论文标题
快速无线电爆发作为z <0.5的星系中磁场的探针
Fast Radio Bursts as Probes of Magnetic Fields in Galaxies at z < 0.5
论文作者
论文摘要
我们提供了9个快速无线电爆发（FRB）的样本，从该样本中，我们得出了由正常代表的宿主星系的磁场强度，$ z <0.5 $ stellar smoses $ m_* \ 10^8 -10^{10.5} {10.5} m_ \ odot $。我们发现FRB旋转度量（RM）和红移之间没有相关性，这表明RM值主要归因于FRB宿主的贡献。在RM和估计的主机分散度度量（$ dm_ {host} $）和宿主范围的galacto-centric Offset（Spearman $ r_s $ r_s $ r_s $值等于0.64 and -0.52）之间，发现了强烈的相关性（Spearman测试概率$ p_s \ simeq 0.05 $）进一步支持这种断言。对于这9个星系，我们估计它们沿着视线$ b $投射的磁场强度，发现低点值为0.5μg$。这意味着我们的主机样品的磁场比太阳能社区的特征弱（约6μg$），但相对与观察到的售价$2-10μg$的下限相对一致，用于星形形成的磁盘星系，尤其是当我们考虑b-field中的逆转时，我们只能探索$ b _} $} $} $} $} $} $} $} $} $}。我们将Auriga项目模拟星系的RMS（磁动力学宇宙学变焦模拟）进行比较，并发现模拟预测观察到的值在$ 95 \％$ CI之内。即将进行的FRB调查将为数百种新的FRB提供高精度的定位，旋转措施和成像随访，以支持对$ z <1 $星系的磁场的进一步研究。
We present a sample of nine Fast Radio Bursts (FRBs) from which we derive magnetic field strengths of the host galaxies represented by normal, $z<0.5$ star-forming galaxies with stellar masses $M_* \approx 10^8 -10^{10.5} M_\odot$. We find no correlation between the FRB rotation measure(RM) and redshift which indicates that the RM values are due mostly to the FRB host contribution. This assertion is further supported by strong correlations (Spearman test probabilities $P_S \simeq 0.05$) found between RM and the estimated host dispersion measure ($DM_{Host}$) and host-normalized galacto-centric offset (Spearman $r_S$ values equal to 0.64 and -0.52). For these nine galaxies, we estimate their magnetic field strengths projected along the sightline $B$ finding a low median value of $0.5 μG$. This implies the magnetic fields of our sample of hosts are weaker than those characteristic of the Solar neighborhood ($\approx 6 μG$), but relatively consistent with a lower limit on observed range of $2-10 μG$ for star-forming, disk galaxies, especially as we consider reversals in the B-field, and that we are only probing $B_{\parallel}$. We compare to RMs from simulated galaxies of the Auriga project -- magneto-hydrodynamic cosmological zoom simulations - and find that the simulations predict the observed values to within the $95\%$ CI. Upcoming FRB surveys will provide hundreds of new FRBs with high-precision localizations, rotation measures, and imaging follow-up to support further investigation on the magnetic fields of a diverse population of $z<1$ galaxies.
