Search Publications
Initiation of Coronal Mass Ejections in a Global Evolution Model
Yeates, A. R.; Mackay, D. H.
Loss of equilibrium of magnetic flux ropes is a leading candidate for the origin of solar coronal mass ejections (CMEs). The aim of this paper is to explore to what extent this mechanism can account for the initiation of CMEs in the global context. A simplified MHD model for the global coronal magnetic field evolution in response to flux emergence…
The Size-Star Formation Relation of Massive Galaxies at 1.5 < z < 2.5
Wuyts, S.; Förster Schreiber, N. M.; Toft, S. +4 more
We study the relation between size and star formation activity in a complete sample of 225 massive (M * > 5 × 1010 M sun) galaxies at 1.5 < z < 2.5, selected from the FIREWORKS UV-IR catalog of the CDFS. Based on stellar population synthesis model fits to the observed rest-frame UV-NIR spectral energy dist…
Successive Solar Flares and Coronal Mass Ejections on 2005 September 13 from NOAA AR 10808
Liu, Chang; Wang, Haimin; Deng, Na +3 more
We present a multiwavelength study of the 2005 September 13 eruption from NOAA AR 10808 that produced total four flares and two fast coronal mass ejections (CMEs) within ~1.5 hr. Our primary attention is paid to the fact that these eruptions occurred in close succession in time, and that all of them were located along an S-shaped magnetic polarity…
Coronal Mass Ejection Induced Outflows Observed with Hinode/EIS
Ding, M. D.; Chen, P. F.; Jin, M. +2 more
We investigate the outflows associated with two halo coronal mass ejections (CMEs) that occurred on 2006 December 13 and 14 in NOAA 10930, using the Hinode/EIS observations. Each CME was accompanied by an EIT wave and coronal dimmings. Dopplergrams in the dimming regions are obtained from the spectra of seven EIS lines. The results show that stron…
Structure of the Accretion Flow in Broad-Line Radio Galaxies: The Case of 3C 390.3
Tavecchio, F.; Reeves, J. N.; Braito, V. +8 more
We present XMM-Newton and Suzaku observations of the broad-line radio galaxy 3C 390.3 acquired in 2004 October and 2006 December, respectively. An archival Swift BAT spectrum from the 9 month survey is also analyzed, as well as an optical spectrum simultaneous to XMM-Newton. At soft X-rays, no absorption features are detected in the Reflection Gra…
A Comprehensive X-Ray Spectral Analysis of the Seyfert 1.5 NGC 3227
Smith, R.; Vaughan, S.; Tombesi, F. +5 more
We present results of a 100 ks XMM-Newton observation of the Seyfert 1.5 AGN NGC 3227. Our best-fit broadband model to the European Photon Imaging Camera (EPIC)-pn spectrum consists of a moderately flat (photon index of 1.57) hard X-ray power law absorbed by cold gas with a column density of 3 × 1021 cm2, plus a strong soft e…
The Complete Initial Mass Function Down to the Subsolar Regime in the Large Magellanic Cloud with Hubble Space Telescope ACS Observations
Henning, Thomas; Da Rio, Nicola; Gouliermis, Dimitrios A.
In this photometric study of the stellar association LH 95 in the Large Magellanic Cloud (LMC) we focus on the pre-main-sequence (PMS) population in order to construct, for the first time, the subsolar initial mass function (IMF) in the LMC. The basis for this investigation consists of the deepest photometry ever performed in the LMC with the Adva…
Rapid Changes of Electron Acceleration Characteristics at the End of the Impulsive Phase of an X-class Solar Flare
Milligan, Ryan O.; Warmuth, Alexander; Holman, Gordon D. +3 more
We present a detailed spectral analysis of the X1.3 flare of 2005 January 19 using hard X-ray (HXR) spectra obtained with RHESSI. This flare exhibits HXR pulses during the impulsive phase, with a particularly pronounced peak at the end of the impulsive phase. This peak is associated with HXR emission up to high energies (>300 keV) but does not …
Solar Activity Phases and Intermediate-Degree Mode Frequencies
Hill, F.; Tripathy, S. C.; Jain, Kiran
We analyze intermediate-degree p-mode eigenfrequencies measured by Global Oscillation Network Group and Michelson Doppler Imager/Solar and Heliospheric Observatory over a solar cycle to study the source of their variability. We carry out a correlation analysis between the change in frequencies and several measures of the Sun's magnetic activity th…
Sunspot Rotation, Flare Energetics, and Flux Rope Helicity: The Eruptive Flare on 2005 May 13
Qiu, Jiong; Longcope, Dana W.; Kazachenko, Maria D. +3 more
We use the Michelson Doppler Imager and TRACE observations of photospheric magnetic and velocity fields in NOAA 10759 to build a three-dimensional coronal magnetic field model. The most dramatic feature of this active region is the 34° rotation of its leading polarity sunspot over 40 hr. We describe a method for including such rotation in the fram…