A5082178565- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Adaptive optics and wavefront sensing
- Dark Matter and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- CCD and CMOS Imaging Sensors
- Remote Sensing in Agriculture
- Neutrino Physics Research
- Optical Systems and Laser Technology
- Scientific Research and Discoveries
- Hydrology and Watershed Management Studies
- Solar and Space Plasma Dynamics
- Recommender Systems and Techniques
- Risk and Safety Analysis
- COVID-19 diagnosis using AI
- Grey System Theory Applications
- Medical Image Segmentation Techniques
Yunnan University
2017-2024
University of Electronic Science and Technology of China
2023
Changchun University of Technology
2022
Beihang University
2016-2017
Peking University
2013-2017
Kavli Institute for Theoretical Sciences
2013
Abstract The Chinese Space Station Optical Survey (CSS-OS) is a planned full sky survey operated by the Telescope (CSST). It can simultaneously perform photometric imaging and spectroscopic slitless surveys, will probe weak strong gravitational lensing, galaxy clustering, individual galaxies clusters, active galactic nucleus, so on. aims to explore properties of dark matter energy other important cosmological problems. In this work, we focus on two main CSS-OS scientific goals, i.e., lensing...
This paper is the first of a series papers constraining cosmological parameters with weak lensing peak statistics using $\sim 450~\rm deg^2$ imaging data from Kilo Degree Survey (KiDS-450). We measure high signal-to-noise ratio (SNR: $\nu$) convergence peaks in range $3<\nu<5$, and employ theoretical models to derive expected values. These are validated suite simulations. take into account two major systematic effects, boost factor effect baryons on mass-concentration relation dark matter...
We derived constraints on cosmological parameters using weak lensing peak statistics measured the $\sim130~{\rm deg}^2$ of Canada-France-Hawaii Telescope Stripe 82 Survey (CS82). This analysis demonstrates feasibility in studies. For our measurements, we considered peaks with signal-to-noise ratio range $\nu=[3,6]$. a flat $\Lambda$CDM model only $(\Omega_{\rm m}, \sigma_8)$ as free parameters, constrained following relation $\Sigma_8=\sigma_8(\Omega_{\rm m}/0.27)^{\alpha}$ to be:...
In this Letter, we report the observational constraints on Hu-Sawicki f(R) theory derived from weak lensing peak abundances, which are closely related to mass function of massive halos. comparison with studies using optical or x-ray clusters galaxies, analyses have advantages not relying mass-baryonic observable calibrations. With observations Canada-France-Hawaii-Telescope Lensing Survey, our give rise a tight constraint model parameter |f_{R0}| for n=1. The 95% C.L. is...
Convolutional Neutral Networks have been successfully applied in searching for strong lensing systems, leading to discoveries of new candidates from large surveys. On the other hand, systematic investigations about their robustness are still lacking. In this paper, we first construct a neutral network, and apply it $r$-band images Luminous Red Galaxies (LRGs) Kilo Degree Survey (KiDS) Data Release 3 search systems. We build two sets training samples, one fully simulations, using LRG stamps...
The interacting dark energy (IDE) model, which considers the interaction between and matter, provides a natural mechanism to alleviate coincidence problem can also relieve observational tensions under $\Lambda$CDM model. Previous studies have put constraints on IDE models by observations of cosmic expansion history, microwave background large-scale structures. However, these data are not yet enough distinguish from effectively. Because non-linear structure formation contains rich...
Abstract SN 2023ixf, recently reported in the nearby galaxy M101 at a distance of 6.85 Mpc, was one closest and brightest core-collapse supernovae last decade. In this work, we present multiwavelength photometric observation 2023ixf with Multi-channel Photometric Survey Telescope (Mephisto) uvgr bands twin 50 cm telescopes griz bands. We find that bolometric luminosity reached maximum value 3 × 10 43 erg s −1 3.9 days after explosion fully settled onto radioactive tail ∼90 days. The...
Abstract We present early-phase good-cadence (hour-to-day) simultaneous multiband ( ugi and vrz bands) imaging of the nearby supernova SN 2024ggi, which exploded in galaxy NGC 3621. A quick follow-up was conducted within less than a day after explosion continued for ∼23 days. The uvg band light curves display rapid rise (∼1.4 mag −1 ) to maximum ∼4 days absolute magnitude M g ∼ −17.75 mag. postpeak decay rate redder bands is ∼0.01 . Different colors (e.g., u − v r 2024ggi are slightly...
Abstract Gamma-ray bursts (GRBs) are the most luminous transients in Universe. The interaction of relativistic jet with circumburst medium produces an afterglow and generates multiwavelength emission. In this work, we present simultaneous multiband photometry GRB 240825A Multi-channel Photometric Survey Telescope (Mephisto) analyze its temporal spectral properties. measurement began 128 s after trigger continued until fourth day, when essentially diminished measured brightness was close to...
Galaxy shear - cosmic microwave background (CMB) lensing convergence cross-correlations contain additional information on cosmology to auto-correlations. While being immune certain systematic effects, they are affected by the galaxy intrinsic alignments (IA). This may be responsible for reported low amplitude of $\times$ CMB cross-correlations, compared standard Planck $\Lambda$CDM (cosmological constant and cold dark matter) prediction. In this work, we investigate how IA affects...
ABSTRACT The interacting dark energy (IDE) model is a promising alternative cosmological that has the potential to solve fine-tuning and coincidence problems by considering interaction between matter energy. Previous studies have shown exchange sector components in this can significantly affect halo properties. In study, utilizing large set of N-body simulations, we analyse redshift evolution concentration–mass (c–M) relation IDE model, show c–M sensitive proxy strength parameter ξ2,...
In this paper, we analyze in detail with numerical simulations how the mask effect can influence weak lensing peak statistics reconstructed from shear measurement of background galaxies. It is found that high fractions are systematically enhanced due to masks, larger masked area, higher enhancement. case about $13\%$ total fraction peaks SNR $ν\ge 3$ $\sim 11\%$ comparison 7\%$ mask-free our considered cosmological model. This induce a large bias on studies statistics. Even for survey area...
ABSTRACT We present a forecast study on the cross-correlation between cosmic shear tomography from Chinese Survey Space Telescope (CSST) and microwave background (CMB) lensing Ali CMB Polarization (AliCPT-1) in Tibet. The correlated galaxy signals were generated Gaussian realizations based inputted auto cross-spectra. To account for error budget, we considered reconstruction noise AliCPT-1 pipeline; shape of measurement; CSST photo-z error; bias; intrinsic alignment (IA) effect;...
Abstract Supernova (SN) 2023ixf was discovered on 2023 May 19. The host galaxy, M101, observed by the Hobby–Eberly Telescope Dark Energy Experiment collaboration over period 2020 April 30–2020 July 10, using Visible Integral-field Replicable Unit Spectrograph (3470 ≲ λ 5540 Å) 10 m Telescope. fiber filling factor within ±30″ of SN is 80% with a spatial resolution 1″. r < 5.″5 surroundings are 100% covered. This allows us to analyze spatially resolved preexplosion local environments...
Abstract We installed two sets of Astronomical Site Monitoring Systems (ASMSs) at Lijiang Observatory (GMG), for the running 2.4-meter optical telescope (LJT) and 1.6-meter Multi-channel Photometric Survey Telescope (Mephisto). The Mephisto is under construction. ASMS has been on robotic mode since 2017. core instruments: Cloud Sensor, All-Sky Camera Autonomous-DIMM that are developed by our group, together with commercial Meteorological Station Sky Quality Meter, combined into astronomical...
We perform weak lensing tomographic peak studies using the first-year shear data from Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) survey. The effective area used in our analyses after field selection, mask and boundary exclusions is $\sim 58 \deg^2$. source galaxies are divided into low- high-redshift bins with $0.2\le z_p\le0.85$ $0.85\le z_p\le1.5$, respectively. utilize halo-based theoretical model including projection effect of large-scale structures to derive cosmological...
High-resolution {\sl Hubble Space Telescope} imaging observations show that the radial distribution of field-decontaminated sample 162 'blue straggler' stars (BSs) in $11.7^{+0.2}_{-0.1}$ Gyr-old Large Magellanic Cloud cluster Hodge 11 exhibits a clear bimodality. In combination with their distinct loci color--magnitude space, this offers new evidence support theoretical expectations suggest different BS formation channels as function stellar density. cluster's diagram, BSs inner 15$"$...
The Multi-channel Photometric Survey Telescope (Mephisto) is a wide-field ground based telescope with 1.6m primary mirror and 2° field of view, proposed by Yunnan University. will be capable imaging the northern sky in three colors simultaneously deliver colored movie universe. R-C system lens corrector was adopted as optical considering image quality requirement, light obscuration camera arrangement, which cubic splitters were for channel beams order to get satisfied over whole view....
Abstract The galaxy intrinsic alignment (IA) is a dominant source of systematics in weak lensing (WL) studies. In this paper, by employing large simulations with semianalytical formation, we investigate the IA effects on WL peak statistics. Different simulated samples different redshift distributions are constructed, where both shear and signals included. Convergence reconstruction statistics then performed for these samples. Our results show that abundances mainly consist two aspects. One...
We propose a novel method to detect cosmic magnification signals by cross-correlating foreground convergence fields constructed from galaxy shear measurements with background positional distributions---namely, shear-number density correlation. apply it the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) survey data. With 27 nonindependent data points and their full covariance, ${\ensuremath{\chi}}_{0}^{2}\ensuremath{\approx}34.1$ ${\ensuremath{\chi}}_{T}^{2}\ensuremath{\approx}24.0$...
The convergence peaks, constructed from galaxy shape measurement in weak lensing, is a powerful probe of cosmology as the peaks can be connected with underlined dark matter haloes. However capability peak statistic affected by noise measurement, signal to ratio well contribution projected mass distribution large-scale structures along line sight (LOS). In this paper we use ray-tracing simulation on curved sky investigate correspondence between and haloes at LOS. We find that, case no for...
Abstract Recent studies have shown the great power of peak counts in weak-lensing maps. In this work, we apply inverse-Gaussianization method proposed Yu et al. to produce convergence maps quickly and investigate statistics, including height steepness these mocks. The distributions are good agreement with simulation results. difference is ≲20% for statistics at source redshift z s = 1. Also, loss off-diagonal elements covariance motivates us consider super-sample variance statistics. We...
The VST Optical Imaging of the CDFS and ES1 Fields (VOICE) Survey is a Guaranteed Time program carried out with ESO/VST telescope to provide deep optical imaging over two 4 deg$^2$ patches sky centred on pointings. We present cosmic shear measurement covering region in $r$-band using LensFit. Each four tiles 1 has more than one hundred exposures, which 50 exposures passed series image quality selection criteria for weak lensing study. $5\sigma$ limiting magnitude $r$- band 26.1 point...
As the first paper in a series on study of galaxy-galaxy lensing from Sloan Digital Sky Survey Data Release 7 (SDSS DR7), we present our image processing pipeline that corrects systematics primarily introduced by Point Spread Function (PSF). Using this pipeline, processed SDSS DR7 imaging data $r$ band and generated background galaxy catalog containing shape information each galaxy. Based own measurements images DR7, extract (GG) signals around foreground spectroscopic galaxies binned...