2001A&A...374...73F


C.D.S. - SIMBAD4 rel 1.7 - 2019.09.22CEST04:28:40

2001A&A...374...73F - Astronomy and Astrophysics, volume 374, 73-82 (2001/7-4)

Excess hard X-ray emission from the obscured low luminosity AGN in the nearby galaxy M 51 (NGC 5194).

FUKAZAWA Y., IYOMOTO N., KUBOTA A., MATSUMOTO Y. and MAKISHIMA K.

Abstract (from CDS):

We observed the nearby galaxy M 51 (NGC 5194) with BeppoSAX. The X-ray properties of the nucleus below 10 keV are almost the same as the ASCA results regarding the hard component and the neutral Fe Kα line, but the intensity is about half of the ASCA 1993 data. Beyond this, in the BeppoSAX PDS data, we detected a bright hard X-ray emission component which dominates above 10keV. The 10-100keV flux and luminosity of this component are respectively 2x10–11erg/s/cm2 and 2x1041erg/s. These are about 10 times higher than the extrapolation from the soft X-ray band, and similar to the flux observed with Ginga, which found a bright power law component in 2-20keV band. Considering other wavelength properties and the X-ray luminosity, together with strong neutral Fe K line, the hard X-ray emission most likely arises from a low luminosity active nucleus, which is obscured with a column density of ∼1024cm–2. This suggests that hidden low luminosity AGNs may well be present in other nearby galaxies. We interpret the discrepancy between Ginga and other X-ray satellites to be due to a large variability of absorption column density toward the line of sight over several years, suggesting that the Compton thick absorption material may be present on a spatial scale of a parsec. Apart from the nucleus, several ultra-luminous off-nuclear X-ray sources detected in M 51 exhibit long-term time variability, suggesting the state transition similar to that observed in Galactic black hole candidates.

Abstract Copyright:

Journal keyword(s): galaxies: active - galaxies: nuclei - galaxies: individual: M 51

Simbad objects: 10

goto Full paper

goto View the reference in ADS

Number of rows : 10

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2019
#notes
1 NGC 1365 Sy1 03 33 36.458 -36 08 26.37 10.48 10.08 9.63 8.79 9.7 ~ 1464 2
2 IC 342 SBG 03 46 48.514 +68 05 45.98   10.5       ~ 1359 1
3 M 82 IG 09 55 52.430 +69 40 46.93 9.61 9.30 8.41     ~ 5198 6
4 NGC 4051 Sy1 12 03 09.6098828919 +44 31 52.693714606   11.08 12.92 9.94   ~ 1945 1
5 M 106 Sy2 12 18 57.620 +47 18 13.39   9.14 8.41 8.11   ~ 2053 3
6 M 51 GiP 13 29 52.698 +47 11 42.93   9.26 8.36 8.40   ~ 3669 4
7 SN 1994I SN* 13 29 54.072 +47 11 30.50     12.9     SNIc 555 1
8 NGC 5195 GiP 13 29 59.590 +47 15 58.06 10.76 10.45 9.55 9.31   ~ 681 3
9 NAME Circinus Galaxy Sy2 14 13 09.906 -65 20 20.47   10.89 9.84 10.6 10.0 ~ 966 2
10 NGC 6552 Sy2 18 00 07.2507502885 +66 36 54.347573772   14.6       ~ 129 2

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2001A&A...374...73F and select 'bookmark this link' or equivalent in the popup menu


2019.09.22-04:28:40

© Université de Strasbourg/CNRS

    • Contact