Search Publications
The local ISM in three dimensions: kinematics, morphology and physical properties
Redfield, Seth; Linsky, Jeffrey L.
We summarize the results of our long-term program to study the kinematics, morphology, and physical properties of warm partially ionized interstellar gas located within 100 pc of the Sun. Using the Space Telescope Imaging Spectrograph (STIS) and other spectrographs on the Hubble Space Telescope (HST), we measure radial velocities of neutral and si…
Oscillations in solar jets observed with the SOT of Hinode: viscous effects during reconnection
Koutchmy, S.; Tavabi, E.
Transverse oscillatory motions and recurrence behavior in the chromospheric jets observed by Hinode/SOT are studied. A comparison is considered with the behavior that was noticed in coronal X-ray jets observed by Hinode/XRT. A jet like bundle observed at the limb in Ca II H line appears to show a magnetic topology that is similar to X-ray jets (i.…
On vortex motion in chromospheric network boundaries
Tavabi, E.
A large percent of spicules shows a surge-like behavior on the solar limb, supporting a multi-component model with twisted threads. The counterpart of limb spicules foot-points is investigated on the disk, and this re-examination indicates that the interpretation of transverse motion of off-limb spicules could directly be related to rotational mot…
A study of line widths and kinetic parameters of ions in the solar corona
Wu, D. J.; Zhao, G. Q.; Wang, C. B.
Solar extreme-ultraviolet (EUV) lines emitted by highly charged ions have been extensively studied to discuss the issue of coronal heating and solar wind acceleration. Based on observations of the polar corona by the SUMER/SOHO spectrometer, this paper investigates the relation between the line widths and kinetic parameters of ions. It is shown th…
The most compact bright radio-loud AGN—I. A new target sample selected for the space VLBI
Frey, Sándor; An, Tao; Wu, Xiaocong
We investigated the archival ground-based VLBI images of the extragalactic radio sources included in both the Wilkinson Microwave Anisotropy Probe (WMAP) and the Planck catalogues, and selected 49 bright and compact sources as potential targets for space Very Long Baseline Interferometry (VLBI) observations at mm wavelengths. These sources have a …
A search for periodicities from a ULX in the LINER galaxy NGC 4736
Balman, Solen; Akyuz, Aysun; Avdan, Hasan +1 more
We report our findings on a new quasi-periodic oscillation (QPO) and a long period from the ultraluminous X-ray source (ULX) X-2 in nearby galaxy NGC 4736 based on the Chandra and XMM-Newton archival data. To examine the timing properties, power density spectra of the source have been obtained using Fast Fourier Transform. Also the spectral parame…
Global spectral energy distributions of the Large Magellanic Cloud with interstellar dust
Chung, Eun Jung; Kim, Sungeun; Kwon, Eunjoo +3 more
The effects of dust on infrared emission vary among galaxies of different morphological types. We investigated integrated spectral energy distributions (SEDs) in infrared and submillimeter/millimeter emissions from the Large Magellanic Cloud (LMC) based on observations from the Herschel Space Observatory (HSO) and near- to mid-infrared observation…
Determination of coronal magnetic fields from 10 to 26R⊙ using the density compression ratios of CME-driven shocks
Moon, Y. -J.; Shanmugaraju, A.; Suresh, K.
Recently, the estimation of coronal magnetic field using new methods, such as standoff distance method or density compression ratio method has been reported. In the present work, we utilized the density compression ratio of CME-driven shocks for 10 events at 29 different locations in the upper solar corona (10–26R⊙) and determined the c…
Old stellar systems in UV: resolved and integrated properties
Dalessandro, E.
The UV properties of old stellar populations have been subject of intense scrutiny from the late sixties, when the UV-upturn in early type galaxies was first discovered. Because of their proximity and relative simplicity, Galactic globular clusters (GGCs) are ideal local templates to understand how the integrated UV light is driven by hot stellar …
Mid- and far-infrared variability of PV Cep
Larionov, V. M.; Arkharov, A. A.; Di Paola, A. +4 more
We present the collection of all the mid- and far-IR observations (λ=3–170 µm) of the young eruptive variable PV Cep available so far in the literature. These data allow us to confirm that flux variability is a prominent feature at mid-IR wavelength (λ=3–25 µm). Color-magnitude plots clearly indicate that the observed variability is no…