Search Publications
The Connection of Solar Wind Parameters with Radio and UV Emission from Coronal Holes
Myagkova, I. N.; Prosovetsky, D. V.
This paper presents the results of a comparison between observations of coronal holes in UV (SOHO EIT) and radio emission (17, 5.7 GHz, 327 and 150.9 MHz, from NoRH, SSRT and Nançay radioheliographs), and solar wind parameters, from ACE spacecraft data over the period 12 March - 31 May 2007. The increase in the solar wind velocity up to ∼ 600 km s…
A Strong Emission Line near 24.8 Å in the X-Ray Binary System MAXI J0556-332: Gravitational Redshift or Unusual Donor?
Raymond, John C.; Miller, Jon M.; Reynolds, Mark T. +1 more
We report the discovery of a strong emission line near 24.8 Å (0.5 keV) in the newly discovered X-ray binary system MAXI J0556-332 with the reflection grating spectrometer (RGS) on board the XMM-Newton observatory. The X-ray light curve morphology during these observations is complex and shows occasional dipping behavior. Here we present time- and…
Dust Around Herbig AE/Be Stars
Suh, Kyung-Won
We model dust around Herbig Ae/Be stars using a radiative transfer model for multiple isothermal circumstellar dust shells to reproduce the multiple broad peaks in their spectral energy distributions (SEDs). Using the opacity functions for various types of dust grains at different temperatures, we calculate the radiative transfer model SEDs for mu…
Cluster energetic electron survey of the high-altitude cusp and adjacent regions
Fritz, T. A.; Walsh, B. M.
A statistical study of the energetic electron population (E > 37 keV) in the high-altitude cusp and surrounding regions is conducted with 7 years of data from the Cluster spacecraft. The progression of Cluster's orbit during this period allows for a wide range of latitude on the dayside magnetosphere to be surveyed. Locations of the spacecraft …
CSO Bolocam 1.1 mm Continuum Mapping of the Braid Nebula Star Formation Region in Cygnus OB7
Pyo, Tae-Soo; Smith, Michael D.; Aspin, Colin +9 more
We present a 1.1 mm map of the Braid Nebula star formation region in Cygnus OB7 taken using Bolocam on the Caltech Submillimeter Observatory. Within the 1 deg2 covered by the map, we have detected 55 cold dust clumps all of which are new detections. A number of these clumps are coincident with IRAS point sources although the majority ar…
Center-limb dependence of photospheric velocities in regions of emerging magnetic fields on the Sun
Khlystova, A.
Aims: We investigate the ratio of the vertical and horizontal velocities of the photospheric plasma flows in the region of emerging magnetic fields on the Sun.
Methods: We carried out a study of photospheric velocities during the first hours of the appearance of 83 active regions with magnetic flux more than 1021 Mx with data …
Observational Evidences for the Existence of 17.4 keV Decaying Degenerate Sterile Neutrinos Near the Galactic Center
Chan, M. H.; Chu, M. -C.
We show that the existence of a degenerate halo of sterile neutrinos with rest mass of 17.4 keV near the Galactic center (GC) can account for both the excess 8.7 keV emission observed by the Suzaku mission and the power needed (1040 erg s-1) to maintain the high temperature of the hot gas (8 keV) near the GC. The required dec…
A Morphological Study of UV-Bright Stars and Emission Nebulae in a Selection of Star Formation Regions in M31
Krienke, O. Karl; Hodge, Paul W.; Luciana, Bianchi
Using the data from the NOAO Local Group Survey, we have measured the Hα fluxes of 291 nebulae associated with 21 of the van den Bergh OB associations. We have combined these data together with six-color HST WFPC2 photometry, in order to identify the most UV-bright stars in the region. The simple purpose of this article is to explore the spatial r…
Time Variable Broad-line Emission in NGC 4203: Evidence for Stellar Contrails
Devereux, Nick
Dual epoch spectroscopy of the lenticular galaxy, NGC 4203, obtained with the Hubble Space Telescope has revealed that the double-peaked component of the broad Hα emission line is time variable, increasing by a factor of 2.2 in brightness between 1999 and 2010. Modeling the gas distribution responsible for the double-peaked profiles indicates that…
Open issues on the synthesis of evolved stellar populations at ultraviolet wavelengths
Chavez, Miguel; Bertone, Emanuele
In this paper we briefly review three topics that have motivated our (and others') investigations in recent years within the context of evolutionary population synthesis techniques. These are: The origin of the FUV up-turn in elliptical galaxies, the age-metallicity degeneracy, and the study of the mid-UV rest-frame spectra of distant red galaxies…