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arXiv 1701.01100astro-ph.HEastro-ph.COastro-ph.GA
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重频快速射电暴FRB 121102的宿主星系和红移

The Host Galaxy and Redshift of the Repeating Fast Radio Burst FRB 121102

Shriharsh P. Tendulkar, Cees Bassa, James M. Cordes, Geoffery C. Bower, Casey J. Law, Shamibrata Chatterjee, Elizabeth A. K. Adams, Slavko Bogdanov, Sarah Burke… 展开作者

Shriharsh P. Tendulkar, Cees Bassa, James M. Cordes, Geoffery C. Bower, Casey J. Law, Shamibrata Chatterjee, Elizabeth A. K. Adams, Slavko Bogdanov, Sarah Burke-Spolaor, Bryan J. Butler, Paul Demorest, Jason W. T. Hessels, Victoria M. Kaspi, T. Joseph W. Lazio, Natasha Maddox, Benito Marcote, Maura A. McLaughlin, Zsolt Paragi, Scott M. Ransom, Paul Scholz, Andrew Seymour, Laura G. Spitler, Huib J. van Langevelde, Robert S. Wharton

摘要:

重复快速射电暴(FRB 121102)的精确定位提供了FRB与光学和持久射电对应物的第一个明确关联(机会重合概率$p\lesssim3\times10^{-4}$)。我们报告的光学成像和光谱学的对应,并发现它是一个扩展($0.6^{\prime\prime}-0.8^{\prime\prime}$)对象显示突出的巴耳末和[OIII]发射线。根据光谱和发射线比,我们将其归类为一个低金属丰度、恒星形成的$m_{r^\prime} = 25.1$ AB等矮星系,红移为$z=0.19273(8)$,对应的光度距离为972 Mpc。从角尺寸、红移和光度,我们估计主星系的直径为$\lesssim4$ kpc,恒星质量为$M_*\sim4-7\times 10^{7}\,M_\odot$,假设质光比在2到3 $\,M_\odot\,L_\odot^{-1}$之间。基于H $α$通量,我们估计宿主的恒星形成率为$0.4\,M_\odot\,\mathrm{yr^{-1}}$和一个相当大的宿主色散测量深度$\lesssim 324\,\mathrm{pc\,cm^{-3}}$。根据几何因素,宿主星系对FRB 121102的净色散测量贡献可能低于这个值。我们发现,Marcote等人(2017)报告的FRB 121102位置的持久射电源与星系的光中心偏移$\sim$ 200 mas,并且宿主星系没有显示AGN活动的光学特征。如果FRB 121102是更广泛的FRB人口的典型,如果未来的干涉定位优先在矮星系中发现它们具有低金属丰度和突出的发射线,它们将与长伽马射线爆发和超亮超新星共享这样的偏好。

英文摘要:

The precise localization of the repeating fast radio burst (FRB 121102) has provided the first unambiguous association (chance coincidence probability $p\lesssim3\times10^{-4}$) of an FRB with an optical and persistent radio counterpart. We report on optical imaging and spectroscopy of the counterpart and find that it is an extended ($0.6^{\prime\prime}-0.8^{\prime\prime}$) object displaying prominent Balmer and [OIII] emission lines. Based on the spectrum and emission line ratios, we classify the counterpart as a low-metallicity, star-forming, $m_{r^\prime} = 25.1$ AB mag dwarf galaxy at a redshift of $z=0.19273(8)$, corresponding to a luminosity distance of 972 Mpc. From the angular size, the redshift, and luminosity, we estimate the host galaxy to have a diameter $\lesssim4$ kpc and a stellar mass of $M_*\sim4-7\times 10^{7}\,M_\odot$, assuming a mass-to-light ratio between 2 to 3$\,M_\odot\,L_\odot^{-1}$. Based on the H$α$ flux, we estimate the star formation rate of the host to be $0.4\,M_\odot\,\mathrm{yr^{-1}}$ and a substantial host dispersion measure depth $\lesssim 324\,\mathrm{pc\,cm^{-3}}$. The net dispersion measure contribution of the host galaxy to FRB 121102 is likely to be lower than this value depending on geometrical factors. We show that the persistent radio source at FRB 121102's location reported by Marcote et al (2017) is offset from the galaxy's center of light by $\sim$200 mas and the host galaxy does not show optical signatures for AGN activity. If FRB 121102 is typical of the wider FRB population and if future interferometric localizations preferentially find them in dwarf galaxies with low metallicities and prominent emission lines, they would share such a preference with long gamma ray bursts and superluminous supernovae.

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。

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