UU Aqr from high to low state

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

13 pages, 8 figures, uses aa.cls, accepted for publication in AN, for associated postscript files, see http://www/DE/Ins/Per

Scientific paper

10.1002/1521-3994(200207)323:2<7

In this paper we present Physical Parameter Eclipse Mapping (PPEM) of UBVRI eclipse light curves of UU Aqr from high to low states. We used a simple, pure hydrogen LTE model to derive the temperature and surface density distribution in the accretion disc. The reconstructed effective temperatures in the disc range between 9000K and 15000K in the inner part of the disc and below 7000K in the outer parts. In the higher states it shows a more or less prominent bright spot with T_eff between about 7000K and 8000K. The inner part of the disc (R < 0.3R_L1) is optically thick at all times, while the outer parts of the disc up to the disc edge (0.51+-0.04R_L1 in the high state and 0.40+-0.03R_L1 in the low state) deviate from a simple black body spectrum indicating that either the outer disc is optically thin or it shows a temperature inversion in the vertical direction. While during high state the disc is variable, it appears rather stable in low state. The variation during high state affects the size of the optically thick part of the disc, the white dwarf or boundary layer temperature and the uneclipsed component (originating in a disc chromosphere and/or cool disc wind), while the actual size of the disc remains constant. The difference between high and low state is expressed as a change in disc size that also affects the size of the optically thick part of the disc and the presence of the bright spot. Using the PPEM method we retrieve a distance for UU Aqr of 207+-10pc, compatible with previous estimates.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

UU Aqr from high to low state 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 UU Aqr from high to low state, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and UU Aqr from high to low state will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-620557

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.