Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-23T16:57:10.873Z Has data issue: false hasContentIssue false

On the intrinsic nature of the updated luminosity time correlation in the X-ray afterglows of GRBs

Published online by Cambridge University Press:  05 September 2012

Maria G. Dainotti
Affiliation:
Astronomical Observatory, Jagellonian University ul. Orla 171, 31-501 Cracow, Poland email: [email protected], [email protected] Department of Physics & Astronomy, University of Stanford, Via Pueblo Mall, email: [email protected], [email protected]
Vahe' Petrosian
Affiliation:
Department of Physics & Astronomy, University of Stanford, Via Pueblo Mall, email: [email protected], [email protected]
Jack Singal
Affiliation:
Department of Physics & Astronomy, University of Stanford, Via Pueblo Mall, email: [email protected], [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Gamma-ray bursts (GRBs) observed up to redshifts z > 9.3 are fascinating objects to study due to their still unexplained relativistic outburst mechanisms and a possible use to test cosmological models. Our analysis of all GRB afterglows with known redshifts and definite plateau (100 GRBs) reveals not only that the luminosity L*X(Ta) - break time T*a correlation, called hereafter LT, (Dainotti et al. 2010a) is confirmed with higher value of the Spearman correlation coefficient for the new updated sample, but also reveals its intrinsic nature throughout the analysis of the Efron & Petrosian (1992) test. The above mentioned test is performed to check if there is redshift evolution in both the luminosity and time. This test shows that the correlation still holds probing that its nature is intrinsic and it is not due to selection biases. The novelty of this approach is that the Efron & Petrosian method has been applied for the first time for a two parameter correlation that involves not only luminosities, but also time. Notwithstanding the intrinsic nature of the correlation, the correction of the observables for the effect of redshift evolution does not lead to a significantly tighter correlation and thus to a better redshift estimator. Therefore, the usage of the L*a correlation is limited, at least with the present data analysis, to constrain physical models of plateau emission. With an enlarged data sample in the future the aim will be to make the luminosity time correlation a useful redshift estimator.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2012

References

Amati, L., Frontera, F., & Guidorzi, C.A&A, 508, 173.Google Scholar
Bernardini, M. G. et al. 2011, accepted on A&A arXiv 1112.1058BGoogle Scholar
Butler, N. R., Kocevski, D., & Bloom, J. S., 2009, ApJL, 694, 76.CrossRefGoogle Scholar
Cabrera, J. I., Firmani, C., Avila-Reese, V., et al. 2007, MNRAS, 382, 342CrossRefGoogle Scholar
Cannizzo, J. K. & Gehrels, N., 2009, ApJ, 700, 1047CrossRefGoogle Scholar
Cannizzo, J. K., Troja, E., & Gehrels, N., 2011, ApJ, 734, 35CCrossRefGoogle Scholar
Dall'Osso, S. et al. 2011, A&A, 526A, 121DGoogle Scholar
Dainotti, M. G., Cardone, V. F. & Capozziello, S. 2008, MNRAS 391L, 79DCrossRefGoogle Scholar
Dainotti, M. G., et al. 2010, ApJL, 722, L215CrossRefGoogle Scholar
Dainotti, M. G., et al. 2011, ApJ, 730, 135DCrossRefGoogle Scholar
Dainotti, M. G., Ostrowski, M. & Willingale, R., 2010, MNRAS, 418, 2202DCrossRefGoogle Scholar
Evans, P., et al. MNRAS 2009 397, 1177CrossRefGoogle Scholar
Efron, B. & Petrosian, V., 1992, ApJ, 399, 345CrossRefGoogle Scholar
Fenimore, E. E. & Ramirez-Ruiz, E. 2000, ApJ, 539, 712vGoogle Scholar
Ghirlanda, G., Ghisellini, G., & Lazzati, D. 2004, ApJ, 616, 331CrossRefGoogle Scholar
Ghirlanda, G., Ghisellini, G. & Firmani, C., 2006, New Journal of Physics, 8, 123.CrossRefGoogle Scholar
Ghisellini, G., et al. 2008, A&A 496 3, 2009.Google Scholar
Lloyd, N., & Petrosian, V.ApJ 511 550, 1999CrossRefGoogle Scholar
Norris, J. P., Marani, G. F., & Bonnell, J. T., 2000, ApJ, 534, 248CrossRefGoogle Scholar
Yonetoku, D., et al. 2004, ApJ, 609, 935YCrossRefGoogle Scholar
O'Brien, P. T., Willingale, R., Osborne, J., et al. 2006, ApJ, 647, 1213CrossRefGoogle Scholar
Petrosian, V. 1998, AAS, 193, 8702PGoogle Scholar
Petrosian, V., et al. 1999 ASPC, 190, 235PGoogle Scholar
Petrosian, V. 2002, ASPC, 284, 389PGoogle Scholar
Riechart, D. E., Lamb, D. Q., Fenimore, E. E., Ramirez-Ruiz, E., & Cline, T. L., 2001, ApJ, 552, 57CrossRefGoogle Scholar
Sakamoto, T., Hill, J., Yamazaki, R., et al. 2007, ApJ, 669, 1115.CrossRefGoogle Scholar
Shahmoradi, A. & Nemiroff, R. J. 2009, AIPC. 1133, 425SGoogle Scholar
Schaefer, B. E., 2003, ApJ, 583, L67CrossRefGoogle Scholar
Singal, J., et al. , 2011, ApJ, 743, 104SCrossRefGoogle Scholar
Singal, J., et al. , 2011, ApJ accepted arXiv1106.3111SGoogle Scholar
Yamazaki, R. 2009, ApJ, 690, L118CrossRefGoogle Scholar
Yu, B., Qi, S., & Lu, T. 2009, ApJL, 705, L15CrossRefGoogle Scholar
Willingale, R. W., et al. , ApJ 2007 662, 1093CrossRefGoogle Scholar