A5015310764- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Atmospheric and Environmental Gas Dynamics
- Nuclear Physics and Applications
- Advanced Sensor Technologies Research
- CCD and CMOS Imaging Sensors
- High-pressure geophysics and materials
- Galaxies: Formation, Evolution, Phenomena
- Optical Systems and Laser Technology
- Neutrino Physics Research
- Geophysics and Gravity Measurements
- Traffic Prediction and Management Techniques
- Traffic control and management
- Particle accelerators and beam dynamics
- Particle physics theoretical and experimental studies
- CO2 Sequestration and Geologic Interactions
- Fire effects on ecosystems
- Fluid Dynamics Simulations and Interactions
Tsinghua University
2011-2024
Yunnan Observatories
2015-2024
Chinese Academy of Sciences
2013-2024
Institute of High Energy Physics
2024
University of Chinese Academy of Sciences
2015-2023
National Astronomical Observatories
2012-2021
Laboratoire de Physique Nucléaire et de Hautes Énergies
2009-2013
Institut National de Physique Nucléaire et de Physique des Particules
2012-2013
Sorbonne Université
2012-2013
Université Paris Cité
2012-2013
The nearby supernova SN 2011fe can be observed in unprecedented detail. Therefore, it is an important test case for Type Ia (SN Ia) models, which may bring us closer to understanding the physical nature of these objects. Here, we explore how available and expected future observations used constrain explosion scenarios. We base our discussion on three-dimensional simulations a delayed detonation Chandrasekhar-mass white dwarf violent merger two dwarfs-realizations models appropriate most...
We present 32 epochs of optical (3300-9700 \AA) spectrophotometric observations the nearby quintessential "normal" type Ia supernova (SN Ia) SN 2011fe in galaxy M101, extending from -15 to +97 d with respect B-band maximum, obtained by Nearby Supernova Factory collaboration. is closest (\mu = 29.04) and brightest (Bmax 9.94 mag) observed since advent modern large scale programs for intensive periodic followup supernovae. Both synthetic light curve measurements spectral feature analysis...
We examine the relationship between Type Ia supernova (SN Ia) Hubble residuals and properties of their host galaxies using a sample 115 SNe from Nearby Supernova Factory. use galaxy stellar masses specific star formation rates fitted photometry for all hosts, as well gas-phase metallicities subset 69 star-forming (non-active galactic nucleus) to show that SN correlate with each these properties. With data we find new evidence correlation intrinsic color metallicity. When combine our those...
Context. Our Local Group of galaxies appears to be moving relative the cosmic microwave background with source peculiar motion still uncertain. While in past this has been studied mostly using as distance indicators, weight type Ia supernovae (SNe Ia) increased recently continuously improving statistics available low-redshift supernovae. Aims. We measured bulk flow nearby universe ($0.015 < z 0.1$) 117 SNe observed by Nearby Supernova Factory, well Union2 compilation SN data already...
We present convincing evidence of unburned carbon at photospheric velocities in new observations 5 Type Ia supernovae (SNe Ia) obtained by the Nearby Supernova Factory. These SNe are identified examining 346 spectra from 124 before +2.5 d relative to maximum. Detections based on presence relatively strong C II 6580 absorption "notches" multiple each SN, aided automated fitting with SYNAPPS code. Four question otherwise spectroscopically unremarkable, ions and ejection typical Ia, but fifth...
Abstract The 11th data release of the LAMOST survey provides fundamental stellar param-&#xD;eters but lacks detailed abundance measurements for α-elements, crucial understanding&#xD;stellar populations and Galactic chemical evolution. In this study, we derive abundances of&#xD;oxygen (O), magnesium (Mg), silicon (Si), calcium (Ca), titanium (Ti) over 6.8 mil-&#xD;lion stars using DR11 low-resolution spectra. To ensure reliable measurements,&#xD;we select 1,086 OCs...
Cellular iron levels must be tightly regulated to ensure sufficient for essential enzymatic functions whilst avoiding the harmful generation of toxic species. Here, better understand how are controlled, we carry out genome-wide mutagenesis screens in human cells. Alongside mapping known components iron-sensing, determine relative contributions uptake, recycling, ferritin breakdown, and mitochondrial flux controlling labile pool. We also identify SETD2, a histone methyltransferase, as...
We present photometric and spectroscopic observations of galaxies hosting Type Ia supernovae (SNe Ia) observed by the Nearby Supernova Factory (SNfactory). Combining GALEX UV data with optical near infrared photometry, we employ stellar population synthesis techniques to measure SN host galaxy masses, star-formation rates (SFRs), reddening due dust. reinforce key role in deriving accurate estimates SFRs dust extinction. Optical spectra are fitted simultaneously for their continua emission...
Ultra-compact X-ray binaries (UCXBs) are low-mass with hydrogen-deficient mass-donors and ultra-short orbital periods. They have been suggested to be the potential Laser Interferometer Space Antenna (LISA) sources in low-frequency region. Several channels for formation of UCXBs proposed so far. In this article, we carried out a systematic study on He star donor channel, which neutron (NS) accretes matter from main-sequence through Roche-lobe overflow, where mass-transfer is driven by...
ABSTRACT Early-time radiative signals from Type Ia supernovae (SNe Ia) can provide important constraints on the explosion mechanism and progenitor system. We present observations analysis of SN 2019np, a nearby discovered within 1–2 days after explosion. Follow-up were conducted in optical, ultraviolet, near-infrared bands, covering phases ∼−16.7 d to ∼+ 367.8 relative its B-band peak luminosity. The photometric spectral evolutions 2019np resemble average behaviour normal SNe Ia. absolute...
Ultra-massive white dwarfs (UMWDs) with masses larger than 1.05Msun are basically believed to harbour oxygen-neon (ONe) cores. Recently, Gaia data reveals an enhancement of UMWDs on Hertzsprung-Russell diagram (HRD), which indicates that extra cooling delay mechanism such as crystallization and elemental sedimentation may exist in the UMWDs. Further studies suggested a portion should have experienced pretty long delays, implying they carbon-oxygen (CO) WDs. However, formation these UMCOWDs...
ABSTRACT Over the past few years, wide-field time-domain surveys such as Zwicky Transient Facility and Optical Gravitational Lensing Experiment have led to discoveries of various types interesting short-period stellar variables, ultracompact eclipsing binary white dwarfs (WDs), rapidly rotating magnetized WDs, transitional cataclysmic variables between hydrogen-rich helium accretion, blue large-amplitude pulsators (BLAPs), which greatly enrich our understandings physics under some extreme...
ABSTRACT SN 2018hti is a Type I superluminous supernova (SLSN I) with an absolute g-band magnitude of −22.2 at maximum brightness, discovered by the Asteroid Terrestrial-impact Last Alert System in metal-poor galaxy redshift 0.0612. We present extensive photometric and spectroscopic observations this supernova, covering phases from ∼−35 d to more than +340 r-band maximum. Combining our BVgri-band photometry Swift UVOT optical/ultraviolet photometry, we calculated peak luminosity as ∼3.5 ×...
Abstract Although multidimensional simulations have investigated the processes of double white dwarf (WD) mergers, postmerger evolution only focused on carbon–oxygen (CO) or helium (He) WD merger remnants. In this work, we investigate for first time remnants stemming from oxygen–neon (ONe) WDs with CO WDs. Our simulation results indicate that can evolve to hydrogen- and helium-deficient giants a maximum radius about 300 R ⊙ . models show evidence more massive than 1.95 M ignite Ne before...
The double-degenerate model, involving the merger of double carbon-oxygen white dwarfs (CO WDs), is one two classic models for progenitors type Ia supernovae (SNe Ia). Previous studies suggested that off-centre carbon burning would occur if mass-accretion rate (Macc) relatively high during merging process, leading to formation oxygen-neon (ONe) cores may collapse into neutron stars. However, still incompletely understood, especially when inwardly propagating wave reaches centre. In this...
Tsinghua University-Ma Huateng Telescopes for Survey (TMTS), located at Xinglong Station of NAOC, has a field view upto 18 deg^2. The TMTS started to monitor the LAMOST sky areas since 2020, with uninterrupted observations lasting about 6 hours on average each area and cadence 1 minute. Here we introduce data analysis preliminary scientific results first-year observations, which covered 188 plates ( 1970 deg^2). These have generated over 4.9 million light curves, least 100 epochs them....
Context. Although type Ia supernovae (SNe Ia) play a key role in astrophysics, the companions of exploding carbon-oxygen white dwarfs (CO WDs) are still not completely identified. It has been suggested recently that He-rich WD (a He or hybrid HeCO WD) merges with CO may produce an SN Ia. This theory was based on double-detonation model, which shock compression core caused by surface explosion shell might lead to whole WD. However, so far, very few binary population synthesis (BPS) studies...
Type Ia supernovae (SNe Ia) play a crucial role in studying cosmology and galactic chemical evolution. They are thought to be thermonuclear explosions of carbon-oxygen white dwarfs (CO WDs) when their masses reach the Chandrasekar mass limit binaries. Previous studies have suggested that He novae may progenitor candidates SNe Ia. However, retention efficiencies during nova outbursts still uncertain. In this article, we aim study investigate whether can produced through outbursts. Using...
The origin of the progenitors Type Ia supernovae (SNe Ia) is still uncertain. core-degenerate (CD) scenario has been proposed as an alternative way for production SNe Ia. In this scenario, are formed at final stage common-envelope evolution from a merger carbon–oxygen white dwarf (CO WD) with CO core asymptotic giant branch companion. However, birthrates not well determined. work, we performed detailed investigation on CD based binary population synthesis approach. SN delay times basically...
In this paper, we report the detection and follow-ups of a super stellar flare GWAC\,181229A with an amplitude $\Delta R\sim$9.5 mag on M9 type star by $\text{SVOM/GWAC}$ dedicated follow-up telescopes. The estimated bolometric energy $E_{bol}$ is $(5.56-9.25)\times10^{34}$ ergs, which places event to be one most powerful flares ultracool stars. magnetic strength inferred (3.6-4.7) kG. Thanks sampling cadence 15 seconds, new component near peak time very steep decay detected in $R$-band...
Abstract In this work, we present a catalog of cataclysmic variables (CVs) identified from the sixth data release (DR6) Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). To single out CV spectra, introduce novel machine-learning algorithm called UMAP to screen total 169,509 H α emission and obtain classification accuracy over 99.6% cross-validation set. We then apply template-matching program PyHammer v2.0 LAMOST spectra optimal spectral type with metallicity, which help us...
Type Ia supernovae (SNe Ia) play an important role in studies of cosmology and galactic chemical evolution. They are believed to be thermonuclear explosions carbon-oxygen white dwarfs (CO WDs) when their masses approach the Chandrasekar (Ch) mass limit. However, it is still not completely understood how a CO WD increases its Ch-mass limit classical single-degenerate (SD) model. In this paper, we studied accretion process SD model examine whether can explode as SN Ia. Employing stellar...