Share This Article:

Dependence of the GRB Lag-Luminosity Relation on Redshift in the Source Frame

DOI: 10.4236/ijaa.2012.21001    4,049 Downloads   7,415 Views   Citations
Author(s)    Leave a comment

ABSTRACT

The lag-luminosity relation for gamma-ray bursts (GRBs) is an anti-correlation between the time lag, ?lag, which represents the delay between the arrival of hard and soft photons, and the isotropic peak luminosity, L. In this paper, we use a sample of 43 Swift bursts, which was taken from Ukwatta et al., to investigate whether this relation depends on redshift. Both the z-correction and the k-correction are taken into account. Our analysis consists of binning the data in redshift, z, then applying a fit of the form: for each bin, where ?lag0 is the time-lag in the burst’s source frame, and is the corresponding mean value for the entire sample. The goal is to see whether the two fitting parameters, A and B, evolve in a systematic way with z. Our results indicate that both the normalization, A, and the slope, B, seem to vary in a systematic way with redshift. We note that although good best-fits were obtained, with reasonable values for both the linear regression coefficient, r, and the reduced chi-squared, the data showed large scatter. Also, the number of GRBs in the sample studied is not large, and thus our conclusions are only tentative at this point. A flat universe with M = 0.27, ?? = 0.73, and a Hubble constant, H0 = 70 km.s-1.Mpc-1 is assumed.

Conflicts of Interest

The authors declare no conflicts of interest.

Cite this paper

W. Azzam, "Dependence of the GRB Lag-Luminosity Relation on Redshift in the Source Frame," International Journal of Astronomy and Astrophysics, Vol. 2 No. 1, 2012, pp. 1-5. doi: 10.4236/ijaa.2012.21001.

References

[1] J. P. Norris, et al., “Connection between Energy Dependent Lags and Peak Luminosity in Gamma-Ray Bursts,” The Astrophysical Journal, Vol. 534, No. 1, 2000, pp. 248-257. doi:10.1086/308725
[2] E. E. Fenimore and E. Ramirez-Ruiz, “Redshifts for 220 BATSE Gamma-Ray Bursts Determined by Variability and the Cosmological Consequences,” 2000, astro-ph/ 0004176.
[3] L. Amati, et al., “Intrinsic Spectra and Energetics of BeppoSAX Gamma-Ray Bursts with Known Redshifts,” Astronomy and Astrophysics, Vol. 390, No. 1, 2002, pp. 81-89. doi:10.1051/0004-6361
[4] L. Amati, “The Ep,i-Eiso correlation in Gamma-Ray Bursts: Updated Observational Status, Re-Analysis and Main Implications,” Monthly Notices of the Royal Astronomical Society, Vol. 372, No. 1, 2006, pp. 233-245. doi:10.1111/j.1365-2966.2006.10840.x
[5] L. Amati, et al., “Measuring the Cosmological Parameters with the Ep,i-Eiso Correlation of Gamma-Ray Bursts,” Monthly Notices of the Royal Astronomical Society, Vol. 391, No. 2, 2008, pp. 577-584. doi:10.1111/j.1365-2966.2008.13943.x
[6] L. Amati, et al., “Extremely Energetic Fermi Gamma- Ray Bursts Obey Spectral Energy Correlations,” Astronomy and Astrophysics, Vol. 508, No. 1, 2009, pp. 173- 180. doi:10.1051/0004-6361/200912788
[7] G. Ghirlanda, et al., “The Collimation-Corrected Gamma- Ray Burst Energies Correlate with the Peak Energy of Their ?F? Spectrum,” The Astrophysical Journal, Vol. 616, No. 1, 2004, pp. 331-338. doi:10.1086/424913
[8] D. Yonetoku, et al., “Gamma-Ray Burst Formation Rate Inferred from the Spectral Peak Energy—Peak Luminosity Relation,” The Astrophysical Journal, Vol. 609, No. 2, 2004, pp. 935-951. doi:10.1086/421285
[9] G. Ghirlanda, et al., “Spectral-Luminosity Relation within Individual Fermi Gamma-Ray Bursts,” Astronomy and Astrophysics, Vol. 511, 2010, pp. A43-A53. doi:10.1051/0004-6361/200913134
[10] E. Liang and B. Zhang, “Model-Independent Multivariable Gamma-Ray Burst Luminosity Indicator and Its Possible Cosmological Implications,” The Astrophysical Journal, Vol. 633, 2005, pp. L611-L623. doi:10.1086/491594
[11] G. Ghirlanda, et al., “Cosmological Constraints with GRBs: Homogeneous vs. Wind Density Profile,” Astronomy and Astrophysics, Vol. 452, No. 3, 2006, pp. 839-844. doi:10.1051/0004-6361
[12] S. Capozziello and L. Izzo, “Cosmography by Gamma- Ray Bursts,” Astronomy and Astrophysics, Vol. 490, No. 1, 2008, pp. 31-36. 10.1051/0004-6361:200810337
[13] M. Demianski and E. Piedipalumbo, “Standarizing the GRBs with the Amati Ep,i-Eiso Relation: The Updated Hubble Diagram and Implications for Cosmography,” Monthly Notices of the Royal Astronomical Society, Vol. 415, No. 4, 2011, pp. 3580-3590. doi:10.1111/j.1365-2966.2011.18975.x
[14] H. Li, et al., “Overcoming the Circular Problem for Gamma-Ray Bursts in Cosmological Global-Fitting Analysis,” The Astrophysical Journal, Vol. 680, No. 1, 2008, pp. 92-99. doi:10.1086/529582
[15] N. R. Butler, et al., “Generalized Tests for Selection Effects in Gamma-Ray Burst High-Energy Correlations,” The Astrophysical Journal, Vol. 694, No. 1, 2009, pp. 76-83. doi:10.1088/0004-637X/694/1/76
[16] G. Ghirlanda, et al., “The Epeak-Eiso Plane of Long Gamma-Ray Bursts and Selection Effects,” Monthly Notices of the Royal Astronomical Society, Vol. 387, No. 1, 2008, pp. 319-330. doi:10.1111/j.1365-2966.2008.13232.x
[17] L. Nava, et al., “Selection Effects on GRB Spectral-En- ergy Correlations,” 2009, arXiv:0902.1522.
[18] C. Graziani, “GRBs as Standard Candles: There Is No ‘Circularity Problem’ (and There Never Was),” New Astronomy, Vol. 16, No. 2, 2011, pp. 57-64. doi:10.1016/j.newast.2010.08.001
[19] M. Arimoto, et al., “Spectral Lag Relations in GRB Pulses Detected with HETE-2,” PASJ, Vol. 62, 2010, pp. 487-499.
[20] R. Margutti, et al., “Lag-Luminosity Relation in γ-Ray Burst X-Ray Flares: A Direct Link to the Prompt Emission,” Monthly Notices of the Royal Astronomical Society, Vol. 406, No. 4, 2010, pp. 2149-2167. doi:10.1111/j.1365-2966.2010.16824.x
[21] L.-X. Li, “Variation of the Amati Relation with Cosmological Redshift: A Selection or an Evolution Effect?” Monthly Notices of the Royal Astronomical Society, Vol. 379, 2007, pp. L55-L59. doi:10.1111/j.1745-3933.2007.00333.x
[22] R. Tsutsui, et al., “Redshift-Dependent Lag-Luminosity Relation in 565 BATSE Gamma-Ray Bursts,” Monthly Notices of the Royal Astronomical Society, Vol. 386, No. 1, 2008, pp. L33-L37. doi:10.1111/j.1745-3933.2008.00455.x
[23] T. N. Ukwatta, et al., “Spectral Lags and the Lag-Luminosity Relation: An Investigation with Swift BAT Gamma- Ray Bursts,” The Astrophysical Journal, Vol. 711, No. 2, 2010, pp. 1073-1086. doi:10.1088/0004-637X/711/2/1073
[24] J. P. Norris, “Implications of the Lag-Luminosity Relationship for Unified Gamma-Ray Burst Paradigms,” The Astrophysical Journal, Vol. 579, No. 1, 2002, pp. 386- 403. doi:10.1086/342747
[25] N. Gehrels, et al., “A New γ-Ray Burst Classification Scheme from GRB060614,” Nature, Vol. 444, No. 7122, 2006, pp. 1044-1046. doi:10.1038/nature05376
[26] B. E. Schaefer, “The Hubble Diagram to Redshift >6 from 69 Gamma-Ray Bursts,” The Astrophysical Journal, Vol. 660, No. 1, 2007, pp. 16-46. doi:10.1086/511742
[27] J. Hakkila et al., “Correlations between Lag, Luminosity, and Duration in Gamma-Ray Burst Pulses,” The Astrophysical Journal, Vol. 677, No. 2, 2008, pp. L81-L84. doi:10.1086/588094
[28] N. Liang, et al., “A Cosmology-Independent Calibration of Gamma-Ray Burst Luminosity Relations and the Hubble Diagram,” The Astrophysical Journal, Vol. 685, No. 1, 2008, pp. 354-360. doi:10.1086/590903
[29] J. D. Salmonson, “On the Kinematic Origin of the Luminosity-Pulse Lag Relationship in Gamma-Ray Bursts,” The Astrophysical Journal, Vol. 544, No. 2, 2000, pp. L115-L117. doi:10.1086/317305
[30] K. Ioka and T. Nakamura, “Peak Luminosity-Spectral Lag Relation Caused by the Viewing Angle of the Collimated Gamma-Ray Bursts,” The Astrophysical Journal, Vol. 554, No. 2, 2001, pp. L163-L167. doi:10.1086/321717
[31] B. E. Schaefer, “Explaining the Gamma-Ray Burst Lag/ Luminosity Relation,” The Astrophysical Journal, Vol. 602, No. 1, 2004, pp. 306-311. doi:10.1086/380898
[32] T. N. Ukwatta, et al., “The Lag-Luminosity Relation in the Gamma-Ray Burst Source-Frame,” 2010, arXiv:1003.0229.
[33] T. N. Ukwatta, et al., “The Lag-Luminosity Relation in the GRB Source-Frame: An Investigation with Swift BAT Bursts,” Monthly Notices of the Royal Astronomical Society, Vol. 419, No. 1, 2012, pp. 614-623. doi:10.1111/j.1365-2966.2011.19723.x
[34] F. Ryde, “Interpretations of Gamma-Ray Burst Spectroscopy. I. Analytical and Numerical Study of Spectral Lags,” Astronomy and Astrophysics, Vol. 429, No. 3, 2005, pp. 869-879.doi:10.1051/0004-6361

  
comments powered by Disqus

Copyright © 2018 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.