Science Archives Publication System

A new model of solar EUV irradiance variability: 1. Model formulation

DOI: 10.1029/2000JA000282 Bibcode: 2001JGR...10615745W

Mariska, J. T.; Warren, H. P.; Lean, J.

We present a new model of solar irradiance variability at extreme ultraviolet wavelengths (EUV, 50-1200 Å). In this model, quiet Sun, coronal hole, and active region intensities for optically thin emission lines are computed from emission measure distributions determined from spectrally and spatially resolved observations. For optically thick emis…

2001 • Journal of Geophysical Research

SOHO 56

Are There Blue, Massive E/S0 Galaxies at z<1? Kinematics of Blue Spheroidal Galaxy Candidates

DOI: 10.1086/322081 Bibcode: 2001AJ....122..750I

Gebhardt, Karl; Faber, S. M.; Willmer, Christopher N. A. +5 more

Several recent studies find that 10%-50% of morphologically selected field early-type galaxies at redshifts z<~1 have blue colors indicative of recent star formation. Such ``blue spheroids'' might be massive early-type galaxies with active star formation, perhaps induced by recent merger events. Alternatively, they could be starbursting, low-ma…

2001 • The Astronomical Journal

eHST 56

Cluster magnetic field observations in the magnetosheath: four-point measurements of mirror structures

DOI: 10.5194/angeo-19-1421-2001 Bibcode: 2001AnGeo..19.1421L

Balogh, A.; Horbury, T. S.; Lucek, E. A. +7 more

The Cluster spacecraft have returned the first simultaneous four-point measurements of the magnetosheath. We present an analysis of data recorded on 10 November 2000, when the four spacecrafts observed an interval of strong mirrorlike activity. Correlation analysis between spacecraft pairs is used to examine the scale size of the mirror structures…

2001 • Annales Geophysicae

Cluster 56

Observation of Polar Plumes at High Solar Altitudes

DOI: 10.1086/318221 Bibcode: 2001ApJ...546..569D

Plunkett, S. P.; Andrews, M. D.; DeForest, C. E.

Using the Large-Angle Spectrometric Coronagraph (LASCO) aboard the Solar and Heliospheric Observatory (SOHO) spacecraft, we have imaged polar plumes extending 30 R_solar from disk center in the image plane and ~45 R_solar in three-dimensional space, a factor of 2-3 farther than previous imaging measurements and well into the co…

2001 • The Astrophysical Journal

SOHO 56

Seeing Galaxies through Thick and Thin. III. Hubble Space Telescope Imaging of the Dust in Backlit Spiral Galaxies

DOI: 10.1086/319386 Bibcode: 2001AJ....121.1442K

White, Raymond E., III; Keel, William C.

We present analysis of Wide Field Planetary Camera 2 imaging of two spiral galaxies partially backlit by elliptical or S0 systems in the pairs AM 1316-241 and AM 0500-620, as well as the (probably spiral) foreground system in NGC 1275. Images in B and I are used to determine the reddening curve of dust in these systems. The foreground spiral compo…

2001 • The Astronomical Journal

eHST 56

Optical spectroscopy and photometry of the neutron star RX J1856.5-3754

DOI: 10.1051/0004-6361:20011272 Bibcode: 2001A&A...378..986V

Kulkarni, S. R.; van Kerkwijk, M. H.

We present spectroscopy and imaging with the Very Large Telescope (VLT) of the neutron star RX J1856.5-3754. Little is known about the nature of this source other than that it is a nearby hot neutron star. Our VLT spectrum does not show any strong emission or absorption features. With considerable care to photometric calibration…

2001 • Astronomy and Astrophysics

eHST 56

Late AGB Magnetic Cycles: Magnetohydrodynamic Solutions for the Hubble Space Telescope Planetary Nebula Rings

DOI: 10.1086/323072 Bibcode: 2001ApJ...560..928G

García-Segura, Guillermo; López, José Alberto; Franco, José

The Hubble Space Telescope (HST) has revealed the existence of multiple, regularly spaced, and faint concentric shells around some planetary nebulae. Here we present two- (and a half) dimensional magnetohydrodynamic numerical simulations of the effects of a solar-like magnetic cycle, with periodic polarity inversions, in the slow wind of an asympt…

2001 • The Astrophysical Journal

eHST 56

High-resolution spectroscopy of the low-mass X-ray binary EXO 0748-67

DOI: 10.1051/0004-6361:20000053 Bibcode: 2001A&A...365L.277C

Kahn, S. M.; Brinkman, A. C.; den Herder, J. W. +2 more

We present initial results from observations of the low-mass X-ray binary EXO 0748-67 with the Reflection Grating Spectrometer on board the XMM-Newton Observatory. The spectra exhibit discrete structure due to absorption and emission from ionized neon, oxygen, and nitrogen. We use the quantitative constraints imposed by the spec…

2001 • Astronomy and Astrophysics

XMM-Newton 55

Chandra X-Ray Observatory Observation of the High-Redshift Cluster MS 1054-0321

DOI: 10.1086/323435 Bibcode: 2001ApJ...562..124J

Donahue, Megan; Garmire, Gordon P.; Canizares, Claude R. +3 more

We observed MS 1054-0321, the highest redshift cluster of galaxies in the Einstein Medium Sensitivity Survey (EMSS), with the Chandra ACIS-S detector. We find the X-ray temperature of the cluster to be 10.4^+1.7_-1.5 keV, lower than, but statistically consistent with, the temperature inferred previously. This temperature agrees…

2001 • The Astrophysical Journal

eHST 55

The Nuclear Dynamics of M32. I. Data and Stellar Kinematics

DOI: 10.1086/319781 Bibcode: 2001ApJ...550..668J

Nelson, C.; Bender, R.; Joseph, C. L. +14 more

We have obtained optical long-slit spectroscopy of the nucleus of M32 using the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope. The stellar rotation velocity and velocity dispersion, as well as the full line-of-sight velocity distribution (LOSVD), were determined as a function of position along the slit using two independen…

2001 • The Astrophysical Journal

eHST 55