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Outliers to the peak energy-isotropic energy relation in gamma-ray bursts

Nakar, Ehud and Piran, Tsvi (2005) Outliers to the peak energy-isotropic energy relation in gamma-ray bursts. Monthly Notices of the Royal Astronomical Society: Letters, 360 (1). L73-L76. ISSN 1745-3925. doi:10.1111/j.1745-3933.2005.00049.x.

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The peak energy–isotropic energy (EpEi) relation is among the most intriguing recent discoveries concerning gamma-ray bursts (GRBs). It can have numerous implications for our understanding of the emission mechanism of the bursts and for the application of GRBs to cosmological studies. However, this relation has been verified only for a small sample of bursts with measured redshifts. We propose here a test of whether a burst with an unknown redshift can potentially satisfy the EpEi relation. Applying this test to a large sample of BATSE bursts, we find that a significant fraction of those bursts cannot satisfy this relation. Our test is sensitive only to dim and hard bursts, and therefore this relation might still hold as an inequality (i.e. there are no intrinsically bright and soft bursts). We conclude that the observed relation seen in the sample of bursts with known redshift might be influenced by observational biases and the inability to locate and to localize well hard and weak bursts that have only a small number of photons. In particular, we point out that the threshold for detection, localization and redshift measurement is essentially higher than the threshold for detection alone. We predict that Swift will detect some hard and weak bursts that would be outliers to the EpEi relation. However, we cannot quantify this prediction. We stress the importance of understanding the detection–localization–redshift threshold for the coming Swift detections.

Item Type:Article
Related URLs:
URLURL TypeDescription
Nakar, Ehud0000-0002-4534-7089
Piran, Tsvi0000-0002-7964-5420
Additional Information:© 2005 RAS. Accepted 2005 April 1. Received 2005 March 25; in original form 2004 December 10; Published: 01 June 2005. This work was supported by a BSF grant to the Hebrew University. We thank Enrico Ramirez-Ruiz, Eli Waxman, Dafne Guetta, Amir Levinson and Re’em Sari for helpful discussions. We thank the anonymous referee for his detailed and constructive report.
Funding AgencyGrant Number
Binational Science Foundation (USA-Israel)UNSPECIFIED
Subject Keywords:gamma-rays: bursts
Issue or Number:1
Record Number:CaltechAUTHORS:20180404-084525963
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Official Citation:Ehud Nakar, Tsvi Piran; Outliers to the peak energy–isotropic energy relation in gamma-ray bursts, Monthly Notices of the Royal Astronomical Society: Letters, Volume 360, Issue 1, 1 June 2005, Pages L73–L76,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:85588
Deposited By: Tony Diaz
Deposited On:04 Apr 2018 17:05
Last Modified:15 Nov 2021 20:30

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