Cosmological Fast Optical Transients with the Zwicky Transient Facility: A Search for Dirty Fireballs-猫眼课题宝

DOI：

10.3847/1538-4357/ac8bd0

发表时间：

2022-01

期刊：

The Astrophysical Journal

影响因子：

通讯作者：

中科院分区：

其他

文献类型：

作者：

A. Ho;D. Perley;Yuhan Yao;D. Svinkin;A. U. Postigo;R. Perley;D. A. Kann;E. Burns;I. Andreoni;E. Bellm;E. Bissaldi;J. Bloom;T. Brink;R. Dekany;A. Drake;J. F. Agüí Fernández;A. Filippenko;D. Frederiks;M. Graham;B. Hristov;M. Kasliwal;S. Kulkarni;H. Kumar;R. Laher;A. Lysenko;B. Mailyan;C. Malacaria;A. Miller;S. Poolakkil;R. Riddle;A. Ridnaia;B. Rusholme;V. Savchenko;J. Sollerman;C. Thöne;A. Tsvetkova;M. Ulanov;A. Kienlin

脏火球是一种假设的相对论大质量恒星爆炸，其初始洛伦兹因子Γinit低于产生长时间伽马射线暴（LGRB）所需的Γinit ~ 100，但仍可能产生类似LGRB余辉的光学发射。在这里，我们提出了使用兹威基瞬态设备（ZTF）搜索轴上光学余辉的结果。我们的研究产生了7个光学瞬态，它们类似于LGRB轴上的余辉，它们的红色（g−r > 0等），暗淡的宿主星系（r > 23等），快速褪色（dr/dt > 1等），在某些情况下，还有x射线和射电发射。在发现后的几天内，瞬态发射的光谱学确定了七个事件中的六个事件的宇宙距离（红移z = 0.876至2.9），这是没有γ射线触发的光学调查中发现的红移测量的余辉数量的三倍。在四个事件（ZTF 20abbiixp/AT 2020kym, ZTF 21aagwbjr/AT 2021buv， ZTF 21aakruew/AT 2021cwd和ZTF 21abfmpwn/AT 2021qbd）之后，发现了一个可能相关的LGRB (GRB 200524A, GRB 210204A， GRB 210212B和GRB 210610B)，而三个事件（ZTF 20aajnksq/AT 2020blt， ZTF 21aaeyldq/AT 2021any和ZTF 21aayokph/AT 2021lfa）没有检测到LGRB对应物。对这三个“孤儿”事件最简单的解释是，由于探测器的灵敏度和占空比的原因，它们是常规的lgrb，被高能卫星错过了，尽管它们可能本质上是γ射线的亚发光，或者被观察到稍微偏离轴。我们排除了这样一种情况，即肮脏的火球与lgrb具有相似的每固角能量，并且更常见。此外，我们对产生γ射线的材料和产生早期光学余辉发射的材料的开口角的比值设置了第一个直接约束，发现它们必须具有可比性。

Dirty fireballs are a hypothesized class of relativistic massive-star explosions with an initial Lorentz factor Γinit below the Γinit ∼ 100 required to produce a long-duration gamma-ray burst (LGRB), but which could still produce optical emission resembling LGRB afterglows. Here we present the results of a search for on-axis optical afterglows using the Zwicky Transient Facility (ZTF). Our search yielded seven optical transients that resemble on-axis LGRB afterglows in terms of their red colors (g − r > 0 mag), faint host galaxies (r > 23 mag), rapid fading (dr/dt > 1 mag day−1), and in some cases X-ray and radio emission. Spectroscopy of the transient emission within a few days of discovery established cosmological distances (redshift z = 0.876 to 2.9) for six of the seven events, tripling the number of afterglows with redshift measurements discovered by optical surveys without a γ-ray trigger. A likely associated LGRB (GRB 200524A, GRB 210204A, GRB 210212B, and GRB 210610B) was identified for four events (ZTF 20abbiixp/AT 2020kym, ZTF 21aagwbjr/AT 2021buv, ZTF 21aakruew/AT 2021cwd, and ZTF 21abfmpwn/AT 2021qbd) post facto, while three (ZTF 20aajnksq/AT 2020blt, ZTF 21aaeyldq/AT 2021any, and ZTF 21aayokph/AT 2021lfa) had no detected LGRB counterpart. The simplest explanation for the three “orphan” events is that they were regular LGRBs missed by high-energy satellites owing to detector sensitivity and duty cycle, although it is possible that they were intrinsically subluminous in γ-rays or viewed slightly off-axis. We rule out a scenario in which dirty fireballs have a similar energy per solid angle to LGRBs and are an order of magnitude more common. In addition, we set the first direct constraint on the ratio of the opening angles of the material producing γ-rays and the material producing early optical afterglow emission, finding that they must be comparable.

Cosmological Fast Optical Transients with the Zwicky Transient Facility: A Search for Dirty Fireballs

文献摘要

相似文献