Search Publications
Intrinsic Shape of Star-forming BzK Galaxies at z ~ 2 in GOODS-N
Kajisawa, Masaru; Ohta, Kouji; Yabe, Kiyoto +2 more
We study the structure of star-forming galaxies at z ~ 2 in a Great Observatories Origins Deep Survey North field selected as star-forming BzK (sBzK) galaxies down to K AB < 24.0 mag. Among 1029 sBzK galaxies, 551 galaxies (54%) show a single component in the Advanced Camera for Survey (ACS)/F850LP image obtained with the Hubble Spac…
XMM-Newton Observations Reveal Very High X-ray Luminosity from the Carbon-rich Wolf-Rayet Star WR 48a
Skinner, Stephen L.; Zhekov, Svetozar A.; Gagné, Marc
We present XMM-Newton observations of the dusty Wolf-Rayet (W-R) star WR 48a. This is the first detection of this object in X-rays. The XMM-Newton EPIC spectra are heavily absorbed and the presence of numerous strong emission lines indicates a thermal origin of the WR 48a X-ray emission, with dominant temperature components at kT cool ≈…
Short-term Evolution of Coronal Hole Boundaries
Gallagher, Peter T.; Krista, Larisza D.; Bloomfield, D. Shaun
The interaction of open and closed field lines at coronal hole (CH) boundaries is widely accepted to be due to interchange magnetic reconnection. To date, it is unclear how the boundaries vary on short timescales and at what velocity this occurs. Here, we describe an automated boundary tracking method used to determine CH boundary displacements on…
Differential Rotation of the Ultraviolet Corona at Solar Maximum
Giordano, Silvio; Mancuso, Salvatore
Synoptic observations of the O VI 1032 Å spectral line from the UltraViolet Coronagraph Spectrometer (UVCS) telescope on board the Solar and Heliospheric Observatory (SOHO) have been analyzed in order to establish the rotational characteristics of the solar corona in the time interval from 1999 March 18 to 2002 December 31, corresponding to the ma…
Solar Wind and Coronal Bright Points inside Coronal Holes
Karachik, Nina V.; Pevtsov, Alexei A.
Observations of 108 coronal holes (CHs) from 1998-2008 were used to investigate the correlation between fast solar wind (SW) and several parameters of CHs. Our main goal was to establish the association between coronal bright points (CBPs; as sites of magnetic reconnection) and fast SW. Using in situ measurements of the SW, we have connected strea…
The 5 hr Pulse Period and Broadband Spectrum of the Symbiotic X-Ray Binary 3A 1954+319
Fürst, Felix; Grinberg, Victoria; Pottschmidt, Katja +7 more
We present an analysis of the highly variable accreting X-ray pulsar 3A 1954+319 using 2005-2009 monitoring data obtained with INTEGRAL and Swift. This considerably extends the pulse period history and covers flaring episodes in 2005 and 2008. In 2006 the source was identified as one of only a few known symbiotic X-ray binaries (SyXBs), i.e., syst…
Spitzer Imaging of Herschel-atlas Gravitationally Lensed Submillimeter Sources
Smail, I.; Rodighiero, G.; Valtchanov, I. +49 more
We present physical properties of two submillimeter selected gravitationally lensed sources, identified in the Herschel Astrophysical Terahertz Large Area Survey. These submillimeter galaxies (SMGs) have flux densities >100 mJy at 500 µm, but are not visible in existing optical imaging. We fit light profiles to each component of the lensi…
Measuring Gravitational Lensing Flexion in A1689 Using an Analytic Image Model
Schechter, Paul L.; Cain, Benjamin; Bautz, M. W.
Measuring dark matter substructure within galaxy cluster halos is a fundamental probe of the ΛCDM model of structure formation. Gravitational lensing is a technique for measuring the total mass distribution which is independent of the nature of the gravitating matter, making it a vital tool for studying these dark-matter-dominated objects. We pres…
Solar Cycle Variations in the Elemental Abundance of Helium and Fractionation of Iron in the Fast Solar Wind: Indicators of an Evolving Energetic Release of Mass from the Lower Solar Atmosphere
McIntosh, Scott W.; Kasper, Justin C.; Stevens, Michael L. +2 more
We present and discuss the strong correspondence between evolution of the emission length scale in the lower transition region and in situ measurements of the fast solar wind composition during the most recent solar minimum. We combine recent analyses demonstrating the variance in the (supergranular) network emission length scale measured by the S…
Radio Observations of the Solar Corona During an Eclipse
Ramesh, R.; Kathiravan, C.; Barve, Indrajit V. +1 more
We carried out radio observations of the solar corona at 170 MHz during the eclipse of 2008 August 1, from the Gauribidanur observatory located about 100 km north of Bangalore in India. The results indicate the presence of a discrete radio source of very small angular dimension (≈15'') in the corona from where the observed radiation originated.