Search Publications
Ultraviolet Spectroscopic Study of BY Circini and V 1425 Aquilae from IUE Satellite
Sanad, M. R.
We present the ultraviolet spectra of two classical novae, BY Circini 1995 and V1425 Aquilae 1995, using observations obtained with the International Ultraviolet Explorer (IUE). The outflow velocity of the ionized ejecta was calculated to be 2100–2700 km s‑1 and 1600–1900 km s‑1 (FWHM) for BY Cir and V1425 Aql, respectively. …
Is Planck data consistent with primordial deuterium measurements?
Melchiorri, Alessandro; Salvati, Laura; Said, Najla
The recent measurements of the cosmic microwave background anisotropies provided by the Planck satellite experiment have significantly improved the constraints on several cosmological parameters. In this brief paper we point out a small but interesting tension present between recent values of the primordial deuterium measured from quasar absorptio…
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…
A multiwavelength analysis of the clumpy FIR-bright sources in M33
Wilson, C. D.; Foyle, K.; Natale, G. +1 more
We present a multiwavelength study of a sample of far-infrared (FIR) sources detected on the Herschel broad-band maps of the nearby galaxy M33. We perform source photometry on the FIR maps as well as mid-infrared (MIR), Hα, far-ultraviolet and integrated H I and CO line emission maps. By fitting MIR/FIR dust emission spectra, the source dust masse…
Herschel out-of-field stray-light characterization
Altieri, B.; Sanchez-Portal, M.; Pilbratt, G. L. +5 more
Out-of-field stray-light spots of the Herschel telescope optics relative to the PACS and SPIRE instrument apertures were modeled by ray tracing simulations with the Advanced Systems Analysis Program (ASAP, by Breault Research Organization) prior to launch. The predicted stray-light behaviour was verified by dedicated stray-light calibration observ…
The Dynamic Quasiperpendicular Shock: Cluster Discoveries
Bale, S. D.; Krasnoselskikh, V.; Walker, S. N. +9 more
The physics of collisionless shocks is a very broad topic which has been studied for more than five decades. However, there are a number of important issues which remain unresolved. The energy repartition amongst particle populations in quasiperpendicular shocks is a multi-scale process related to the spatial and temporal structure of the electrom…
Test for the zero mean hypothesis in cosmology
Ichiki, Kiyotomo
One working hypothesis on which analyses of cosmological data are based is the zero ensemble mean hypothesis, which is related to the statistical homogeneity of cosmological perturbations. This hypothesis, however, should be tested by observational data in the current era of precision cosmology. Herein, we test the hypothesis by analyzing recent, …
Time-Series Analysis of Supergranule Characteristics at Solar Minimum
Williams, Peter E.; Pesnell, W. Dean
Sixty days of Doppler images from the Solar and Heliospheric Observatory (SOHO) / Michelson Doppler Imager (MDI) investigation during the 1996 and 2008 solar minima have been analyzed to show that certain supergranule characteristics (size, size range, and horizontal velocity) exhibit fluctuations of three to five days. Cross-correlating parameter…
Variations in EUV Irradiance: Comparison between LYRA, ESP, and SWAP Integrated Flux
Poedts, Stefaan; Yalim, Mehmet Sarp
The Sun Watcher Using Active Pixel System Detector and Image Processing (SWAP) telescope and Large Yield Radiometer (LYRA) are the two Sun observation instruments on-board PROBA2. SWAP extreme ultraviolet images, if presented in terms of the integrated flux over solar disk, in general, correlate well with LYRA channel 2-4 (zirconium filter) and ch…
Spectral behavior of 44 (iota) Bootis and VW Cephei in the ultraviolet
Sanad, M. R.; Bobrowsky, M.
We present ultraviolet spectra of two W UMa-type binary systems, 44 (iota) Boo and VW Cep, with good coverage over their 0.268-day and 0.278-day periods, respectively, using observations obtained with the International Ultraviolet Explorer (IUE) during the period of 1978-1989 and 1978-1992. Three profiles of 44 (iota) Boo and VW Cep showing variat…