A5103234241- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Advanced Optical Sensing Technologies
- Radio Astronomy Observations and Technology
- Adaptive optics and wavefront sensing
- Real-time simulation and control systems
Peking University
2023-2024
Kavli Institute for Theoretical Sciences
2023-2024
University of Science and Technology of China
2022-2023
Abstract We present a study of seven spectroscopically confirmed (Ly α -emitting) galaxies at redshift z ≃ 6 using the JWST/NIRCam imaging data. These galaxies, with wide range Ly luminosities, were recently observed in series NIRCam broad and medium bands. constrain rest-frame UV/optical continua measure H line emission combination archival HST/WFC3 infrared photometry. further estimate escape fractions their photons ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Abstract We present constraints on the spacetime variation of fine-structure constant α at redshifts 2.5 ≤ z < 9.5 using JWST emission-line galaxies (ELGs). The galaxy sample consists 621 high-quality spectra with strong and narrow [O iii ] λλ 4959,5007 doublet emission lines from 578 galaxies, including 232 > 5. are arguably best to probe in . divide our into six subsamples based redshift calculate relative Δ / for individual subsamples. calculated values consistent zero within 1 σ...
Cosmic reionization represents the latest phase transition of intergalactic medium (IGM) in Universe. It has long been debated whether galaxies or active galactic nuclei (AGNs) are major source Lyman continuum (LyC) photons responsible for reionization. Previous observations slightly favored as ionizing source. However, James Webb Space Telescope (JWST) recently discovered an unexpectedly high density AGN candidates at redshift, which largely enhanced influence AGNs. Here we derive a...
We present a study of sample 45 spectroscopically confirmed, UV luminous galaxies at $z\sim 6$. They were selected as bright Lyman-break (LBGs) using deep multi-band optical images in more than 2 deg$^2$ the sky, and subsequently identified via their strong Ly$\alpha$ emission. The majority these LBGs span an absolute magnitude range from $-22.0$ to $-20.5$ mag with equivalent width (EW) between $\sim$10 $\sim$200 \AA, representing most 6$ terms both continuum emission line model SEDs 10...
Abstract We report results for a complete sample of 10 luminous radio-quiet quasars with large C iv equivalent widths (EW ≥ 150 Å). For 8/10 we performed Chandra snapshot observations. find that, in addition to the enhanced line EW, their He ii and Mg lines are enhanced, but iii ] is not. Their X-ray emission substantially stronger than expected from ultraviolet luminosity. Additionally, these EW show small blueshifts possibly low Eddington ratios, suggesting that they “extreme Eigenvector 1...
ABSTRACT A unique X-ray occultation event in NGC 6814 during an XMM–Newton observation 2016 has been reported, providing useful information of the absorber and corona. We revisit with aid hardness ratio (HR)–count rate (CR) plot comparison two other absorption-free XMM exposures 2009 2021. exhibits a clear ‘softer-when-brighter’ variation pattern exposures, but exposure significantly deviates from HR–CR plot. While spectral fitting does yield transient Compton-thin absorption corresponding...
Abstract We present a study of sample 45 spectroscopically confirmed, UV luminous galaxies at z ∼ 6. They were selected as bright Lyman-break (LBGs) using deep multiband optical images in more than 2 deg the sky, and subsequently identified via their strong Ly α emission. The majority these LBGs span an absolute magnitude range from −22.0 to −20.5 mag with equivalent width (EW) between ∼10 ∼200 Å, representing most 6 terms both continuum emission line model spectral energy distributions 10...
We present constraints on the spacetime variation of fine-structure constant $\alpha$ at redshifts $3<z<10$ using JWST emission-line galaxies. The galaxy sample consists 572 high-quality spectra with strong and narrow [O III] $\lambda\lambda$4959,5007 doublet emission lines from 522 galaxies, including 267 $z>5$. are arguably best to probe in $\alpha$. divide our into 5 subsamples based redshift calculate relative $\Delta\alpha/\alpha$ for individual subsamples. calculated values consistent...
We present a study of seven spectroscopically confirmed (Ly$α$ emitting) galaxies at redshift $z\simeq6$ using the $JWST$/NIRCam imaging data. These galaxies, with wide range Ly$α$ luminosities, were recently observed in series NIRCam broad- and medium-bands. constrain rest-frame UV/optical continua measure H$α$ line emission combination archival $HST$/WFC3 infrared photometry. further estimate their escape fractions photons ($f_{\rm esc}^{\rm Lyα}$) production efficiency ionizing ($ξ_{\rm...
A unique X-ray occultation event in NGC 6814 during an XMM-Newton observation 2016 has been reported, providing useful information of the absorber and corona. We revisit with aid hardness ratio (HR) - count rate (CR) plot comparison two other absorption-free XMM exposures 2009 2021. exhibits a clear "softer-when-brighter" variation pattern exposures, but exposure significantly deviates from HR CR plot. While spectral fitting does yield transient Compton-thin absorption corresponding to...