Science Archives Publication System

The Structure and Appearance of Protostellar Accretion Disks: Limits on Disk Flaring

DOI: 10.1086/304514 Bibcode: 1997ApJ...486..372B

Henning, Th.; Bell, K. R.; Cassen, P. M. +1 more

Vertical structure models are used to investigate the structure of protostellar, α-law, accretion disks. Conditions investigated cover a range of mass fluxes (10^-9 to 10^-5 M_⊙ yr^-1), viscous efficiencies (α = 10^-2 and 10^-4), and stellar masses (0.5-3 M_⊙). Analytic formulae…

1997 • The Astrophysical Journal

eHST 272

The nature of intermediate-redshift damped Lyα absorbers.

DOI: 10.48550/arXiv.astro-ph/9611031 Bibcode: 1997A&A...321..733L

Deharveng, J. M.; Bergeron, J.; Le Brun, V. +1 more

We present HST/WFPC2 high-spatial resolution images in the R and B bands of the close environment of the sightlines to seven quasars which spectra show either a damped Lyα absorption line, 21cm absorption, or a very strong MgII/FeII absorption system at intermediate redshifts (0.4<=z<=1). Objects down to about 0.3", or 2.0kpc at z=0.6 (H_0_=…

1997 • Astronomy and Astrophysics

eHST 271

A subsurface flow of material from the Sun's equator to its poles

DOI: 10.1038/36294 Bibcode: 1997Natur.390...52G

Scherrer, P. H.; Bogart, R. S.; Duvall, T. L. +1 more

Gas on the Sun's surface has been observed to flow away from the equator towards both poles. If the same flow persists to great depths, it could play an important dynamical role in the eleven-year sunspot cycle, by carrying the magnetic remnants of the sunspots to high latitudes. An even deeper counterflow, which would be required to maintain mass…

1997 • Nature

SOHO 270

Structure and Rotation of the Solar Interior: Initial Results from the MDI Medium-L Program

DOI: 10.1023/A:1004949311268 Bibcode: 1997SoPh..170...43K

Kosovichev, A. G.; Hoeksema, J. T.; Scherrer, P. H. +31 more

The medium-l program of the Michelson Doppler Imager instrument on board SOHO provides continuous observations of oscillation modes of angular degree, l, from 0 to ∽ 300. The data for the program are partly processed on board because only about 3% of MDI observations can be transmitted continuously to the ground. The on-board data processing, the …

1997 • Solar Physics

SOHO 269

Evolutionary models for metal-poor low-mass stars. Lower main sequence of globular clusters and halo field stars

DOI: 10.48550/arXiv.astro-ph/9704144 Bibcode: 1997A&A...327.1054B

Hauschildt, P. H.; Allard, F.; Baraffe, I. +1 more

We have performed evolutionary calculations of very-low-mass stars from 0.08 to 0.8 M_sunl for different metallicites from [M/H]= -2.0 to -1.0 and we have tabulated the mechanical, thermal and photometric characteristics of these models. The calculations include the most recent interior physics and improved non-grey atmosphere models. The models r…

1997 • Astronomy and Astrophysics

eHST 263

Cluster - Science and Mission Overview

DOI: 10.1023/A:1004923124586 Bibcode: 1997SSRv...79...11E

Escoubet, C. P.; Goldstein, M. L.; Schmidt, R.

1997 • Space Science Reviews

Cluster 263

The Electric Field and Wave Experiment for the Cluster Mission

DOI: 10.1023/A:1004975108657 Bibcode: 1997SSRv...79..137G

Thomsen, M.; Wygant, J.; Gustafsson, G. +24 more

1997 • Space Science Reviews

Cluster 262

Discovery of Extended Blue Horizontal Branches in Two Metal-rich Globular Clusters

DOI: 10.1086/310758 Bibcode: 1997ApJ...484L..25R

Rich, R. Michael; Renzini, Alvio; Piotto, Giampaolo +7 more

We have used WFPC2 to construct B, V color-magnitude diagrams of four metal-rich globular clusters, NGC 104 (47 Tuc), NGC 5927, NGC 6388, and NGC 6441. All four clusters have well populated red horizontal branches (RHB), as expected for their metallicity. However, NGC 6388 and 6441 also exhibit a prominent blue horizontal-branch (BHB) extension, i…

1997 • The Astrophysical Journal

eHST 261

Evolution of the Galaxy Population Based on Photometric Redshifts in the Hubble Deep Field

DOI: 10.1086/118231 Bibcode: 1997AJ....113....1S

Yee, H. K. C.; Lin, H.; Sawicki, M. J.

This paper presents the results of a photometric redshift study of galaxies in the Hubble Deep Field (HDF). The method of determining redshifts from broadband colors is described, and the dangers inherent in using it to estimate redshifts, particularly at very high z, are discussed. In particular, the need for accurate high-z spectral energy distr…

1997 • The Astronomical Journal

eHST 256

The Nature of Compact Galaxies in the Hubble Deep Field. II. Spectroscopic Properties and Implications for the Evolution of the Star Formation Rate Density of the Universe1,

DOI: 10.1086/304797 Bibcode: 1997ApJ...489..559G

Illingworth, Garth D.; Faber, S. M.; Koo, David C. +5 more

We present a spectroscopic study of 51 compact field galaxies with redshifts z < 1.4 and apparent magnitudes I₈₁₄ < 23.74 in the flanking fields of the Hubble Deep Field. These galaxies are compact in the sense that they have small apparent half-light radii (r_1/2 <= 0.5") and high surface brightnesses (µ_I8…

1997 • The Astrophysical Journal

eHST 255