Discovery of the Faint X-Ray Pulsar AX J1820.5-1434 with ASCA
Author
Japanese:
Kinugasa, K.,
Torii, K.,
Hashimoto, Y.,
Tsunemi, H.,
Hayashida, K.,
Kitamoto, S.,
Kamata, Y.,
Dotani, T.,
Nagase, F.,
Sugizaki, M.,
Ueda, Y.,
河合 誠之,
Makishima, K.,
Yamauchi, S..
English:
Kinugasa, K.,
Torii, K.,
Hashimoto, Y.,
Tsunemi, H.,
Hayashida, K.,
Kitamoto, S.,
Kamata, Y.,
Dotani, T.,
Nagase, F.,
Sugizaki, M.,
Ueda, Y.,
Kawai, N.,
Makishima, K.,
Yamauchi, S..
Language
English
Journal/Book name
Japanese:
English:
Astrophysical Journal
Volume, Number, Page
Vol. 495
pp. 435
Published date
Mar. 1998
Publisher
Japanese:
English:
Conference name
Japanese:
English:
Conference site
Japanese:
English:
Abstract
A new X-ray pulsar, AX J1820.5-1434, has been discovered during the ASCA Galactic plane survey project on April 9, at R.A. = 18h20m29.s5, decl. = -14 deg34'24" (equinox 2000.0; error radius 0.'5). A coherent pulsation was detected from the source with an apparent barycentric pulse period of 152.26 +/- 0.04 s. The mean flux, not corrected for the interstellar absorption, was 2.3 x 10-11 ergs s-1 cm-2 in the 2-10 keV energy band. The energy spectra obtained by the GIS and SIS can be fitted by a power-law model (photon index = 0.9 +/- 0.2) with a large column density of 9.8 +/- 1.7 x 1022 H atoms cm-2. These parameters indicate that the new pulsar is a highly obscured accretion-driven binary X-ray pulsar. This discovery of a faint pulsar suggests existence of many hidden pulsars in our Galaxy.