Probing Curvature Effects in the Fermi GRB 110920

Abstract

Curvature effects in Gamma-ray bursts (GRBs) have long been a source of considerable interest. In a collimated relativistic GRB jet, photons that are off-axis relative to the observer arrive at later times than on-axis photons and are also expected to be spectrally softer. In this work, we invoke a relatively simple kinematic two-shell collision model for a uniform jet profile and compare its predictions to GRB prompt-emission data for observations that have been attributed to curvature effects such as the peak-flux--peak-frequency relation, i.e., the relation between the $\nu$F${}_{\nu }$ flux and the spectral peak, E${}_{pk}$ in the decay phase of a GRB pulse, and spectral lags. In addition, we explore the behavior of pulse widths with energy. We present the case of the single-pulse Fermi GRB 110920, as a test for the predictions of the model against observations.

8 pages, 11 figures, Accepted for publication in ApJ

References in corpus (3)

• Curvature Effect of a Non-Power-Law Spectrum and Spectral Evolution of GRB X-Ray Tails
• A test of the power law relationship between gamma-ray burst pulse width ratio and energy expected in fireballs or uniform jets
• Accounting for the XRT early steep decay in models of the prompt GRB emission

Cited by in corpus (17)

• Towards an understanding of GRB prompt emission mechanism: I. The origin of spectral lags
• GRB 200415A: A Short Gamma-Ray Burst from a Magnetar Giant Flare?
• Spectral evolution in gamma-ray bursts: predictions of the internal shock model and comparison to observations
• Thermal Components in Gamma-ray Bursts. I. How Do They Affect Non-Thermal Spectral Parameters?
• GRB 210121A: A Typical Fireball Burst Detected by Two Small Missions
• Lorentz Invariance Violation Limits from the Spectral Lag Transition of GRB~190114C
• Synchrotron emission in GRBs observed by Fermi: Its limitations and the role of the photosphere
• A Statistical Study of GRB X-ray Flares: Evidence of Ubiquitous Bulk Acceleration in the Emission Region
• Non-thermal Gamma-ray Emission from Delayed Pair Breakdown in a Magnetized and Photon-rich Outflow
• Time-Reversed Gamma-Ray Burst Light Curve Characteristics as Transitions between Subluminal and Superluminal Motion
• Modelling the prompt optical emission of GRB 180325A: the evolution of a spike from the optical to gamma-rays
• Spectral Lag for a Radiating Jet Shell with a High Energy Cut-off Radiation Spectrum
• Hard X-ray Spectral Investigations of Gamma-ray Bursts, 120521C and 130606A, at High-redshift z~6
• Temporal and Spectral Evolution of Gamma-ray Burst Broad Pulses: Identification of High Latitude Emission in the Prompt Emission
• Spectral evolution responsible for the transition from positive lags to negative lags in Gamma-ray Bursts
• A Concept of Assessment of LIV Tests with THESEUS Using the Gamma-Ray Bursts Detected by Fermi/GBM
• Time stretching of the GeV emission of GRBs: Fermi-LAT data vs geometrical model