Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2610.41895

The 943 MHz radio-SFR relation of nearby galaxies observed with ASKAP

Shengtao Wang·Xiaohui Sun·Jiangtao Li·Chao-Wei Tsai·Jianghui Xu
View original source ↗Read source document ↗Export metadata ↓

Abstract

We investigate the integrated 943 MHz radio-infrared and radio-star-formation-rate (SFR) relations of 875 nearby galaxies within $D<50$ Mpc using public Australian SKA Pathfinder (ASKAP) observations. After excluding galaxies with identified or candidate AGN activity, 594 galaxies remain in the AGN-cleaned sample. We used Bayesian errors-in-variables models that account for measurement uncertainties, intrinsic scatter, and correlated distance errors. The AGN-cleaned radio-infrared relation is nearly linear, $L_{ν,943}\propto L_{ν,\mathrm{W4}}^{1.09\pm0.02}$, with an orthogonal intrinsic scatter of $0.21\pm0.01$ dex, and is tighter than the AGN-host relation. For 592 AGN-cleaned galaxies, the radio-SFR relation is approximately linear, $L_{ν,943}\propto{\rm SFR}^{1.02\pm0.02}$, with an intrinsic scatter of $0.25\pm0.01$ dex. Semi-calorimetric models reveal positive secondary dependences on stellar mass, $γ=0.09\pm0.03$, and rotation velocity, $δ=0.24\pm0.08$. The consistency between these two secondary trends suggests that the galaxy gravitational potential may weakly regulate CRE confinement and synchrotron-radiation efficiency. Our results provide an integrated 943 MHz radio-SFR calibration for nearby galaxies and show that, although radio luminosity scales nearly proportionally with SFR on average, weak secondary dependences on galaxy properties remain.

Explore related subjects

astro-ph.GA

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Shengtao Wang, Xiaohui Sun, Jiangtao Li, Chao-Wei Tsai, Jianghui Xu. 2026-10-30. The 943 MHz radio-SFR relation of nearby galaxies observed with ASKAP. https://arxiv.org/abs/2610.41895

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

SDSS-V LVM: Revealing the Physical and Chemical Structure of the Helix Nebula

We present the first spatially contiguous study of the physical and chemical structure of the Helix Nebula (NGC~7293, PNG 036.1-57.1) based on integral-field spectroscopy from the SDSS-V Local Volume Mapper (LVM). The wide-field observations provide nearly complete spectroscopic coverage of the nebula, enabling a spaxel-by-spaxel analysis of extinction, electron density and temperature, ionisation structure, and chemical abundances. We reconstruct calibrated datacubes from the LVM row-stacked spectra and measure 41 optical emission lines, including hydrogen, helium, and collisionally excited metal lines. The resulting maps reveal a strongly stratified nebula, with highly ionised gas traced by \heii~concentrated toward the central cavity, low-ionisation material dominating the bright shell, and neutral or transition-zone gas enhanced in the outer regions. The Helix is a low-density object, with typical electron densities of $\sim10^{2}\mathrm{cm^{-3}}$, and exhibits a non-uniform temperature structure, with variations of several thousand Kelvin across different ionisation zones. We derive a near-solar oxygen abundance, $12+\log(\mathrm{O/H})\simeq8.7$, consistent with spatially complete sampling. The central abundance pattern indicates a significant contribution from unobserved O$^{3+}$, suggesting that apparent abundance variations are primarily driven by ionisation effects rather than true chemical inhomogeneities. We also find evidence for a sulfur deficit of $\sim$1 dex, consistent with the planetary-nebula sulfur anomaly. The helium and nitrogen abundances place the Helix near the classical boundary of Type~I planetary nebulae, suggesting moderate chemical enrichment by its progenitor star.

astro-ph.GA↗
arXiv2026

Infrared spectroscopy of gas-phase hydrogenated and methylated pyrenes: from laboratory spectra to the simulated 3.4 $μ$m emission band

Observations of the aromatic infrared emission band at 3.3 mic often reveal satellite emission features in the 3.4 - 3.6 mic range. While the 3.3 mic band is attributed to the CH stretching vibration of polycylic aromatic hydrocarbons (PAHs), the satellite bands - particularly its prominent 3.4 mic component - is assigned to aliphatic CH stretching vibrations in hydrogenated and methylated PAH-like species. Our aim is to derive state-of-the-art infrared emission spectra for aliphatic-containing pyrene derivatives and compare them with astronomical observations. This will help refine our understanding of the contribution of these species to the 3.4 mic emission band. Mid-infrared spectra (1.4-25 mic of gas-phase dihydropyrene, tehtrahydropyrene, hexahydropyrene methylated pyrene, and pyrene were recorded at temperatures ranging from 373 to 673 K, depending on the species. The band profiles were analyzed using a multi-component fitting tool, and empirical anharmonicity laws were derived to quantify the evolution of the band positions and widths with temperature. The obtained spectral data was combined with the results of a Monte Carlo emission model to simulate the emission spectra following UV-photon absorption, up to the dissociation limit (<6 eV). The resulting synthetic spectra were compared with James Webb Space Telescope observations of the Orion Bar region (PDRs4All program). Based on these state-of-the-art simulated spectra, we show that 1,2,3,6,7,8-hexahydropyrene matches all the constrains to fit the red component of the 3.4 mic band observed at 3.403 mic. While 1-methylpyrene may also contribute to the underlying emission plateau, its lack of a strong infrared band complicates detection in observed spectra, unlike hexahydropyrene. All experimental spectra and their temperature-dependent analyses are available in the new cosmicPAH-IRDB database.

astro-ph.GA↗
arXiv2026

Revealing a multi-zone circumnuclear dust response in UGC 11487 through phase-resolved WISE W1--W2 diagnostics

Mid-infrared (MIR) flares provide a direct probe of dust reprocessing in obscured tidal disruption event (TDE) candidates when the primary optical or ultraviolet flare is weak, missed, or strongly attenuated. We present a phase-resolved analysis of the WISE/NEOWISE W1-W2 evolution of the MIR-selected TDE candidate UGC 11487/WTP14adeqka over 2014-2024. We combine timing, colour, and flux diagnostics with phenomenological modelling, hydrodynamically motivated clumpy dust-echo calculations, and an aperture-matched ultraviolet-to-radio spectral energy distribution of the host. The decade-long flare shows a delayed and broader W2 response, colour hysteresis, and cooling from approximately 900 K to 500-600 K. Positive-fluence centroids yield a preferred delay of $224 +/- 45$ d, corresponding to $0.188 +/- 0.038$ pc. The effective infrared luminosity peaks at approximately $3 x 10^{43}$ erg s$^{-1}$, and the integrated infrared energy is $(2.9-3.8) x 10^{51}$ erg. A single self-similar MIR response is strongly disfavoured, with Delta BIC = 281.7, while the preferred compact description is a two-component phenomenological model. Representative hydro-clumpy calculations reproduce the empirical diagnostics in a structured, multi-zone dust-response scenario. The host is a moderately star-forming isolated barred disc without a dominant persistent active galactic nucleus component. These results support an obscured TDE-like accretion transient reprocessed by structured circumnuclear dust and show that phase-resolved WISE diagnostics can recover characteristic sub-parsec response scales in obscured accretion-powered nuclear transients.

astro-ph.GA↗