GRB 210217A: A short or a long GRB?

Abstract

Gamma-ray bursts are traditionally classified as short and long bursts based on their $T_{90}$ value (the time interval during which an instrument observes $5\%$ to $95\%$ of gamma-ray/hard X-ray fluence). However, $T_{90}$ is dependent on the detector sensitivity and the energy range in which the instrument operates. As a result, different instruments provide different values of $T_{90}$ for a burst. GRB 210217A is detected with different duration by {\it Swift} and {\it Fermi}. It is classified as a long/soft GRB by {\it Swift}-BAT with a $T_{90}$ value of 3.76 sec. On the other hand, the sub-threshold detection by {\it Fermi}-GBM classified GRB 210217A as a short/hard burst with a duration of 1.024 sec. We present the multi-wavelength analysis of GRB 210217A (lying in the overlapping regime of long and short GRBs) to identify its actual class using multi-wavelength data. We utilized the $T_{90}$-hardness ratio, $T_{90}$-\Ep, and $T_{90}$-$t_{\mathrm{mvts}}$ distributions of the GRBs to find the probability of GRB 210217A being a short GRB. Further, we estimated the photometric redshift of the burst by fitting the joint XRT/UVOT SED and place the burst in the Amati plane. We found that GRB 210217A is an ambiguous burst showing properties of both short and long class of GRBs.

arXiv commentAccepted for Special Issue of Journal of Astrophysics and Astronomy, 2022, Astrophysical jets and observational facilities: National perspective, 05 -09 April 2021, ARIES Nainital

References in corpus (35)

• emcee: The MCMC Hammer
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Spectra and Light Curves of Gamma-Ray Burst Afterglows
• The Physics of Gamma-Ray Bursts
• Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs
• The Burst Alert Telescope (BAT) on the Swift MIDEX Mission
• An Ordinary Short Gamma-Ray Burst with Extraordinary Implications: Fermi-GBM Detection of GRB 170817A
• Gamma-Ray Bursts and the Fireball Model
• Intrinsic spectra and energetics of BeppoSAX Gamma-Ray Bursts with known redshifts
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Sky Maps, Systematic Errors, and Basic Results
• Calibration of X-ray absorption in our Galaxy
• The Observed Offset Distribution of Gamma-Ray Bursts from Their Host Galaxies: A Robust Clue to the Nature of the Progenitors
• A Decade of Short-duration Gamma-ray Burst Broad-band Afterglows: Energetics, Circumburst Densities, and Jet Opening Angles
• The Ep,i - Eiso correlation in GRBs: updated observational status, re-analysis and main implications
• The gamma-ray burst GRB060614 requires a novel explosive process
• Gamma-Ray Burst Peak Duration as a Function of Energy
• Demographics of the Galaxies Hosting Short-duration Gamma-Ray Bursts
• Short versus Long Gamma-Ray Bursts: spectra, energetics, and luminosities
• Discovery and confirmation of the shortest gamma ray burst from a collapsar
• The Ep,i - Eiso correlation: type I gamma-ray bursts and the new classification method
• Correlations of Prompt and Afterglow Emission in Swift Long and Short Gamma Ray Bursts
• GRB090426: the farthest short gamma-ray burst?
• The hardness-duration correlation in the two classes of gamma-ray bursts
• Short Gamma-Ray Bursts with Extended Emission Observed with Swift/BAT and Fermi/GBM
• Comparing the spectral lag of short and long gamma-ray bursts and its relation with the luminosity
• The Energy-Dependence of GRB Minimum Variability Timescales
• Minimum Variability Time Scales of Long and Short GRBs
• On the Spectral Lags of the Short Gamma-Ray Bursts
• A Comparative Study of Long and Short GRBs. I. Overlapping Properties
• Euclidean vs. non-Euclidean Gamma-Ray Bursts
• Statistical classification of gamma-ray bursts based on the Amati relation
• Peculiar prompt emission and afterglow in H.E.S.S. detected GRB 190829A
• The Minimum Variability Time Scale and its Relation to Pulse Profiles of Fermi GRBs
• Gamma-Ray Bursts: Temporal Scales and the Bulk Lorentz Factor
• GRB 140102A: Insight into Prompt Spectral Evolution and Early Optical Afterglow Emission