Astronomy and Astrophysics – Astronomy
Scientific paper
Nov 1998
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998larm.confe..26b&link_type=abstract
"IX Latin American Regional IAU Meeting, "Focal Points in Latin American Astronomy", held in Tonantzintla, Mexico, Nov 9-13, 199
Astronomy and Astrophysics
Astronomy
Scientific paper
The results of two recent eclipse mapping experiments are presented and discussed. Time-resolved spectroscopy of the novalike variable UU Aquarii is analyzed with eclipse mapping techniques to produce spatially resolved spectra of its accretion disc and gas stream as a function of distance from disc centre in the range 3600-7000 \AA. The spatially-resolved spectra show that the continuum emission becomes progressively fainter and redder for increasing disk radius -- reflecting the radial temperature gradient -- and reveal that the HI and HeI lines appear as deep, narrow absorption features in the inner disk regions transitioning to emission with P Cyg profiles for larger disk radii. The spectrum of the uneclipsed component is dominated by strong HI and HeI emission lines plus a Balmer jump in emission and is explained as optically thin emission from a vertically extended disk chromosphere + wind. Together, these results yield strong evidence for gas outflow in a disk wind and indicate that the optical emission lines in UU Aqr are produced in the wind and not in a Keplerian disk. We also report on the analysis of high-speed photometry of the dwarf-nova HS1804+67 through its outburst cycle with eclipse mapping techniques. Average light curves at 11 different outburst phases are used to follow the time evolution of the accretion disk structure through the outburst cycle. The results suggest the formation of a spiral structure in the disk in the early rise to maximum and show how the disk expands during the rise until its fills most of the primary Roche lobe at maximum light. During the decline phase, the disk becomes progressively fainter as the cooling front moves inwards from the outer regions, until only a small bright region around the white dwarf is left at minimum light. The time dependence of the uneclipsed component suggests that a non-negligible fraction of this light arises from outside orbital plane, probably in a disk wind, the intensity of which varies in phase with that of the inner disk regions.
Baptista Raymundo
Catalan S.
Horne Keith
Silveira C.
Steiner Joao Evangelista
No associations
LandOfFree
Structure, spectra and time evolution of accretion disks in cataclysmic bina ries 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 Structure, spectra and time evolution of accretion disks in cataclysmic bina ries, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Structure, spectra and time evolution of accretion disks in cataclysmic bina ries will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-802411