Article
Astronomy & Astrophysics
Tomos R. L. Meredith, Graham A. Wynn, Philip A. Evans
Summary: We analyzed observational data from the Swift Burst Analyser for a sample of 15 short gamma-ray bursts with extended emission (SGRBEEs), applying error propagation to the flux measurements. We found clear differences in the light curve morphology between different energy bands. By fitting a magnetar-powered model to the data, we showed that the model's physical parameters are loosely constrained and inconsistent across two energy bands when error propagation is included. This highlights the importance of the Swift data processing methodology in physical model fits to SGRBEEs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Zhao Joseph Zhang, Bin-Bin Zhang, Yan-Zhi Meng
Summary: Magnetar giant flares (MGFs) are believed to contribute to some short gamma-ray bursts (GRBs). The recent discovery of short GRB 200415A in NGC 253 has established a connection between these two phenomena. The paper proposes a new model for MGFs, which involves an expanding fireball Comptonized by the relativistic magnetar wind at the photosphere radius. By fitting the observational spectra of GRB 200415A, the model predictions are found to be consistent with the observations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
R. L. Becerra, A. Klotz, J. L. Atteia, D. Guetta, A. M. Watson, F. De Colle, C. Angulo-Valdez, N. R. Butler, S. Dichiara, N. Fraija, K. Garcia-Cifuentes, A. S. Kutyrev, W. H. Lee, M. Pereyra, E. Troja
Summary: This study collected optical light-curve data of 227 gamma-ray bursts (GRBs) and investigated their observational and intrinsic properties. The observational properties, such as the optical brightness function and the temporal slope of the afterglow, were examined. The redshift distribution within the sample was estimated, and intrinsic properties, including the average X-ray and optical light curves in the rest frame, were analyzed. The study also explored microphysical parameters related to the bright GRB jet.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
S. Xiao, S. L. Xiong, S. N. Zhang, L. M. Song, F. J. Lu, Y. Huang, C. Cai, Q. B. Yi, X. Y. Song, W. Chen, M. Y. Ge, C. Z. Liu, X. B. Li, C. K. Li, Y. Zhao
Summary: This paper proposes a method using the Modified Cross-correlation Function (Li-CCF) to accurately determine the time delay of gamma-ray transients based on high time resolution light curves. The method has been shown to significantly reduce localization errors compared to traditional methods, with uncertainties as low as 0.3 degrees.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Dimple, K. Misra, D. A. Kann, K. G. Arun, A. Ghosh, R. Gupta, L. Resmi, J. F. Agui Fernandez, C. C. Thone, A. de Ugarte Postigo, S. B. Pandey, L. Yadav
Summary: We present a detailed analysis of short GRB 201221D at redshift z = 1.045. The burst has similar prompt emission characteristics to other short gamma-ray bursts (SGRBs) except for the peak energy (E-p), which is lower. The host galaxy properties are estimated by fitting the spectral energy distribution. Comparison with other SGRBs at different redshifts reveals that some high-redshift SGRBs exhibit properties similar to long GRBs, suggesting they may originate from collapsars.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Amir Shahmoradi, Joshua Alexander Osborne, Fatemeh Bagheri
Summary: The knowledge of redshifts of Short-duration Gamma-Ray Bursts (SGRBs) is crucial for understanding cosmic rates and related phenomena. This study presents a generic data-driven probabilistic modeling framework to infer the unknown redshifts of SGRBs and provides insights on applying this technique to other astronomical surveys.
Article
Astronomy & Astrophysics
Hua-Yang Li, Hao-Ning He, Da-Ming Wei, Zhi-Ping Jin
Summary: This study focuses on the multiwavelength afterglow radiation of GRB 200415A and finds that the contribution of the forward and reverse shocks varies in different wavelength bands. Additionally, future telescopes are predicted to detect the optical and infrared afterglow emission from giant flares similar to GRB 200415A.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Ore Gottlieb, Alexander Tchekhovskoy, Raffaella Margutti
Summary: We propose a model to explain fast blue optical transients (FBOTs) as relativistic jets launched by hydrogen-rich collapsing stars. The interaction between the jet and the star forms an inner cocoon, which produces cooling emission dominant in the high velocity optical signal. The interaction between the cocoon and the circumstellar winds generates synchrotron self-absorbed emission in the radio bands. After deceleration, the relativistic outflow powers the peak of the radio light curve and becomes optically thin to X-rays. The volumetric rates of cooling emission in FBOTs are higher than gamma-ray bursts.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Fan Xu, Jin-Jun Geng, Xu Wang, Liang Li, Yong-Feng Huang
Summary: This study investigates the spin-velocity alignment and high velocity of a pulsar, suggesting that they can be explained by the electromagnetic rocket mechanism. The study finds that the kick process of the pulsar can generate a relativistic jet, which may result in a gamma-ray burst. Furthermore, the study calculates the dynamical evolution of the jet and the velocity of the burst remnant, finding consistency with observational data.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
R. L. Becerra, E. Troja, A. M. Watson, B. O'Connor, P. Veres, S. Dichiara, N. R. Butler, F. De Colle, T. Sakamoto, K. O. C. Lopez, K. Aoki, N. Fraija, M. Im, A. S. Kutyrev, W. H. Lee, G. S. H. Paek, M. Pereyra, S. Ravi, Y. Urata
Summary: GRB 210704A is an intermediate duration burst that shows an optical excess. The properties of the burst do not fit well into the established classification scheme of gamma-ray bursts, making the nature of its progenitor uncertain. Multiwavelength observations and detailed analysis suggest three possible scenarios: a neutron star merger, a collapsing massive star, or an atypical explosion possibly hosted in a cluster of galaxies. The optical excess does not match well with traditional models, suggesting an exotic high-energy merger.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
A. G. Suvorov, K. D. Kokkotas
Summary: This study found that 16 out of 25 magnetars associated with X-ray light curves exhibiting a plateau show evidence of precession. The analysis of the light curves allows for an independent measure of the extent of star deformation and distribution of magnetic-energy ratios.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
G. Bruni, B. O'Connor, T. Matsumoto, E. Troja, T. Piran, L. Piro, R. Ricci
Summary: GRB 200522A is a short-duration gamma-ray burst at redshift z=0.554, possibly characterized by the onset of a luminous kilonova powered by a rapidly rotating and highly magnetized neutron star, known as a magnetar. Long-term radio monitoring may be key to discriminating between different models, and observations over several years post-merger could provide a robust test for the magnetar scenario.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Ore Gottlieb, Aretaios Lalakos, Omer Bromberg, Matthew Liska, Alexander Tchekhovskoy
Summary: We present the first suite of 3D GRMHD collapsar simulations, covering the self-consistent jet launching by an accreting Kerr black hole to the breakout from the star. Three types of outflows are identified based on angular momentum and magnetic field on the black hole horizon. Jets can suppress the accretion rate and their duration is limited by the magnetization profile in the star. Progenitors with steep inner density power-law indices face challenges as gamma-ray burst progenitors. The wide variety of observed explosion appearances and characteristics of emitting relativistic outflows can be explained by differences in the progenitor structure.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
B. O'Connor, E. Troja, S. Dichiara, E. A. Chase, G. Ryan, S. B. Cenko, C. L. Fryer, R. Ricci, F. Marshall, C. Kouveliotou, R. T. Wollaeger, C. J. Fontes, O. Korobkin, P. Gatkine, A. Kutyrev, S. Veilleux, N. Kawai, T. Sakamoto
Summary: We conducted a detailed multiwavelength analysis of two short gamma-ray bursts (sGRBs) observed by the Neil Gehrels Swift Observatory. The sGRBs, GRB 160624A and GRB 200522A, exhibited different properties in their emission and environments. GRB 160624A was associated with an older galaxy with moderate star formation, while GRB 200522A showed a luminous and red counterpart, possibly due to either kilonova emission or extinction effects.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Paz Beniamini, Ramandeep Gill, Jonathan Granot
Summary: This article investigates the angular structure of ultra-relativistic outflows powering gamma-ray bursts through their interaction with external material. It demonstrates the use of multi-wavelength afterglow lightcurves to constrain the outflow structure and other parameters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)