Search Publications
Dust-scattering Halo and Giant Hard X-Ray Flare from the Supergiant Fast X-Ray Transient IGR J16479-4514 Investigated with XMM-Newton and INTEGRAL
Tiengo, A.; Sidoli, L.; Bird, A. J. +1 more
We report results from the analysis of XMM-Newton and INTEGRAL data of IGR J16479-4514. The unpublished XMM-Newton observation, performed in 2012, occurred during the source eclipse. No pointlike X-ray emission was detected from the source; conversely, extended X-ray emission was clearly detected up to a size distance compatible with a dust-scatte…
Excitation Sources of Oscillations in Solar Coronal Loops: A Multi-wavelength Analysis
Conde C., Sandra M.; Jain, Rekha; Jatenco-Pereira, Vera
An investigation into the excitation sources of oscillations detected in a coronal loop structure is carried out using the images obtained with Interface Region Imaging Spectrometer (IRIS) and the Atmospheric Imaging Assembly (AIA) instrument on board the Solar Dynamics Observatory (SDO). A loop structure in the active region AR 11967 on 2014 Janu…
Unveiling the Hierarchical Structure of Open Star Clusters: The Perseus Double Cluster
Diaferio, Antonaldo; Li, Lu; Shao, Zhengyi +1 more
We introduce a new kinematic method to investigate the structure of open star clusters. We adopt a hierarchical clustering algorithm that uses the celestial coordinates and the proper motions of the stars in the field of view of the cluster to estimate a proxy of the pairwise binding energy of the stars and arrange them in a binary tree. The clust…
A Solar Magnetic-fan Flaring Arch Heated by Nonthermal Particles and Hot Plasma from an X-Ray Jet Eruption
Lee, Kyoung-Sun; Hara, Hirohisa; Panesar, Navdeep K. +10 more
We have investigated an M1.3 limb flare, which develops as a magnetic loop/arch that fans out from an X-ray jet. Using Hinode/EIS, we found that the temperature increases with height to a value of over 107 K at the loop top during the flare. The measured Doppler velocity (redshifts of 100-500 km s-1) and the nonthermal veloci…
A Herschel Mapping of [{C}{II}],[{O}{I}], and [{O}{III}] Lines from the Circumnuclear Region of M31
Smith, Matthew W. L.; Gao, Yu; Li, Zhiyuan +1 more
The circumnuclear region of M31, consisting of multiphase interstellar media, provides a close-up view of the interaction of the central supermassive black hole and surrounding materials. Far-infrared (FIR) fine-structure lines and their flux ratios can be used as diagnostics of physical properties of the neutral gas in this region. Here we presen…
Recurrent Solar Energetic Particle Flux Enhancements Observed near Earth and Mars
Bhardwaj, Anil; Lee, Christina O.; Thampi, Smitha V. +3 more
The period 2016 August 1 to November 15 was characterized by the presence of corotating interaction regions (CIRs) and a few weak coronal mass ejections (CMEs) in the heliosphere. In this study we show recurrent energetic electron and proton enhancements observed near Earth (1 au) and Mars (1.43-1.38 au) during this period. The observations near E…
The Coronal Mass Ejection Visibility Function of Modern Coronagraphs
St. Cyr, O. C.; Vourlidas, Angelos; Xie, H. +1 more
We analyze the detection capability of coronal mass ejections (CMEs) for all currently operating coronagraphs in space. We define as CMEs events that propagate beyond 10 solar radii with morphologies broadly consistent with a magnetic flux-rope presence. We take advantage of multi-viewpoint observations over five month-long intervals, correspondin…
Tests of AGN Feedback Kernels in Simulated Galaxy Clusters
Voit, G. Mark; Glines, Forrest W.; O'Shea, Brian W.
In cool-core galaxy clusters with central cooling times much shorter than a Hubble time, condensation of the ambient central gas is regulated by a heating mechanism, probably an active galactic nucleus. Previous analytical work has suggested that certain radial distributions of heat input may result in convergence to a quasi-steady global state th…
Spectral Modeling of Charge Exchange in the Central Region of M51
Zhang, Shuinai; Ji, Li; Yang, Hang
Charge exchange (CX) emission reveals the significant interaction between neutral and ionized interstellar medium components of the dense, multiphase, circumnuclear region of a galaxy. We use a model including a thermal and CX components to describe the high-resolution XMM-Newton/RGS spectrum of the diffuse emission in the central region of M51. R…
Serial Flaring in an Active Region: Exploring Why Only One Flare Is Eruptive
Harra, Louise K.; Matthews, Sarah A.; Kusano, Kanya +2 more
Over a four hour period between 2014 June 12-13 a series of three flares were observed within AR 12087. This sequence of flares started with a non-eruptive M-class flare, followed by a non-eruptive C-class flare, and finally ended with a second C-class flare that had an associated filament eruption. In this paper we combine spectroscopic analysis …