EDP Sciences
Free Access
Volume 382, Number 1, January IV 2002
Page(s) L1 - L4
Section Letters
DOI https://doi.org/10.1051/0004-6361:20011763
Published online 15 January 2002

A&A 382, L1-L4 (2002)
DOI: 10.1051/0004-6361:20011763


Detection of a high frequency break in the X-ray power spectrum of Ark 564

I. E. Papadakis1, 2, W. Brinkmann3, H. Negoro4 and M. Gliozzi3

1  IESL, Foundation for Research and Technology-Hellas, PO Box 1527, 711 10 Heraklion, Crete, Greece
2  Physics Department, University of Crete, PO Box 2208, 710 03 Heraklion, Greece
3  Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, 85740 Garching, Germany
4  Cosmic Radiation Laboratory, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-01, Japan

(Received 22 October 2001 / Accepted 10 December 2001 )

We present a power spectrum analysis of the long ASCA observation of in June/July 2001. The observed power spectrum covers a frequency range of ~3.5 decades. We detect a high frequency break at ~ $2\times
10^{-3}$  Hz. The power spectrum has an rms of ~30% and a slope of ~-1 and ~-2 below and above the break frequency. When combined with the results from a long RXTE observation (Pounds et al. 2001), the observed power spectra of and Cyg X-1 (in the low/hard state) are almost identical, showing a similar shape and rms amplitude. However, the ratio of the high frequency breaks is very small (~ 103-4), implying that these characteristic frequencies are not indicative of the black hole mass. This result supports the idea of a small black hole mass/high accretion rate in .

Key words: galaxies: active -- galaxies: Seyfert -- galaxies: individual: Ark 564 -- X-rays: galaxies

Offprint request: I. E. Papadakis, jhep@physics.uoc.gr

SIMBAD Objects

© ESO 2002

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.