温暖的、兴奋的和分子气体：GRB 121024 A在其恒星形成星系中闪耀
The warm, the excited, and the molecular gas: GRB 121024A shining through its star-forming galaxy
摘要：
我们提出了第一个报告的情况下，同时金属丰度测定的伽马射线暴（GRB）的主机星系，从余辉吸收线以及强发射线诊断。使用光谱和成像观测的余辉和主机的长时间斯威夫特GRB 121024 A在z = 2.30，我们给出了迄今为止最完整的观点之一的伽玛射线暴主机/环境。我们观察到一个强阻尼的Ly-alpha吸收体（DLA），其氢柱密度为log N（HI）= 21.88 +/- 0.10，H2吸收在Lyman-Werner带中（log（f）的分子分数~ -1.4; GRB-DLA中分子氢的第四次固体探测），星云发射线H-α，H-β，[O II]，[O III]和[N II]，以及金属吸收线。我们发现一个伽玛暴宿主星系是高度恒星形成的（SFR ~ 40太阳质量/年），沿视线的尘埃校正金属丰度[Zn/H]corr = -0.6 +/- 0.2（[O/H] ~ -0.3从发射线），和耗尽因子[Zn/Fe] = 0.85 +/- 0.04。分子气体以400 km/s（和1-3 kpc）的速度与伽马射线暴光激发的气体分离。这意味着一个相当大质量的宿主，与导出的恒星质量log（M/M_solar）= 9.9+/- 0.2一致。我们解剖宿主星系的分子组成，激发气体，和线发射恒星形成区域的特点。发现视线的消光曲线异常平坦（Rv ~15）。我们讨论了反常粒度分布的可能性。我们还讨论了不同的金属丰度测定从吸收和发射线，这给出了一致的结果，视线到GRB 121024 A。
英文摘要：
We present the first reported case of the simultaneous metallicity determination of a gamma-ray burst (GRB) host galaxy, from both afterglow absorption lines as well as strong emission-line diagnostics. Using spectroscopic and imaging observations of the afterglow and host of the long-duration Swift GRB121024A at z = 2.30, we give one of the most complete views of a GRB host/environment to date. We observe a strong damped Ly-alpha absorber (DLA) with a hydrogen column density of log N(HI) = 21.88 +/- 0.10, H2 absorption in the Lyman-Werner bands (molecular fraction of log(f)~ -1.4; fourth solid detection of molecular hydrogen in a GRB-DLA), the nebular emission lines H-alpha, H-beta, [O II], [O III] and [N II], as well as metal absorption lines. We find a GRB host galaxy that is highly star-forming (SFR ~ 40 solar masses/yr ), with a dust-corrected metallicity along the line of sight of [Zn/H]corr = -0.6 +/- 0.2 ([O/H] ~ -0.3 from emission lines), and a depletion factor [Zn/Fe] = 0.85 +/- 0.04. The molecular gas is separated by 400 km/s (and 1-3 kpc) from the gas that is photoexcited by the GRB. This implies a fairly massive host, in agreement with the derived stellar mass of log(M/M_solar ) = 9.9+/- 0.2. We dissect the host galaxy by characterising its molecular component, the excited gas, and the line-emitting star-forming regions. The extinction curve for the line of sight is found to be unusually flat (Rv ~15). We discuss the possibility of an anomalous grain size distributions. We furthermore discuss the different metallicity determinations from both absorption and emission lines, which gives consistent results for the line of sight to GRB 121024A.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
