Poster Presentation

Candidate of possible variable gamma-ray pulsars

CHIA HSUN WU(NTHU, Taiwan), Albert KONG(NTHU, Taiwan), David C. Y. Hui(Department of Astronomy & Space Science Chungnam National University, ROK)

PSR J2021 +4026 is the first variable gamma-ray pulsar detected by Fermi Large Area Telescope (LAT). There’s an unexpected decrease in flux of long-term light curves over a time scale shorter than a week. The frequency spin-down rate also increased. Here we present the study of finding possible candidates of variable pulsars based on the following methods i) Use the variability index offered by 2nd Fermi catalog (2FGL) and select those of 5% at the high end. ii) Use long-term light curves obtained by aperture photometry to finding those are more variable. iii) Use parameters files of gamma-ray timing models and selecting those which have a great deal of parameters. After completing these three methods, we find some possible candidates that might be variable pulsars. Next, we will analyze the possible candidates in detail to see whether they are variable gamma-ray pulsars just like PSR J2021+4026 or not.