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Title: A New Stellar Atmosphere Grid and Comparisons with HST /STIS CALSPEC Flux Distributions

Abstract

The Space Telescope Imaging Spectrograph has measured the spectral energy distributions for several stars of types O, B, A, F, and G. These absolute fluxes from the CALSPEC database are fit with a new spectral grid computed from the ATLAS-APOGEE ATLAS9 model atmosphere database using a chi-square minimization technique in four parameters. The quality of the fits are compared for complete LTE grids by Castelli and Kurucz (CK04) and our new comprehensive LTE grid (BOSZ). For the cooler stars, the fits with the MARCS LTE grid are also evaluated, while the hottest stars are also fit with the NLTE Lanz and Hubeny OB star grids. Unfortunately, these NLTE models do not transition smoothly in the infrared to agree with our new BOSZ LTE grid at the NLTE lower limit of T {sub eff} = 15,000 K. The new BOSZ grid is available via the Space Telescope Institute MAST archive and has a much finer sampled IR wavelength scale than CK04, which will facilitate the modeling of stars observed by the James Webb Space Telescope . Our result for the angular diameter of Sirius agrees with the ground-based interferometric value.

Authors:
; ; ;  [1]; ;  [2]
  1. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
  2. ELTE Gothard Astrophysical Observatory, H-9700 Szombathely, Szent Imre Herceg St. 112 (Hungary)
Publication Date:
OSTI Identifier:
22663661
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (Online); Journal Volume: 153; Journal Issue: 5; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPARATIVE EVALUATIONS; ENERGY SPECTRA; INTERFEROMETRY; SPACE; STAR MODELS; STARS; STELLAR ATMOSPHERES; TELESCOPES; WAVELENGTHS

Citation Formats

Bohlin, Ralph C., Fleming, Scott W., Gordon, Karl D., Koekemoer, Anton M., Mészáros, Szabolcs, and Kovács, József. A New Stellar Atmosphere Grid and Comparisons with HST /STIS CALSPEC Flux Distributions. United States: N. p., 2017. Web. doi:10.3847/1538-3881/AA6BA9.
Bohlin, Ralph C., Fleming, Scott W., Gordon, Karl D., Koekemoer, Anton M., Mészáros, Szabolcs, & Kovács, József. A New Stellar Atmosphere Grid and Comparisons with HST /STIS CALSPEC Flux Distributions. United States. doi:10.3847/1538-3881/AA6BA9.
Bohlin, Ralph C., Fleming, Scott W., Gordon, Karl D., Koekemoer, Anton M., Mészáros, Szabolcs, and Kovács, József. Mon . "A New Stellar Atmosphere Grid and Comparisons with HST /STIS CALSPEC Flux Distributions". United States. doi:10.3847/1538-3881/AA6BA9.
@article{osti_22663661,
title = {A New Stellar Atmosphere Grid and Comparisons with HST /STIS CALSPEC Flux Distributions},
author = {Bohlin, Ralph C. and Fleming, Scott W. and Gordon, Karl D. and Koekemoer, Anton M. and Mészáros, Szabolcs and Kovács, József},
abstractNote = {The Space Telescope Imaging Spectrograph has measured the spectral energy distributions for several stars of types O, B, A, F, and G. These absolute fluxes from the CALSPEC database are fit with a new spectral grid computed from the ATLAS-APOGEE ATLAS9 model atmosphere database using a chi-square minimization technique in four parameters. The quality of the fits are compared for complete LTE grids by Castelli and Kurucz (CK04) and our new comprehensive LTE grid (BOSZ). For the cooler stars, the fits with the MARCS LTE grid are also evaluated, while the hottest stars are also fit with the NLTE Lanz and Hubeny OB star grids. Unfortunately, these NLTE models do not transition smoothly in the infrared to agree with our new BOSZ LTE grid at the NLTE lower limit of T {sub eff} = 15,000 K. The new BOSZ grid is available via the Space Telescope Institute MAST archive and has a much finer sampled IR wavelength scale than CK04, which will facilitate the modeling of stars observed by the James Webb Space Telescope . Our result for the angular diameter of Sirius agrees with the ground-based interferometric value.},
doi = {10.3847/1538-3881/AA6BA9},
journal = {Astronomical Journal (Online)},
number = 5,
volume = 153,
place = {United States},
year = {Mon May 01 00:00:00 EDT 2017},
month = {Mon May 01 00:00:00 EDT 2017}
}