Science Archives Publication System

The heliospheric current sheet

DOI: 10.1029/2000JA000120 Bibcode: 2001JGR...10615819S

Smith, Edward J.

The heliospheric current sheet (HCS) is the boundary between open oppositely directed magnetic field lines which commonly originate as the outward extension of the solar magnetic dipole. The dipole tilt, the rotation of the Sun, and the outward propagation of the solar wind cause peaks and valleys in the current sheet which spiral outward. The HCS…

2001 • Journal of Geophysical Research

Ulysses 209

Isocam-Cvf 5-12 Micron Spectroscopy of Ultraluminous Infrared Galaxies

DOI: 10.1086/320543 Bibcode: 2001ApJ...552..527T

Lutz, D.; Genzel, R.; Sturm, E. +10 more

We present low-resolution mid-infrared (MIR) spectra of 16 ultraluminous infrared galaxies (ULIRGs) obtained with the circular variable filter (CVF) spectroscopy mode of ISOCAM on board the Infrared Space Observatory (ISO). Our sample completes previous ISO spectroscopy of ultra- and hyperluminous infrared galaxies toward higher luminosities. The …

2001 • The Astrophysical Journal

ISO 206

The Distribution of Thermal Pressures in the Interstellar Medium from a Survey of C I Fine-Structure Excitation

DOI: 10.1086/323326 Bibcode: 2001ApJS..137..297J

Tripp, Todd M.; Jenkins, Edward B.

We used the Space Telescope Imaging Spectrograph (STIS) with its smallest entrance aperture (0.03" wide slit) and highest resolution echelle gratings (E140H and E230H) to record the interstellar absorption features for 10 different multiplets of neutral carbon at a resolving power of λ/Δλ=200,000 in the UV spectra of 21 early-type stars. Our objec…

2001 • The Astrophysical Journal Supplement Series

IUE eHST 206

WFPC2 Images of the Central Regions of Early-Type Galaxies. I. The Data

DOI: 10.1086/320370 Bibcode: 2001AJ....121.2431R

van den Bosch, Frank C.; Rest, Armin; Ford, Holland C. +5 more

We present high-resolution R-band images of the central regions of 67 early-type galaxies obtained with the Wide Field and Planetary Camera 2 (WFPC2) aboard the Hubble Space Telescope (HST). This homogeneously selected sample roughly doubles the number of early-type galaxies that have now been imaged at HST resolution and complements similar data …

2001 • The Astronomical Journal

eHST 206

A Search for L Dwarf Binary Systems

DOI: 10.1086/318023 Bibcode: 2001AJ....121..489R

Kirkpatrick, J. Davy; Gizis, John E.; Reid, I. Neill +1 more

We present analysis of Hubble Space Telescope (HST) planetary camera images of 20 L dwarfs identified in the course of the Two Micron All Sky Survey. Four of the targets, 2MASSW J0746425+200032, 2MASSs J0850359+105716, 2MASSW J0920122+351742, and 2MASSW J1146345+223053, have faint red companions at separations between 0.07" and 0.29" (1.6-7.6 AU).…

2001 • The Astronomical Journal

eHST 202

The deuterium abundance in Jupiter and Saturn from ISO-SWS observations

DOI: 10.1051/0004-6361:20010259 Bibcode: 2001A&A...370..610L

Lellouch, E.; Encrenaz, T.; de Graauw, T. +3 more

Observations with the Short Wavelength Spectrometer (SWS) onboard the Infrared Space Observatory (ISO) are used to determine the D/H ratio in Jupiter's and Saturn's atmospheres. The D/H ratio is measured independently in hydrogen (i.e. from the HD/H₂ ratio) and methane (from CH₃D/CH₄). Observations of the HD R(2) a…

2001 • Astronomy and Astrophysics

ISO 201

A New Measurement of the Primordial Abundance of Deuterium: Toward Convergence with the Baryon Density from the Cosmic Microwave Background?

DOI: 10.1086/322510 Bibcode: 2001ApJ...560...41P

Bowen, David V.; Pettini, Max

From the analysis of the near-UV spectrum of the quasar (QSO)2206-199, obtained with a long series of exposures with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope, we deduce a value D/H=(1.65+/-0.35)×10^-5 (1 σ error) for the abundance of deuterium in the z_abs=2.0762 damped Lyα system (DLA) along this …

2001 • The Astrophysical Journal

eHST 201

H₂ and CO Emission from Disks around T Tauri and Herbig Ae Pre-Main-Sequence Stars and from Debris Disks around Young Stars: Warm and Cold Circumstellar Gas

DOI: 10.1086/323361 Bibcode: 2001ApJ...561.1074T

Thi, W. F.; Natta, A.; van Dishoeck, E. F. +8 more

We present ISO Short-Wavelength Spectrometer observations of H₂ pure-rotational line emission from the disks around low- and intermediate-mass pre-main-sequence stars as well as from young stars thought to be surrounded by debris disks. The pre-main-sequence sources have been selected to be isolated from molecular clouds and to have cir…

2001 • The Astrophysical Journal

ISO 199

The Nuclear and Circumnuclear Stellar Population in Seyfert 2 Galaxies: Implications for the Starburst-Active Galactic Nucleus Connection

DOI: 10.1086/318295 Bibcode: 2001ApJ...546..845G

Heckman, Timothy; Leitherer, Claus; González Delgado, Rosa M.

We report the results of a spectroscopic investigation of a sample of 20 of the brightest type 2 Seyfert nuclei. Our goal is to search for the direct spectroscopic signature of massive stars and thereby probe the role of circumnuclear starbursts in the Seyfert phenomenon. The method used is based on the detection of the higher order Balmer lines a…

2001 • The Astrophysical Journal

eHST 198

Flash Mixing on the White Dwarf Cooling Curve: Understanding Hot Horizontal Branch Anomalies in NGC 2808

DOI: 10.1086/323862 Bibcode: 2001ApJ...562..368B

Brown, Thomas M.; Hubeny, Ivan; Sweigart, Allen V. +2 more

We present an ultraviolet color-magnitude diagram (CMD) spanning the hot horizontal branch (HB), blue straggler, and white dwarf populations of the globular cluster NGC 2808. These data were obtained with the far-UV and near-UV cameras on the Space Telescope Imaging Spectrograph (STIS). Although previous optical CMDs of NGC 2808 show a high-temper…

2001 • The Astrophysical Journal

eHST 196