Conveners
Contributed talks: Day 1 Session 1
- Franz Bauer (Universidad de Tarapaca)
Contributed talks: Day 1 Session 2
- Franz Bauer (Universidad de Tarapaca)
Contributed talks: Day 1 Session 3
- Fuyan Bian (European Southern Observatory)
Contributed talks: Day 1 Session 4
- Fuyan Bian (European Southern Observatory)
Contributed talks: Day 2 Session 1
- Jiasheng Huang (NAOC/CASSACA)
Contributed talks: Day 2 Session 2
- Jiasheng Huang (NAOC/CASSACA)
Contributed talks: Day 2 Session 3
- Quentin Parker (LSR, HKU)
Contributed talks: Day 2 Session 4
- Quentin Parker (LSR, HKU)
Contributed talks: Day 3 Session 1
- Chenggang Shu (Shanghai Normal University)
Contributed talks: Day 2 Session 2
- Chenggang Shu (Shanghai Normal University)
Contributed talks: Day 4 Session 1
- Guido Garay (Universidad de Chile)
Contributed talks: Day 4 Session 2
- Guido Garay (Universidad de Chile)
Contributed talks: Day 4 Session 3
- Francisco Forster (Universidad de Chile)
Contributed talks: Day 4 Session 4
- Francisco Forster (Universidad de Chile)
Contributed talks: Day 5 Session 1
- Patricio Rojo (U Chile)
Contributed talks: Day 5 Session 2
- Patricio Rojo (U Chile)
In this talk, I will present a study using the accretion disk fitting method to measure black hole masses in quasars at z~6. The quasar sample includes 42 quasars at a redshift range of 5.8 < z < 6.5 selected from the XQR-30, which is an ESO large program to obtain deep X-shooter spectra of quasars at z~6. We derived the supermassive black hole mass using the slim and thin disk models adopted...
I will present our progress of quasar surveys in China, including LAMOST quasar survey, luminous high-redshift quasar survey and Galactic Plane background quasar survey. These surveys discovered more than 30k quasars at z=0-5, 100 quasars at z>5 and 1500 quasars behind the Galactic Plane respectively, and provided valuable database for studying changing-look quasars, supermassive black hole...
A prominent feature of Active Galactic Nuclei (AGNs) is their significant X-ray emission. However, we have systematically discovered a class of AGNs characterized by extreme X-ray weakness (more than 10 times weaker) and extreme X-ray variability transitioning from a weak state to a normal state. These AGNs do not exhibit corresponding significant variations in optical-infrared continuum or...
High-redshift ($z \gtrsim 6$) quasars are signposts of the earliest supermassive black holes and intense star formation, offering key laboratories for black hole--galaxy evolution at cosmic dawn. While far-infrared studies revealed large dust reservoirs and strong [C II] emission, the physical condition and molecular gas content of their interstellar medium (ISM) remain uncertain.
We present...
The energy released by active galactic nuclei (AGNs) is considered to have a profound impact on the cold gas properties of their host galaxies, potentially heating or removing the gas and further suppressing star formation. To understand the feedback from AGN radio activity, we investigate its impacts on the cold gas reservoirs in AGNs with different radio activity levels. We construct a...
Strong nebular emission lines in the optical are routinely used to study the ISM of galaxies. In fact, thanks to the JWST, such measurements are now possible for galaxies at very high redshifts (z>7), well into the epoch of reionization (EoR). Often, the physical properties derived from these lines rely on local calibrations that are not necessarily accurate for the extreme populations that...
The study of distant galaxy groups and clusters at the peak epoch of star formation has been limited by the lack of a statistically significant, homogeneously selected, and spectroscopically confirmed sample, with most wok focusing on individual case studies. We carried out a large NOEMA program, the Noema formIng Cluster survEy (NICE), to spectroscopically confirm the nature of 65...
We present a detailed stellar population and dust-continuum analysis of the strongly lensed dusty star-forming galaxy (DSFG) PLCK G165.7+49.0 DSFG-1 (the โEmeraldโ) at z = 2.236, based on JWST NIRCam imaging and Submillimeter Array (SMA) millimeter observations. The system is multiply imaged into two components: image 1a, with a moderate magnification of ฮผ โ 3.8, and image 1bc, with an extreme...
Recent JWST observations have shed light on galaxy assembly and evolution from cosmic reionization to cosmic noon. In this talk, I will review some recent work in our group. First, we focus on [OIII]-bright galaxies at z~7. By spatially resolved studies of hundreds of these โLittle Green Dotsโ, we find these galaxies exhibit compact, centrally concentrated star formation, rising star formation...
Using state-of-the-art reduction methods, we analyze the new JWST data acquired by the NIRISS/NIRCam wide-field slitless spectroscopy (WFSS) and NIRSpec in the multi-object slit-stepping spectroscopy mode. These complementary spectroscopic data sets obtained from multiple instruments open up key window on unbiased investigation of star formation, feedback, and ISM properties in and beyond the...
The Leighton Chajnantor Telescope (LCT) project is poised to open new opportunities for large astronomical surveys and advanced technology development at submillimetre wavelengths. The project will relocate the worldโs most accurate 10-m-class submm telescopeโthe Leighton Telescope of the former Caltech Submillimeter Observatory (CSO)โfrom Maunakea to a superior observing site on Cerro Toco...
The report comprehensively presents our recent advancements in ground-based solar coronagraph research, particularly the achievements in western solar site selection and the development of medium-small aperture coronagraphs. We are also planning to construct larger-aperture coronagraphs and develop advanced terminal observation systems to study the fine structure and dynamic characteristics of...
The Sun Yat-sen University (SYSU) 80 cm infrared telescope was commissioned in October 2024 at the Lenghu Observatory on the Tibetan Plateau, China. The telescope is equipped with J and K band cameras and is designed for time-domain observations in the near-infrared. Its primary scientific goals include follow-up observations of high-energy transients, such as gamma-ray bursts (GRBs) and...
Leighton Chajnator Telescope (LCT, i.e., the former Caltech Submillimeter Observatory telescope) will be reassembled in Chile in 2026. Reassembly of its 10.4m segmented primary reflector is of great importance because it determines the surface accuracy and hence the performances of the antennaโs radiation pattern, which has significant influence on the angular resolution of the telescope. In...
The reflector panel of large aperture submillimeter wave telescopes usually adopts the sub aperture splicing method, and its surface accuracy depends on the production accuracy of splicing a single sub aperture panel and the splicing accuracy of multiple sub apertures. This paper takes the main reflector of Xue-shan-mu-chang 15-meter Submillimeter Telescope๏ผXSMT๏ผ as the research object, and...
Detection and characterization of exoplanets is at the forefront of astronomical research, and over 6000 exoplanets have been detected and confirmed up to now. Most successful high-contrast instruments are available on highly competitive 8~10-meter class telescope (e.g., GPI@Gemini, SPHERE@VLT, IRCS@Subaru, NIRC2@Keck).
In this presentation, a new ground-based instrumentation HIF...
As a space telescope, the China Space Station Survey Telescope (CSST) will face significant challenges from cosmic ray (CR) contamination. These CRs will severely degrade image quality and further influence scientific analysis. Due to the CSST's sky survey strategy, traditional multi-frame stacking methods become invalid. The limited revisits prompted us to develop an effective single-image CR...
The Chinese Space Station Survey Telescope (CSST) is Chinaโs first 2-meter-aperture space telescope. Over a period of ten years, the Survey Camera (SC) on CSST will perform 17500 deg$^2$ wide-field and 400 deg$^2$ deep-field multi-band imaging and slit-less spectroscopic surveys, covering a wavelength range of 255-1000nm. The SC focal plane array consists of 31 charge-coupled devices (CCD) of...
Hot dust-obscured galaxies (Hot DOGs) are a rare class of hyper-luminous, dust-obscured quasars with accretion rates approaching or exceeding the Eddington limit. They are likely in a critical phase of galaxy evolution, where intense AGN-driven outflows exert feedback effects on their host galaxies and subsequently suppress star formation. W2246-0526 at z = 4.6, the brightest known Hot DOG and...
The galaxy massโmetallicity relation is essential for chemical evolution studies, yet its dependence on star formation rate (the so-called fundamental metallicity relation) remains contentious due to different metallicity calibrations. We present a photoionization modelโbased metallicity calibration that yields selfโconsistent metallicity and ionization parameter estimates for MaNGA galaxies...
Dating the ages and weighting the stellar populations in galaxies are essential steps when studying galaxy formation through cosmic times. Evolutionary population synthesis models with different input physics are used for this purpose. Moreover, the contribution from the thermally pulsing asymptotic giant branch (TP-AGB) stellar phase, which peaks for intermediate-age 0.6โ2 Gyr systems, has...
Accuracy photometric redshift (photo-z) estimation is crucial in imaging surveys. We present the photo-z estimation by the normalizing flow, a powerful deep learning method that can approximate complex probability distribution. We demonstrate that the method is able to give reliable photo-z estimation across a number of datasets. Besides accurate photo-z estimation, the characterization of the...
Before and during cosmic reionization, the universe is filled with small gaseous structures, e.g. minihalos (with halo mass between 10^4 and 10^8 solar mass). These structures can influence the 21cm signal and slow down the ionization fronts during cosmic reionization.
To investigate their influence, we perform high resolution cosmological simulations using our newly-developed moment-based...
Our current knowledge of galaxy formation and evolution relies on the comprehensive analysis of data which are analyzed using SED fitting techniques. The insights from these observations have been used for the development of sophisticated cosmological hydrodynamic simulations. Currently at the forefront of exploring galaxy evolution our community uses extensively data from JWST and...
The ongoing and upcoming space-based planet survey missions, such as TESS, PLATO, and ET, are expected to discover thousands of small- to medium-sized planets via the transit method, including over 100 potentially habitable rocky planets. To further study these terrestrial planets, especially those with lower temperatures and wider orbits, the exoplanetary science community has proposed...
The Wide Field Survey Telescope (WFST) is a dedicated photometric surveying facility being built jointly by University of Science and Technology of China (USTC) and the Purple Mountain Observatory (PMO). It is equipped with a 2.5-meter diameter primary mirror, an active optics system, and a mosaic CCD camera with 0.73 gigapixels on the primary focal plane for high-quality image capture over a...
The filamentary pattern in which the Universe's matter concentrates, the cosmic web, is predicted by the ฮCDM cosmological model and contains the majority of the universe's matter. Detailed mapping of this interconnected structure of gaseous filaments, galaxies, quasars, dark matter, and voids, is central to a comprehensive understanding of the origin and evolution of our Universe. Deep,...
We present a search for new spider pulsar candidates through multi-wavelength cross-matching, including $\gamma$-ray, X-ray, and optical data. A search for sinusoidal-like optical modulations in TESS data of 183 eROSITA X-ray sources coincident with unassociated \textit{Fermi}-LAT $\gamma$-ray sources led to the identification of four promising spider pulsar candidates. We found optical...
This report articulates a two-fold investigation. First, it establishes Pulsar Wind Nebulae (PWNe) as a pivotal source class for the acceleration of Galactic cosmic rays (CRs), concentrating on the origin and propagation of CR protons. The analysis delineates the proton acceleration mechanism at the PWN termination shock and their ensuing escape into the interstellar medium. A key finding is...
Radio transients, such as pulsars and fast radio bursts (FRBs), are primarily detected at centimetre (cm) radio wavelengths, where higher luminosities are found. However, could we study them at millimetre (mm) waves? For pulsars, this window remains poorly studied, but it represents a stepping stone to connecting the cm-radio emission with infrared/optical wavelengths and to discerning where...
Over the years, the Xinjiang Astronomical Observatory of the Chinese Academy of Sciences (XAO) has established itself as one of the leading institutions in pulsar research in China. Through sustained efforts in pulsar observation and analysis, the XAO has developed substantial expertise and generated a series of findings with significant academic impact. In this presentation, we will provide a...
Spectra of ultracool stars exhibit strong absorption features by water-vapor in their atmospheres. Normally, ground-based observations in 1.4 $\mu m$ are limited by strong absorption of telluric water-vapor. However, Dome A, Antarctica has exceptionally dry conditions that offer a unique opportunity for observations in this band. We designed a new filter covering 1.34--1.48 $\mu m$, namely...
Supernovae are related to many frontiers of astrophysics, i.e., from probes of extreme physics to discovery of accelerating unvierse. Their distribution and birth rates can help constrain progenitor models and stellar evolution theory. Thanks to the wide-field transient surveys conducted over the past decade, the discovery of nearby supernovae tends to be relatively complete. We compiled a...
Star formation is a complex, multi-variate process, with competing physical mechanisms (e.g., gravity, turbulence, magnetic field) being entangled. What determines the rate and efficiency of star formation remains a fundamental question in the field of star formation. We Utilize the probability distribution function of gas column density (N-PDF) to separate turbulence-dominated gas and...
Star formation is a complex process shaped by the interplay of gravity, magnetic fields, turbulence, etc. Recent polarization observations find that the magnetic field's significance across various stages of star formation, yet its precise role remains elusive. Here, we present studies of diverse star-forming regions to explore how magnetic field behavior varies across different environments.
Hong Kong is rapidly positioning itself within the global Space economy, supported by a new wave of entrepreneurial actors and recent regulatory developments enabling space-related innovation. Entrepreneurial ecosystem research shows that high-growth entrepreneurship depends on the configuration of culture, networks, finance, policy, and human capital rather than isolated firms or instruments...
Unveiling the true nature of Dark Matter (DM), which manifests itself only through gravity, is one of the principal quests in physics. Leading candidates for DM are weakly interacting massive particles (WIMPs) or ultralight bosons (axions), at opposite extremes in mass scales, that have been postulated by competing theories to solve deficiencies in the Standard Model of particle physics....
Optical strong-line ratio diagnostics are standard tools for diagnosing the physical conditions of ionised gas in star-forming galaxies. However, traditional 2D BPT diagrams are not optimal for visualising inconsistency between data and model in multi-D line ratio space due to poor projection angles. Ji & Yan 2020 showed that using reprojections of 3D line ratio space will help visualise the...
Cosmological hydrodynamical simulations are one of the most important methods to understand galaxy formation and evolution. Current hydro-simulations are able to produce many observables in the galaxy surveys. However, detailed comparisons between simulations and observations indicate apparent discrepancies. This raises the question whether the discrepancy is caused by the wrong physical...
In the standard cosmology, dark matter drives the structure formation of galaxies and constructs potential wells within which galaxies may form. The baryon fraction in dark halos can reach the Universal value (15.7%) in massive clusters and decreases rapidly as the mass of the system decreases. The formation of dwarf galaxies is sensitive both to baryonic processes and the properties of dark...
The gas cycle, comprising both inflow and outflow, is critical to galaxy evolution. Within this cycle, cold gas supplies raw material for star formation and black hole growth via inflow, and dominates the mass and energy of outflow. To investigate the role of cold gas cycle in galaxy evolution, we firstly collected a sample of gas-star misaligned galaxies from the MaNGA survey, which are...
The Hong Kong / AAO / Strasbourg H-alpha Planetary Nebulae research platform and catalogue "HASH" has become the gold standard community resource when working on Galactic and Magellanic Cloud PNe with more than 1200 registered users 60+ countries. I will present the current state of play and recent research highlights from our HKU based HASH team and the legacy and future of HASH as its...
Only 5 Planetary Nebulae (PNe) among the previously known Galactic Open Cluster (OC) population of โผ 1,100 are known to date. They are extremely valuable because their properties can be directly linked to their progenitor stars, something that cannot be done for PNe in the general field. Since the first data release of the GAIA astrometric satellite, โ7,200 new OC candidates have been...
HuBi 1 is a born-again PNe that underwent a very late thermal pulse (VLTP). The previous research suggests it experienced a rapid brightness decline over five decades, mostly attributable to dust obscuration formed through VLTP. Furthermore, VLTP-born-again objects experience a brightening phase due to the expansion of the star driven by the He-shell flash before the formation of the dust. In...
The satellite galaxies around our Milky Way (MW) are excellent laboratories for studying stellar evolution and galaxy evolution under different environments, even testing various cosmological models. Recently, we derived up to 13 chemical abundances in several MW satellite galaxies (e.g., Fnx, Scl) using high-resolution APOGEE spectra. Particularly, [Si/Fe] vs. [Fe/H] graph shows patterns...
We present a new two-fluid conduction scheme to simulate the evolution of an isolated, self-gravitating, equilibrium cluster of stars and collisionless dark matter on secular (gravothermal) timescales. We integrate the equations in Lagrangian coordinates via a second-order, semi-implicit algorithm, which is unconditionally stable when the mass of the lighter species is much less than that of...
The year 2025 marks a milestone in exoplanet research, commemorating three decades since the groundbreaking discovery of 51 Peg bโthe first planet found orbiting a Sun-like star. This seminal achievement, which earned the 2019 Nobel Prize in Physics, inaugurated an entirely new field of astronomy. Over the past thirty years, the field has evolved from initial, sporadic discoveries to the...
We will report on our recent progress in the atmospheric characterizations of exoplanets, using ground-based telescopes, including the 4.1m SOAR telescope, VLT, and CFHT. We have studied 5 hot Jupiters (WASP69b, 121b, 77Ab, 85Ab and MASCARA-4b) with low-resolution transmission spectroscopy and/or high-resolution Doppler spectroscopy. We demonstrate that a 4m class ground-based telescope can...
Spectroscopic observations of ultra-hot Jupiters (UHJs) are a primary means of understanding their origins and the formation mechanisms of their atmospheric structures. The James Webb Space Telescope (JWST), with its broad spectral coverage and high-precision instrumentation from near- to mid-infrared wavelengths, provides an ideal opportunity to probe the chemistry and physics in these...
We present N-body simulations of the Solar System incorporating non-gravitational forces (NGFs) generated by volatile sublimation in comets, using the REBOUND code. Our study focuses on quantifying how these jet forces influence comet dynamics and their role in delivering water to early Earth. By tracking close approaches within Earth's Hill sphere, we evaluate how NGFs modified the impact...
Dust particles are the dominant source of opacity at infrared and (sub)millimeter wavelengths. While accurate dust opacities are crucial for modeling protoplanetary disks properties, their estimation is highly uncertain in this regime: dust opacities values used in models are mostly extrapolations in wavelength and grain sizes. To tackle this problem we have established the UDP Cosmic Dust...
Highly excited molecules and clusters can emit visible and infrared radiation from thermally excited electronic states. This radiation, known as recurrent fluorescence, is particularly intense for carbon clusters and carbon-based molecules due to their high stabilities which allows them to store large amounts of excitation energy and thereby have the possibility to promote electrons to...
The lack of natural sources of carbon fullerenes on Earth and within the solar system is one of the puzzles of astrochemistry, astrophysics and planetary science. Recently, Sittler et al. [1] have hypothesized that the ionospheric formation of these exotic species in the Titan atmosphere can occur from simple molecules such as methane. This can change our understanding of the carbon cycle...
The exoplanet group at Universidad de Chile conducts a broad range of research on exoplanets and planetary atmospheres. This work is made possible through the efforts of several students and collaborations with focus in the analysis of ground-base observations using state-of-the-art techniques and instrumentation. In this talk, I will summarize both published and ongoing projects, which...
Young planets offer a unique window into the early stages of planetary evolution. Insights into their orbital architectures are powerful to trace their formation environment and constrain the timescales of various dynamical processes. AU Mic is one of the nearest pre-main sequence stars (โผ20 Myr), hosting 2 Neptune-sized planets and a debris disk. Previous studies have shown that the rotation...
A tidal disruption event (TDE) occurs when a star passes within the tidal radius of a supermassive black hole (SMBH). In TDEs it is expected that the orbital angular momentum of the disrupted star is generally misaligned with the SMBH spin axis, which should result in a misaligned super-Eddington disk precessing around the SMBH spin axis due to the Lense-Thirring effect. In this paper, we...
Magnetic fields are believed to play a crucial role in star formation and have been detected across all evolutionary stages. Their strengths have been measured in both the early, pre-stellar core stage and the later, well-formed protostellar and disk stages. However, during the intermediate stageโwhen the envelope is rapidly infalling and assembling the starโdisk systemโno robust method exists...
We conducted a series of VLT/FORS2 spectroscopic observations targeting a sample of fast X-ray transients and optical counterparts discovered by the Einstein Probe during 2024A. The observed events include supernova-like transients, GRBโassociated events, and other rapidly evolving extragalactic sources. These observations provide key redshift measurements and early-time spectral features that...
The origins of cosmic dust remain a mystery, with supernovae (SNe) identified as significant contributors to dust production. Molecule formation following SNe explosions plays a crucial role in this process, as it efficiently cools the ejecta to a temperature suitable for dust condensation. To date, carbon monoxide (CO) molecules have been observed in only a few core-collapse SNe. In this...
Massive stars end their lives as core-collapse supernovae, among which
some extremes are broad-lined type Ic supernovae from WolfโRayet stars
associated with long-duration gamma-ray bursts (LGRBs) with powerful
relativistic jets. Their less-extreme brethren make unsuccessful jets that are choked inside the stars, appearing as X-ray flashes or low-luminosity GRBs. However, there exists a...
Vector-tensor theories of gravity have received renewed attention in recent years as a compelling candidate to explain cosmic acceleration in a dynamical way, while also addressing the shortcomings of the more familiar scalar-tensor class of models. After a review of these developments, I will present a novel theory characterized by its simplicity and phenomenological features: it predicts...
Low-mass galaxies are the building blocks of massive galaxies in the framework of hierarchical structure formation. To enable a detailed study of their galactic ecosystems by spatially resolving different galactic components, we conducted the Dwarf Galaxy Integral-field Survey (DGIS) using VLT/MUSE and ANU-2.3m/WiFeS. The sample comprises 63 dwarf galaxies at a spatial resolution of 10-100 pc....
Dust attenuation modifies the spectra of galaxies over a wide range of wavelength. Integral field spectroscopy surveys of nearby galaxies such as MaNGA, NUV imaging from Swift/UVOT and NIR imaging from 2MASS combine to provide measurements of dust attenuation curves at ~3 arcsec resolution, corresponding to ~kpc scales in nearby galaxies. I will present these measurements for a sample of ~500...
The QiTai radio Telescope (QTT) is a fully steerable, Gregorian-type telescope with an aperture diameter of 110 meters. It is located in Qitai County, Xinjiang Uygur Autonomous Region, China. Construction of the QTT began in 2022 and is scheduled for completion in 2028. The observing frequency range of the QTT spans from 150 MHz to 115 GHz. The QTT features an active main surface, with...
