Letter to the Editor

A possible use of Fourier Transform analysis method as a distance estimator

¹ Korea Institute for Advanced Study 207-43 Cheongryangri-dong, Dongdaemun-gu, Seoul 130-012, Korea e-mail: hyc@ns.kias.re.kr
² Center for Space Astrophysics and Department of Astronomy Yonsei University, 134 Shinchon-dong Seodaemun-gu, Seoul 120-749, Korea e-mail: sjyoon@csa.yonsei.ac.kr
³ Korea Astronomy Observatory 36-1 Hwaam-dong, Yusong-gu, Taejon 305-348, Korea e-mail: cschoi@kao.re.kr

Corresponding author: H.-Y. Chang, hyc@kias.re.kr

Received: 26 September 2001
Accepted: 6 November 2001

Abstract

We speculate on the possibility of using the Fourier transform analysis method as a distance estimator of the observed gamma-ray bursts (GRBs). It is based on a hypothetical empirical relation between the redshift and the power-law index of power density spectra (PDSs) of the observed GRBs. This relation is constructed by using the fact that the observed power-law index is dependent upon a characteristic timescale of GRB light curves. The rms error of redshift estimates is 0.42 for an empirical relation obtained with the 7 long () GRBs observed by the BATSE whose redshift information is available. We attempt to determine the spatial distribution of the GRBs observed by the BATSE as a function of redshifts on the basis of the resulting redshift estimator. We discuss possible uncertainties of the suggested method.