Revealing the High-redshift Host Galaxy of the Short GRB 061201 with JWST
利用 JWST 揭示短 GRB 061201 的高红移宿主星系
Using deep near-infrared and optical JWST and Hubble Space Telescope imaging, we identify a new host-galaxy candidate for the short GRB 061201 at an angular offset of ∼2″ from the optical afterglow, with a best-fit photometric redshift of z ∼ 1.2. We compare it with the prior putative host candidate at z = 0.111. The new candidate has a chance-coincidence probability of P<SUB>cc</SUB> = 0.18, above the classical 0.1 threshold but consistent with a physical association given the depth of the JWST imaging. In contrast, the lower P<SUB>cc</SUB> = 0.11 of the z = 0.111 galaxy is driven primarily by bright-tail statistics. A high-redshift origin is favored by three lines of evidence. First, although both scenarios satisfy the Amati (E<SUB>p,i</SUB>─E<SUB>iso</SUB>) relation, the beaming-corrected energy at z = 0.111 makes GRB 061201 an outlier in the Ghirlanda (E<SUB>p,i</SUB>─E<SUB>γ</SUB>) relation. Second, near-infrared data disfavor an AT2017gfo-like kilonova at z = 0.111. Third, afterglow modeling favors the high-redshift scenario, with the Akaike information criterion (AIC) for the z = 1.2 model lower than that for z = 0.111 by ∆AIC = 16.35. Adopting the z ∼ 1.2 candidate as the host gives a physical offset of 16.4─16.9 kpc (substantially reduced from ∼42 kpc implied under the low-redshift scenario) and a stellar age of ∼2 Gyr, consistent with the general population of short gamma-ray bursts (sGRBs). Furthermore, a low-redshift origin implies a binary neutron-star merger rate of ∼1400 Gpc<SUP>−3</SUP> yr<SUP>−1</SUP>, in tension with gravitational-wave constraints. We conclude that a moderately high-redshift host provides a more self-consistent physical framework for GRB 061201, demonstrating the capability of deep JWST imaging for historically hostless sGRBs.
展开 ▾将历史上无宿主短暴 GRB 061201 的宿主候选体从 z=0.111 修正为 z∼1.2;综合 Amati/Ghirlanda 关系、千新星约束、余辉建模 AIC 及并合率,证明深场 JWST 能解决模糊宿主问题。
以往对短伽马暴的宿主证认常受限于地面或 HST 深度,许多事件因候选体概率不足而被称为无宿主暴。本文对 GRB 061201 利用 JWST 深红外/光学成像,将候选宿主从低红移亮星系修正为 z∼1.2 的暗弱星系,说明深场数据可改变宿主判定。综合高能关系、千新星与余辉模型等独立证据,表明单一概率阈值不足以确定宿主,需要物理一致性检验。未来随着 JWST 对更多历史无宿主短暴的观测,可能系统更新其红移分布、年龄与并合率统计,从而更好连接短暴与双中子星并合及引力波事件。
接收 2026-07-09 · 刊出 2026-08-03 · 收录 2026-08-20