy Schwarzschild technique, evolve systems for 200 Keplerian dynamical times (at typical length 1.0 kpc)....
The recent years have seen combined measurements of X-ray and (weak) lensing contours for colliding galaxy clusters such as, instance, the famous "Bullet" cluster. These observations revealed offsets in peaks baryonic (dominant) gravitational matter component order ~(100-200) kpc. Such discrepancies are difficult to explain using modified theories gravity other than dark matter. Or they not? Here we use concept "phantom matter" that is based upon a Newtonian interpretation MONDian potential....
The accuracy and robustness of a simple method to estimate the total mass profile galaxy are tested using sample 65 cosmological zoom simulations individual galaxies. only requires information on optical surface brightness projected velocity dispersion profiles, therefore can be applied even in case poor observational data. In simulated sample, massive galaxies (σ≃ 200–400 km s−1) at redshift z= 0 have almost isothermal rotation curves for broad range radii (rms ≃ 5 per cent circular speed...
The Bekenstein-Milgrom gravity theory with a modified Poisson equation is tested here for the existence of triaxial equilibrium solutions. Using non-negative least square method, we show that self-consistent galaxies exist baryonic models mild density cusp $ρ\sim {Σ\over r}$. Self-consistency achieved wide range central concentrations, $Σ\sim 10-1000\mathrm{M_{\odot}pc^{-2}}$, representing low-to-high surface brightness galaxies. Our results demonstrate first time orbit superposition...
We study the evolution of phase-space collisionless N-body systems under repeated stirrings or perturbations. find convergence towards a limited solution group, in accordance with Hansen 2010, that is independent initial system and environmental conditions, paying particular attention to assumed gravitational paradigm (Newtonian MOND). examine effects changes perturbation scheme doing so identify large group perturbations featuring radial orbit instability (ROI) which always lead...
Previous studies of globular cluster (GC) systems show that there appears to be a universal specific GC formation efficiency η which relates the total mass GCs virial host dark matter haloes, Mvir. In this paper, frequency, SN, and efficiency, η, are derived as functions Mvir in Milgromian dynamics, i.e. modified Newtonian dynamics. for galaxies with GCs, system, MGC, is two-component function instead simple linear relation. An observer universe, who interprets universe being...
We study the evolution of star clusters located in outer regions a galaxy undergoing sudden mass loss through gas expulsion framework Milgromian dynamics (MOND) by means N-body simulations. find that, to leave bound cluster, formation efficiency (SFE) an embedded cluster dominated deep MOND gravity can be reduced down $2.5\%$. For given SFE, that survive bind larger fraction compared Newtonian dynamics. Moreover, more diffuse is, less substantial size expansion final is. The density profiles...
Ring galaxies are rare in the Universe. A head-on or off-centre collision between an intruder galaxy and a disc leads to collisional ring (CRG) when intruder-to-target mass ratio (ITMR) is over 0.1 Newtonian dynamics. Within framework of Milgromian dynamics, strong equivalence principle violated due presence external field. When two collide towards each other, dynamical phantom dark halo suppressed by field induced other galaxy. As consequence such suppression, gravitational perturbation for...
Abstract Galaxies are observed to be lopsided, meaning that they more massive and extended along one side than the opposite side. In this work, we provide a statistical analysis of lopsided morphology 1780 isolated satellite galaxies generated by TNG50-1 simulation, incorporating effect tidal fields from halo centers. The satellites without nearby substructures whose mass is over 1% within their virial radii. We study radial alignment (RA) between major axes direction centers in ranges 0–2,...
The stellar shells surrounding an elliptical galaxy, as remnants of a dwarf galaxy disrupted during merging, reveal the distribution energy and angular momentum progenitor galaxy. We develop semi-analytical model to describe changes $\Delta E_i$ Lz_i$ for particles first infall. show that these changes, induced by self-gravity progenitor, are important in broadening initial Plummer or Hernquist model. Consequently, crucial shaping shells. In free fall stage following disintegration...