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A New Approach to the Study of Stellar Populations in Early-Type Galaxies: K-Band Spectral Indices and an Application to the Fornax Cluster
Kuntschner, Harald; Lyubenova, Mariya; Silva, David R.
The strong spectral features near 2.2 µm in early-type galaxies remain relatively unexplored. Yet, they open a tightly focused window on the coolest giant stars in these galaxies—a window that can be used to explore both age and metallicity effects. Here, new measurements of K-band spectral features are presented for 11 early-type galaxies i…
Geological context of water-altered minerals in Valles Marineris, Mars
Hynek, Brian M.; Chojnacki, Matthew
Greater than 15,000 km2 of the layered deposits within Valles Marineris are associated with water-altered minerals, yet their origin and history of alteration remain a mystery. There are numerous competing hypotheses for the formation of the interior layered deposits including aeolian, lacustrine, and volcanic. Recent orbiter spectrosco…
The relationship between EUV dimming and coronal mass ejections. I. Statistical study and probability model
Harrison, R. A.; Brown, D. S.; Bewsher, D.
Aims:There have been many studies of extreme-ultraviolet (EUV) dimming in association with coronal mass ejection (CME) onsets. However, there has never been a thorough statistical study of this association, covering appropriate temperature ranges. Thus, we make use of a large campaign database utilising the Coronal Diagnostic Spectrometer (CDS) an…
First results from the Cassini radio occultations of the Titan ionosphere
French, Richard G.; Flasar, F. Michael; Marouf, Essam A. +10 more
The first four sets of radio occultations of the Titan's ionosphere were obtained by the Cassini spacecraft between March 2006 and May 2007. These occultations occurred at middle and high latitudes, at solar zenith angles from about 86° to 96°. The main ionospheric peak was seen, as expected from modeling and previous observations, near 1200 km, w…
Multifractal Properties of Evolving Active Regions
Maguire, K.; Gallagher, P. T.; Young, C. A. +5 more
Magnetohydrodynamic turbulence is thought to be responsible for producing complex, multiscale magnetic field distributions in solar active regions. Here we explore the multiscale properties of a number of evolving active regions using magnetograms from the Michelson Doppler Imager (MDI) on the Solar and Heliospheric Observatory (SOHO). The multifr…
ENA periodicities at Saturn
Krimigis, S. M.; Mitchell, D. G.; Paranicas, C. +2 more
The Magnetospheric Imaging Instrument (MIMI) on the Cassini spacecraft has observed energetic neutral atoms (ENA) at Saturn for three years from 2004 to 2007. The 20-50 keV hydrogen and 64-144 keV oxygen neutrals were examined for periodic behavior by projecting their images onto a plane perpendicular to Saturn's equatorial plane and summing the e…
The Globular Cluster System of M60 (NGC 4649). II. Kinematics of the Globular Cluster System
Rey, Soo-Chang; Lee, Myung Gyoon; Hwang, Ho Seong +7 more
We present a kinematic analysis of the globular cluster (GC) system in the giant elliptical galaxy (gE) M60 in the Virgo Cluster, using a photometric and spectroscopic database of 121 GCs (83 blue and 38 red GCs). We have found that the M60 GC system shows a significant overall rotation. The rotation amplitude of the blue GCs is slightly smaller t…
The Variation of Relative Magnetic Helicity around Major Flares
Yang, Guo; Jing, Ju; Wang, Haimin +5 more
We have investigated the variation of magnetic helicity over a span of several days around the times of 11 X-class flares which occurred in seven active regions (NOAA 9672, 10030, 10314, 10486, 10564, 10696, and 10720) using the magnetograms taken by the Michelson Doppler Imager (MDI) on board the Solar and Heliospheric Observatory (SOHO). As a ma…
Suzaku Observations of AWM 7 Cluster of Galaxies: Temperatures, Abundances, and Bulk Motions
Ishida, Manabu; Sato, Kosuke; Ohashi, Takaya +4 more
We carried out 3 observations of the cluster of galaxies AWM 7, for the central region and 20'-east and 20'-west offset regions, with Suzaku. Temperature and abundance profiles were measured out to 27' simeq 570 h70-1kpc, which corresponded to ∼0.35r180. The temperature of the intra-cluster medium (ICM) slightly de…
a New View of the Super Star Clusters in the Low-Metallicity Galaxy SBS 0335-052
Hunt, Leslie K.; Johnson, Kelsey E.; Reines, Amy E.
We present a study of the individual super star clusters (SSCs) in the low-metallicity galaxy SBS 0335-052 using new near-infrared (near-IR) and archival optical Hubble Space Telescope observations. The physical properties of the SSCs are derived from fitting model spectral energy distributions (SEDs) to the optical photometry, as well as from the…