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Testing the Paradigm that Ultraluminous X-ray Sources as a Class Represent Accreting Intermediate-Mass Black Holes
C. T. Berghea, K. A. Weaver, E. J. M. Colbert +1
To test the idea that ultraluminous X-ray sources (ULXs) in external galaxies represent a class of accreting intermediate-mass black holes (IMBHs), we have undertaken a program to…
New Hubble Space Telescope imaging of the counterparts to six ultraluminous X-ray sources
T. P. Roberts, A. J. Levan, M. R. Goad
We report the results of new Hubble Space Telescope imaging of the positions of six ultraluminous X-ray sources (ULXs). Using images in three ACS filters we detect good candidate c…
New insights into the X-ray properties of the nearby barred spiral galaxy NGC 1672
L. P. Jenkins, W. N. Brandt, E. J. M. Colbert +4
We present some preliminary results from new Chandra and XMM-Newton X-ray observations of the nearby barred spiral galaxy NGC1672. It shows dramatic nuclear and extra-nuclear star…
The XMM-Newton Serendipitous Survey V. Optical identification of the XMM-Newton Medium sensitivity Survey (XMS)
X. Barcons, F. J. Carrera, M. T. Ceballos +53
We present the XMM-Newton Medium sensitivity Survey (XMS), including a total of 318 X-ray sources found among the serendipitous content of 25 XMM-Newton target fields. The XMS comp…
The Orbital Period of the Wolf-Rayet Binary IC 10 X-1; Dynamic Evidence that the Compact Object is a Black Hole
A. H. Prestwich, R. Kilgard, P. A. Crowther +6
IC 10 X-1 is a bright (Lx=10^38 ergs/s) variable X-ray source in the local group starburst galaxy IC 10. The most plausible optical counterpart is a luminous Wolf-Rayet star, makin…
An XMM-Newton view of M101 - III. Diffuse X-ray emission
R. S. Warwick, L. P. Jenkins, A. M. Read +2
We present a study of the X-ray properties of the nearby face-on Scd spiral galaxy M101 based on recent XMM-Newton observations. In this third and final paper in the present series…
Chandra monitoring observations of the ultraluminous X-ray source NGC 5204 X-1
T. P. Roberts, R. E. Kilgard, R. S. Warwick +2
We report the results of a 2-month campaign conducted with the Chandra X-ray observatory to monitor the ultraluminous X-ray source (ULX) NGC 5204 X-1. This was composed of a 50-ks…
XMM-Newton observations of the brightest Ultraluminous X-ray sources
A-M. Stobbart, T. P. Roberts, J. Wilms
We present an analysis of 13 of the best quality EPIC ULX datasets. We utilise the high signal-to-noise in these ULX spectra to investigate the best descriptions of their spectral…
New insights into ultraluminous X-ray sources from deep XMM-Newton observations
T. P. Roberts, A. -M. Stobbart, M. R. Goad +4
The controversy over whether ultraluminous X-ray sources (ULXs) contain a new intermediate-mass class of black holes (IMBHs) remains unresolved. We present new analyses of the deep…
A deep XMM-Newton observation of the ultraluminous X-ray source HoII X-1 : the case against a 1000 solar mass black hole
M. R. Goad, T. P. Roberts, J. N. Reeves +1
We present results from a 112 ks long look by XMM-Newton at the ultraluminous X-ray source (ULX) Holmberg II X-1, long thought to be the one of best candidates for the missing clas…
M74 X-1 (CXOU J013651.1+154547): An Extremely Variable Ultraluminous X-Ray Source
M. I. Krauss, R. E. Kilgard, M. R. Garcia +2
Ultraluminous X-ray sources (ULXs) have been described variously as the most luminous normal X-ray binaries, as hypernovae, and as "intermediate-mass" black holes with masses of hu…
Discovery of multiple ultraluminous X-ray sources in the galaxy KUG 0214-057
M. G. Watson, T. P. Roberts, M. Akiyama +1
We report the serendipitous discovery of several unresolved X-ray sources lying in the prominent spiral arms of the galaxy KUG 0214-057 in XMM-Newton observations. The location of…
XMM-Newton EPIC observations of the ultraluminous X-ray source NGC 5204 X-1
T. P. Roberts, R. S. Warwick, M. J. Ward +2
We present the results of two XMM-Newton observations of the ultraluminous X-ray source (ULX) NGC 5204 X-1. The EPIC spectra are well-fit by the standard spectral model of a black-…
An XMM-Newton view of M101 - II. Global X-ray source properties
L. P. Jenkins, T. P. Roberts, R. S. Warwick +2
We present the global X-ray properties of the point source population in the grand-design spiral galaxy M101, as seen with XMM-Newton. 108 X-ray sources are detected within the D25…
XMM-Newton observations of the interacting galaxy pairs NGC7771/0 and NGC2342/1
L. P. Jenkins, T. P. Roberts, M. J. Ward +1
We present XMM-Newton X-ray observations of the interacting galaxy pairs NGC7771/7770 and NGC2342/2341. In NGC7771, for the first time we are able to resolve the X-ray emission int…
XMM-Newton observations of the starburst merger galaxies NGC 3256 & NGC 3310
L. P. Jenkins, T. P. Roberts, M. J. Ward +1
We present XMM-Newton EPIC observations of the two nearby starburst merger galaxies NGC 3256 & NGC 3310. The broad-band (0.3-10 keV) integrated X-ray emission from both galaxies sh…
A dipping black-hole X-ray binary candidate in NGC 55
A-M. Stobbart, T. P. Roberts, R. S. Warwick
XMM-Newton EPIC observations have revealed a bright point-like X-ray source in the nearby Magellanic-type galaxy NGC 55. At the distance of NGC 55, the maximum observed X-ray lumin…
Chandra observations of five ultraluminous X-ray sources in nearby galaxies
T. P. Roberts, R. S. Warwick, M. J. Ward +1
We report the results of a programme of dual-epoch Chandra ACIS-S observations of five ultraluminous X-ray sources (ULXs) in nearby spiral galaxies. All five ULXs are detected as u…
The nature of ultraluminous X-ray sources in nearby galaxies
T. P. Roberts, M. R. Goad, M. J. Ward +2
The advanced capabilities of the Chandra and XMM-Newton observatories mean that, for the first time, the detailed study of the brightest point-like X-ray sources in nearby galaxies…
XMM-Newton observations of NGC 253: Resolving the emission components in the disk and nuclear area
W. Pietsch, T. P. Roberts, M. J. Freyberg +11
The high XMM-Newton throughput allows a detailed investigation of the spatial, spectral and variability properties of the extended and point source emission of the starburst galaxy…