other query
modes : |
Identifier query |
Coordinate query |
Criteria query |
Reference query |
Basic query |
Script submission |
TAP |
Output options |
Object types |
Help |

**
2001ApJ...552...57R -
**
*
Astrophys. J., 552, 57-71 (2001/May-1)
*

* *

**
A possible cepheid-like luminosity estimator for the long gamma-ray bursts.
**

*
REICHART D.E., LAMB D.Q., FENIMORE E.E., RAMIREZ-RUIZ E., CLINE T.L. and HURLEY K.
*

**
Abstract (from CDS):
**

We present a possible Cepheid-like luminosity estimator for the long gamma-ray bursts based on the variability of their light curves. To construct the luminosity estimator, we use *CGRO*/BATSE data for 13 bursts, *Wind*/Konus data for five bursts, *Ulysses*/GRB data for one burst, and *NEAR*/XGRS data for one burst. Spectroscopic redshifts, peak fluxes, and high-resolution light curves are available for 11 of these bursts; partial information is available for the remaining nine bursts. We find that the isotropic equivalent peak luminosities *L* of these bursts positively correlate with a rigorously constructed measure *V* of the variability of their light curves. We fit to these data a model that accommodates both intrinsic scatter (statistical variance) and extrinsic scatter (sample variance). We find that L∼V^{3.3}+1.1^{}-0.9_^. If one excludes GRB 980425 from the fit, on the grounds that its association with SN 1998bw at a redshift of *z*=0.0085 is not secure, the luminosity estimator spans ~2.5 orders of magnitude in *L*, and the slope of the correlation between *L* and *V* is positive with a probability of 1-(1.4x10^{–4}) (3.8 σ). Although GRB 980425 is excluded from this fit, its *L* and *V* values are consistent with the fitted model, which suggests that GRB 980425 may well be associated with SN 1998bw and that GRB 980425 and the cosmological bursts may share a common physical origin. If one includes GRB 980425 in the fit, the luminosity estimator spans ~6.3 orders of magnitude in *L*, and the slope of the correlation is positive with a probability of 1-(9.3x10^{–7}) (4.9 σ). In either case, the luminosity estimator yields best-estimate luminosities that are accurate to a factor of ~4, or best-estimate luminosity distances that are accurate to a factor of ~2. Regardless of whether GRB 980425 should be included in the fit, its light curve is unique in that it is much less variable than the other ~17 light curves of bursts in our sample for which the signal-to-noise ratio is reasonably good.

**
Abstract Copyright:
**
∼

**
Journal keyword(s):
**
*
Gamma Rays: Bursts
*

**
CDS comments:
**
In tables 1 and 2 GB 980308 misprint for 990308

**
Simbad objects:
**
20

To bookmark this query, right click on this link: simbad:2001ApJ...552...57R and select 'bookmark this link' or equivalent in the popup menu