论文标题
在其主机银河系的螺旋臂中解剖FRB 190608的当地环境
Dissecting the Local Environment of FRB 190608 in the Spiral Arm of its Host Galaxy
论文作者
论文摘要
我们对快速无线电爆发（FRB）〜190608的主机银河系进行了高分辨率分析，$ z = 0.11778 $（以下简称HG 190608）的SB（R）C星系，以剖定其本地环境及其对FRB属性的贡献。我们的Hubble空间望远镜宽场摄像头3紫外线和可见光图像表明，FRB 〜190608的次级定位与恒星形成的结一致（$σ_{\ rm sfr} = 1.5 \ times 10^{ - 2} { - 2} 〜M _ _} \，kpc^{ - 2} $）在HG〜190608的西北螺旋臂中。使用H $β$排放中存在的凯克宇宙Web成像器的积分谱，其表面亮度为$μ_ {\ rmhβ} = \ Mathrm {（3.36 \ PM0.21）\ times10^{ - 17} \; erg; s^{ - 1} \; cm^{ - 2} \; arcsec^{ - arcsec^{ - 2}} $ 190608 $ \ rm dm _ {\ rm host，ism} = 94 \ pm 38〜 \; pc \; cm^{ - 3} $。星系以圆速度$ v _ {\ rm circ} = \ rm 141 \ pm 8〜 km \; s^{ - 1} $在倾斜度$ i _ {\ mathrm {gas}} = 37 \ pm 3^\ circ $ a}时，在\大约10^{11.96 \ pm 0.08} 〜m _ {\ odot} $。这意味着对$ \ rm dm _ {\ rm主机的DM的光环贡献，halo} = \ rm 55 \ pm25 \; pc \; cm^{ - 3} $，可能会在保留的桶中的密度和分数上遵守假设。从星系旋转曲线中，我们使用线性共振理论来推断$ω_p= 34 \ pm 6 \; \ mathrm {km \; s^{ - 1} \; kpc^{ - 1}} $使用线性谐振理论的键值的模式速度。然后，我们使用距离本地化中的臂前缘的祖先的星形成恒星形成以来的最大时间，并找到$ t _ {\ mathrm {engrm {eng}} = 21 _ { - 6}^{+25} $ myr。与以前对FRB环境的高分辨率研究不同，我们没有发现FRB 190608的形态，排放或运动学受到干扰的证据。
We present a high-resolution analysis of the host galaxy of fast radio burst (FRB)~190608, an SB(r)c galaxy at $z=0.11778$ (hereafter HG 190608), to dissect its local environment and its contributions to the FRB properties. Our Hubble Space Telescope Wide Field Camera 3 ultraviolet and visible light image reveals that the subarcsecond localization of FRB~190608 is coincident with a knot of star-formation ($Σ_{\rm SFR} = 1.5 \times 10^{-2}~ M_{\odot} \, \rm \, yr^{-1} \, kpc^{-2}$) in the northwest spiral arm of HG~190608. Using H$β$ emission present in our Keck Cosmic Web Imager integral field spectrum of the galaxy with a surface brightness of $μ_{\rm Hβ}= \mathrm{(3.36\pm0.21)\times10^{-17}\;erg\;s^{-1}\;cm^{-2}\;arcsec^{-2}}$, we infer an extinction-corrected H$α$ surface brightness and compute a dispersion measure (DM) from the interstellar medium of HG 190608 of $\rm DM_{\rm Host,ISM} = 94 \pm 38~ \;pc\;cm^{-3}$. The galaxy rotates with a circular velocity $v_{\rm circ} = \rm 141 \pm 8~ km\;s^{-1}$ at an inclination $i_{\mathrm{gas}} = 37 \pm 3^\circ$, giving a dynamical mass $M_{\rm halo}^{\rm dyn} \approx 10^{11.96 \pm 0.08}~M_{\odot}$. This implies a halo contribution to the DM of $\rm DM_{\rm Host,Halo}= \rm 55\pm25 \;pc\;cm^{-3}$ subject to assumptions on the density profile and fraction of baryons retained. From the galaxy rotation curve, we infer a bar-induced pattern speed of $Ω_p=34\pm 6\;\mathrm{km\;s^{-1}\;kpc^{-1}}$ using linear resonance theory. We then calculate the maximum time since star-formation for a progenitor using the furthest distance to the arm's leading edge within the localization, and find $t_{\mathrm{enc}} = 21_{-6}^{+25}$ Myr. Unlike previous high-resolution studies of FRB environments, we find no evidence of disturbed morphology, emission, or kinematics for FRB 190608.
