Volume 538, February 2012
|Number of page(s)||5|
|Published online||14 February 2012|
New three-parameter correlation for gamma-ray bursts with a plateau phase in the afterglow
1 Department of Astronomy, Nanjing University, 210093 Nanjing, PR China
2 Department of Physics, Yunnan University, 650091 Kunming, PR China
3 Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, PR China
Received: 22 July 2011
Accepted: 25 November 2011
Aims. Gamma ray bursts (GRBs) offer strong advantages because of their huge burst energies, luminosities, and high redshifts in probing the Universe. A few interesting luminosity correlations of GRBs have been used to test cosmology models. Especially, for a subsample of long GRBs with known redshifts and a plateau phase in the afterglow, a correlation between the end time of the plateau phase (in the GRB rest frame) and the corresponding X-ray luminosity has been found. Here, we add the isotropic γ-ray energy release as a third parameter to get a tighter three-parameter correlation.
Methods. We reanalyzed the subsample and found that a significantly tighter correlation exists when we add the isotropic γ-ray energy release into the consideration. We used the Markov-chain Monte Carlo techniques to get the best-fit coefficients.
Results. A new three-parameter correlation is found for the GRBs with an obvious plateau phase in the afterglow. The best fit correlation is found to be LX ∝ Ta-0.87 Eγ, iso0.88. Additionally, both long and intermediate duration GRBs are consistent with the same three-parameter correlation equation.
Conclusions. We argue that the new three-parameter correlation is consistent with the hypothesis that the subsample of GRBs with a plateau phase in the afterglow is associated with the birth of rapidly rotating magnetars and that the plateau is due to the continuous energy-injection from the magnetar. It is suggested that the newly born millisecond magnetars associated with GRBs might provide a good standard candle in the Universe.
Key words: ISM: jets and outflows / gamma-ray burst: general
© ESO, 2012
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.