Search Publications
Deep radio imaging of the SCUBA 8-mJy survey fields: submillimetre source identifications and redshift distribution
Ivison, R. J.; Smail, Ian; Dunlop, J. S. +12 more
The SCUBA 8-mJy survey is the largest submillimetre (submm) extragalactic mapping survey undertaken to date, covering 260 arcmin2 to a 4 σ detection limit of ~=8 mJy at 850 µm, centred on the Lockman Hole and ELAIS N2 regions. Here, we present the results of new 1.4-GHz imaging of these fields, of the depth and resolution necessar…
A long hard look at MCG-6-30-15 with XMM-Newton
Young, A. J.; Nandra, K.; Iwasawa, K. +6 more
We present the first results from a 325-ks observation of the Seyfert 1 galaxy MCG-6-30-15 with XMM-Newton and BeppoSAX. The strong, broad, skewed iron line is clearly detected and is well characterized by a steep emissivity profile within 6rg (i.e. 6GM/c2) and a flatter profile beyond. The inner radius of the emission appear…
The magnetic field and wind confinement of θ1 Orionis C
Donati, J. -F.; Babel, J.; Harries, T. J. +3 more
We report the detection, through spectropolarimetric observations, of a strong dipolar magnetic field of presumably fossil origin at the surface of the very young O star θ1 Ori C. The Stokes V signatures we detect are variable with time, the variations being consistent with rotational modulation. A detailed modelling of our observations…
How the X-ray spectrum of a narrow-line Seyfert 1 galaxy may be reflection-dominated
Merloni, A.; Iwasawa, K.; Vaughan, S. +3 more
A model for the inner regions of accretion flows is presented where, owing to disc instabilities, cold and dense material is clumped into deep sheets or rings. Surrounding these density enhancements is hot, tenuous gas where coronal dissipation processes occur. We expect this situation to be most relevant when the accretion rate is close to Edding…
XMM-Newton discovery of a sharp spectral feature at ~ 7 keV in the narrow-line Seyfert 1 galaxy 1H 0707 - 49
Sunyaev, R.; Brandt, W. N.; Iwasawa, K. +6 more
We report the first detection of a sharp spectral feature in a narrow-line Seyfert 1 galaxy. Using XMM-Newton we have observed 1H 0707-495 and find a drop in flux by a factor of more than 2 at a rest-frame energy of ~7 keV without any detectable narrow Fe Kα line emission. The energy of this feature suggests a connection with the neutral iron K ph…
High-resolution X-ray imaging and spectroscopy of the core of NGC 4945 with XMM-Newton and Chandra
Schurch, N. J.; Warwick, R. S.; Roberts, T. P.
We utilize the complementary capabilities of XMM-Newton and Chandra to conduct a detailed imaging and spectral study of the nearby galaxy NGC 4945 focusing on its nucleus and immediate surroundings (within ~ kpc of the nucleus). A complex morphology is revealed including a predominantly hard, but partially resolved, nuclear source plus a spectrall…
Timing analysis of the isolated neutron star RX J0720.4-3125
Cropper, Mark; Zavlin, Vyacheslav E.; Haberl, Frank +4 more
We present a combined analysis of XMM-Newton, Chandra and ROSAT observations of the isolated neutron star RX J0720.4-3125, spanning a total period of ~7yr. We develop a maximum likelihood periodogram for our analysis based on the ΔC statistic and the maximum likelihood method, which are appropriate for the treatment of sparse event lists. Our resu…
An XMM-Newton observation of Ton S180: constraints on the continuum emission in ultrasoft Seyfert galaxies
Brandt, W. N.; Vaughan, S.; Fabian, A. C. +3 more
We present an XMM-Newton observation of the bright, narrow-line, ultrasoft type 1 Seyfert galaxy Ton S180. The 0.3-10 keV X-ray spectrum is steep and curved, showing a steep slope above 2.5 keV (Γ~ 2.3) and a smooth, featureless excess of emission at lower energies. The spectrum can be adequately parametrized using a simple double power-law model.…
On the detectability of distant Compton-thick obscured quasars
Fabian, A. C.; Crawford, C. S.; Wilman, R. J.
Chandra and XMM-Newton have resolved the 2-8keV X-ray background (XRB) into point sources. Many of the fainter sources are obscured active galactic nuclei (AGN) with column densities in the range of 1022-1023cm-2, some of which have quasar-like luminosities. According to obscuration models, the XRB above 8keV is do…
Multiple X-ray reflection from ionized slabs
Fabian, A. C.; Ross, R. R.; Ballantyne, D. R.
Multiple reflection of X-rays may be important when an accretion disc and its hot corona have a complicated geometry, or if returning radiation due to gravitational light bending is important, or in emission from a funnel such as proposed in some γ-ray burst models. We simulate the effects of multiple reflection by modifying the boundary condition…