论文标题
ZTF20AAJNKSQ（AT2020BLT）：$ z \ $ z \ 2.9 $的快速光学瞬变，未检测到的伽马射线爆发对应
ZTF20aajnksq (AT2020blt): A Fast Optical Transient at $z \approx 2.9$ With No Detected Gamma-Ray Burst Counterpart
论文作者
论文摘要
我们提出了ZTF20AAJNKSQ（AT2020BLT），一种快速（$ΔR= 2.4 $ mag，in $ΔT= 1.3 $ days）红色（$ G-R \ of0.6 $ mag）和发光（$ M_ {1626} = -25.9 $）在$ z = 2.9 $ the Zwicky的Zwicky（Zwicky）（Zwicky）（Zwicky）（ZT）。 AT2020BLT与余滴共享多个功能，可与长期伽马射线爆发（GRBS）：（1）一个光灯曲线，由损坏的幂律很好地描述，断裂为$ t_ \ mathrm {j j} = 1 $ day（observer-frame-frame）; （2）一个发光$（l_x = 10^{46} $ $ \ Mathrm {erg} $ $ $ \ MATHRM {s}^{ - 1}）$ x-ray对准;和（3）发光（$L_ν= 4 \ times 10^{31} $ $ \ Mathrm {erg} $ $ $ \ MATHRM {sec}^{ - 1} $ $ $ \ MATHRM {Hz}^{ - 1} $ 10 GHz）无线电发射。但是，在上次ZTF非检测（$ r> 20.64 $）和第一个ZTF检测（$ r = 19.57 $）之间，在0.74D中未检测到GRB，对均等等值的gamma-ray gamma-ray $ e_ e_ _ {γ，\ mathrm的$ e_ {c，\ mathrm {iso} $ er {$ er的gam ray释放的上限有上限。因此，AT2020BLT是未检测到的GRB对应物（PTF11AGG和ZTF19ABVIZSW之后）发现的第三个余辉的瞬态，而第二个（ZTF19ABVIZSW之后）进行了红移测量。我们得出的结论是，AT2020BLT的性质与经典的（初始Lorentz因子$γ_0\ gtrsim 100 $）在轴上GRB一致，该轴GRB被高能量卫星所遗漏。此外，通过估算ZTF高振动数据中的光曲线类似于AT2020BLT的瞬态速率，我们同意以前的结果，即没有证据表明像经典GRB相比，这种现象类似于恒星类似现象。我们通过讨论广阔的高环境光学调查中快速频率搜索的状态和未来的结论。
We present ZTF20aajnksq (AT2020blt), a fast-fading ($Δr=2.4$ mag in $Δt=1.3$ days) red ($g-r\approx0.6$ mag) and luminous ($M_{1626}=-25.9$) optical transient at $z=2.9$ discovered by the Zwicky Transient Facility (ZTF). AT2020blt shares several features in common with afterglows to long-duration gamma-ray bursts (GRBs): (1) an optical light curve well-described by a broken power-law with a break at $t_\mathrm{j}=1$ day (observer-frame); (2) a luminous $(L_X = 10^{46}$ $\mathrm{erg}$ $\mathrm{s}^{-1})$ X-ray counterpart; and (3) luminous ($L_ν= 4 \times 10^{31}$ $\mathrm{erg}$ $\mathrm{sec}^{-1}$ $\mathrm{Hz}^{-1}$ at 10 GHz) radio emission. However, no GRB was detected in the 0.74d between the last ZTF non-detection ($r > 20.64$) and the first ZTF detection ($r = 19.57$), with an upper limit on the isotropic-equivalent gamma-ray energy release of $E_{γ,\mathrm{iso}} < 7 \times 10^{52}$ erg. AT2020blt is thus the third afterglow-like transient discovered without a detected GRB counterpart (after PTF11agg and ZTF19abvizsw) and the second (after ZTF19abvizsw) with a redshift measurement. We conclude that the properties of AT2020blt are consistent with a classical (initial Lorentz factor $Γ_0 \gtrsim 100$) on-axis GRB that was missed by high-energy satellites. Furthermore, by estimating the rate of transients with light curves similar to that of AT2020blt in ZTF high-cadence data, we agree with previous results that there is no evidence for an afterglow-like phenomenon that is significantly more common than classical GRBs. We conclude by discussing the status and future of fast-transient searches in wide-field high-cadence optical surveys.
