论文标题
使用Eagle模拟研究观察性约束对星系中HI不对称测定的影响
Using EAGLE simulations to study the effect of observational constraints on the determination of HI asymmetries in galaxies
论文作者
论文摘要
我们研究了观察性约束的影响，例如信噪比，分辨率和色谱柱密度水平对HI形态不对称（$ \ MATHRM {a} _ \ MATHRM {MODRM {MOD} $）以及噪声对HI Global Profile（$ \ MATHRM {A} _ \ MATHRM {flux} $）的影响。使用来自Eagle模拟的模拟星系，我们找到了对$ \ Mathrm {a} _ \ Mathrm {mathrm {mod} $ balaxy值的最佳组合，这些观察性约束所需的观察性约束，这是银河系的值：一个星系的值：一个列密度阈值$ 5 \ times10^{19} cm^{19} cm^{-2} $ sinim a Calion and A Minim a and a Minim a Calion and a Minim a Calion and A Minim a Minim and A Minim a Catrim and a Minim at A Minim at A Minim at A Minim at A Minim at A Minim at A Minip用至少11个梁解决。我们还使用模拟星系来研究噪声对$ \ mathrm {a} _ \ mathrm {flux} $值的影响，并得出结论，具有大于5.5的全局轮廓以实现对不对称的强大测量。 We investigate the relation between $\mathrm{A}_\mathrm{mod}$ and $\mathrm{A}_\mathrm{flux}$ indices and find them to be uncorrelated which implies that $\mathrm{A}_\mathrm{flux}$ values cannot be used to predict morphological asymmetries in galaxies.
We investigate the effect of observational constraints such as signal-to-noise, resolution and column density level on the HI morphological asymmetry ($\mathrm{A}_\mathrm{mod}$) and the effect of noise on the HI global profile ($\mathrm{A}_\mathrm{flux}$) asymmetry indices. Using mock galaxies from the EAGLE simulations we find an optimal combination of the observational constraints that are required for robust measurement of the $\mathrm{A}_\mathrm{mod}$ value of a galaxy: a column density threshold of $5\times10^{19}cm^{-2}$ or lower at a minimal signal-to-noise of 3 and a galaxy resolved with at least 11 beams. We also use mock galaxies to investigate the effect of noise on the $\mathrm{A}_\mathrm{flux}$ values and conclude that a global profile with signal-to-noise ratio greater than 5.5 is required to achieve a robust measurement of asymmetry. We investigate the relation between $\mathrm{A}_\mathrm{mod}$ and $\mathrm{A}_\mathrm{flux}$ indices and find them to be uncorrelated which implies that $\mathrm{A}_\mathrm{flux}$ values cannot be used to predict morphological asymmetries in galaxies.
