Search Publications
Active-region Tilt Angles: Magnetic versus White-light Determinations of Joy's Law
Li, J.; Wang, Y. -M.; Baranyi, T. +1 more
The axes of solar active regions are inclined relative to the east-west direction, with the tilt angle tending to increase with latitude ("Joy's law"). Observational determinations of Joy's law have been based either on white-light images of sunspot groups or on magnetograms, where the latter have the advantage of measuring directly the physically…
Relations Between Microwave Bursts and Near-Earth High-Energy Proton Enhancements and Their Origin
Grechnev, V. V.; Chertok, I. M.; Kiselev, V. I. +1 more
We further study the relations between parameters of bursts at 35 GHz recorded with the Nobeyama Radio Polarimeters during 25 years and solar proton events (Grechnev et al. in Publ. Astron. Soc. Japan65, S4, 2013a). Here we address the relations between the microwave fluences at 35 GHz and near-Earth proton fluences above 100 MeV to find informati…
Gaia's potential for the discovery of circumbinary planets
Sahlmann, J.; Martin, D. V.; Triaud, A. H. M. J.
The abundance and properties of planets orbiting binary stars - circumbinary planets - are largely unknown because they are difficult to detect with currently available techniques. Results from the Kepler satellite and other studies indicate a minimum occurrence rate of circumbinary giant planets of ∼10 per cent, yet only a handful are presently k…
Constraints on the Nambu-Goto cosmic string contribution to the CMB power spectrum in light of new temperature and polarisation data
Lazanu, Andrei; Shellard, Paul
Cosmic strings generate vector and tensor modes in the B-channel of polarisation, as well as the usual temperature power spectrum and E-mode polarisation spectrum. We use the power spectrum obtained from high-resolution Nambu-Goto cosmic string simulations together with the Planck and BICEP2 likelihoods to explore the degeneracies appearing betwee…
Dependence of the dayside magnetopause reconnection rate on local conditions
Kistler, Lynn M.; Wang, Shan; Mouikis, Christopher G. +1 more
We estimate the reconnection rates for eight dayside magnetopause reconnection events observed by the Cluster spacecraft and compare them with the predictions of the Cassak-Shay Formula (Rcs) Cassak and Shay (2007). The measured reconnection rate is determined by calculating the product of the inflow velocity and magnetic field in the m…
The WEBT campaign on the BL Lac object PG 1553+113 in 2013. An analysis of the enigmatic synchrotron emission
Lähteenmäki, A.; Umana, G.; Giroletti, M. +59 more
A multifrequency campaign on the BL Lac object PG 1553+113 was organized by the Whole Earth Blazar Telescope (WEBT) in 2013 April-August, involving 19 optical, two near-IR, and three radio telescopes. The aim was to study the source behaviour at low energies during and around the high-energy observations by the Major Atmospheric Gamma-ray Imaging …
Predicting CME Ejecta and Sheath Front Arrival at L1 with a Data-constrained Physical Model
Hess, Phillip; Zhang, Jie
We present a method for predicting the arrival of a coronal mass ejection (CME) flux rope in situ, as well as the sheath of solar wind plasma accumulated ahead of the driver. For faster CMEs, the front of this sheath will be a shock. The method is based upon geometrical separate measurement of the CME ejecta and sheath. These measurements are used…
Accurate shear measurement with faint sources
Zhang, Jun; Luo, Wentao; Foucaud, Sebastien
For cosmic shear to become an accurate cosmological probe, systematic errors in the shear measurement method must be unambiguously identified and corrected for. Previous work of this series has demonstrated that cosmic shears can be measured accurately in Fourier space in the presence of background noise and finite pixel size, without assumptions …
Anatomy of the AGN in NGC 5548. III. The high-energy view with NuSTAR and INTEGRAL
Harrison, F.; Kriss, G. A.; Bianchi, S. +15 more
We describe the analysis of the seven broad-band X-ray continuum observations of the archetypal Seyfert 1 galaxy NGC 5548 that were obtained with XMM-Newton or Chandra, simultaneously with high-energy (>10 keV) observations with NuSTAR and INTEGRAL. These data were obtained as part of a multiwavelength campaign undertaken from the summer of 201…
Multi-wavelength Observations of 3FGL J2039.6-5618: A Candidate Redback Millisecond Pulsar
Greiner, J.; Belfiore, A.; Marelli, M. +8 more
We present multi-wavelength observations of the unassociated γ-ray source 3FGL J2039.6-5618 detected by the Fermi Large Area Telescope. The source γ-ray properties suggest that it is a pulsar, most likely a millisecond pulsar, for which neither radio nor γ-ray pulsations have been detected. We observed 3FGL J2039.6-5618 with XMM-Newton and discove…