Search Publications
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…
Frequency and properties of bars in cluster and field galaxies at intermediate redshifts
Jogee, S.; Pelló, R.; White, S. D. M. +15 more
We present a study of large-scale bars in field and cluster environments out to redshifts of ~0.8 using a final sample of 945 moderately inclined disk galaxies drawn from the EDisCS project. We characterize bars and their host galaxies and look for relations between the presence of a bar and the properties of the underlying disk. We investigate wh…
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…
Venus Express mission
Witasse, O.; Svedhem, H.; Titov, D. +1 more
Venus Express is well and healthy and has now been providing exciting new data from Venus, our nearby twin planet, for over 2 years. Many of the new results are presented and discussed in the subsequent papers in this special section. The overall scientific objective of Venus Express is to carry out a detailed study of the atmosphere of Venus, inc…
Study of CME Propagation in the Inner Heliosphere: SOHO LASCO, SMEI and STEREO HI Observations of the January 2007 Events
Webb, D. F.; Harrison, R. A.; Odstrcil, D. +8 more
We are investigating the geometric and kinematic characteristics of interplanetary coronal mass ejections (ICMEs) using data obtained by the LASCO coronagraphs, the Solar Mass Ejection Imager (SMEI), and the SECCHI imaging experiments on the STEREO spacecraft. The early evolution of CMEs can be tracked by the LASCO C2 and C3 and SECCHI COR1 and CO…
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…
PMAS optical integral field spectroscopy of luminous infrared galaxies. I. The atlas
Colina, L.; Monreal-Ibero, A.; Arribas, S. +4 more
Context: Luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) are key cosmological classes since they account for most of the co-moving star formation rate density at z ∼ 1-2. It is then important to have detailed studies of local samples of their counterparts for understanding the internal and dynamical processes taking place at high-z…
Temporal comparison of nonthermal flare emission and magnetic-flux change rates
Veronig, A. M.; Vršnak, B.; Miklenic, C. H.
Context: To understand the mechanisms that trigger solar flares, we require models describing and quantifying observable responses to the original energy release process, since the coronal energy release site itself cannot be resolved with current technical equipment. Testing the usefulness of a particular model requires the comparison of its pred…