A5085316826- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Catalysis for Biomass Conversion
- Advanced Battery Materials and Technologies
- Advancements in Battery Materials
- Electrocatalysts for Energy Conversion
- Carbon Nanotubes in Composites
- Porphyrin and Phthalocyanine Chemistry
- Magnetic and Electromagnetic Effects
- Astrophysics and Cosmic Phenomena
- Advanced Battery Technologies Research
- Electromagnetic Fields and Biological Effects
- Space Exploration and Technology
- Fullerene Chemistry and Applications
- Molecular Spectroscopy and Structure
- Cancer therapeutics and mechanisms
- Advanced Condensed Matter Physics
- Catalysis and Oxidation Reactions
- Catalysis and Hydrodesulfurization Studies
- Catalytic Processes in Materials Science
University of Hertfordshire
2018-2025
University of Valparaíso
2022-2025
Millennium Institute of Astrophysics
2025
Millenium Nucleus for Planet Formation
2022-2024
Federico Santa María Technical University
2023-2024
Tongji University
2024
Shanghai Tenth People's Hospital
2024
East China University of Science and Technology
2020-2022
Peking University
2015-2022
Jilin Medical University
2021-2022
We present ground-based and Swift photometric spectroscopic observations of the candidate tidal disruption event (TDE) ASASSN-14li, found at center PGC 043234 ($d\simeq90$ Mpc) by All-Sky Automated Survey for SuperNovae (ASAS-SN). The source had a peak bolometric luminosity $L\simeq10^{44}$ ergs s$^{-1}$ total integrated energy $E\simeq7\times10^{50}$ radiated over $\sim6$ months presented. UV/optical emission is well-fit blackbody with roughly constant temperature $T\sim35,000$ K, while...
Novel covalently porphyrin-functionalized single-walled carbon nanotubes (SWNTs) have been synthesized by the reaction of SWNTs with in situ generated porphyrin diazonium compounds. The resulting nanohybrid was characterized spectroscopic (UV-Vis-NIR, FTIR and Raman) microscopic (TEM AFM) methods. Raman absorption spectroscopy data showed that electronic properties modified tubes were mostly retained, without damaging their one-dimensional properties. fluorescence from moiety almost...
Abstract We present early-time, hour-to-day cadence spectroscopy of the nearby Type II supernova (SN II) 2024ggi, which was discovered at a phase when SN shock had just emerged from red supergiant (RSG) progenitor star. Over first few days after light, 2024ggi exhibited prominent narrow emission lines formed through intense and persistent photoionization circumstellar material (CSM). In 63 hr, spectral He, C, N, O revealed rapid rise in ionization as result progressive sweeping up CSM by...
ABSTRACT During the pre-main-sequence (pre-MS) evolution stage of a star, significant amounts stellar mass are accreted during episodic accretion events, such as multidecade FUor-type outbursts. Here, we present near-infrared spectroscopic follow-up study 33 high-amplitude (most with ΔKs > 4 mag) variable sources discovered by Vista Variables in Via Lactea (VVV) survey. Based on spectral features, 25 classified eruptive young objects (YSOs), including 15 newly identified FUors, six...
We present basic statistics for all supernovae discovered by the All-Sky Automated Survey SuperNovae (ASAS-SN) during its first year-and-a-half of operations, spanning 2013 and 2014. also same information other bright ($m_V\leq17$), spectroscopically confirmed from 2014 May 1 through end 2014, providing a comparison to ASAS-SN sample starting point where became operational in both hemispheres. In addition, we collected redshifts near-UV IR magnitudes, available, host galaxies samples. This...
ABSTRACT Episodic accretion is one of the competing models to explain observed luminosity spread in young stellar clusters. These short-lived high events could also have a strong impact on planet formation. Observations high-amplitude variability objects (YSOs) due large changes rate provide direct observational evidence for episodic accretion. However, there are still uncertainties frequency these and if universal among YSOs. To determine outbursts Class I YSOs, we built robust sample at...
We have performed a comprehensive search of VISTA Variables in the Via Lactea (VVV) database 9.5 yr light curves for variable sources with $\Delta K_s \ge 4$ mag, aiming to provide large sample high amplitude eruptive young stellar objects (YSOs) and detect unusual or new types infrared source. find 222 transient Galactic bulge disc, most which are discoveries. The mainly comprises novae, YSOs, microlensing events, Long Period Variable stars (LPVs) few rare unclassified sources....
Context. The ESO public survey VISTA Variables in the Vía Láctea (VVV) surveyed inner Galactic bulge and adjacent southern disk from 2009–2015. Upon its conclusion, complementary VVV extended (VVVX) has expanded both temporal as well spatial coverage of original area, widening it 562 to 1700 sq. deg., providing additional epochs JHK s filters 2016–2023. Aims. With completion VVVX observations during first semester 2023, we present here observing strategy, a description data quality access,...
Abstract The mass accretion process controls pre-main-sequence evolution, although its intrinsic instability has yet to be fully understood, especially towards the protostellar stage. In this work, we have undertaken a thorough examination of mid-infrared variability Spitzer-selected YSOs in Cygnus-X star-forming region over last decade, using NEOWISE time series. This work compares two groups young stars: embedded Class I objects, and more evolved flat-spectrum/Class II sources. We report...
This manuscript presents information for all supernovae discovered by the All-Sky Automated Survey SuperNovae (ASAS-SN) during 2015, its second full year of operations. The same is presented bright (mV ≤ 17), spectroscopically confirmed other sources in 2015. As with first ASAS-SN supernova catalogue, we also present redshifts and near-ultraviolet through infrared magnitudes host galaxies both samples. Combined our previous this work comprises a complete catalogue 455 from multiple...
Abstract We present the four-year survey results of monthly submillimeter monitoring eight nearby (<500 pc) star-forming regions by JCMT Transient Survey. apply Lomb–Scargle Periodogram technique to search for and characterize variability on 295 peaks brighter than 0.14 Jy beam −1 , including 22 disk sources (Class II), 83 protostars 0/I), 190 starless sources. uncover 18 secular variables, all them protostars. No single-epoch burst or drop events no inherently stochastic are observed....
Abstract The Hubble UV Legacy Library of Young Stars as Essential Standards (ULLYSES) Director’s Discretionary Program low-mass pre-main-sequence stars, coupled with forthcoming data from Atacama Large Millimeter/submillimeter Array and James Webb Space Telescope, will provide the foundation to revolutionize our understanding relationship between young stars their protoplanetary disks. A comprehensive evaluation physics disk evolution planet formation requires intricate relationships mass...
Abstract Accretion plays a central role in the physics that governs evolution and dispersal of protoplanetary disks. The primary goal this paper is to analyze stability over time mass accretion rate onto TW Hya, nearest accreting solar-mass young star. We measure veiling across optical spectrum 1169 archival high-resolution spectra obtained from 1998–2022. then converted using 26 flux-calibrated cover Balmer jump. measured excess continuum has an average 2.51 × 10 −9 M ⊙ yr −1 Gaussian...
The mass accretion process controls pre-main-sequence evolution, although its intrinsic instability has yet to be fully understood, especially towards the protostellar stage. In this work, we have undertaken a thorough examination of mid-infrared variability Spitzer-selected YSOs in Cygnus-X star-forming region over last decade, using NEOWISE time series. This work compares two groups young stars: embedded Class I objects, and more evolved flat-spectrum/Class II sources. We report on 48...
Context . High reddening near the Galactic plane hampers observations and proper characterization of globular clusters (GCs) located toward inner regions Milky Way. Aims The VISTA Variables in Vía Láctea (VVV) survey observed bulge adjacent disk for several years, providing multi-epoch, near-infrared images 41 GCs. Detecting RR Lyrae variable stars belonging to these GCs will aid their accurate parameterization. Methods By fully leveraging astrometric, photometric, variability VVV catalogs,...
High reddening near the Galactic plane hampers observations and proper characterization of globular clusters (GCs) located toward inner regions Milky Way. The VISTA Variables in Via Lactea (VVV) survey observed bulge adjacent disk for several years, providing multi-epoch, near-infrared images 41 GCs. Detecting RRLyrae variables belonging to these GCs will aid their accurate parameterization. By fully leveraging astrometric, photometric, variability VVV catalogs, we searched stars associated...
Pt nanoparticles supported on multiwalled carbon nanotubes (MWNT) were synthesized and applied in the catalytic hydrogenation of furfural, model reaction mild stabilization reactive bio-oil. The properties catalysts modified by changing surface concentration oxygen-containing groups (OCGs) MWNT. Various characterization techniques, including fluorescent labeling, nitrogen physisorption, powder X-ray diffraction, transmission electron microscopy, situ DRIFTS analysis, employed to study both...
Lanthanum phosphate (LaP) nano-rods were synthesized using n-butylamine as a shape-directing agent (SDA). The resulting catalysts applied in the dehydration of lactic acid to acrylic acid. Aiming understand nature active sites, chemical and physical properties LaP materials studied variety characterization techniques. This study showed that SDA not only affected porosity but also modified acid-base properties. Clearly, modification played more critical role determining catalytic performance...