Magnetar Central Engines in Gamma-Ray Bursts Follow the Universal Relation of Accreting Magnetic Stars
Gamma-ray bursts (GRBs), both long and short, are explosive events whose inner engine is generally expected to be a black hole or a highly magnetic neutron star (magnetar) accreting high-density matter. Recognizing the nature of GRB central engines, and in particular the formation of neutron stars (...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/2041-8213/acccec |
| _version_ | 1797699897103745024 |
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| author | Simone Dall’Osso Giulia Stratta Rosalba Perna Giovanni De Cesare Luigi Stella |
| author_facet | Simone Dall’Osso Giulia Stratta Rosalba Perna Giovanni De Cesare Luigi Stella |
| author_sort | Simone Dall’Osso |
| collection | DOAJ |
| description | Gamma-ray bursts (GRBs), both long and short, are explosive events whose inner engine is generally expected to be a black hole or a highly magnetic neutron star (magnetar) accreting high-density matter. Recognizing the nature of GRB central engines, and in particular the formation of neutron stars (NSs), is of high astrophysical significance. A possible signature of NSs in GRBs is the presence of a plateau in the early X-ray afterglow. Here we carefully select a subset of long and short GRBs with a clear plateau, and look for an additional NS signature in their prompt emission, namely a transition between the accretion and propeller phases in analogy with accreting, magnetic compact objects in other astrophysical sources. We estimate from the prompt emission the minimum accretion luminosity below which the propeller mechanism sets in, and the NS magnetic field and spin period from the plateau. We demonstrate that these three quantities obey the same universal relation in GRBs as in other accreting compact objects switching from accretion to propeller. This relation provides also an estimate of the radiative efficiency of GRBs, which we find to be several times lower than radiatively efficient accretion in X-ray binaries and in agreement with theoretical expectations. These results provide additional support to the idea that at least some GRBs are powered by magnetars surrounded by an accretion disk. |
| first_indexed | 2024-03-12T04:14:30Z |
| format | Article |
| id | doaj.art-ec8f5149fa7c45369676c8183f25dd07 |
| institution | Directory Open Access Journal |
| issn | 2041-8205 |
| language | English |
| last_indexed | 2024-03-12T04:14:30Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal Letters |
| spelling | doaj.art-ec8f5149fa7c45369676c8183f25dd072023-09-03T10:43:26ZengIOP PublishingThe Astrophysical Journal Letters2041-82052023-01-019492L3210.3847/2041-8213/acccecMagnetar Central Engines in Gamma-Ray Bursts Follow the Universal Relation of Accreting Magnetic StarsSimone Dall’Osso0https://orcid.org/0000-0003-4366-8265Giulia Stratta1https://orcid.org/0000-0003-1055-7980Rosalba Perna2https://orcid.org/0000-0002-3635-5677Giovanni De Cesare3https://orcid.org/0000-0003-0869-7183Luigi Stella4https://orcid.org/0000-0002-0018-1687Istituto Nazionale di Fisica Nucleare—Roma 1 , Piazzale Aldo Moro 2, I-00185 Roma, Italy ; simoneda@roma1.infn.itIstituto Nazionale di Fisica Nucleare—Roma 1 , Piazzale Aldo Moro 2, I-00185 Roma, Italy ; simoneda@roma1.infn.it; Institut für Theoretische Physik, Goethe Universität , Max-von-Laue-Str. 1, D-60438 Frankfurt am Main, Germany; Istituto di Astrofisica e Planetologia Spaziali , via Fosso del Cavaliere 100, I-00133 Roma, Italy; INAF—Osservatorio Astornomico di Bologna , viale P.Gobetti, Bologna, ItalyDepartemnt of Physics & Astronomy, Stony Brook University , Stony Brook, NY 11794, USA; Center for Computational Astrophysics, Flatiron Institute , New York, NY 10010, USAINAF—Osservatorio Astornomico di Bologna , viale P.Gobetti, Bologna, ItalyINAF—Osservatorio Astornomico di Roma , via Frascati 33, I-00078, Monte Porzio Catone, Roma, ItalyGamma-ray bursts (GRBs), both long and short, are explosive events whose inner engine is generally expected to be a black hole or a highly magnetic neutron star (magnetar) accreting high-density matter. Recognizing the nature of GRB central engines, and in particular the formation of neutron stars (NSs), is of high astrophysical significance. A possible signature of NSs in GRBs is the presence of a plateau in the early X-ray afterglow. Here we carefully select a subset of long and short GRBs with a clear plateau, and look for an additional NS signature in their prompt emission, namely a transition between the accretion and propeller phases in analogy with accreting, magnetic compact objects in other astrophysical sources. We estimate from the prompt emission the minimum accretion luminosity below which the propeller mechanism sets in, and the NS magnetic field and spin period from the plateau. We demonstrate that these three quantities obey the same universal relation in GRBs as in other accreting compact objects switching from accretion to propeller. This relation provides also an estimate of the radiative efficiency of GRBs, which we find to be several times lower than radiatively efficient accretion in X-ray binaries and in agreement with theoretical expectations. These results provide additional support to the idea that at least some GRBs are powered by magnetars surrounded by an accretion disk.https://doi.org/10.3847/2041-8213/acccecGamma-ray burstsMagnetarsStellar accretion disksHigh energy astrophysics |
| spellingShingle | Simone Dall’Osso Giulia Stratta Rosalba Perna Giovanni De Cesare Luigi Stella Magnetar Central Engines in Gamma-Ray Bursts Follow the Universal Relation of Accreting Magnetic Stars The Astrophysical Journal Letters Gamma-ray bursts Magnetars Stellar accretion disks High energy astrophysics |
| title | Magnetar Central Engines in Gamma-Ray Bursts Follow the Universal Relation of Accreting Magnetic Stars |
| title_full | Magnetar Central Engines in Gamma-Ray Bursts Follow the Universal Relation of Accreting Magnetic Stars |
| title_fullStr | Magnetar Central Engines in Gamma-Ray Bursts Follow the Universal Relation of Accreting Magnetic Stars |
| title_full_unstemmed | Magnetar Central Engines in Gamma-Ray Bursts Follow the Universal Relation of Accreting Magnetic Stars |
| title_short | Magnetar Central Engines in Gamma-Ray Bursts Follow the Universal Relation of Accreting Magnetic Stars |
| title_sort | magnetar central engines in gamma ray bursts follow the universal relation of accreting magnetic stars |
| topic | Gamma-ray bursts Magnetars Stellar accretion disks High energy astrophysics |
| url | https://doi.org/10.3847/2041-8213/acccec |
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