Search Publications
Geometrical beaming of stellar mass ULXs
Middleton, Matthew J.; King, Andrew
The presence or lack of eclipses in the X-ray light curves of ultraluminous X-ray sources (ULXs) can be directly linked to the accreting system geometry. In the case where the compact object is stellar mass and radiates isotropically, we should expect eclipses by a main-sequence to sub-giant secondary star on the recurrence time-scale of hours to …
Evidence for an evolving cyclotron line energy in 4U 1538-522
Hemphill, Paul B.; Rothschild, Richard E.; Fürst, Felix +6 more
We have performed a full time and luminosity-resolved spectral analysis of the high-mass X-ray binary 4U 1538-522 using the available RXTE, INTEGRAL, and Suzaku data, examining both phase-averaged and pulse-phase-constrained data sets and focusing on the behaviour of the cyclotron resonance scattering feature (CRSF). No statistically significant t…
On the covering fraction variability in an EUV mini-BAL outflow from PG 1206+459
Muzahid, S.; Srianand, R.; Charlton, J. +1 more
We report on the first detection of extreme-ultraviolet (EUV) absorption variability in the Ne VIII λλ770, 780 mini-broad absorption line (mini-BAL) in the spectrum of the quasar (QSO) PG 1206+459. The observed equivalent width (EW) of the Ne VIII doublet shows a ∼4σ variation over a time-scale of 2.8 months in the QSO's rest frame. Both members o…
INTEGRAL study of temporal properties of bright flares in Supergiant Fast X-ray Transients
Sidoli, L.; Postnov, K.; Paizis, A.
We have characterized the typical temporal behaviour of the bright X-ray flares detected from the three Supergiant Fast X-ray Transients (SFXTs) showing the most extreme transient behaviour (XTE J1739-302, IGR J17544-2619, SAX J1818.6-1703). We focus here on the cumulative distributions of the waiting-time (time interval between two consecutive X-…
Constraints on small-scale cosmological fluctuations from SNe lensing dispersion
Ben-Dayan, Ido; Takahashi, Ryuichi
We provide predictions on small-scale cosmological density power spectrum from supernova lensing dispersion. Parametrizing the primordial power spectrum with running α and running of running β of the spectral index, we exclude large positive α and β parameters which induce too large lensing dispersions over current observational upper bound. We ra…
YSO jets in the Galactic plane from UWISH2 - III. Jets and outflows in Cassiopeia and Auriga
Froebrich, D.; Makin, S. V.
We present the analysis of 35.5 deg2 of images in the 1-0 S(1) line of H2 from the UK Widefield Infrared Survey for H2 (UWISH2) towards Cassiopeia and Auriga. We have identified 98 Molecular Hydrogen emission-line Objects (MHOs) driven by Young Stellar Objects, 60 per cent of which are bipolar outflows and all are …
V4743 Sgr, a magnetic nova?
Mukai, K.; Orio, M.; Bianchini, A. +3 more
Two XMM-Newton observations of Nova V4743 Sgr (Nova Sgr 2002) were performed shortly after it returned to quiescence, 2 and 3.5 yr after the explosion. The X-ray light curves revealed a modulation with a frequency of ≃0.75 mHz, indicating that V4743 Sgr is most probably an intermediate polar (IP). The X-ray spectra have characteristics in common w…
Radio-optical galaxy shape correlations in the COSMOS field
Brown, Michael L.; Harrison, Ian; Tunbridge, Ben
We investigate the correlations in galaxy shapes between optical and radio wavelengths using archival observations of the Cosmic Evolution Survey (COSMOS) field. Cross-correlation studies between different wavebands will become increasingly important for precision cosmology as future large surveys may be dominated by systematic rather than statist…
The massive dark halo of the compact early-type galaxy NGC 1281
Gebhardt, Karl; van de Ven, Glenn; Husemann, Bernd +7 more
We investigate the compact, early-type galaxy NGC 1281 with integral field unit observations to map the stellar line-of-sight velocity distribution (LOSVD) out to five effective radii and construct orbit-based dynamical models to constrain its dark and luminous matter content. Under the assumption of mass-follows-light, the H-band stellar mass-to-…
A giant radio halo in a low-mass SZ-selected galaxy cluster: ACT-CL J0256.5+0006
Bond, J. R.; Menanteau, F.; Bharadwaj, V. +19 more
We present the detection of a giant radio halo (GRH) in the Sunyaev-Zel'dovich (SZ)-selected merging galaxy cluster ACT-CL J0256.5+0006 (z = 0.363), observed with the Giant Metrewave Radio Telescope at 325 and 610 MHz. We find this cluster to host a faint (S610 = 5.6 ± 1.4 mJy) radio halo with an angular extent of 2.6 arcmin, correspond…