arXiv subjects

Lei Hao

Publications and source records attributed to Lei Hao.

At least 19 recordsLinked to original sources

arXiv2026

Widespread Inflows Reveal Baryonic Cycling in Star-forming and Quiescent Galaxies

Cool-gas inflows, required to sustain star formation, have been fundamental in simulations yet remained observationally elusive. Using DESI spectroscopy of ~30,000 galaxies, we identify coherent inflowing gas (~100 km/s) in 20-50% of the sample, yielding a population-level census of gas flows. We uncover a striking inversion: inflows are detected in quiescent galaxies, whereas star-forming systems are dominated by gravitationally bound outflows. At fixed age, galaxies with inflows, outflows, or no/weak flows share similar masses, environments, and structures, indicating that these properties do not differentiate flow states. Instead, gas-flow state is linked to stellar population age and recent evolutionary history, consistent with age-dependent gas flows in two regimes. In some star-forming galaxies, elevated star formation surface densities drive outflows that recycle on ~0.5 Gyr timescales, consistent with a galactic fountain. In quiescent systems, low-level ``drizzling'' inflows persist, consistent with slowly cooling enriched halo gas and weak radio-mode nuclear activity. Broad gas-phase metallicity distributions---and absence of a pristine dilution signature---indicate that detected inflows are predominantly recycled or enriched. Detectability is modulated by dust, ionization, and geometry: in star-forming disks, inflowing gas lies near the disk plane and is obscured or ionized, while outflow hosts exhibit higher dust and metal content. As star formation declines, cold-outflow signatures weaken, and recycled or slowly cooling gas is more readily detected as inflow. Post-starburst galaxies provide snapshots of this transition. Our results resolve the scarcity of observed inflows, provide evidence for widespread gas accretion and recycling in present day galaxies, and establish an observational framework linking gas flows to star formation, chemical evolution, and galaxy structure.

astro-ph.GA↗

arXiv2026

The Structural Abundance Crisis of Massive Galaxies in Current Cosmological Simulations

The internal structure of galaxies encodes the complex baryon cycle driven by gas accretion, star formation, and feedback, together with secular evolution and environmentally driven processes such as mergers and tidal interactions. We present a population-level census of massive nearby galaxies ($\log(M_\star/M_\odot) > 10$) by comparing Hyper Suprime-Cam Subaru Strategic Program observations with matched mock images from IllustrisTNG, EAGLE, and SIMBA. Using a consistent, like-for-like imaging pipeline, we construct structural abundance functions (SAFs) for key morphological parameters, revealing a structural abundance crisis. Across S\'{e}rsic index, concentration, size, and ellipticity, all simulations exhibit large, systematic discrepancies ($>5\sigma$; RMSE $\sim 0.2$--$1.8$\,dex), typically corresponding to abundance differences of factors of several. While individual simulations display diverse failures---underproducing or overproducing compact spheroids, extended or round galaxies ---all underproduce highly flattened disks. Although TNG shows the closest agreement and SIMBA the largest offsets, this shared failure indicates that current models---despite matching global demographics such as the stellar mass function---do not uniquely constrain internal galaxy structure. Our results demonstrate that agreement in integrated observables can mask fundamental shortcomings in the modelling of mass and angular momentum redistribution. We therefore establish SAFs as a stringent, multidimensional, and observationally accessible benchmark for testing and calibrating next-generation galaxy formation models in the era of upcoming deep, wide-field surveys.

astro-ph.GA↗

arXiv2026

The Narrow-Line Seyfert 1 Phenomenon: Accretion State Versus Host Galaxy Properties

The physical origin of the narrow-line Seyfert 1 (NLS1) and broad-line Seyfert 1 (BLS1) dichotomy remains debated, with competing scenarios invoking host-galaxy evolution or intrinsic accretion physics. We analysed host-galaxy properties and AGN luminosities obtained from CIGALE spectral energy distribution fitting for $\sim$12,000 Type 1 AGNs from the Sloan Digital Sky Survey, of which 29\% are NLS1s. Globally, NLS1s have lower virial black hole masses, higher inferred Eddington ratios, lower stellar masses, and higher specific star formation rates than BLS1s. In the FWHM(\Hb)--$L_{\rm AGN}$ plane, the conventional 2000 km s$^{-1}$ boundary is better viewed as an empirical division within a continuous parameter space rather than a physical threshold, with Fe~II tracing the high-accretion end. In a host-matched subsample of 767 NLS1--BLS1 pairs with statistically indistinguishable stellar mass, black hole mass, and redshift, NLS1s still show higher Eddington ratios, stronger Fe~II emission, and bluer optical continua, together with elevated SFR and dust attenuation, suggesting that the NLS1 phenomenon is most naturally associated with a high-accretion state within the continuous distribution of Type 1 AGNs, while host-galaxy gas supply may also play a role in modulating its strength. In this picture, NLS1 and BLS1 classifications reflect different locations within a continuous accretion sequence of the same underlying population rather than two physically disjoint classes.

astro-ph.GA↗

arXiv2026

GS-Playground: A High-Throughput Photorealistic Simulator for Vision-Informed Robot Learning

Embodied AI research is undergoing a shift toward vision-centric perceptual paradigms. While massively parallel simulators have catalyzed breakthroughs in proprioception-based locomotion, their potential remains largely untapped for vision-informed tasks due to the prohibitive computational overhead of large-scale photorealistic rendering. Furthermore, the creation of simulation-ready 3D assets heavily relies on labor-intensive manual modeling, while the significant sim-to-real physical gap hinders the transfer of contact-rich manipulation policies. To address these bottlenecks, we propose GS-Playground, a multi-modal simulation framework designed to accelerate end-to-end perceptual learning. We develop a novel high-performance parallel physics engine, specifically designed to integrate with a batch 3D Gaussian Splatting (3DGS) rendering pipeline to ensure high-fidelity synchronization. Our system achieves a breakthrough throughput of 10^4 FPS at 640x480 resolution, significantly lowering the barrier for large-scale visual RL. Additionally, we introduce an automated Real2Sim workflow that reconstructs photorealistic, physically consistent, and memory-efficient environments, streamlining the generation of complex simulation-ready scenes. Extensive experiments on locomotion, navigation, and manipulation demonstrate that GS-Playground effectively bridges the perceptual and physical gaps across diverse embodied tasks. Project homepage: https://gsplayground.github.io.

cs.RO↗

arXiv2026

Beyond Mass and Multiscale Environments: What Shapes Low Surface Brightness Galaxies? Evidence from MaNGA

The origin of low surface brightness (LSB) galaxies remains a key open question in galaxy formation, reflecting the balance internal mechanisms and environmental influence. Using MaNGA integral-field spectroscopy, we investigate whether LSB and high surface brightness (HSB) galaxies of comparable stellar mass ($9 < \log M_\ast < 10$) occupy distinct environments or differ primarily through internal evolution. Our late-type sample comprises 113 central and 29 satellite LSB galaxies, and 374 central and 142 satellite HSB galaxies. We characterize environments on scales from 100 kpc to 10 Mpc, analyzing radial profiles of stellar mass surface density ($\Sigma_\ast$), star formation activity, and gas-phase metallicity. Central LSB and HSB galaxies inhabit similarly low-density large-scale ($>$200 kpc) environments, but LSB galaxies are more isolated on small scales ($\sim$100 kpc). Even after matching in stellar mass and environment, LSB galaxies show systematically lower $\Sigma_\ast$, $\Sigma_{SFR}$, and metallicities, often hosting diffuse, weakly star-forming bulges embedded in extended disks. These results indicate that LSB structure and star formation are not primarily governed by large-scale environment or halo mass. While secondary halo properties such as spin, concentration, or gas accretion history are often invoked, their environmental dependence appears weak. Instead, LSB-HSB differences for centrals likely reflect divergent assembly or interaction histories and internal processes -- such as angular momentum-driven disk evolution or inefficient gas conversion -- largely decoupled from large-scale environment. Nonetheless, environment still influences the observed star formation and chemical differences between central and satellite LSB galaxies.

astro-ph.GA↗

arXiv2026

Communication Gain and Delay Cost Under Cross-Timestep Delays in Cooperative Multi-Agent Reinforcement Learning

Communication is essential for coordination in \emph{cooperative} multi-agent reinforcement learning under partial observability, yet \emph{cross-timestep} delays cause messages to arrive multiple timesteps after generation, inducing temporal misalignment and making information stale when consumed. We formalize this setting as a delayed-communication partially observable Markov game (DeComm-POMG) and decompose a message's effect into \emph{communication gain} and \emph{delay cost}, yielding the Communication Gain and Delay Cost (CGDC) metric. We further establish a value-loss bound showing that the degradation induced by delayed messages is upper-bounded by a discounted accumulation of an information gap between the action distributions induced by timely versus delayed messages. Guided by CGDC, we propose \textbf{CDCMA}, an actor--critic framework that requests messages only when predicted CGDC is positive, predicts future observations to reduce misalignment at consumption, and fuses delayed messages via CGDC-guided attention. Experiments on no-teammate-vision variants of Cooperative Navigation and Predator Prey, and on SMAC maps across multiple delay levels show consistent improvements in performance, robustness, and generalization, with ablations validating each component.

cs.AI↗

arXiv2026

SDSS-IV MaNGA: Distinct Structural Growth and Star Formation in Low and High Surface Brightness Disks

We analyze a clean sample of 1,118 late-type, face-on galaxies without AGN contamination from the MaNGA survey. Their photometric structures are quantified via two-component (bulge+disk) decompositions on deep $g$-band images from the DESI Legacy Survey. Using a disk central surface brightness of $\mu_{\rm 0,d,cor}$(g) = 22 $\pm$ 0.3 mag arcsec$^{-2}$ (corrected for inclination and cosmic dimming) as the classification threshold, we identify 159 low surface brightness (LSB) galaxies, 388 LSB candidates, and 571 high surface brightness (HSB) galaxies. LSB galaxies are predominantly low-mass ($M_\ast < 3 \times 10^{10}$ M$_\odot$), exhibiting 29\% larger effective radii, 15\% lower star formation rates (SFRs), and 12\% reduced gas-phase metallicities than HSB counterparts at comparable masses. These differences cause systematic offsets from standard scaling relations. Despite comparable gas content, LSB galaxies host older stellar populations, longer gas depletion times, and less efficient star formation. Spatially resolved analyses further reveal that LSB galaxies display centrally suppressed $\Sigma_{\rm SFR}$, flatter SFR gradients, and rising specific SFR profiles toward their outskirts. Together with steeper negative metallicity gradients, these trends suggest ongoing gas accretion fueling outer-disk star formation. Consistently, the outer regions of LSB galaxies exhibit stronger H$\delta_A$ absorption and lower D$_n$4000 indices, indicating fading A-star populations. Moreover, LSB galaxies show lower $\Sigma_{\ast}$ across all $R/R_e$ and more centrally depleted stellar mass profiles on an absolute radial scale, compared with HSB and large-size star-forming galaxies. Collectively, LSB galaxies represent a distinct population with slow evolution, inefficient star formation, and continued susceptibility to late-time gas accretion and peripheral star formation.

astro-ph.GA↗

arXiv2026

Inverse orbital Hall effect induced terahertz emission enabled by a ferromagnet with quenched orbital moment in Fe/Pt/W trilayers

The inverse orbital Hall effect (IOHE) has recently attracted considerable attention as an emerging mechanism for terahertz (THz) emission based on ultrafast angular-momentum-to-charge conversion. Most experimental studies have focused on materials with strong spin-orbit coupling or pronounced orbital character, where sizable orbital Hall responses are expected. Elemental ferromagnets such as Fe are generally regarded as quenched orbital sources and are not expected to exhibit orbital-dominated THz emission. Here, we report a pronounced enhancement of THz emission in Fe/Pt/W trilayer heterostructures, despite the absence of detectable orbital contributions in the corresponding Fe/Pt and Fe/W bilayers. Thickness-dependent measurements reveal long-distance signal persistence, systematic delay accumulation, and pronounced pulse broadening with increasing W thickness. These features are inconsistent with diffusive spin transport and indicate that orbital angular momentum transport in the W layer, converted into charge current via the IOHE, becomes a dominant channel for THz emission in the trilayer configuration. Our results demonstrate that strong IOHE can emerge in heterostructures incorporating a quenched orbital ferromagnet, providing an effective route to enhance spintronic THz emitters through orbital Hall physics.

cond-mat.mtrl-sci↗

arXiv2026

ELFO: A Python Package for Emission Line Fitting Optimization in Integral Field Spectroscopy Data

Integral field spectroscopy (IFS) provides spatially resolved spectra, enabling detailed studies that address the physical and kinematic properties of the interstellar medium. A critical step in analyzing IFS data is the decomposition of emission lines, where different velocity components are often modeled with Gaussian profiles. However, conventional fitting methods that treat each spectrum independently often yield spatial discontinuities in the fitting results. Here, we present Emission Line Fitting Optimization (ELFO), a Python package for IFS spectral fitting. ELFO uses the results of neighboring spectra to determine multiple initial guesses and selects the result that exhibits spatial smoothness. We tested ELFO on IFS data of two quasars obtained from the Multi-Unit Spectroscopic Explorer, where it successfully corrected anomalous fits, revealed previously unresolved substructures, and made large-scale kinematic structures more evident. With minor modifications, this method can also be easily adapted to other IFS data and different emission lines.

astro-ph.GA↗

arXiv2025

Antarctic TianMu Staring Observation Project I: Overview and Implementation of the Prototype Telescope

Wide-field rapid sky surveys serve as critical observational methods for time-domain astronomical research. The Antarctic region, with several months of continuous dark nights annually, is an ideal site for time-domain astronomical observations. The Antarctic TianMu Staring Observation Project aims to deploy a fleet of small telescopes, adopting an array observation model to conduct time-domain optical observations in Antarctica, featuring wide-sky coverage, high-cadence sampling, long-period staring, and simultaneous multi-band measurements. Considering the severe challenges optical telescopes face in Antarctica, including extremely low temperatures, unattended operation, and limited power supply and network transmission, we have designed and developed the Antarctic TianMu prototype telescope based on drift-scan charge-coupled device technology. In October 2022, our prototype (with an aperture of 18 cm), named AT-Proto was transported to Zhongshan Station in Antarctica aboard China's 39th Antarctic Research Expedition. It has since operated stably and reliably in the frigid environment for over two years, demonstrating the significant advantages of this technology in polar astronomical observations. The experimental observation results of AT-Proto provide a solid foundation for the subsequent construction of a time-domain astronomy observation array in Antarctica.

astro-ph.IM↗

arXiv2025

The Narrow Emission Lines of Seyfert 1 Galaxies: Comparisons with a Large SDSS Sample

We analyzed a large sample of SDSS spectra of Seyfert galaxies, subdividing Seyfert 1s based on their narrow-to-broad Halpha components. Comparing their narrow-lines (NL) to Seyfert2s in line-ratio diagrams, most of the NL of strong Sy 1.0 and Sy 1.2s (with dominant broad lines) are the same as those of pure Sy2s. In contrast, only 25-30 percent of the Sy1.8 and Sy1.9 nuclei (with weak broad lines) are located in the pure Sy2 region, with the rest falling in the composite-star-forming region. We explain these Seyfert-plus-star-formation spectra with a simple model. It shows that 85 percent of NL in Sy1.9 are from HII-regions, while 88 percent of the NL in Sy 1.0 arise from the same NLR as in pure Sy2. About 6 percent of the strong and weak Sy1's have NL dominated by LINER emission, while 15 percent of intermediate Seyferts (Sy 1.5 and Sy 1.6) do. To confirm this Seyfert 1 AGN plus star formation combination, we used stellar absorption-lines to compare their stellar populations. Their Hdelta strengths show that LINERs, pure Sy2s, and also the broad-line dominated Sy1s have old stellar populations. The weak Sy 1s show stronger Hdelta absorption, indicating larger proportions of young stars. About one third of the u band light in Sy1.0 and 1.2 is blended Balmer lines and continuum from the BLR. The NL gas reddening increases as the BLR strength decreases, from Sy1.0 (0.13 mag), to Sy1.9 (0.40 mag), to Sy2s and LINERs both with 0.50 mag. Our data do not support the simplest version of Seyfert 1 and 2 unification, where both AGN classes have identical NL.

astro-ph.GA↗

arXiv2025

Mock Observations for the CSST Mission: Integral Field Spectrograph--Instrument Simulation

The Chinese Space Station Survey Telescope (CSST) is a next-generation Stage-IV facility renowned for its wide field of view, high image quality, and multi-band observational capabilities. Among the five instruments onboard the CSST, the Integral Field Spectrograph (IFS) offers the unique ability to simultaneously capture spatial and spectral information across a field of view of no less than $6^{''}\times6^{''}$. Key advantages of the IFS include a high spatial resolution of $0.2^{''}$ and a broad spectral coverage from 350 to 1000 nm, making it an ideal instrument for studying physical processes in the vicinity of supermassive black holes within galaxies. To more accurately assess the technical and scientific performance of the CSST-IFS, it is essential to develop a simulation tool that incorporates realistic effects from all optical components. Such a simulation will form an integral part of the CSST-IFS data and pipeline system, enabling the development of the data reduction pipeline well ahead of actual observations. This paper presents an end-to-end simulation workflow for the CSST-IFS, incorporating a wide range of instrumental effects that may influence its spectral and imaging performance. The simulation accounts for optical diffraction effects introduced by all components, such as image slicers and slit array, as well as sub-pixel effects from gratings. It also includes various detector noises, frame-shifting effects, and charge-transfer inefficiency. Real observational conditions--such as target Doppler shift, cosmic rays, and other in-orbit operational effects--are also considered. We describe the technical implementation of the simulation and present results that quantitatively characterize key instrument parameters.

astro-ph.IM↗

arXiv2025

Mock Observations for the CSST Mission: Integral Field Spectrograph--GEHONG: A Package for Generating Ideal Datacubes

We developed a Python package GEHONG to mock the three-dimensional spectral data cube under the observation of an ideal telescope for the Integral Field Spectrograph of the Chinese Space Station Telescope (CSST-IFS). This package can generate one-dimensional spectra corresponding to local physical properties at specific positions according to a series of two-dimensional distributions of physical parameters of target sources. In this way, it can produce a spatially resolved spectral cube of the target source. Two-dimensional distributions of physical parameters, including surface brightness, stellar population, and line-of-sight velocity, can be modeled using the parametric model or based on real observational data and numerical simulation data. For the generation of one-dimensional spectra, we have considered four types of spectra, including the stellar continuum spectra, ionized gas emission lines, AGN spectra, and stellar spectra. That makes GEHONG able to mock various types of targets, including galaxies, AGNs, star clusters, and HII regions.

astro-ph.IM↗

arXiv2025

Introduction to the Chinese Space Station Survey Telescope (CSST)

The Chinese Space Station Survey Telescope (CSST) is an upcoming Stage-IV sky survey telescope, distinguished by its large field of view (FoV), high image quality, and multi-band observation capabilities. It can simultaneously conduct precise measurements of the Universe by performing multi-color photometric imaging and slitless spectroscopic surveys. The CSST is equipped with five scientific instruments, i.e. Multi-band Imaging and Slitless Spectroscopy Survey Camera (SC), Multi-Channel Imager (MCI), Integral Field Spectrograph (IFS), Cool Planet Imaging Coronagraph (CPI-C), and THz Spectrometer (TS). Using these instruments, CSST is expected to make significant contributions and discoveries across various astronomical fields, including cosmology, galaxies and active galactic nuclei (AGN), the Milky Way and nearby galaxies, stars, exoplanets, Solar System objects, astrometry, and transients and variable sources. This review aims to provide a comprehensive overview of the CSST instruments, observational capabilities, data products, and scientific potential.

astro-ph.IM↗

arXiv2025

LASFNet: A Lightweight Attention-Guided Self-Modulation Feature Fusion Network for Multimodal Object Detection

Effective deep feature extraction via feature-level fusion is crucial for multimodal object detection. However, previous studies often involve complex training processes that integrate modality-specific features by stacking multiple feature-level fusion units, leading to significant computational overhead. To address this issue, we propose a new fusion detection baseline that uses a single feature-level fusion unit to enable high-performance detection, thereby simplifying the training process. Based on this approach, we propose a lightweight attention-guided self-modulation feature fusion network (LASFNet), which introduces a novel attention-guided self-modulation feature fusion (ASFF) module that adaptively adjusts the responses of fusion features at both global and local levels based on attention information from different modalities, thereby promoting comprehensive and enriched feature generation. Additionally, a lightweight feature attention transformation module (FATM) is designed at the neck of LASFNet to enhance the focus on fused features and minimize information loss. Extensive experiments on three representative datasets demonstrate that, compared to state-of-the-art methods, our approach achieves a favorable efficiency-accuracy trade-off, reducing the number of parameters and computational cost by as much as 90% and 85%, respectively, while improving detection accuracy (mAP) by 1%-3%. The code will be open-sourced at https://github.com/leileilei2000/LASFNet.

cs.CV↗

arXiv2025

Multi-Component Ionized Gas Outflows in a Hot Dust-Obscured Galaxy W2026+0716 with Keck/OSIRIS

We present narrowband-filtered integral field unit (IFU) observations of the Hot Dust-Obscured Galaxy (Hot DOG) WISE J202615.27$+$071624.0 (hereafter W2026$+$0716) at redshift $z=2.570$ using Keck/OSIRIS. Our analysis reveals a multi-component ionized gas outflow structure in this heavily obscured AGN host galaxy. Multi-component Gaussian decomposition of the [O III] and H$\alpha$ emission lines uncovers extremely broad and asymmetric profiles, characteristic of AGN-driven outflows. Kinematic mapping shows spatially distinct structures: the [O III] and H$\alpha$ dominated components (with radii of $1.20 \pm 0.56$ kpc) are separated by a projected offset of $\sim 1.1$ kpc and exhibit divergent velocity regimes. The [O III] outflow reaches a velocity of 3210 $\pm$ 50 km s$^{-1}$, while the H$\alpha$ outflow component attains 2310 $\pm$ 840 km s$^{-1}$. Dynamical modeling supports a biconical outflow structure, with [O III] and H$\alpha$ emissions dominating separate cones and significant dust obscuration of the redshifted outflow. Their comparable momentum outflow rates and energy outflow rates suggest a potential physical connection in their driving mechanisms. Spectral energy distribution (SED) analysis reveals anomalous optical/UV excess, attributed to AGN photon scattering by dust or outflowing material, classifying W2026+0716 as a "Blue Hot DOG". The derived outflow timescale ($\sim10^{5}$ yr) aligns with the evolutionary phase of Blue Hot DOGs, suggesting AGN feedback operates persistently during this transitional stage.

astro-ph.GA↗

arXiv2025

Extended Emission-line Region in a Poststarburst Galaxy Hosting Tidal Disruption Event AT2019qiz and Quasiperiodic Eruptions

We present a comprehensive analysis of the extended emission line region (EELR) in the host galaxy of the tidal disruption event (TDE) AT2019qiz, utilizing VLT/MUSE integral-field spectroscopy. The high spatial-resolution data reveal a bi-conical emission structure approximately $3.7~\mathrm{kpc}$ in scale within the galactic center, characterized by a prominent [OIII] line in the nucleus and significant [NII] line emission extending into the EELR. Spectral analysis of the EELR indicates line ratios consistent with Seyfert ionization in the center and LINER-type ionization in the outer diffuse region, suggesting ionization from galactic nuclear activity. The required ionizing luminosity, estimated from the H$\rm{\alpha}$ and H$\rm{\beta}$ luminosities based on the photoionization and recombination balance assumption, is $10^{41.8}$ $\mathrm{erg\,s^{-1}}$ for all spaxels classified as active galactic nucleus (AGN), and $10^{40.7}$ $\mathrm{erg\,s^{-1}}$ for spaxels in the central $0.9~\mathrm{kpc}$ Seyfert region. However, the current bolometric luminosity of the nucleus $L_{\text{bol}} \leq 10^{40.8}\,\mathrm{erg\,s^{-1}}$, estimated from quiescent-state soft X-ray observations, is insufficient to ionize the entire EELR, implying a recently faded AGN or a delayed response to historical activity. Stellar population analysis reveals a post-starburst characteristic in the EELR, and the gas kinematics show disturbances and non-circular components compared to the stellar kinematics. Notably, the recent detection of quasi-periodic eruptions (QPEs) in the X-ray light curve of AT2019qiz confirms the TDE-QPE association. Our findings provide direct evidence for an AGN-like EELR in the host galaxy of the nearest TDE with QPE detection, offering new insights into the complex interplay between TDEs, QPEs, AGN activity, and host galaxy evolution.

astro-ph.GA↗

arXiv2024

Metal-strong Inflows at the Outer-galactic-scale of a Quasar

We present an analysis of the absorption-line system in the Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph spectrum at a redshift of $z_{\rm a}={3.1448}$ associated with the quasar SDSS J122040.23+092326.96, whose systematic redshift is $z_{\rm e}=3.1380\pm0.0007$, measured from the ${\rm H}\beta$+[O III] emission lines in our newly acquired NIR P200/TripleSpec data. This absorbing system, detected in numerous absorption lines including the N V, N III, C IV, C III, Si IV, Si III, and H I Lyman series, can be resolved into seven kinematic components with red-shifted velocities ranging from 200 to $900\,\rm km\,s^{-1}$. The high-ionization N V doublet detected and the rather narrow Lyman series measured ($b\approx14\,\rm km\,s^{-1}$) suggest that the absorption gas is photo ionized, possibly by the quasar. A low density is inferred by the fact that N III $\lambda989.80$ is significantly detected while N III* $\lambda991.51$ (${\rm log}\,n_{\rm c}=3.3\,\rm cm^{-3}$) is undetectably weak. A firm lower limit of a solar value to the abundance of the gas can be set based on the measurements of Si IV and H I column densities, as first proposed by F. Hamann. Detailed photoionization simulations indicate that $T1$, and possibly the absorber as a whole, has metallicities of $Z\sim1.5-6.0\,Z\rm\,sun$, and is located at $\sim15\,\rm kpc$ from the quasar nucleus. The metal-strong absorption inflows at the outskirt of the quasar host galaxy is most likely originated in situ and were driven by stellar processes, such as stellar winds and/or supernova explosions. Such a relatively rare system may hold important clues to understanding the baryonic cycling of galaxies, and more cases could be picked out using relatively strong Si IV and weak Lyman absorption lines.

astro-ph.GA↗