Dimple

Wild behaviour near the finish line: the Type Ibn SN 2020able and its stratified environment

L. Tartaglia, E. Cappellaro, G. Valerin +29

We present spectrophotometric observations of the Type Ibn supernova SN~2020able, along with a comprehensive analysis and modelling of its evolution. The transient occurred in SDSS…

Modeling the late time merger ejecta emission in short Gamma Ray Bursts

Ankur Ghosh, Kuntal Misra, C. S. Vaishnava +5

The short Gamma Ray Bursts (GRBs) are the aftermath of the merger of binary compact objects (neutron star -- neutron star or neutron star -- black hole systems). With the simultane…

astro-ph.HE2023

Evidence for two distinct populations of kilonova-associated Gamma Ray Bursts

Dimple, K. Misra, K. G. Arun

Identification of Gamma Ray Burst (GRB) progenitors based on the duration of their prompt emission ( $T_{90}$ ) has faced several roadblocks recently. Long-duration GRBs (with $T_{90…

astro-ph.IM2023

Characterization of a deep-depletion 4K x 4K CCD Detector System designed for ADFOSC

Dimple, T. S. Kumar, A. Omar +1

We present the characterization of the CCD system developed for the ADFOSC instrument on the 3.6m Devasthal Optical Telescope (DOT). We describe various experiments performed to tu…

Diversity in Fermi/GBM Gamma Ray Bursts: New insights from Machine Learning

Dimple, K. Misra, K. G. Arun

Classification of gamma-ray bursts (GRBs) has been a long-standing puzzle in high-energy astrophysics. Recent observations challenge the traditional short vs. long viewpoint, where…

Magnetar Giant Flare Originated GRB 200415A: Transient GeV emission, Time-Resolved $E_{p} - L_{iso}$ Correlation, and Implications

Vikas Chand, Jagdish C. Joshi, Rahul Gupta +12

Giant flares (GFs) are unusual bursts from soft gamma-ray repeaters (SGRs) that release an enormous amount of energy in a fraction of a second. The afterglow emission of these SGR-…

GRB 210704A: A Luminous Fast Blue Transient in a GRB Afterglow at $z = 2.34$

DaniÃ«lle L. A. Pieterse, Andrew J. Levan, Maria E. Ravasio +27

We present detailed, multi-wavelength analysis of GRB 210704A: a Fermi Gamma-ray Burst Monitor discovered and Fermi Large Area Telescope (LAT) detected gamma-ray burst (GRB). The b…

Revealing nature of GRB 210205A, ZTF21aaeyldq (AT2021any), and follow-up observations with the 4K $\times$ 4K CCD Imager+3.6m DOT

Rahul Gupta, Amit Kumar, Shashi Bhushan Pandey +14

Optical follow-up observations of optical afterglows of gamma-ray bursts are crucial to probe the geometry of outflows, emission mechanisms, energetics, and burst environments. We…

Probing into emission mechanisms of GRB 190530A using time-resolved spectra and polarization studies: Synchrotron Origin?

Rahul Gupta, S. Gupta, T. Chattopadhyay +47

Multi-pulsed GRB 190530A, detected by the GBM and LAT onboard \fermi, is the sixth most fluent GBM burst detected so far. This paper presents the timing, spectral, and polarimetric…

astro-ph.HE2023

Insights into the properties of GRBs with TeV emission

Kuntal Misra, Dimple, Ankur Ghosh

This study investigates the environments and characteristics of Gamma-Ray Bursts (GRBs) exhibiting very high energy (VHE) emission. Recent detections of VHE emission, up to TeV ene…

Multi-wavelength analysis of short GRB 201221D and its comparison with other high \& low redshift short GRBs

Dimple, K. Misra, D. A. Kann +9

We present a detailed analysis of short GRB 201221D lying at redshift $z = 1.045$ . We analyse the high-energy data of the burst and compare it with the sample of short gamma-ray bur…

Rates and beaming angles of GRBs associated with compact binary coalescences

Shasvath J. Kapadia, Dimple, Dhruv Jain +3

Some, if not all, binary neutron star (BNS) coalescences, and a fraction of neutron - star black hole (NSBH) mergers, are thought to produce sufficient mass-ejection to power Gamma…

Early Multiwavelength Observations of AT 2026fgk: The Luminous Afterglow to Sub-luminous GRB 260310A, Identified Independently of a Gamma-ray Trigger

K. -R. Hinds, A. Y. Q. Ho, Y. Wagh +103

The origins of sub-luminous ( $L_{I^^{3}, iso} < 1 0^{49.5}$ \,erg\,s $^{- 1}$ ) gamma-ray bursts (GRBs) associated with broad-lined Type~Ic supernovae (Ic-BL SNe) are poorly…

The day-long, repeating GRB 250702BDE / EP250702a: A unique extragalactic transient

Andrew J. Levan, Antonio Martin-Carrillo, Tanmoy Laskar +42

Gamma-ray bursts (GRBs) are singular outbursts of high-energy radiation with durations typically lasting from milliseconds to minutes and, in extreme cases, a few hours. They are a…

SVOM GRB 250314A at z $≃$ 7.3: an exploding star in the era of reionization

B. Cordier, J. Y. Wei, N. R. Tanvir +103

Most long Gamma-ray bursts originate from a rare type of massive stellar explosion. Their afterglows, while rapidly fading, can be initially extremely luminous at optical/near-infr…

GRB 210217A: A short or a long GRB?

Dimple, Kuntal Misra, Ankur Ghosh +6

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 g…

GRB 140102A: Insight into Prompt Spectral Evolution and Early Optical Afterglow Emission

Rahul Gupta, S. R. Oates, S. B. Pandey +38

We present and perform a detailed analysis of multi-wavelength observations of \thisgrb, an optical bright GRB with an observed reverse shock (RS) signature. Observations of this G…

Low frequency view of GRB 190114C reveals time varying shock micro-physics

K. Misra, L. Resmi, D. A. Kann +25

We present radio and optical afterglow observations of the TeV-bright long Gamma Ray Burst (GRB) 190114C at a redshift of $z = 0.425$ , which was detected by the MAGIC telescope. Our…

astro-ph.HE2023

Investigating high redshift short GRBs: signatures of collapsars?

Dimple, Kuntal Misra, Lallan Yadav

The conventional classification of Gamma-Ray Bursts (GRBs) as short or long bursts based on their duration is widely accepted as arising from different progenitor sources identifie…

Photometric and spectroscopic analysis of the Type II SN 2020jfo with a short plateau

B. Ailawadhi, R. Dastidar, K. Misra +34

We present high-cadence photometric and spectroscopic observations of SN~2020jfo in ultraviolet and optical/near-infrared bands starting from $\sim 3$ to $\sim 434$ days after the…

Prompt Periodicity in the GRB 211211A Precursor: Black-hole or magnetar engine?

Gavin P. Lamb, Thomas Baxter, Conor M. B. Omand +18

The merger origin long GRB 211211A was a class (re-)defining event. A precursor was identified with a $\sim 1$ s separation from the main burst, as well as a claimed candidate quas…

The radio flare and multi-wavelength afterglow of the short GRB 231117A: energy injection from a violent shell collision

G. E. Anderson, G. P. Lamb, B. P. Gompertz +64

We present the early radio detection and multi-wavelength modeling of the short gamma-ray burst (GRB) 231117A at redshift $z = 0.257$ . The Australia Telescope Compact Array automatic…

Prompt emission properties of GRB~200613

Ankur Ghosh, Kuntal Misra, Dimple

We study the prompt emission properties of the long duration GRB~200613A using \textit{Fermi}-Gamma-Ray Burst Monitor (GBM) and Large Area Telescope (LAT) data. The prompt emission…

astro-ph.HE2020

Peculiar prompt emission and afterglow in H.E.S.S. detected GRB 190829A

Vikas Chand, Ankush Banerjee, Rahul Gupta +10

We present the results of a detailed investigation of the prompt and afterglow emission in the HESS detected GRB 190829A. Swift and Fermi observations of the prompt phase of this G…

What do gravitational-wave observations tell us about Luminous Red Novae?

Dhruv Jain, Shasvath J. Kapadia, Kuntal Misra +4

Luminous Red Novae (LRNe) have been argued to be related to the ejection of common envelopes (CEs) in binary star systems. Ejection of CEs leads to tightened stellar orbits capable…

JWST Spectroscopy of GRB 250702B: An Extremely Rare and Exceptionally Energetic Burst in a Dusty, Massive Galaxy at $z = 1.036$

Benjamin P. Gompertz, Andrew J. Levan, Tanmoy Laskar +25

We present follow-up observations of the day-long, repeating GRB 250702B with the Near Infrared Spectrograph (NIRSpec) on board the James Webb Space Telescope (JWST). Through the i…

Exploring the multi-wavelength properties of the high energetic event ZTF20abbiixp/GRB 200524A: from prompt emission to afterglow

A. Ghosh, Dimple, K. Misra +32

We conducted a comprehensive multi-wavelength analysis of a high energetic long-duration ZTF20abbiixp / GRB~200524A detected by \textit{Fermi} Gamma Ray Burst Monitor (GBM). Our st…

The long-active afterglow of GRB 210204A: Detection of the most delayed flares in a Gamma-Ray Burst

Harsh Kumar, Rahul Gupta, Divita Saraogi +22

We present results from extensive broadband follow-up of GRB 210204A over the period of thirty days. We detect optical flares in the afterglow at 7.6 x 10^5 s and 1.1 x 10^6 s afte…

ENGRAVE follow-up of a type IIb supernova spatially coincident with the sub-threshold gravitational wave trigger S250818k

K. Ackley, M. T. Botticella, A. Boye +54

The candidate gravitational wave (GW) event S250818k was one of only three non-retracted LIGO-Virgo-KAGRA public alerts issued during the fourth observing run of the network (O4) w…