Search Publications
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…
Absolute magnitude calibration for red clump stars
Bilir, S.; Karaali, S.; Yaz Gökçe, E.
We combined the (Ks, J‑Ks) data in Laney et al. (Mon. Not. R. Astron. Soc. 419:1637, 2012) with the V apparent magnitudes and trigonometric parallaxes taken from the Hipparcos catalogue and used them to fit the
Model of outgrowths in the spiral galaxies NGC 4921 and NGC 7049 and the origin of spiral arms
Carlqvist, Per
NGC 4921 and 7049 are two spiral galaxies presenting narrow, distinct dust features. A detailed study of the morphology of those features has been carried out using Hubble Space Telescope archival images. NGC 4921 shows a few but well-defined dust arms midway to its centre while NGC 7049 displays many more dusty features, mainly collected within a…
Similarities and differences in the spectral behavior of W Ser and UX Mon in the ultraviolet
Sanad, M. R.; Bobrowsky, M.
We present ultraviolet spectra of two eclipsing interacting binary systems, W Ser and UX Mon, with good coverage over the 14.16-day and 5.9-day orbital periods, respectively, using observations taken by the International Ultraviolet Explorer (IUE) during the period between 1978–1993 and 1981–1991. Two profiles of W Ser and UX Mon showing variation…
Evidences to the pulse like origin of double spicules based on Hinode/SOT observations
Ebadi, H.
We analyze the time series of Hα line obtained from Hinode/SOT on the solar limb. The wavelet analysis shows that there are nice correlations between dynamical properties of the two parts of a double spicule. The dominant periods for height variations are estimated ∼90 and ∼180 s. The length of two parts of the spicule oscillates with the period o…
New face in the spectral behavior of Capella in the UV
Sanad, M. R.
We present low and high resolution ultraviolet spectra of the Capella spectroscopic binary system from the observations taken by the International Ultraviolet Explorer (IUE) during the period between 1978–1990 and 1978–1995. Thirteen profile of Capella showing variations of line fluxes at different orbital phases are presented. This paper focuses …