| Issue |
A&A
Volume 382, Number 3, FebruaryII 2002
|
|
|---|---|---|
| Page(s) | L13 - L16 | |
| Section | Letters | |
| DOI | https://doi.org/10.1051/0004-6361:20011776 | |
| Published online | 15 February 2002 | |
Letter to the Editor
Population X: Are the super-Eddington X-ray sources beamed jets in microblazars or intermediate mass black holes?
Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
Corresponding author: E. Körding, körding@mpifr-bonn.mpg.de
Received:
27
August
2001
Accepted:
12
December
2001
Recent X-ray observations reveal an increasing number of
X-ray sources in nearby galaxies exceeding luminosities of 
. Assuming isotropic
emission, the Eddington limit suggests a population of
intermediate-mass black holes of 
. However,
Markoff et al. ([CITE]) proposed that jets may be
contributing to the X-ray emission from X-ray binaries (XRBs), implying that
some X-ray sources may be relativistically beamed. This could reduce
the required black hole masses to standard values. To test this
hypothesis, we investigate a simple X-ray population synthesis model
for X-ray point sources in galaxies with relativistic beaming and
compare it with an isotropic emission model. The model is used to
explain a combined data set of X-ray point sources in nearby
galaxies. We show that the current distributions are consistent with
black hole masses 
and bulk Lorentz factors for jets in
microquasars of 
. Alternatively, intermediate
mass black holes up to 1000 
are required which are
distributed in a powerlaw with roughly 
.
Key words: X-rays: binaries / accretion, accretion disks / black hole physics / radiation mechanisms: non-thermal
© 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.