Chronicling the Host Galaxy Properties of the Remarkable Repeating FRB 20201124A
Chronicling the Host Galaxy Properties of the Remarkable Repeating FRB 20201124A
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DOI：
10.3847/2041-8213/ac242b
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发表时间：
2021-10-01
影响因子：
7.9
通讯作者：
Tejos, Nicolas
中科院分区：
文献类型：
--
作者：
Fong, Wen-fai;Dong, Yuxin;Tejos, Nicolas
我们介绍了澳大利亚平方公里阵列探路器对重复快速射电爆发(FRB)源FRB 20201124A的宿主星系的定位和后续观测，FRB 20201124A是第五个具有已识别主机的银河系外重复FRB。从6.5m MMT天文台的光谱观测中，我们得到了红移z=0.0979+/-0.0001，由Hα发射的Sfr(Hα)近似为2.1M(圆点)Yr(-1)的恒星形成速率，以及12+log(O/H)的气相金属丰度近似为9.0。通过对12个滤光片的光学-中红外(MIR)测光和光谱的联合模拟，我们推断出恒星质量的中位数类似于2×10(10)M(圆点)，内部尘埃消光A(V)近似于1-1.5Mag，质量加权恒星群年龄类似于5-6Gyr。将这些数据与射电和X射线观测联系起来，我们无法调和宽带行为与强烈的活动星系核活动，相反，我们将持续射电发射的主要来源归因于恒星的形成，很可能来自宿主的核周区域。模型还表明，热尘成分对MIR光度的贡献类似于10%-30%。我们模拟了宿主星系的恒星形成和质量聚集历史，发现宿主星系在1年前聚集了其质量的90%，并且在其存在的大部分时间里表现出相当恒定的SFR，没有明确的证据表明过去的星暴活动。
We present the Australian Square Kilometre Array Pathfinder localization and follow-up observations of the host galaxy of the repeating fast radio burst (FRB) source, FRB 20201124A, the fifth such extragalactic repeating FRB with an identified host. From spectroscopic observations using the 6.5 m MMT Observatory, we derive a redshift z = 0.0979 +/- 0.0001, a star formation rate inferred from H alpha emission SFR(H alpha) approximate to 2.1 M (circle dot) yr(-1), and a gas-phase metallicity of 12+log(O/H) approximate to 9.0. By jointly modeling the 12 filter optical-mid-infrared (MIR) photometry and spectroscopy of the host, we infer a median stellar mass of similar to 2 x 10(10) M (circle dot), internal dust extinction A ( V ) approximate to 1-1.5 mag, and a mass-weighted stellar population age of similar to 5-6 Gyr. Connecting these data to the radio and X-ray observations, we cannot reconcile the broadband behavior with strong active galactic nucleus activity and instead attribute the dominant source of persistent radio emission to star formation, likely originating from the circumnuclear region of the host. The modeling also indicates a hot dust component contributing to the MIR luminosity at a level of similar to 10%-30%. We model the host galaxy's star formation and mass assembly histories, finding that the host assembled >90% of its mass by 1 Gyr ago and exhibited a fairly constant SFR for most of its existence, with no clear evidence of past starburst activity.