Photometric redshift estimation for gamma-ray bursts from the early Universe

DOI: 
10.1093/mnras/stad2996
Publication date: 
11/12/2023
Main author: 
Fausey, H. M.
IAA authors: 
Kann, D. A.
Authors: 
Fausey, H. M.;van der Horst, A. J.;White, N. E.;Seiffert, M.;Willems, P.;Young, E. T.;Kann, D. A.;Ghirlanda, G.;Salvaterra, R.;Tanvir, N. R.;Levan, A.;Moss, M.;Chang, T. -C.;Fruchter, A.;Guiriec, S.;Hartmann, D. H.;Kouveliotou, C.;Granot, J.;Lidz, A.
Journal: 
Monthly Notices of the Royal Astronomical Society
Publication type: 
Article
Volume: 
526
Pages: 
4599
Abstract: 
Future detection of high-redshift gamma-ray bursts (GRBs) will be an important tool for studying the early Universe. Fast and accurate redshift estimation for detected GRBs is key for encouraging rapid follow-up observations by ground- and space-based telescopes. Low-redshift dusty interlopers pose the biggest challenge for GRB redshift estimation using broad photometric bands, as their high extinction can mimic a high-redshift GRB. To assess false alarms of high-redshift GRB photometric measurements, we simulate and fit a variety of GRBs using PHOZZY, a simulation code developed to estimate GRB photometric redshifts, and test the ability to distinguish between high- and low-redshift GRBs when using simultaneously observed photometric bands. We run the code with the wavelength bands and instrument parameters for the Photo-z Infrared Telescope (PIRT), an instrument designed for the Gamow mission concept. We explore various distributions of host galaxy extinction as a function of redshift, and their effect on the completeness and purity of a high-redshift GRB search with the PIRT. We find that for assumptions based on current observations, the completeness and purity range from ~82 to 88 per cent and from ~84 to $\gt 99~{{\ \rm per\ cent}}$, respectively. For the priors optimized to reduce false positives, only $\sim 0.6~{{\ \rm per\ cent}}$ of low-redshift GRBs will be mistaken as a high-redshift one, corresponding to ~1 false alarm per 500 detected GRBs.
Database: 
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/2023MNRAS.526.4599F/abstract
ADS Bibcode: 
2023MNRAS.526.4599F
Keywords: 
methods: statistical;techniques: photometric;software: simulations;gamma-ray bursts;Astrophysics - Instrumentation and Methods for Astrophysics;Astrophysics - High Energy Astrophysical Phenomena