A5002486880- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
- Astrophysics and Star Formation Studies
- Pulsars and Gravitational Waves Research
- Superconducting Materials and Applications
- Stellar, planetary, and galactic studies
- Nuclear Physics and Applications
- Astro and Planetary Science
- X-ray Spectroscopy and Fluorescence Analysis
- Galaxies: Formation, Evolution, Phenomena
- Laser-Plasma Interactions and Diagnostics
- Earthquake Detection and Analysis
- High-pressure geophysics and materials
- Scientific Measurement and Uncertainty Evaluation
- Astronomy and Astrophysical Research
- Fluid Dynamics and Turbulent Flows
- Solar and Space Plasma Dynamics
Liupanshui Normal University
2022-2025
Osservatorio Astronomico di Padova
2021-2022
Xinjiang Astronomical Observatory
2017
Abstract Novae are found to have GeV TeV gamma-ray emission, which reveals the shock acceleration from white dwarfs. Recently, V1405 Cat was reported radiated suspicious by Fermi-LAT with low significance (4.1 σ) after optical maximum. Radio observations reveal that it is one of five brightest novae surrounded low-density ionized gas columns. Here we report continuous search for Fermi-LAT. No \g\ were found. For Cas, flux level lower than other well-studied Fermi novae, and maximum appear at...
Abstract GK Persei, an old nova and intermediate polar (IP), exhibited a dwarf (DN) outburst in 2010. This was extensively observed by the Neil Gehrels Swift Observatory, beginning 1.95 days after eruption continuing until 13.9 before maximum of optical. In this paper, we present timing spectral analyses, comparing results with those other outbursts. We confirm spin modulation 2 − 10 keV X-ray range period PWD = 351.325(9) s. Additionally, detected 0.3 band during second half observations,...
GK Persei, an old nova and intermediate polar (IP), exhibited a dwarf (DN) outburst in 2010. This was extensively observed by the Neil Gehrels Swift Observatory, beginning 1.95 days after eruption continuing until 13.9 before maximum of optical. In this paper, we present timing spectral analyses, comparing results with those other outbursts. We confirm spin modulation 2 $-$ 10 keV X-ray range period $P_{\rm WD} = 351.325(9)$ s. Additionally, detected 0.3 band during second half observations,...
Abstract In this study, we present a detailed analysis of public archival soft X-ray data on the classical nova V339 Delphini (Nova Del 2013) during its outburst, obtained using Chandra High-Resolution Camera Spectrometer (HRC-S) and Low Energy Transmission Grating (LETG), as well XMM-Newton in 2013. The observations, spanning from day 85.2 to 112.0 after optical maximum, capture luminous supersoft source (SSS) phase. spectra reveal numerous absorption features with blue-shifted velocities...
We monitored four supersoft sources - two persistent ones, CAL 83 and MR Vel, the recent novae YZ Ret (Nova 2020) V1674 Her 2021) with NICER. The SSS were observed unvaried X-ray flux level spectrum, respectively, 13 20 years after last observations. Short period modulations of source (SSS) appear where spectrum luminous central was fully visibl (in Her) absent in which originated photoionized or shocked plasma, while white dwarf (WD) not observable. thus suggest that pulsations occur on,...
Abstract The 2021 outburst of the symbiotic recurrent nova RS Oph was monitored with Neutron Star Interior Composition Explorer Mission (NICER) in 0.2–12 keV range from day one after optical maximum, until 88, producing an unprecedented, detailed view development. X-ray flux preceding supersoft phase peaked almost 5 days maximum and originated only shocked ejecta for 21–25 days. emission thermal; first days, a non-collisional-ionization equilibrium model fits spectrum, transition to occurred...
ABSTRACT The old nova and intermediate polar (IP) GK Persei underwent one of its recurrent dwarf (DN) outbursts in 2018. We proposed monitoring it UV X-rays with the Neil Gehrels Swift Observatory, starting less than six days after eruption, until 16 eruption ended. For first time, we could follow decay to minimum light X-rays. present timing spectral analysis, comparing results previous quiescent status. confirm spin modulation a period PWD = 351.325(9) s, only 2–10 keV range. was not...
The XCO factor is defined as XCO=N(H2)/W12CO. It useful for estimating cloud mass. However, there only limited research on how the varies within a single cloud. Employing 12CO(J=1-0) and 13CO(J=1-0) spectral data, we computed an of 3.6 ×1020cm−2 (K km s−1)−1 luminous gas N55 region. Our analysis revealed V-shaped correlation between H2 column densities, while relationship with excitation temperature exhibited obscurity. This suggests that CO-to-H2 conversion not consistent small scale (∼1...
In this study we present an analysis of the archival X-ray data eclipsing supersoft binary CAL 87 observed with Chandra Advanced CCD Imaging Spectrometer (ACIS) camera and Low Energy Transmission Grating (LETG) in 2001 August XMM-Newton 2003 April. The high-resolution spectra are almost unchanged on two different dates. average unabsorbed luminosity during exposure was 4.64 − 5.46 × 10 36 ergs s −1 4.54 4.82 2003, prominent redshifted emission lines, mostly nitrogen, oxygen, iron, argon,...
We examine four high resolution reflection grating spectrometers (RGS) spectra of the February 2009 outburst luminous recurrent nova LMC 2009a. They were very complex and rich in intricate absorption emission features. The continuum was consistent with a dominant component originating atmosphere shell burning white dwarf (WD) peak effective temperature between 810,000 K million K, mass 1.2-1.4 M$_\odot$ range. A moderate blue shift features few hundred km s$^{-1}$ can be explained residual...
We analyse here four observations of nova KT Eri (Nova 2009) done with the Chandra High Resolution Camera Spectrometer (HRC-S) and Low Energy Transmission Grating (LETG) in 2010, from day 71 until 159 after optical maximum, luminous supersoft X-ray phase. The spectrum presents many absorption features a large range velocity, few hundred km s$^{-1}$ to 3100 same observation, prominent emission features, generally redshifted by more than 2000 s$^{-1}$. Although uncertainty on distance WD...
The old nova and intermediate polar (IP) GK Persei underwent one of its recurrent dwarf (DN) outbursts in 2018. We proposed monitoring it UV X-rays with the Neil Gehrels Swift Observatory, starting less than six days after eruption, until 16 eruption ended. For first time we could follow decay to minimum light X-rays. present timing spectral analysis, comparing results previous quiescent status. confirm spin modulation a period 351.325(9) s, only 2-10 keV range. was not detected 0.3-2 range...
In this study, we present an analysis of the archival X-ray data eclipsing supersoft binary CAL 87 observed with {\it Chandra} Advanced CCD Imaging Spectrometer (ACIS) camera and Low Energy Transmission Grating (LETG) in 2001 August XMM-Newton} 2003 April. The high resolution spectra are almost unchanged two different dates. average unabsorbed luminosity during exposure was 4.64$-$5.46$\times10^{36}$ ergs s$^{-1}$ 4.54$-$4.82 $\times10^{36}$ 2003, prominent red-shifted emission lines, mostly...
The 2021 outburst of the symbiotic recurrent nova RS Oph was monitored with Neutron Star Interior Composition Explorer Mission (NICER) in 0.2-12 keV range from day one after optical maximum, until 88, producing an unprecedented, detailed view development. X-ray flux preceding supersoft phase peaked almost 5 days maximum and originated only shocked ejecta for 21 to 25 days. emission thermal; first a non-collisional-ionization equilibrium model fits spectrum, transition occurred between 6 12....
Abstract We analyzed the influence of outflow feedback from two perspectives: turbulent support and potential disruptive effect, which 694 clumps 188 have been identified as candidates. For support, we find slopes E turb − R clump (turbulent energy radius clump) P momentum no difference are consistent with expected values whether there is in or not. The ratios to turbulence ( flow / , ) show that majority not enough turbulence. Meanwhile, correlation between velocity dispersion radius....