The Closure Relations in High-Energy Gamma-ray Bursts Detected by Fermi-LAT
Gamma-ray bursts (GRBs) are brief, intense pulses of high-energy emission associated with extreme astrophysical phenomena, e.g. the death of massive stars or the coalescence of compact objects. They have been observed at high energies by the Fermi Large Area Telescope (LAT), which detects GRBs in th...
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| Format: | Article |
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MDPI AG
2023-02-01
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| Series: | Galaxies |
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| Online Access: | https://www.mdpi.com/2075-4434/11/1/25 |
| _version_ | 1797620912191700992 |
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| author | Maria Dainotti Delina Levine Nissim Fraija Donald Warren Peter Veres Shashwat Sourav |
| author_facet | Maria Dainotti Delina Levine Nissim Fraija Donald Warren Peter Veres Shashwat Sourav |
| author_sort | Maria Dainotti |
| collection | DOAJ |
| description | Gamma-ray bursts (GRBs) are brief, intense pulses of high-energy emission associated with extreme astrophysical phenomena, e.g. the death of massive stars or the coalescence of compact objects. They have been observed at high energies by the Fermi Large Area Telescope (LAT), which detects GRBs in the 20 MeV–300 GeV energy range. The Fermi-LAT Second GRB Catalog (2FLGC) presents information on 186 GRBs observed from 2008 to 2018. We consider the GRBs that have been fitted in the 2FLGC with a broken (21 GRBs) or simple power law (65 GRBs), compiling a total sample of 86 GRBs. We analyze the relationship between the spectral and temporal indices using closure relations according to the synchrotron forward-shock model evolving in stratified environments (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>n</mi><mo>∝</mo><msup><mi>r</mi><mrow><mo>−</mo><mi>k</mi></mrow></msup></mrow></semantics></math></inline-formula>). We find that the model without energy injection is preferred over the one with energy injection. There is a clear preference for the cooling conditions <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>ν</mi><mo>></mo></mrow></semantics></math></inline-formula> max{<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>ν</mi><mi>c</mi></msub><mo>,</mo><msub><mi>ν</mi><mi>m</mi></msub></mrow></semantics></math></inline-formula>} and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>ν</mi><mi>m</mi></msub><mo><</mo><mi>ν</mi><mo><</mo><msub><mi>ν</mi><mi>c</mi></msub></mrow></semantics></math></inline-formula> (where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>ν</mi><mi>c</mi></msub></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>ν</mi><mi>m</mi></msub></semantics></math></inline-formula> are the cooling and characteristic frequencies, namely the frequency at the spectral break). Within these cooling conditions, density profiles <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>r</mi><mrow><mo>−</mo><mi>k</mi></mrow></msup></semantics></math></inline-formula> with values of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>k</mi><mo>=</mo><mn>1.5</mn></mrow></semantics></math></inline-formula> and 2 generally have a higher rate of occurrence when considering relations with and without energy injection. |
| first_indexed | 2024-03-11T08:48:18Z |
| format | Article |
| id | doaj.art-ce8fa17221454751b3b8aa2ab48c5aa6 |
| institution | Directory Open Access Journal |
| issn | 2075-4434 |
| language | English |
| last_indexed | 2024-03-11T08:48:18Z |
| publishDate | 2023-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Galaxies |
| spelling | doaj.art-ce8fa17221454751b3b8aa2ab48c5aa62023-11-16T20:38:24ZengMDPI AGGalaxies2075-44342023-02-011112510.3390/galaxies11010025The Closure Relations in High-Energy Gamma-ray Bursts Detected by Fermi-LATMaria Dainotti0Delina Levine1Nissim Fraija2Donald Warren3Peter Veres4Shashwat Sourav5National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, JapanDepartment of Astronomy, University of Maryland, College Park, MD 20742, USAInstituto de Astronomía, Universidad Nacional Autónoma de México Circuito Exterior, C.U., A. Postal 70-264, Mexico 04510, MexicoRIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS), Wakō, Saitama 351-0198, JapanCenter for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, 320 Sparkman Drive, Huntsville, AL 35899, USADepartment of Engineering Sciences, Indian Institute of Science Education and Research, Bhopal 462066, IndiaGamma-ray bursts (GRBs) are brief, intense pulses of high-energy emission associated with extreme astrophysical phenomena, e.g. the death of massive stars or the coalescence of compact objects. They have been observed at high energies by the Fermi Large Area Telescope (LAT), which detects GRBs in the 20 MeV–300 GeV energy range. The Fermi-LAT Second GRB Catalog (2FLGC) presents information on 186 GRBs observed from 2008 to 2018. We consider the GRBs that have been fitted in the 2FLGC with a broken (21 GRBs) or simple power law (65 GRBs), compiling a total sample of 86 GRBs. We analyze the relationship between the spectral and temporal indices using closure relations according to the synchrotron forward-shock model evolving in stratified environments (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>n</mi><mo>∝</mo><msup><mi>r</mi><mrow><mo>−</mo><mi>k</mi></mrow></msup></mrow></semantics></math></inline-formula>). We find that the model without energy injection is preferred over the one with energy injection. There is a clear preference for the cooling conditions <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>ν</mi><mo>></mo></mrow></semantics></math></inline-formula> max{<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>ν</mi><mi>c</mi></msub><mo>,</mo><msub><mi>ν</mi><mi>m</mi></msub></mrow></semantics></math></inline-formula>} and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>ν</mi><mi>m</mi></msub><mo><</mo><mi>ν</mi><mo><</mo><msub><mi>ν</mi><mi>c</mi></msub></mrow></semantics></math></inline-formula> (where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>ν</mi><mi>c</mi></msub></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>ν</mi><mi>m</mi></msub></semantics></math></inline-formula> are the cooling and characteristic frequencies, namely the frequency at the spectral break). Within these cooling conditions, density profiles <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>r</mi><mrow><mo>−</mo><mi>k</mi></mrow></msup></semantics></math></inline-formula> with values of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>k</mi><mo>=</mo><mn>1.5</mn></mrow></semantics></math></inline-formula> and 2 generally have a higher rate of occurrence when considering relations with and without energy injection.https://www.mdpi.com/2075-4434/11/1/25gamma-ray burstgeneral–methodsdata analysis |
| spellingShingle | Maria Dainotti Delina Levine Nissim Fraija Donald Warren Peter Veres Shashwat Sourav The Closure Relations in High-Energy Gamma-ray Bursts Detected by Fermi-LAT Galaxies gamma-ray burst general–methods data analysis |
| title | The Closure Relations in High-Energy Gamma-ray Bursts Detected by Fermi-LAT |
| title_full | The Closure Relations in High-Energy Gamma-ray Bursts Detected by Fermi-LAT |
| title_fullStr | The Closure Relations in High-Energy Gamma-ray Bursts Detected by Fermi-LAT |
| title_full_unstemmed | The Closure Relations in High-Energy Gamma-ray Bursts Detected by Fermi-LAT |
| title_short | The Closure Relations in High-Energy Gamma-ray Bursts Detected by Fermi-LAT |
| title_sort | closure relations in high energy gamma ray bursts detected by fermi lat |
| topic | gamma-ray burst general–methods data analysis |
| url | https://www.mdpi.com/2075-4434/11/1/25 |
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