论文标题
在附近的星形星系中的冷，富含金属的银河喷泉流的运动学上
On the Kinematics of Cold, Metal-enriched Galactic Fountain Flows in Nearby Star-forming Galaxies
论文作者
论文摘要
我们使用中等分辨率的凯克/棘轮光谱仪和明亮的类星体的成像仪光谱研究通过CAII 3934,3969和NAI 5891,5897吸收在星际/圆形介质中的21个前景星形星体的星际媒体中的媒介中的速度<Z <0.03 <Z <0.20 <Z <Z <0.20 <Z <Z <0.20 <Z <0.20 <10.6。从一个独特的sloan数字天空调查的类星体光谱中汲取了类星 - - 加拉克斯对，因此具有介入的螺旋发射，因此具有异常紧密的冲击参数（r_perp <13 kpc）。该线发射的强度意味着星系的恒星形成速率（SFR）占据了广泛的范围，其中几个远高于星形形成序列。我们使用VOIGT曲线建模来得出每种吸收器的列密度和组件速度，发现列密度N（CAII）> 10^12.5 cm^-2（N（NAI）> 10^12.0 cm^-2）发生在发生率f_c（caii）= 0.63^+0.10_-0.11（f_cii）= 0.63^+0.10_-0.11（f_cii）时，我们找不到证据表明f_c或RE_PERP或M_*上的RETART-FRAME等效宽度W_R（CAII K）或W_R（NAI 5891）的依赖性。取而代之的是，W_R（CAII K）与> 3 sigma的局部SFR相关，表明CAII痕迹痕迹星形形成驱动的流出。尽管大多数吸收剂的速度在+/- 50 km/s的宿主红移之内，但它们的速度宽度（以Delta V_90为特征）通常比通过倾斜速度模型所隐含的30-177 km/s大30-177 km/s。这些运动学必须追踪银河喷泉流，并证明它们持续到R_PERP> 5 kpc。最后，我们评估了粉尘红粉与W_R（CAII K）（W_R（NAI 5891））之间的关系，发现33％（24％）的吸收剂与最合适的银河系E（B-V）-W_R的关系不一致，以> 3sigma的意义。
We use medium-resolution Keck/Echellette Spectrograph and Imager spectroscopy of bright quasars to study cool gas traced by CaII 3934,3969 and NaI 5891,5897 absorption in the interstellar/circumgalactic media of 21 foreground star-forming galaxies at redshifts 0.03 < z < 0.20 with stellar masses 7.4 < log M_*/M_sun < 10.6. The quasar-galaxy pairs were drawn from a unique sample of Sloan Digital Sky Survey quasar spectra with intervening nebular emission, and thus have exceptionally close impact parameters (R_perp < 13 kpc). The strength of this line emission implies that the galaxies' star formation rates (SFRs) span a broad range, with several lying well above the star-forming sequence. We use Voigt profile modeling to derive column densities and component velocities for each absorber, finding that column densities N(CaII) > 10^12.5 cm^-2 (N(NaI) > 10^12.0 cm^-2) occur with an incidence f_C(CaII) = 0.63^+0.10_-0.11 (f_C(NaI) = 0.57^+0.10_-0.11). We find no evidence for a dependence of f_C or the rest-frame equivalent widths W_r(CaII K) or W_r(NaI 5891) on R_perp or M_*. Instead, W_r(CaII K) is correlated with local SFR at >3sigma significance, suggesting that CaII traces star formation-driven outflows. While most of the absorbers have velocities within +/-50 km/s of the host redshift, their velocity widths (characterized by Delta v_90) are universally 30-177 km/s larger than that implied by tilted-ring modeling of the velocities of interstellar material. These kinematics must trace galactic fountain flows and demonstrate that they persist at R_perp > 5 kpc. Finally, we assess the relationship between dust reddening and W_r(CaII K) (W_r(NaI 5891)), finding that 33% (24%) of the absorbers are inconsistent with the best-fit Milky Way E(B-V)-W_r relations at >3sigma significance.
