Search Publications
Discovery of a glitch in the accretion-powered pulsar SXP 1062
Serim, M. M.; Şahiner, Ş.; ćerri-Serim, D. +2 more
We present timing analysis of the accretion-powered pulsar SXP 1062, based on the observations of Swift, XMM-Newton and Chandra satellites covering a time span of about 2 yr. We obtain a phase coherent timing solution that shows that SXP 1062 has been steadily spinning down with a rate -4.29(7) × 10-14 Hz s-1 leading to a sur…
Long-term survival of surface water ice on comet 67P
Jorda, L.; Lamy, P. L.; Lara, L. M. +53 more
Numerous water-ice-rich deposits surviving more than several months on comet 67P/Churyumov-Gerasimenko were observed during the Rosetta mission. We announce the first-time detection of water-ice features surviving up to 2 yr since their first observation via OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) NAC (narrow angle came…
Obscured active galactic nuclei triggered in compact star-forming galaxies
Juneau, Stéphanie; Capak, Peter; McCracken, H. J. +10 more
We present a structural study of 182 obscured active galactic nuclei (AGNs) at z ≤ 1.5, selected in the Cosmic Evolution Survey field from their extreme infrared to X-ray luminosity ratio and their negligible emission at optical wavelengths. We fit optical to far-infrared spectral energy distributions and analyse deep Hubble Space Telescope imagin…
The puzzling orbital period evolution of the LMXB AX J1745.6-2901
Stella, L.; Nandra, K.; Ponti, G. +2 more
The orbital period evolution of X-ray binaries provides fundamental clues to understanding mechanisms of angular momentum transfer and loss in these systems. We present an X-ray eclipse timing analysis of the transient low-mass X-ray binary AX J1745.6-2901. This system shows full eclipses and thus is one of the few objects of this class for which …
Lower hybrid waves at comet 67P/Churyumov-Gerasimenko
André, M.; Karlsson, T.; Henri, P. +9 more
We investigate the generation of waves in the lower hybrid frequency range by density gradients in the near plasma environment of comet 67P/Churyumov-Gerasimenko. When the plasma is dominated by water ions from the comet, a situation with magnetized electrons and unmagnetized ions is favourable for the generation of lower hybrid waves. These waves…
Revisiting the extremely fast disc wind in a gravitationally lensed quasar APM 08279+5255
Done, Chris; Takahashi, Tadayuki; Hagino, Kouichi +2 more
The gravitationally lensed quasar APM 08279+5255 has the fastest claimed wind from any active galactic nucleus, with velocities of 0.6-0.7c, requiring magnetic acceleration as special relativistic effects limit all radiatively driven winds to v < 0.3-0.5c. However, this extreme velocity derives from interpreting both the narrow and broad absorp…
A close encounter of the massive kind
Maíz Apellániz, J.; Sana, H.; Barbá, R. H. +2 more
We have used (I) Hubble Space Telescope Advanced Camera for Surveys imaging and Space Telescope Imaging Spectrograph spectroscopy, (II) ground-based Precision Integrated-Optics Near-infrared Imaging ExpeRiment/Very Large Telescope long-baseline interferometry, and (III) ground-based spectroscopy from different instruments to study the orbit of the…
Outbursts of the intermediate-mass black hole HLX-1: a wind-instability scenario
Soria, Roberto; Wu, Kinwah; Zampieri, Luca +5 more
We model the intermediate-mass black hole HLX-1, using the Hubble Space Telescope, XMM-Newton and Swift. We quantify the relative contributions of a bluer component, function of X-ray irradiation, and a redder component, constant and likely coming from an old stellar population. We estimate a black hole mass {≈ } (2^{+2}_{-1}) × 10^4 M_{⊙}, a spin…
Expanding hot flow in the black hole binary SWIFT J1753.5-0127: evidence from optical timing
Gandhi, Poshak; Tsygankov, Sergey S.; Poutanen, Juri +5 more
We describe the evolution of optical and X-ray temporal characteristics during the outburst decline of the black hole X-ray binary SWIFT J1753.5-0127. The optical/X-ray cross-correlation function demonstrates a single positive correlation at the outburst peak, then it has multiple dips and peaks during the decline stage, which are then replaced by…
Detection of an ∼20 kpc coherent magnetic field in the outskirt of merging spirals: the Antennae galaxies
Mao, S. A.; Zweibel, Ellen G.; Basu, Aritra +3 more
We present a study of the magnetic field properties of NGC 4038/9 (the `Antennae' galaxies), the closest example of a late stage merger of two spiral galaxies. Wideband polarimetric observations were performed using the Karl G. Jansky Very Large Array between 2 and 4 GHz. Rotation measure synthesis and Faraday depolarization analysis was performed…