A comprehensive analysis of Fermi Gamma-Ray Burst Data: IV. Spectral lag and Its Relation to Ep Evolution

Abstract

The spectral evolution and spectral lag behavior of 92 bright pulses from 84 gamma-ray bursts (GRBs) observed by the Fermi GBM telescope are studied. These pulses can be classified into hard-to-soft pulses (H2S, 64/92), H2S-dominated-tracking pulses (21/92), and other tracking pulses (7/92). We focus on the relationship between spectral evolution and spectral lags of H2S and H2S-dominated-tracking pulses. %in hard-to-soft pulses (H2S, 64/92) and H2S-dominating-tracking (21/92) pulses. The main trend of spectral evolution (lag behavior) is estimated with $\log E_p\propto k_E\log (t+t_0)$ ($\hat{\tau }\propto k_{\hat{\tau }}\log E$), where $E_p$ is the peak photon energy in the radiation spectrum, $t+t_0$ is the observer time relative to the beginning of pulse $-t_0$, and $\hat{\tau }$ is the spectral lag of photons with energy $E$ with respect to the energy band $8$-$25$ keV. For H2S and H2S-dominated-tracking pulses, a weak correlation between $k_{\hat{\tau }}/W$ and $k_E$ is found, where $W$ is the pulse width. We also study the spectral lag behavior with peak time $t_{{\mathrm{p}}_{\mathrm{E}}}$ of pulses for 30 well-shaped pulses and estimate the main trend of the spectral lag behavior with $\log t_{{\mathrm{p}}_{\mathrm{E}}}\propto k_{t_p}\log E$. It is found that $k_{t_p}$ is correlated with $k_E$. We perform simulations under a phenomenological model of spectral evolution, and find that these correlations are reproduced. We then conclude that spectral lags are closely related to spectral evolution within the pulse. The most natural explanation of these observations is that the emission is from the electrons in the same fluid unit at an emission site moving away from the central engine, as expected in the models invoking magnetic dissipation in a moderately-high-$\sigma$ outflow.

arXiv comment58 pages, 11 figures, 3 tables. ApJ in press

References in corpus (41)

• The Supernova -- Gamma-Ray Burst Connection
• Gamma-Ray Bursts as the Death Throes of Massive Binary Stars
• The Physics of Gamma-Ray Bursts and Relativistic Jets
• The Internal-Collision-Induced Magnetic Reconnection and Turbulence (ICMART) Model of Gamma-Ray Bursts
• The BATSE Gamma-Ray Burst Spectral Catalog. I. High Time Resolution Spectroscopy of Bright Bursts using High Energy Resolution Data
• Swift detects a remarkable gamma-ray burst, GRB 060614, that introduces a new classification scheme
• Connection Between Energy-dependent Lags And Peak Luminosity In Gamma-ray Bursts
• Short Gamma-Ray Bursts with Extended Emission
• Discerning the physical origins of cosmological Gamma-ray bursts based on multiple observational criteria: the cases of z=6.7 GRB 080913, z=8.3 GRB 090423, and some short/hard GRBs
• Fermi Observations of GRB 090510: A Short Hard Gamma-Ray Burst with an Additional, Hard Power-Law Component from 10 keV to GeV Energies
• The Hubble Diagram to Redshift >6 from 69 Gamma-Ray Bursts
• Long-lag, Wide-Pulse Gamma-Ray Bursts
• A Comprehensive Analysis of Fermi Gamma-Ray Burst Data. I. Spectral Components and Their Possible Physical Origins of LAT/GBM GRBs
• A Comprehensive Analysis of Fermi Gamma-ray Burst Data: II. $E_{\mathrm{p}}$-Evolution Patterns and Implications for the Observed Spectrum-Luminosity Relations
• Gamma-Ray Burst Spectral Evolution Through Crosscorrelations of Discriminator Light Curves
• Search for Relativistic Curvature Effects in Gamma-Ray Burst Pulses
• Lag-luminosity relation in gamma-ray burst X-ray flares: a direct link to the prompt emission
• Spectral Lags and the Lag-Luminosity Relation: An Investigation with Swift BAT Gamma-ray Bursts
• A Comprehensive Analysis of Fermi Gamma-ray Burst Data: III. Energy-Dependent T90 Distributions of GBM GRBs and Instrumental Selection Effect on Duration Classification
• GRB 061121: Broadband spectral evolution through the prompt and afterglow phases of a bright burst
• Low Energy Spectral Index and $E_p$ evolution of Quasi-thermal Photosphere Emission of Gamma-Ray Bursts
• Gamma-Ray Burst Prompt Emission Light Curves and Power Density Spectra in the ICMART Model
• Comparing the spectral lag of short and long gamma-ray bursts and its relation with the luminosity
• The Lag-Luminosity Relation in the GRB Source-Frame: An Investigation with Swift BAT Bursts
• Correlations Between Lag, Luminosity, and Duration in Gamma-ray Burst Pulses
• On the Spectral Lags of the Short Gamma-Ray Bursts
• Unification of Pulses in Long and Short Gamma-Ray Bursts: Evidence from Pulse Properties and their Correlations
• Internal Energy Dissipation of Gamma-Ray Bursts Observed with Swift: Precursors, Prompt Gamma-rays, Extended emission and Late X-ray Flares
• Temporal Profiles and Spectral Lags of XRF 060218
• Towards an understanding of GRB prompt emission mechanism: I. The origin of spectral lags
• Relativistic MHD simulations of collision-induced magnetic dissipation in Poynting-flux-dominated jets/outflows
• The Spectral Lag of GRB060505: A Likely Member of the Long Duration Class
• The $E_{\mathrm{p}}$-Flux Correlation in the Rising and Decaying Phases of Gamma-Ray Burst Pulses: Evidence for Viewing Angle Effect?
• Gamma-Ray Burst Pulse Shapes: Evidence for Embedded Shock Signatures?
• Properties of Short Gamma-Ray Burst Pulses from A BATSE TTE GRB Pulse Catalog
• Luminosity correlations for gamma-ray bursts and implications for their prompt and afterglow emission mechanisms
• Swift Observations of Gamma-Ray Burst Pulse Shapes: GRB Pulse Spectral Evolution Clarified
• Spectral Lag Relations in GRB Pulses Detected with HETE-2
• Which $E_{\mathrm{peak}}$? - The Characteristic Energy of Gamma-Ray Burst Spectra
• A New Correlation Between GRB X-Ray Flares And The Prompt Emission
• Statistical properties of Fermi GBM GRBs' spectra

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