论文标题
与不同程度相互作用的星系中的气体分数和耗尽时间
Gas fractions and depletion times in galaxies with different degrees of interaction
论文作者
论文摘要
我们研究了近1500个星系的样品，研究了原子气体含量和中央恒星质量浓度，以研究星爆的性质以及星系 - 果胶相互作用对恒星形成（SF）的影响。我们在S $^4 $ g调查中使用了分类的相互作用和非相互作用星系样本 - 以及档案中的HI GAS块，恒星群众（$ M _ {\ ast} $）和SF速率，来自$ IRAS $ iras $ far -infrared fluxes-并计算出消耗的时间和气体分数。我们从旋转曲线的恒星成分的内斜率上追踪了中央恒星质量浓度。相对于非相互作用星系的控制样本，$ \ pm \ pm 0.2 $ dex in Stellar质量的$ \ pm dex和$ \ pm 1 $ in $ t $ type中的非相互作用星系样本相对于一个因子$> 4 $增强的SF速率，将Starbursts定义为具有因子$> 4 $增强的SF速率。 Starbursts主要是早期类型（$ t \ Lessim 5 $），巨大的螺旋星系（$ M _ {\ ast} \ gtrsim 10^{10} m _ {\ odot} $）不一定是相互作用的。对于给定的恒星质量箱，与非星堡星系相比，恒星爆炸的特征是气体耗竭时间较低，气体级数相似，中央恒星质量浓度较大。对于相互作用和非相互作用的星系，气体分数和气体耗竭时间的全球分布在统计上没有不同。但是，在当前合并星系的情况下，中位气体耗竭时间为0.4 \ pm 0.2 $ 0.2 $ 0.2 $，即控制样品星系的损耗，即使中位气体分数相似，它们的SF率也是$ 1.9 \ pm 0.5 $增强的因子。 Starburst在周环区域中呈现长期的SF，这会在相互作用和非相互作用系统中$ z \ of Boty $ z \ of Bote的中央恒星密度增强。 Starburst的气体耗尽时间尺度低，但与正常的主要序列星系相似。星系合并导致SF效率的中等增强（删节）。
We study the atomic gas content and the central stellar mass concentration for a sample of almost 1500 nearby galaxies to investigate the nature of starbursts and the influence of galaxy-galaxy interactions on star formation (SF). We used a sample of catalogued interacting and non-interacting galaxies in the S$^4$G survey - along with archival HI gas masses, stellar masses ($M_{\ast}$), and SF rates from $IRAS$ far-infrared fluxes - and calculate depletion times and gas fractions. We traced the central stellar mass concentration from the inner slope of the stellar component of the rotation curves. Starbursts are defined as galaxies with a factor $>4$ enhanced SF rate relative to a control sample of non-interacting galaxies which are $\pm 0.2$ dex in stellar mass and $\pm 1$ in $T$-type. Starbursts are mainly early-type ($T\lesssim 5$), massive spiral galaxies ($M_{\ast}\gtrsim 10^{10}M_{\odot}$) that are not necessarily interacting. For a given stellar mass bin, starbursts are characterised by lower gas depletion times, similar gas fractions, and larger central stellar mass concentrations than non-starburst galaxies. The global distributions of gas fraction and gas depletion time are not statistically different for interacting and non-interacting galaxies. However, in the case of currently merging galaxies, the median gas depletion time is a factor of $0.4 \pm 0.2$ that of control sample galaxies, and their SF rates are a factor of $1.9 \pm 0.5$ enhanced, even though the median gas fraction is similar. Starbursts present long-lasting SF in the circumnuclear regions that causes an enhancement of the central stellar density at $z\approx0$ in both interacting and non-interacting systems. Starbursts have low gas depletion timescales, yet similar gas fractions as normal main-sequence galaxies. Galaxy mergers cause a moderate enhancement of the SF efficiency (Abridged).
