Jun Yi Koay
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View article: Ring or No Ring—Revisiting the Multiphase Nuclear Environment in M31
Ring or No Ring—Revisiting the Multiphase Nuclear Environment in M31 Open
Nuclear rings, prevalent in barred galaxies, are essential to understanding gas transport toward galactic nuclei. However, the peculiar nuclear ring in our neighboring galaxy M31 remains poorly understood. Here we present a comprehensive s…
View article: Probing the Hot Gaseous Halo of the Low-mass Disk Galaxy NGC 7793 with eROSITA and Chandra
Probing the Hot Gaseous Halo of the Low-mass Disk Galaxy NGC 7793 with eROSITA and Chandra Open
Galaxy formation models predict that local galaxies are surrounded by hot X-ray-emitting halos, which are technically difficult to detect due to their extended and low surface brightness nature. Previous X-ray studies have mostly focused o…
View article: The HASHTAG project II. Giant molecular cloud properties across the M31 disc
The HASHTAG project II. Giant molecular cloud properties across the M31 disc Open
We present a study of giant molecular cloud (GMC) properties in the Andromeda galaxy (M31) using CO(3-2) data from the James Clerk Maxwell Telescope (JCMT) in selected regions across the disc and in the nuclear ring, and comparing them wit…
View article: Flares in the changing look AGN Mrk 590 – II. Deep X-ray observations reveal a Comptonizing inner accretion flow
Flares in the changing look AGN Mrk 590 – II. Deep X-ray observations reveal a Comptonizing inner accretion flow Open
Mrk 590 is a changing look active galactic nucleus (AGN) currently in an unusual repeat X-ray and UV flaring state. Here, we report on deep X-ray observations with XMM–Newton, NuSTAR, and NICER, obtained at a range of X-ray flux levels. We…
View article: Prediction for close approaches with terrestrial planets of asteroids from the main belt
Prediction for close approaches with terrestrial planets of asteroids from the main belt Open
Potentially Hazardous Asteroids (PHAs), a special subset of Near-Earth Objects, are both dangerous and scientifically valuable. PHAs that truly undergo close approaches with the Earth (dubbed CAPHAs) are of particular interest and extensiv…
View article: Prediction for close approaches with terrestrial planets of asteroids from the main belt
Prediction for close approaches with terrestrial planets of asteroids from the main belt Open
Potentially Hazardous Asteroids (PHAs), a special subset of Near-Earth Objects, are both dangerous and scientifically valuable. PHAs that truly undergo close approaches with the Earth (dubbed CAPHAs) are of particular interest and extensiv…
View article: Demographics of black holes at $<$100 R$_{\rm g}$ scales: accretion flows, jets, and shadows
Demographics of black holes at $<$100 R$_{\rm g}$ scales: accretion flows, jets, and shadows Open
Using the Event Horizon Telescope (EHT), the gravitationally lensed rings around the supermassive black holes (SMBHs) in Messier 87 (M87) and Sagittarius A* (Sgr A*) have now been successfully imaged at a resolution under 10 gravitational …
View article: Robust Detection of Hot Intragroup Medium in Optically Selected, Poor Galaxy Groups by eROSITA
Robust Detection of Hot Intragroup Medium in Optically Selected, Poor Galaxy Groups by eROSITA Open
Over the last several decades, extensive research has been conducted on the baryon cycles within cosmic structures, encompassing a broad mass range from dwarf galaxies to galaxy clusters. However, a notable gap in understanding the cosmic …
View article: The Faraday Rotation Measure of the M87 Jet at 3.5 mm with ALMA
The Faraday Rotation Measure of the M87 Jet at 3.5 mm with ALMA Open
Faraday rotation is an important probe of the magnetic fields and magnetized plasma around active galactic nuclei jets. We present a Faraday rotation measure (RM) image of the M87 jet between 85.2 and 101.3 GHz with a resolution of ∼2″ wit…
View article: Automated compound speciation, cluster analysis, and quantification of organic vapors and aerosols using comprehensive two-dimensional gas chromatography and mass spectrometry
Automated compound speciation, cluster analysis, and quantification of organic vapors and aerosols using comprehensive two-dimensional gas chromatography and mass spectrometry Open
The advancement of analytical techniques, such as comprehensive two-dimensional gas chromatography coupled with mass spectrometry (GC×GC–MS), enables the efficient separation of complex organics. Developing innovative methods for data proc…
View article: The Faraday rotation measure of the M87 jet at 3.5mm with the Atacama Large Millimeter/submillimeter Array
The Faraday rotation measure of the M87 jet at 3.5mm with the Atacama Large Millimeter/submillimeter Array Open
Faraday rotation is an important probe of the magnetic fields and magnetized plasma around active galactic nuclei (AGN) jets. We present a Faraday rotation measure image of the M87 jet between 85.2 GHz and 101.3 GHz with a resolution of ~2…
View article: Mapping Anisotropies in the Stochastic Gravitational-Wave Background with TianQin
Mapping Anisotropies in the Stochastic Gravitational-Wave Background with TianQin Open
In the milli-Hertz frequency band, stochastic gravitational-wave background can be composed of both astronomical and cosmological sources, both can be anisotropic. Numerically depicting these anisotropies can be critical in revealing the u…
View article: First Very Long Baseline Interferometry Detections at 870 μm
First Very Long Baseline Interferometry Detections at 870 μm Open
The first very long baseline interferometry (VLBI) detections at 870 μ m wavelength (345 GHz frequency) are reported, achieving the highest diffraction-limited angular resolution yet obtained from the surface of the Earth and the highest-f…
View article: Spatially Resolved Analysis of Stellar Populations in NGC 2992: Impact of Active Galactic Nucleus Feedback
Spatially Resolved Analysis of Stellar Populations in NGC 2992: Impact of Active Galactic Nucleus Feedback Open
In NGC 2992, a galaxy-scale ionized gas outflow driven by active galactic nuclei (AGNs) has long been recognized, yet its impact on the host galaxy has remained elusive. In this paper, we utilize data from the archival Very Large Telescope…
View article: Observational Evidence for Hot Wind Impact on Parsec Scales in Low-luminosity Active Galactic Nuclei
Observational Evidence for Hot Wind Impact on Parsec Scales in Low-luminosity Active Galactic Nuclei Open
Supermassive black holes in galaxies spend the majority of their lifetime in the low-luminosity regime, powered by hot accretion flow. Strong winds launched from the hot accretion flow have the potential to play an important role in active…
View article: Automated compound speciation, cluster analysis, and quantification of organic vapours and aerosols using comprehensive two-dimensional gas chromatography and mass spectrometry
Automated compound speciation, cluster analysis, and quantification of organic vapours and aerosols using comprehensive two-dimensional gas chromatography and mass spectrometry Open
The advancement of analytical techniques, such as comprehensive two-dimensional gas chromatography coupled with mass spectrometry (GC×GC-MS), enables the efficient separation of complex organic matrix. Developing innovative methods for dat…
View article: Supplementary material to "Automated compound speciation, cluster analysis, and quantification of organic vapours and aerosols using comprehensive two-dimensional gas chromatography and mass spectrometry"
Supplementary material to "Automated compound speciation, cluster analysis, and quantification of organic vapours and aerosols using comprehensive two-dimensional gas chromatography and mass spectrometry" Open
S1. Indicative reaction schemes that are included in the model developmentCompounds containing hydrocarbon chains give rise to a series of ions distant from each other by 14 Da (-CH2-) and the masses where they appear depend on the chemica…
View article: Spatially resolved analysis of Stellar Populations in NGC 2992: Impact of AGN feedback
Spatially resolved analysis of Stellar Populations in NGC 2992: Impact of AGN feedback Open
In NGC 2992, a galaxy-scale ionized gas outflow driven by AGN has long been recognized, yet its impact on the host galaxy has remained elusive. In this paper, we utilize data from the archival Very Large Telescope (VLT)/MUSE to present a s…
View article: Uncovering an Excess of X-Ray Point Sources in the Halos of Virgo Late-type Galaxies
Uncovering an Excess of X-Ray Point Sources in the Halos of Virgo Late-type Galaxies Open
We present a systematic search for extraplanar X-ray point sources around 19 late-type, highly inclined disk galaxies residing in the Virgo cluster, based on archival Chandra observations reaching a source detection sensitivity of L (0.5–8…
View article: MARTIANS (MARs2020, TIANwen and So on) would see more potentially hazardous asteroids than Earthlings
MARTIANS (MARs2020, TIANwen and So on) would see more potentially hazardous asteroids than Earthlings Open
Potentially Hazardous Asteroids (PHAs) are a special subset of Near-Earth Objects (NEOs) that can come close to the Earth and are large enough to cause significant damage in the event of an impact. Observations and researches of Earth-PHAs…
View article: CHANG-ES. XXX. 10 kpc Radio Lobes in the Sombrero Galaxy
CHANG-ES. XXX. 10 kpc Radio Lobes in the Sombrero Galaxy Open
We report the discovery of the 10 kpc scale radio lobes in the Sombrero galaxy (NGC 4594), using data from the Continuum Halos in Nearby Galaxies—an Expanded Very Large Array Survey project. We further examine the balance between the magne…
View article: Uncovering an Excess of X-ray Point Sources in the Halos of Virgo Late-type Galaxies
Uncovering an Excess of X-ray Point Sources in the Halos of Virgo Late-type Galaxies Open
We present a systematic search for extraplanar X-ray point sources around 19 late-type, highly inclined disk galaxies residing in the Virgo cluster, based on archival Chandra observations reaching a source detection sensitivity of $L\rm(0.…
View article: A <i>Chandra</i> search for periodic X-ray sources in the bulge of M31
A <i>Chandra</i> search for periodic X-ray sources in the bulge of M31 Open
We present a systematic search for periodic X-ray sources in the bulge of M31, using ∼2 Ms of archival Chandra observations spanning a temporal baseline of 16 yr. Utilizing the Gregory–Loredo algorithm that is designed for photon-counting,…
View article: A Chandra Search for Periodic X-ray Sources in the Bulge of M31
A Chandra Search for Periodic X-ray Sources in the Bulge of M31 Open
We present a systematic search for periodic X-ray sources in the bulge of M31, using ~ 2 Ms of archival Chandra observations spanning a temporal baseline of 16 years. Utilizing the Gregory-Loredo algorithm that is designed for photon-count…
View article: An X-Ray Census of Active Galactic Nuclei in the Virgo and Fornax Clusters of Galaxies with SRG/eROSITA
An X-Ray Census of Active Galactic Nuclei in the Virgo and Fornax Clusters of Galaxies with SRG/eROSITA Open
We present a uniform and sensitive X-ray census of active galactic nuclei (AGNs) in the two nearest galaxy clusters, Virgo and Fornax, utilizing the newly released X-ray source catalogs from the first all-sky scan of Spectrum-Roentgen-Gamm…
View article: CHANG-ES. XXX. 10 kpc Radio Lobes in The Sombrero Galaxy
CHANG-ES. XXX. 10 kpc Radio Lobes in The Sombrero Galaxy Open
We report the discovery of the 10 kilo-parsec (kpc) scale radio lobes in the Sombrero galaxy (NGC 4594), using data from the Continuum Halos in Nearby Galaxies - an Expanded Very Large Array (VLA) Survey (CHANG-ES) project. We further exam…
View article: Heat-killed Prevotella intermedia promotes the progression of oral squamous cell carcinoma by inhibiting the expression of tumor suppressors and affecting the tumor microenvironment
Heat-killed Prevotella intermedia promotes the progression of oral squamous cell carcinoma by inhibiting the expression of tumor suppressors and affecting the tumor microenvironment Open
Background Oral microbial dysbiosis contributes to the development of oral squamous cell carcinoma (OSCC). Our previous study showed that Prevotella intermedia ( P . intermedia ) were enriched in the oral mucosal surface, plaque, and saliv…
View article: Observational Evidence for Hot Wind Impact on pc-scale in Low-luminosity Active Galactic Nucleus
Observational Evidence for Hot Wind Impact on pc-scale in Low-luminosity Active Galactic Nucleus Open
Supermassive black holes in galaxies spend majority of their lifetime in the low-luminosity regime, powered by hot accretion flow. Strong winds launched from the hot accretion flow have the potential to play an important role in active gal…
View article: An X-ray Census of Active Galactic Nuclei in the Virgo and Fornax Clusters of Galaxies with SRG/eROSITA
An X-ray Census of Active Galactic Nuclei in the Virgo and Fornax Clusters of Galaxies with SRG/eROSITA Open
We present a uniform and sensitive X-ray census of active galactic nuclei (AGNs) in the two nearest galaxy clusters, Virgo and Fornax, utilizing the newly released X-ray source catalogs from the first all-sky scan of SRG/eROSITA. A total o…