A Spectral Atlas of the Herbig Ae-Star Ab-Aurigae - the Visible Domain from 391-NM to 874-NM

Details A Spectral Atlas of the Herbig Ae-Star Ab-Aurigae - the Visible Domain from 391-NM to 874-NM A Spectral Atlas of the Herbig Ae-Star Ab-Aurigae - the Visible Domain from 391-NM to 874-NM

Nov 1993

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993a%26as..101..629b&link_type=abstract

Astronomy and Astrophysics Supplement, Vol.101, NO. 3/NOVI, P. 629, 1993

Astronomy and Astrophysics

Astrophysics

48

Spectral Atlas, Lines: Identification, Stars: Activity Of, Stars: Atmosphere Of, Stars: Pre-Main Sequence

Scientific paper

The visible spectrum of the pre-main-sequence Herbig Ae star AB Aur (A0Ve), recorded by the MUSICOS echelle spectrograph, was used to elaborate a high resolution (R = 38000) spectral atlas, with line identification in the wavelength range 391-874 nm. The numerous spectral features were individually measured and their identification was carried out with the help of a synthetic spectrum and a laboratory wavelength list for relevant atomic species. For 120 spectral features present in the spectrum, we identified contributions from about 215 lines. The presence of 19 ions from 15 different elements is firmly established. From the analysis of several well-defined photospheric lines, we determined for AB Aur a υsini value of 80±5 km s-1. From a detailed comparison of the photospheric lines with the synthetic spectra calculated with classical photospheric models of Kurucz (1979), we deduced an effective temperature Teff = 10220+150-100 K and a surface gravity log (9) = 4.10±0.06. Upper limits were derived for the veiling of photospheric lines reaching from 3.5% at 4500 Å to 16% at 6100 Å. If AB Aur possesses an accretion disk with an optically thin inner region, as conjectured by Hillenbrand et al. (1992), then the absence of veiling implies an accretion rate lower than 7.5 10-8 Msun yr-1. The spectral lines in the spectrum of AB Aur can be classified in 6 categories: photospheric lines identical to those of a synthetic spectrum calculated with a classical photospheric model; lines with filled-in cores; asymmetric absorption lines; emission lines; lines which are deeper than predicted; P Cygni profiles for the first lines of the H I Balmer series. All these different features are consistent with a model including a photosphere with Teff = 10000 K and log (9) = 4, an extended chromosphere with a temperature reaching 17000 K, and a stellar wind. The regions of formation of a set of typical lines of this spectrum were compared with each other, by computing absorption coefficients at line center, using an existing atmospheric model for AB Aur.

Affiliated with

Also associated with

No associations

Rating

A Spectral Atlas of the Herbig Ae-Star Ab-Aurigae - the Visible Domain from 391-NM to 874-NM does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A Spectral Atlas of the Herbig Ae-Star Ab-Aurigae - the Visible Domain from 391-NM to 874-NM, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Spectral Atlas of the Herbig Ae-Star Ab-Aurigae - the Visible Domain from 391-NM to 874-NM will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-807579