Detection of Water Vapor in the Photosphere of Arcturus

Details Detection of Water Vapor in the Photosphere of Arcturus Detection of Water Vapor in the Photosphere of Arcturus

2002-07-17

arxiv.org/abs/astro-ph/0207368v1

Astrophys.J. 580 (2002) 447-458

Astronomy and Astrophysics

Astrophysics

To appear in ApJ. See also http://www.astro.uu.se/~ryde/ART/

Scientific paper

10.1086/343040

We report detections of pure rotation lines of OH and H2O in the K1.5 III red-giant star Arcturus (alpha Bootis) using high-resolution, infrared spectra covering the regions 806-822 cm-1 (12.2-12.4 um) and 884-923 cm-1 (10.8-11.3 um). Arcturus is the hottest star yet to show water-vapor features in its disk-averaged spectrum. We argue that the water vapor lines originate from the photosphere, albeit in the outer layers. We are able to predict the observed strengths of OH and H2O lines satisfactorily after lowering the temperature structure of the very outer parts of the photosphere (log tau_500=-3.8 and beyond) compared to a flux-constant, hydrostatic, standard MARCS model photosphere. Our new model is consistently calculated including chemical equilibrium and radiative transfer from the given temperature structure. Possible reasons for a temperature decrease in the outer-most parts of the photosphere and the assumed break-down of the assumptions made in classical model-atmosphere codes are discussed.

Affiliated with

Also associated with

No associations

Rating

Detection of Water Vapor in the Photosphere of Arcturus 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 Detection of Water Vapor in the Photosphere of Arcturus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Detection of Water Vapor in the Photosphere of Arcturus will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-208936