Search Publications
The Sloan Digital Sky Survey Reverberation Mapping Project: the XMM-Newton X-Ray Source Catalog and Multiband Counterparts
Green, Paul J.; Shen, Yue; Nandra, Kirpal +10 more
The XMM-RM project was designed to provide X-ray coverage of the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) field. Forty-one XMM-Newton exposures, placed surrounding the Chandra AEGIS field, were taken, covering an area of 6.13 deg2 and reaching a nominal exposure depth of ∼15 ks. We present an X-ray catalog of 3553 source…
A White-light Flare Powered by Magnetic Reconnection in the Lower Solar Atmosphere
Chen, Yajie; Song, Yongliang; Tian, Hui +3 more
White-light flares (WLFs), first observed in 1859, refer to a type of solar flare showing an obvious enhancement of the visible continuum emission. This type of enhancement often occurs in most energetic flares, and is usually interpreted as a consequence of efficient heating in the lower solar atmosphere through nonthermal electrons propagating d…
Constraining Type Iax supernova progenitor systems with stellar population age dating
Foley, Ryan J.; Rest, Armin; Fong, Wen-fai +6 more
Type Iax supernovae (SNe Iax) are the most common class of peculiar SNe. While they are thought to be thermonuclear white-dwarf (WD) SNe, SNe Iax are observationally similar to, but distinct from SNe Ia. Unlike SNe Ia, where roughly 30 per cent occur in early-type galaxies, only one SN Iax has been discovered in an early-type galaxy, suggesting a …
Sudden and steady orbital period changes across six classical Nova Eruptions: the end of hibernation and two serious challenges for the magnetic braking model of cataclysmic variable evolution
Schaefer, Bradley E.
I report on two new measures of the sudden change in the orbital period (P) across the nova eruption (ΔP) and the steady period change in quiescence (\dot{P}) for classical novae (CNe) RR Pic and HR Del, bringing a total of six such measures for CNe, all in a final report of my large and long observing program. The fractional changes (ΔP/P) in par…
A disc reflection model for ultra-soft narrow-line Seyfert 1 galaxies
Fabian, Andrew C.; Reynolds, Christopher S.; Jiang, Jiachen +2 more
We present a detailed analysis of the XMM-Newton observations of five narrow-line Seyfert 1 galaxies (NLS1s). They all show very soft continuum emission in the X-ray band with a photon index of Γ ≳ 2.5. Therefore, they are referred to as 'ultra-soft' NLS1s in this paper. By modelling their optical/UV-X-ray spectral energy distribution (SED) with a…
An underlying clock in the extreme flip-flop state transitions of the black hole transient Swift J1658.2-4242
Nandra, K.; Ponti, G.; Miller-Jones, J. C. A. +8 more
Aims: Flip-flops are top-hat-like X-ray flux variations, which have been observed in some transient accreting black hole binary systems, and feature simultaneous changes in the spectral hardness and the power density spectrum (PDS). They occur at a crucial time in the evolution of these systems, when the accretion disc emission starts to domi…
Observations of a mix of cold and warm electrons by RPC-MIP at 67P/Churyumov-Gerasimenko
Henri, P.; Rubin, M.; Eriksson, A. I. +8 more
Context. The Mutual Impedance Probe (MIP) of the Rosetta Plasma Consortium (RPC) onboard the Rosetta orbiter which was in operation for more than two years, between August 2014 and September 2016 to monitor the electron density in the cometary ionosphere of 67P/Churyumov-Gerasimenko. Based on the resonance principle of the plasma eigenmodes, recen…
Deflection of the hypervelocity stars by the pull of the Large Magellanic Cloud on the Milky Way
Erkal, D.; Boubert, D.; Gualandris, A.
Stars slingshotted by the supermassive black hole at the Galactic Centre escape from the Milky Way so quickly that their trajectories are almost straight lines. Previous works have shown how these 'hypervelocity stars' (stars moving faster than the local Galactic escape speed) are subsequently deflected by the gravitational field of the Milky Way …
The Relationship between Chirality, Sense of Rotation, and Hemispheric Preference of Solar Eruptive Filaments
Wang, Yuming; Liu, Rui; Jiang, Chaowei +4 more
The orientation, chirality, and dynamics of solar eruptive filaments are key to our understanding of the magnetic field of coronal mass ejections (CMEs), and therefore to predicting the geoeffectiveness of CMEs arriving at Earth. However, confusion and contention remain over the relationship between the filament chirality, magnetic helicity, and t…
The distribution of dark matter and gas spanning 6 Mpc around the post-merger galaxy cluster MS 0451-03
Smith, Graham P.; Ellis, Richard S.; Massey, Richard +11 more
Using the largest mosaic of Hubble Space Telescope images around a galaxy cluster, we map the distribution of dark matter throughout an ∼6 × 6 Mpc2 area centred on the cluster MS 0451-03 (z = 0.54, $M_{200}=1.65\times 10^{15}\, {\rm M}_{\odot }$ ). Our joint strong- and weak-lensing analysis shows three possible filaments extending from…