AI 中文总结
研究利用130个纯HI选且有已分辨HI运动学的星系，在z≈0.09处测得RAR和bTFR，发现bTFR零点演化趋势受拟合方向影响，正向拟合偏差源于选择效应，需谨慎处理以可靠测量动力学标度关系的红移演化。
AI 中文摘要
重子-塔利-费希尔关系（bTFR）和径向加速度关系（RAR）将星系中观测到的动力学与其重子质量分布所预期的动力学联系起来。这些关系的本征散射很小，对星系形成模型、暗物质属性以及修正动力学理论施加了严格约束，但在极近邻宇宙之外的详细测量仍很有限。我们利用130个纯HI选且具有已分辨HI运动学和重子质量分布的星系，测量红移z≈0.09范围内的bTFR和RAR。我们测得的RAR紧密，加速度标度a₀=(1.50±0.05)×10⁻¹⁰ m·s⁻²，本征散射为0.096±0.006 dex，与近邻结果一致。我们以“逆”方向拟合bTFR，以M_bar为条件减轻与HI流量相关的选择效应，测得对数斜率为0.27±0.01（对应正向斜率为3.72±0.16），垂直本征散射σ⊥≈0.05 dex。将MOND插值函数的通用δ族拟合到RAR，我们推断δ=4.10⁺¹·⁴₋₀.₆₈，与太阳系引力约束和宽双星测试零结果所需的值一致。我们发现纯HI选样本的RAR加速度标度无显著红移演化，但bTFR零点呈现明显的演化趋势，且该趋势强烈依赖于拟合方向：传统正向拟合得出对z演化的8.7σ偏好，而我们的基准逆拟合中，该偏好降至3.4σ，处于RAR演化约束的≈2σ范围内。这表明选择效应会使正向拟合产生偏差，未来研究需仔细考虑此类效应，以可靠测量动力学标度关系的红移演化。
英文摘要
The baryonic Tully-Fisher relation (bTFR) and the radial acceleration relation (RAR) link the observed dynamics in galaxies to that expected from their baryonic mass distributions. The relations' small intrinsic scatters place strong constraints on galaxy formation models, dark matter properties and theories of modified dynamics, yet detailed measurements beyond the very local Universe remain limited. We use 130 purely HI-selected galaxies with resolved HI kinematics and baryonic mass profiles to measure the bTFR and RAR up to $z\approx0.09$. We measure a tight RAR with an acceleration scale $a_0=(1.50\pm0.05)\times10^{-10},{\rm m,s^{-2}}$ and an intrinsic scatter of $0.096\pm0.006$ dex, consistent with local results. We fit the bTFR in the `inverse' direction, conditioning on $M_{\rm bar}$ to mitigate HI flux-related selection effects, measuring a logarithmic slope of $0.27\pm0.01$ (corresponding to a forward slope of $3.72\pm0.16$), with vertical intrinsic scatter $σ_\perp\approx0.05$ dex. Fitting the general $δ$-family of MOND interpolating functions to the RAR, we infer $δ=4.10^{+1.4}_{-0.68}$, consistent with the value required by Solar System gravitational constraints and a null Wide Binary Test. We find no significant redshift evolution in the RAR acceleration scale for our pure HI-selected sample. However, the bTFR zero-point shows an apparent evolutionary trend that is strongly dependent on the fit direction: the traditional forward fit yields an $8.7σ$ preference for $z$ evolution, while for our fiducial inverse fit, this reduces to $3.4σ$, within $\approx2σ$ of the RAR evolution constraint. This suggests selection effects bias the forward fit; a careful consideration of such effects will be required in future endeavours to robustly measure the redshift evolution of dynamical scaling relations.
Comments21 pages, 18 figures
