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Ming Zhu

Publications and source records attributed to Ming Zhu.

At least 19 recordsLinked to original sources
arXiv2026

An HI study of a large sample of ultra-diffuse galaxies

By cross-matching the SMUDGes catalog with the FASHI and ALFALFA HI surveys, we construct an HI-detected sample of 112 ultra-diffuse galaxies (UDGs) and 48 low-surface-brightness (LSB) galaxies, providing HI-based redshifts for 76 galaxies for the first time. Using DESI DR1 redshifts, we assemble an HI-non-detected sample of 168 galaxies for stacking analysis, with detections in two stellar mass bins below 10^{8.5} M_sun. Combining optical, UV, and HI data, we investigate stellar masses, star formation rates, gas fractions, and kinematics. We present a systematic analysis of the HI mass--optical size relation for UDGs and LSBs, showing both populations follow a mass--optical size scaling similar to normal galaxies, suggesting an average HI surface density, under the assumption that the optical size traces the extent of the HI distribution. Their stellar mass--size relation indicates nearly constant stellar surface densities for galaxies with central surface brightness mu_{0,g}>~24mag arcsec^{-2}, independent of UDG or LSB classification. Many UDGs and LSB galaxies are systematically offset from the baryonic Tully--Fisher relation toward higher baryonic masses at a given velocity, consistent with trends found in UDGs with resolved HI kinematics. Both populations exhibit low star formation efficiencies and long gas depletion times, supporting multiple formation pathways for UDGs.

astro-ph.GA↗
arXiv2026

FASHI DR2: A Catalog of 132 Low-Redshift HI 21 cm Absorption Systems

We present an untargeted survey of 21 cm HI absorption systems based on the second data release of the FAST All Sky HI survey (FASHI DR2), covering approximately 19,500 deg$^{2}$ at $z\lesssim0.09$. A total of 132 HI absorbers are identified, including approximately 60 new discoveries, forming one of the largest homogeneous samples of low-redshift HI absorbers assembled to date. The sample extends to continuum flux densities as low as 2.6 mJy, substantially below the limits of previous flux-limited surveys. The absorber population is dominated by narrow systems ($W_{50}<100$ km s$^{-1}$), while broad absorbers ($W_{50}>200$ km s$^{-1}$) account for 13.6% of the sample. Most absorbers are optically thin, with a median optical depth of $\tau_{\rm HI}\approx0.14$. The velocity-offset distribution is broadly symmetric about the systemic velocities of the host galaxies. The associated absorbers are preferentially found in massive, actively star-forming galaxies. We find tentative evidence for a weak anti-correlation between HI column density and stellar mass, although the relation exhibits substantial scatter. These results provide the first statistical characterization of the low-redshift HI absorber population based on the FASHI DR2 sample and establish a valuable benchmark for future HI absorption surveys with next-generation radio facilities.

astro-ph.GA↗
arXiv2026

HI Depletion Begins Well Beyond the Virial Radius: A FAST Stacking Study of 36 Galaxy Clusters to 5R200

We present a stacking study of the neutral atomic hydrogen (HI) content in and around 36 local galaxy clusters at $z<0.07$, using a combination of the FAST all sky HI survey (FASHI) and the extensive spectroscopic catalog mainly from the Dark Energy Spectroscopic Instrument (DESI). We employ spectral stacking techniques to probe the average HI mass and HI-to-stellar mass ratio ($M_{\rm HI}/M_*$) for member galaxies down to stellar masses of $M_*\sim 10^9M_\odot$, spanning a projected cluster-centric distance to $5R_{200}$. Our analysis reveals a pronounced environmental effect: both $M_{\rm HI}$ and $M_{\rm HI}/M_*$ decrease steadily towards the cluster center, dropping by $\sim 0.5$ dex on average from the outskirts to the core. Crucially, we find that $M_{\rm HI}/M_*$ of galaxies remain lower than the field galaxies even at the $5R_{200}$. This provides direct, statistical evidence for substantial gas stripping and pre-processing in the cluster outskirts, likely occurring in infalling groups and large-scale filaments. By further splitting the sample by $g-r$ color, we show that the HI deficiency persists at fixed galaxy color: even the bluest cluster members exhibit $\sim 0.5$~dex lower $M_{\rm HI}/M_*$ than field galaxies of similar color, reflecting environmental effects on the cold gas reservoir prior to full optical transformation. The total HI mass within clusters and their outskirts agrees broadly with predictions from cosmological simulation. Our results underscore the critical role of the extended cluster environment in quenching galaxies by depleting their cold gas reservoirs well before they enter the dense cluster core.

astro-ph.GA↗
arXiv2026

The FAST HI 21-cm Absorption Blind Survey. III. OH Absorption Search in the 21-cm Absorber Sample and Continued HI Absorption Search

We present the first blind search for OH 18-cm absorption with the Five-hundred-meter Aperture Spherical Telescope (FAST), conducted alongside the HI 21-cm absorption search. Our previous FAST blind HI absorption search identified 34 systems. In this work, we extend the search using 2024 and part of the 2025 CRAFTS and FASHI data (394.4 hr and 1622.1 deg$^{2}$) together with FATHOMER observations, yielding three known and four new HI absorbers, for a total of 41 HI absorption systems. We search for OH absorption in 19 HI absorption systems whose OH redshifted frequencies fall within the FAST band. The known OH absorber towards PKS 1413+135 was re-detected, making our survey the first blind survey to detect OH absorption. No new OH absorbers were identified. We examine the relationship between $N_{\rm{OH}}$ and $N_{\rm{HI}}$, applying survival analysis to account for upper limits. The analysis does not provide statistically significant evidence for either an $N_{\rm{OH}}$-$N_{\rm{HI}}$ correlation or redshift evolution of $N_{\rm{OH}}$/$N_{\rm{HI}}$. Finally, spectral stacking sets 3$\sigma$ OH column density upper limits of 4.93, 1.64, and 1.72 $T_{\rm{ex}}$/$c_{\rm{f,OH}}\times$10$^{12}$cm$^{-2}$K$^{-1}$ for associated, intervening, and combined samples, corresponding to [\rm{OH}]/[\rm{HI}] ratios of $<$1.66$\times$10$^{-8}$, $<$1.42$\times$10$^{-8}$, and $<$0.90$\times$10$^{-8}$, assuming $T_{\rm{ex}}$=10K for OH and $T_{\rm{s}}$=100K for HI. These results place the strongest constraints to date on the OH content in radio-selected HI absorbers and establish a blind-survey benchmark for future studies of molecular gas in HI-selected systems. They also demonstrate that known HI 21-cm absorbers provide an effective parent sample for systematic OH absorption searches, paving the way for future larger surveys.

astro-ph.GA↗
arXiv2026

A Catalog of Compact High-Velocity Clouds from the FAST All-Sky HI Survey (FASHI) DR2

High-velocity clouds (HVCs) -- especially compact HVCs (CHVCs) -- are thought to serve as gaseous tracers of dark-matter-dominated subhalos, providing a crucial empirical link between the predicted dark matter substructure and observed satellite galaxies. In this paper, we present a new catalog of 192 CHVCs identified from the FAST All-Sky HI Survey (FASHI) Data Release 2 (DR2). Among these, 108 are ultra-compact HVCs (UCHVCs), the majority of which are new discoveries. We find that 185 of the 192 CHVCs are spatially and kinematically concentrated around the Andromeda galaxy (M31), with a median LSR velocity of -296.1 km/s, suggesting physical association with M31. Adopting an M31 distance of 0.8 Mpc, we derive HI masses in the range 1.9*10^{5} to 4.0*10^{6} Msun and dynamical masses from 1.0*10^{7} to 6.3*10^{8} Msun. Approximately half of the CHVCs follow the baryonic Tully--Fisher relation. No optical counterparts are detected in Pan-STARRS1 imaging down to a limiting magnitude of m_g = 22.8. We conclude that these CHVCs likely represent a population of gas-rich, starless minihalos and provide an excellent sample for the search for dark galaxies.

astro-ph.GA↗
arXiv2026

The nature of Cloud-9: a compact core embedded in a diffuse envelope

We present new HI observations of Cloud-9 with the Five-hundred-meter Aperture Spherical Telescope (FAST), measuringvtotal flux of 0.35 +- 0.03 Jy km/s. Combined with Very Large Array (VLA) data, the HI shows a two-component structure: a compact, kinematically quiescent core and an extended envelope. The outer component exhibits a coherent velocity gradientvof ~25 km/s across ~7 kpc. The position-velocity structure does not support rotation; instead, the gradient is consistent with ordered large-scale motion, induced by environmental interaction with M94. The coexistence of a compact, kinematically quiescent core and an extended structured envelope is difficult to reconcile with a unbound or purely gaseous system. While the extended component is more naturally interpreted as environmentally shaped gas, the compact core suggests gravitational confinement beyond that provided by the observed baryonic content, without requiring strict long-term dynamical equilibrium. Deep optical limits further rule out a significant stellar component. Taken together, our results indicate that Cloud-9 is most naturally interpreted as a dark matter-dominated system undergoing environmental interaction. The observed morphology and kinematics are consistent with a stripped RELHIC scenario, in which a compact gas-rich core is embedded within an extended envelope shaped by ram-pressure interaction with the circumgalactic medium of M94.

astro-ph.GA↗
arXiv2026

Weak Evolution of Cosmic Atomic Hydrogen over the Past 4.5 Billion Years

The cosmic star formation rate density (CSFRD) has declined sharply toward the present day, but the roles of the atomic and molecular gas reservoirs remain uncertain. We measure the cosmic HI density, $\Omega_{\mathrm{HI}}$, over $0<z<0.41$ by combining HI spectra from the Five-hundred-meter Aperture Spherical Telescope with optical spectroscopy from the Dark Energy Spectroscopic Instrument for $\sim2.5$ million galaxies across $\sim12,000\,{\rm deg}^2$. We measure a raw decrease in $\Omega_{\mathrm{HI}}$ by a factor of $1.35\pm0.10$ over the past 4.5 Gyr. Even after applying the conservative systematic corrections from our forward model, the inferred decline is only $1.12\pm0.10$ -- still far weaker than the CSFRD decline (a factor of 2.46). The molecular gas density, in contrast, is known to evolve more closely with star formation. At fixed stellar mass, the average HI gas fraction evolves by less than 0.2 dex, showing that the weak evolution is present across the galaxy population. These quantitative differences rule out rapid depletion of galaxy HI as the primary driver of the late-time CSFRD decline, and provide a stringent benchmark for models of gas accretion, phase conversion and star-formation regulation.

astro-ph.GA↗
arXiv2026

The FAST All Sky HI Survey DR2: the FASHI Catalog and the HI Mass Function

The FAST All Sky HI Survey (FASHI) conducted with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) has mapped $\sim 19500\,\mathrm{deg}^2$ of the sky north of DEC $= -14^{\circ}$, detecting $156411$ extragalactic HI sources at $z< 0.09$ with a median sensitivity of $0.57\,\mathrm{mJy}\,\mathrm{beam}^{-1}$ at a velocity resolution of $6.4\,\mathrm{km}\,\mathrm{s}^{-1}$. The survey achieves unprecedented depth and area coverage, significantly improving upon previous single-dish surveys. Through a detailed completeness analysis that accounts for the survey's non-uniform sensitivity and line-width dependence, we construct a robust HI mass function (HIMF) using a completeness-corrected sample of over $109000$ sources. The HIMF is robustly constrained down to $M_{\mathrm{HI}}\sim 10^{6.2}\,M_{\odot}$. When systematic uncertainties are included, the HIMF is well described by a single-Schechter function with a characteristic mass $\log (M_{*} / h_{70}^{-2}M_{\odot}) = 9.89\pm 0.02$, low-mass end slope $\alpha = -1.31\pm 0.02$, and amplitude $\phi_{*} = (6.38\pm 0.49)\times 10^{-3}\,h_{70}^{3}\,\mathrm{Mpc}^{-3}\,\mathrm{dex}^{-1}$. The derived cosmic HI density is $\Omega_{\mathrm{HI}} = (4.71\pm 0.03_{\mathrm{stat}}\pm 0.40_{\mathrm{sys}})\times 10^{-4}\,h_{70}^{-1}$. FASHI provides the most extensive and sensitive HI catalog to date, establishing an important benchmark for studies of gas accretion, galaxy evolution, and large-scale structure in the local universe.

astro-ph.GA↗
arXiv2026

BehaviorBench: Modeling Real-World User Decisions from Behavioral Traces

Many decision-support settings require systems that adapt to individual users, but evaluation data for this problem remain limited. Existing benchmarks for user understanding often rely on simulated users or model-generated behavior, even though recent work cautions that model-based simulations can diverge systematically from human behavior. We introduce \textsc{BehaviorBench}, a benchmark for evaluating personalized decision modeling from real-world behavioral traces. \textsc{BehaviorBench} reconstructs wallet-level decision histories from observed public prediction-market and on-chain records, and organizes them into two complementary task layers: \emph{Belief prediction}, which predicts a user's final revealed stance and confidence in a market, and \emph{Trade prediction}, which predicts the direction and amount of individual transactions. Across 2,000 evaluation wallets, the benchmark contains 141,445 Belief instances and 1,485,972 Trade instances, with disjoint support pools for retrieval-based evaluation. We evaluate frontier and open-weight generative models under four history interfaces: no personalization, direct recent history, generated user profiles, and retrieved support-wallet evidence. Personalization improves Belief prediction more consistently than Trade prediction, model rankings change across task layers and metrics, and different history interfaces expose different failure modes. \textsc{BehaviorBench} provides an evaluation setting for studying whether personalized methods can use real-world behavioral evidence rather than simulated users alone.

cs.AI↗
arXiv2026

HiFAST: An HI data calibration and imaging pipeline for the FAST IV: The stray-radiation correction

Stray radiation is a considerable challenge for radio telescopes, requiring careful assessment due to its effects. This is crucial when the strong background flux from side lobes significantly affects the total flux, especially for extended sources. In this study, we introduced the beam pattern of the L-band receiver on the Five-hundred-meter Aperture Spherical Telescope (FAST), covering various frequencies based on recent observations. We discovered that the main beam efficiency of all beams exceeds 90\% throughout the L band frequencies, with efficiency decreasing slowly as frequency increases. Subsequently, we developed a module to mitigate stray radiation effects, incorporating it into FAST's standard \HI data reduction process, referred to as \texttt{HiFAST}. Our analysis shows that side lobe flux's influence, particularly for extended sources with significant surface density gradients, necessitates detailed evaluation. Corrections for the extended M33 galaxy can reach up to 20\%. Moreover, the pattern data presented here is vital for studying HI intensity maps at high redshift. The module, along with HiFAST and beam pattern data across 15 frequency bins, can be accessed at \textrm{https://hifast.readthedocs.io}. The datasets of beam pattern presented in this paper, are openly available at \textrm{https://doi.org/10.57760/sciencedb.j00113.00266} (https://www.scidb.cn/s/bqQRNv).

astro-ph.IM↗
arXiv2026

A Spatially Resolved HI Survey of Seyfert Galaxies: the Role of AGN Feedback in Shaping Atomic Gas Reservoirs

Active galactic nucleus (AGN) feedback is a key ingredient in galaxy evolution, yet its impact on the cold atomic gas reservoir -- the neutral hydrogen (HI) phase -- remains poorly constrained. We present the most extensive spatially resolved HI 21-cm survey of Seyfert AGN hosts to date, based on observations with the Giant Metrewave Radio Telescope (GMRT). Our high-resolution HI maps of eight Seyfert galaxies reveal detailed kinematics and surface density distributions of their atomic gas disks. We find that AGN-host galaxies exhibit a slightly shallower HI mass-size relation than the canonical relation or the SIMBA simulation predictions; however, the measured slope remains consistent with the canonical value within $2\sigma$ uncertainties. This result suggests that AGN feedback does not significantly disrupt the global extent or large-scale structure of atomic gas reservoirs. To investigate the internal HI kinematics in greater detail, we perform a 3D kinematic forward modeling of the HI disk in UGC 4503. Our analysis reveals an elevated intrinsic velocity dispersion of $\sigma = 14.9^{+6.1}_{-3.8}$ km/s and a reduced level of rotational support, with $V/\sigma = 14.28_{-4.17}^{+4.97}$, compared to large-sample star-forming spirals. These kinematic signatures, together with localized residuals in the velocity field, indicate that AGN-driven outflows or jets may inject or indirectly affect the turbulence in the atomic gas disk, potentially regulating the cold gas reservoir. Future GMRT observations, combined with optical integral-field spectroscopy from MaNGA, will enable quantitative constraints on the role of AGN feedback in regulating star formation efficiency across a larger and more representative galaxy sample.

astro-ph.GA↗
arXiv2026

Whisper-AuT: Domain-Adapted Audio Encoder for Efficient Audio-LLM Training

Audio-native large language models (audio-LLMs) commonly use Whisper as their audio encoder. However, Whisper was trained exclusively on speech data, producing weak representations for music and environmental sound. This forces downstream audio-LLMs to compensate through extensive training on large-scale non-speech data. We present Whisper-AuT, a domain-adapted audio encoder obtained by fine-tuning Whisper-large-v3 on a curated mixture of speech (80%), environmental sound (10%), and music (10%) totaling approximately 20M samples. The full encoder-decoder is trained end-to-end with a seq2seq captioning objective; the decoder is then discarded and only the encoder is retained. Linear probe evaluations show that Whisper-AuT achieves +23.0% on ESC-50 (environmental sound), +5.0% on GTZAN (music genre), and +0.7% on Speech Commands (keyword spotting) compared to the original Whisperlarge-v3 encoder. Whisper-AuT is designed as a drop-in replacement for Whisper in audio-LLM architectures, with the goal of reducing downstream training cost by providing stronger initial audio representations for non-speech domains.

cs.SD↗
arXiv2026

Optical identification of the FASHI sources: toward the extended Local Volume

We extracted a list of 662 nearby (within $\sim16$ Mpc) HI-detection sources from the Five-hundred-meter Aperture Spherical radio Telescope (FAST) All Sky HI Survey (FASHI) and made a visual identification of them with optical counterpart. This inspection led to the discovery of 71 new dwarf galaxies. All of them are dwarf irregular galaxies with ongoing star formation. They are characterized by the following median parameters: visual magnitude of $g=17.8$ mag and color $(g-r)=0.29$ mag, HI-flux $S_\mathrm{HI}=718$ mJy km/s, HI-mass $M_\mathrm{HI}=3.7\times10^7$ $M_\odot$, as well as the HI line-width of $W_{50}=37$ km/s.

astro-ph.GA↗
arXiv2026

RealUserSim: Bridging the Reality Gap in Agent Benchmarking via Grounded User Simulation

LLM-based user simulation is the primary mechanism for end-to-end agent evaluation, yet simulated users are poor proxies for real humans: unconstrained LLM defaults produce a Formalism Ceiling (style match rates of 6-8% against real users), while hand-crafted behavioral directives trigger Directive Amplification, where models hyper-interpret instructions into unnatural behavioral extremes that vary dramatically across simulator models. We present RealUserSim, the first user simulation framework grounded in real behavioral data. From 14,000+ authentic human-LLM conversations (WildChat), we extract 7,275 executable behavioral profiles and use them to ground LLM simulators. A fidelity benchmark (PT3) on 600 conversations across 71+ domains with anti-leakage controls shows that grounded simulation raises match rate from 24.2% to 45.3% across five behavioral dimensions. Agent evaluation on TauBench with 6 simulator models and extensive analysis shows that grounded simulation acts as a realistic stress test, surfacing three failure mechanisms invisible to cooperative simulators (mean -3.2% to -3.5% task success degradation), while Directive Amplification in existing benchmarks produces unrealistic behavior that compromises the validity of agent evaluation.

cs.HC↗
arXiv2026

Robust topological BIC nanocavities for upconversion directional emission

Photonic bound states in the continuum (BICs) provide a revolutionary paradigm for boosting light-matter interactions in integrated nanocavity systems. Nevertheless, precise manipulation of open cavity-emitter architectures still faces critical challenges, especially in realizing deterministic directional radiation and suppressing the perturbation of intrinsic cavity modes induced by emitters as local impurities. Conventional investigations on cavity-emitter coupling are predominantly based on ensemble measurements, which inevitably mask the intrinsic physics underlying individual light-matter interactions. Here, we propose a robust strategy to control the upconversion and emission of a single-particle emitter using a topological plasmonic cavity with broken {\sigma}h mirror symmetry. This structured design enables the transition from symmetry-protected BICs to a multi-BIC regime with finite but ultrahigh confinement, where nontrivial phase evolution and hybridization of transverse electric and magnetic modes open a well-defined far-field radiation channel for directional emission. Leveraging this scheme, we experimentally demonstrate dramatically enhanced radiation intensity from a single point-like emitter, together with uniform and deterministic directional emission, while achieving excellent structural robustness against local perturbations. This work establishes a general framework for engineering coherent directional light emission at the nanoscale, which lays a solid foundation for high-performance chip-scale integrated nanophotonic applications.

physics.optics↗
arXiv2026

HI Gas and Star Formation in Major Galaxy Pairs from the FAST All-Sky HI Survey (FASHI)

Atomic hydrogen (HI) plays a fundamental role in fueling star formation in galaxies. However, the behavior of HI gas in interacting systems, particularly galaxy pairs, remains elusive. In this work, we investigate the HI content of major mergers by cross-matching the extragalactic HI catalog from the FAST All-Sky HI Survey (FASHI) with a previously established sample of isolated galaxy pairs. With the superior sensitivity of FAST, we have constructed the largest sample of major mergers with HI detections, consisting of $440$ galaxy pairs: $364$ spiral-spiral (S+S) and $76$ spiral-elliptical (S+E) systems. We examine the HI gas fraction ($f_{\mathrm{HI}}$), star formation rate (SFR) and HI star formation efficiency ($\mathrm{SFE_{HI}}=\mathrm{SFR}/M_{\rm HI}$) for individual galaxies in pairs. The control sample is matched in both stellar mass and redshift. We find that paired galaxies, particularly those in pairs with small projected separations ($d_{\mathrm{p}}<50\ h^{-1}\mathrm{kpc}$), exhibit systematically lower (by $8.8\%$) HI gas fractions compared to the control galaxies. The SFR is enhanced for galaxies in S+S pairs. $\mathrm{SFE_{HI}}$ is $\sim15\%$ higher for galaxies in S+S pairs than in the control galaxies, while spiral galaxies in S+E pairs show no significant difference in $\mathrm{SFE_{HI}}$ compared to the control sample. These findings suggest that the merging process triggers efficient HI gas depletion and enhances star formation, especially in close S+S pairs. Notably, our sample includes $26$ red spirals in paired systems. These galaxies exhibit HI deficiency and suppressed star formation activity compared to the isolated galaxies, indicating that interactions may affect quiescent spirals differently, potentially due to mechanisms similar to ellipticals.

astro-ph.GA↗
arXiv2026

Enterprise Sales Copilot: Enabling Real-Time AI Support with Automatic Information Retrieval in Live Sales Calls

During live sales calls, customers frequently ask detailed product questions that require representatives to manually search internal databases and CRM systems. This process typically takes 25-65 seconds per query, creating awkward pauses that hurt customer experience and reduce sales efficiency. We present SalesCopilot, a real-time AI-powered assistant that eliminates this bottleneck by automatically detecting customer questions, retrieving relevant information from the product database, and displaying concise answers on the representative's dashboard in seconds. The system integrates streaming speech-to-text transcription, large language model (LLM)-based question detection, and retrieval-augmented generation (RAG) over a structured product database into a unified real-time pipeline. We demonstrate SalesCopilot on an insurance sales scenario with 50 products spanning 10 categories (2,490 FAQs, 290 coverage details, and 162 pricing tiers). In our benchmark evaluation, SalesCopilot achieves a measured mean response time of 2.8 seconds with 100% question detection rate, representing a 14xspeedup compared to manual CRM search in an internal study. The system is domain-agnostic and can be adapted to any enterprise sales domain by replacing the product database.

cs.SD↗
arXiv2026

\HI 21-cm Line Properties of the Nearby LIRG IRAS 04296+2923

We present an analysis of archival Very Large Array (VLA) and Five-hundred-meter Aperture Spherical radio Telescope (FAST) \HI\ 21 cm data, together with archival multi-band radio continuum observations, of the nearby luminous infrared galaxy IRAS~04296+2923. The system, located behind the Taurus dark cloud at a distance of $\sim$29 Mpc, forms a small galaxy group consisting of five members as revealed by the \HI\ imaging. IRAS~04296+2923 has a close companion, HI~0432+2926, with a projected separation of $\sim$40 kpc, a small line-of-sight velocity difference of $\Delta$ v = 26 km s$^{-1}$, and comparable total \HI\ masses of order $10^{9}$~$M_{\odot}$. Both galaxies exhibit regular \HI\ velocity fields and characteristic double-horn profiles in the VLA and FAST data, accompanied by only subtle asymmetries and extended \HI\ structures, indicating rotation-dominated kinematics with early signs of weak tidal interaction. Radio continuum emission is detected only from IRAS~04296+2923 and is confined to its nuclear region, consistent with previous studies. Modeling of its multi-band radio spectrum reveals a significant contribution from free--free emission at high frequencies ($>$30 GHz) and a high FIR-to-radio flux ratio ($q_{8.4}\simeq3.2$), implying a young, dust-obscured nuclear starburst. Taken together, the regular \HI\ kinematics, the small velocity offset, and the group-scale environment favor an interpretation in which IRAS~04296+2923 and HI~0432+2926 form a gravitationally bound, orbiting galaxy pair embedded in a small group, rather than an advanced merger. In this context, the luminous infrared galaxy (LIRG) nature of IRAS~04296+2923 is more plausibly driven by internal processes, such as bar-induced gas inflow, possibly modulated by long-timescale, low-level tidal interactions with nearby group companions.

astro-ph.GA↗