GRB 180418A: A Possibly Short Gamma-Ray Burst with a Wide-angle Outflow in a Faint Host Galaxy
| Autor: | Adam Goldstein, Matt Nicholl, B. E. Cobb, E. L. M. Burns, A. J. Levan, Nial R. Tanvir, Nathan Smith, Edo Berger, Kerry Paterson, Brian D. Metzger, P. K. Blanchard, Tanmoy Laskar, Antonino Cucchiara, W. Fong, A. Rouco Escorial, Peter Milne, Raffaella Margutti, A. E. Nugent, D. Cornish, Péter Veres, A. Y. Lien, S. B. Cenko, M. Lally |
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| Rok vydání: | 2021 |
| Předmět: |
Physics
astro-ph.HE 010504 meteorology & atmospheric sciences Astronomy Astrophysics::High Energy Astrophysical Phenomena Astronomy and Astrophysics Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Galaxy Space and Planetary Science 0103 physical sciences Outflow Gamma-ray burst 010303 astronomy & astrophysics Host (network) Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences |
| Zdroj: | Rouco Escorial, A, Fong, W, Veres, P, Laskar, T, Lien, A, Paterson, K, Lally, M, Blanchard, P K, Nugent, A E, Tanvir, N R, Cornish, D, Berger, E, Burns, E, Cenko, S B, Cobb, B E, Cucchiara, A, Goldstein, A, Margutti, R, Metzger, B D, Milne, P, Levan, A, Nicholl, M & Smith, N 2021, ' GRB 180418A : A Possibly Short Gamma-Ray Burst with a Wide-angle Outflow in a Faint Host Galaxy ', Astrophysical Journal, vol. 912, no. 2, 95 . https://doi.org/10.3847/1538-4357/abee85 The Astrophysical Journal, 912, 2, pp. 1-19 The Astrophysical Journal, 912, 1-19 |
| ISSN: | 0004-637X |
| DOI: | 10.3847/1538-4357/abee85 |
| Popis: | We present X-ray and multiband optical observations of the afterglow and host galaxy of GRB 180418A, discovered by Swift/BAT and Fermi/GBM. We present a reanalysis of the GBM and BAT data deriving durations of the prompt emission of T 90 ≈ 2.56 and 1.90 s, respectively. Modeling the Fermi/GBM catalog of 1405 bursts (2008–2014) in the hardness–T 90 plane, we obtain a probability of ≈60% that GRB 180418A is a short-hard burst. From a combination of Swift/XRT and Chandra observations, the X-ray afterglow is detected to ≈38.5 days after the burst and exhibits a single power-law decline with F X ∝ t −0.98. Late-time Gemini observations reveal a faint r ≈ 25.69 mag host galaxy at an angular offset of ≈0.″16. At the likely redshift range of z ≈ 1–2.25, we find that the X-ray afterglow luminosity of GRB 180418A is intermediate between short and long gamma-ray bursts (GRBs) at all epochs during which there are contemporaneous data and that GRB 180418A lies closer to the E γ,peak–E γ,iso correlation for short GRBs. Modeling the multiwavelength afterglow with the standard synchrotron model, we derive the burst explosion properties and find a jet opening angle of θ j ≳ 9°–14°. If GRB 180418A is a short GRB that originated from a neutron star merger, it has one of the brightest and longest-lived afterglows along with an extremely faint host galaxy. If, instead, the event is a long GRB that originated from a massive star collapse, it has among the lowest-luminosity afterglows and lies in a peculiar space in terms of the hardness–T 90 and E γ,peak–E γ,iso planes. |
| Databáze: | OpenAIRE |
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