Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Full Refereed Journal Article (PDF/Postscript)
· Full Refereed Scanned Article (GIF)
· References in the article
· Citations to the Article (34) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (1)
· Reads History
·
· Translate This Page
Title:
Doppler imaging of abundance features on AP stars - The Si II distribution on Gamma2 ARIETIS
Authors:
Hatzes, Artie P.; Penrod, G. Donald; Vogt, Steven S.
Affiliation:
AA(Lick Observatory, Santa Cruz, CA), AB(Lick Observatory, Santa Cruz, CA), AC(Lick Observatory, Santa Cruz, CA)
Publication:
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 341, June 1, 1989, p. 456-473. (ApJ Homepage)
Publication Date:
06/1989
Category:
Astrophysics
Origin:
STI
NASA/STI Keywords:
A STARS, ABUNDANCE, PECULIAR STARS, SILICON, STELLAR COMPOSITION, STELLAR SPECTRA, IMAGE RECONSTRUCTION, ITERATIVE SOLUTION, LINE SPECTRA, MAGNETIC STARS, MAXIMUM ENTROPY METHOD, SPECTRUM ANALYSIS
DOI:
10.1086/167507
Bibliographic Code:
1989ApJ...341..456H

Abstract

It is shown that an improved version of the Doppler imaging technique which incorporates the maximum entropy formalism can be used to obtain accurate maps of the surface distribution of elements on rapidly rotating Ap stars strictly from the spectral line variations. Not only can the method accurately recover complex spot distributions such as rings, but it also can reconstruct spot distributions with both depleted and enhanced abundance regions in spite of the assumption that the intrinsic line profile for both regions is the same. The technique is applied to the B9pSiCr star Gamma2 Arieti using the Si II 6347 A line. The resulting reconstruction shows that silicon is depleted near the magnetic poles and that it is enhanced in an incomplete, nonuniform annulus near the negative magnetic pole. This image provides direct observational support for the theory that diffusion is the process responsible for the abundance variations in Ap stars.

Printing Options

Print whole paper
Print Page(s) through

Return 600 dpi PDF to Acrobat/Browser. Different resolutions (200 or 600 dpi), formats (Postscript, PDF, etc), page sizes (US Letter, European A4, etc), and compression (gzip,compress,none) can be set through the Printing Preferences


More Article Retrieval Options

HELP for Article Retrieval
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
  New!

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints