Details

Autor(en) / Beteiligte

• Mendigutia, I
• Oudmaijer, R D
• Mourard, D
• Muzerolle, J

Titel

The compact Hα emitting regions of the Herbig Ae/Be stars HD 179218 and HD 141569 from CHARA spectro-interferometry

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2017-01, Vol.464 (2), p.1984-1984

Ort / Verlag

Oxford University Press (OUP): Policy P - Oxford Open Option A

Erscheinungsjahr

2017

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• This work presents CHARA/VEGA Ha spectro-interferometry (R ~ 6000, and .../2B ~ 1 mas) of HD 179218 and HD 141569, doubling the sample of Herbig Ae/Be (HAeBe) stars for which this type of observations is available so far. The observed Ha emission is spatially unresolved, indicating that the size of the Ha emitting region is smaller than ~0.21 and 0.12 au for HD 179218 and HD 141529 (~15 and 16 R*, respectively). This is smaller than for the two other HAeBes previously observed with the same instrumentation. Two different scenarios have been explored in order to explain the compact line emitting regions. A hot, several thousand K, blackbody disc is consistent with the observations of HD 179218 and HD 141569. Magnetospheric accretion (MA) is able to reproduce the bulk of the Ha emission shown by HD 179218, confirming previous estimates from MA shock modelling with a mass accretion rate of 10 super( -8) M... yr super( -1), and an inclination to the line of sight between 30... and 50... The Ha profile of HD 141569 cannot be fitted from MA due to the high rotational velocity of this object. Putting the CHARA sample together, a variety of scenarios is required to explain the Ha emission in HAeBe stars -- compact or extended, discs, accretion, and winds -- in agreement with previous Br gamma spectro-interferometric observations. (ProQuest: ... denotes formulae/symbols omitted.)