Search Publications
High Energy Spectral Evolution of V404 Cygni during the 2015 June Outburst as Observed by INTEGRAL
Ubertini, Pietro; Bazzano, Angela; Jourdain, Elisabeth +3 more
The black hole binary GS 2023+338 exhibited an unprecedently bright outburst in 2015 June. On 2015 June 17, the high energy instruments on board INTEGRAL detected an extremely variable emission during both bright and low luminosity phases, with dramatic variations of the hardness ratio on timescales of approximately seconds. The analysis of the IB…
An Off-nucleus Nonstellar Black Hole in the Seyfert Galaxy NGC 5252
Ho, Luis C.; Kim, Minjin; Bianchi, Stefano +6 more
We report the discovery of an ultraluminous X-ray source (ULX; CXO J133815.6+043255) in NGC 5252. This ULX is an off-nuclear point source, which is 22″ away from the center of NGC 5252, and has an X-ray luminosity of 1.5 × 1040 erg s-1. It is one of the rare examples of a ULX, which exhibits clear counterparts in radio, optic…
Responsibility of a Filament Eruption for the Initiation of a Flare, CME, and Blast Wave, and its Possible Transformation into a Bow Shock
Grechnev, V. V.; Chertok, I. M.; Kochanov, A. A. +3 more
Multi-instrument observations of two filament eruptions on 24 February and 11 May 2011 suggest the following updated scenario for eruptive flare, coronal mass ejection (CME), and shock wave evolution. An initial destabilization of a filament results in stretching out of the magnetic threads belonging to its body that are rooted in the photosphere …
Objective Image-Quality Assessment for High-Resolution Photospheric Images by Median Filter-Gradient Similarity
Cao, Wenda; Ji, Kaifan; Wang, Feng +6 more
All next-generation ground-based and space-based solar telescopes require a good quality-assessment metric to evaluate their imaging performance. In this paper, a new image quality metric, the median filter-gradient similarity (MFGS) is proposed for photospheric images. MFGS is a no-reference/blind objective image-quality metric (IQM) by a measure…
A method to derive maps of ionospheric conductances, currents, and convection from the Swarm multisatellite mission
Escoubet, C. P.; Kauristie, K.; Amm, O. +7 more
The European Space Agency (ESA) Swarm spacecraft mission is the first multisatellite ionospheric mission with two low-orbiting spacecraft that are flying in parallel at a distance of ~100-140 km, thus allowing derivation of spatial gradients of ionospheric parameters not only along the orbits but also in the direction perpendicular to them. A thir…
Self-consistent Castaing Distribution of Solar Wind Turbulent Fluctuations
Perri, S.; Carbone, V.; Sorriso-Valvo, L. +2 more
The intermittent behavior of solar wind turbulent fluctuations has often been investigated through the modeling of their probability distribution functions (PDFs). Among others, the Castaing model has successfully been used in the past. In this paper, the energy dissipation field of solar wind turbulence has been studied for fast, slow, and polar …
Can we trace very cold dust from its emission alone?
Juvela, M.; Pagani, L.; Pelkonen, V. -M. +2 more
Context. Dust is a good tracer of cold dark clouds but its column density is difficult to quantify.
Aims: We want to check whether the far-infrared and submillimeter high-resolution data from Herschel PACS and SPIRE and cameras combined with ground-based telescope bolometers allow us to retrieve the whole dust content of cold dark clouds.
Suzaku monitoring of the Wolf-Rayet binary WR 140 around periastron passage: An approach for quantifying the wind parameters
Hamaguchi, Kenji; Sugawara, Yasuharu; Maeda, Yoshitomo +7 more
Suzaku observations of the Wolf-Rayet (W-R) binary WR 140 (WC7pd+O5.5fc) were made at four different times around periastron passage in 2009 January. The spectra changed in shape and flux with the phase. As periastron approached, the column density of the low-energy absorption increased, which indicates that the emission from the wind-wind collisi…
A Likely Millisecond Pulsar Binary Counterpart for Fermi Source 2FGL J2039.6-5620
Romani, Roger W.
We have identified an optical/X-ray binary with an orbital period of Pb = 5.47 hr as the likely counterpart of the Fermi source 2FGL J2039.6-5620. GROND, SOAR, and DES observations provide an accurate orbital period and allow us to compare to the light curve of an archival XMM exposure. Like many short-period optical/X-ray binaries asso…
Dynamics of On-disk Plumes as Observed with the Interface Region Imaging Spectrograph, the Atmospheric Imaging Assembly, and the Helioseismic and Magnetic Imager
Krishna Prasad, S.; Pant, Vaibhav; Dolla, Laurent +3 more
We examine the role of small-scale transients in the formation and evolution of solar coronal plumes. We study the dynamics of plume footpoints seen in the vicinity of a coronal hole using the Atmospheric Imaging Assembly (AIA) images, the Helioseismic and Magnetic Imager magnetogram on board the Solar Dynamics Observatory and spectroscopic data f…