our goal is to measure the masses of circumstellar disks associated with young binary stars, and thereby to investigate the evolution of disks in binary environments. the formation of binaries is accompanied by the formation of protostellar disks. dynamical theory predicts that a binary embedded within a disk will evacuate a gap, producing circum- stellar and circumbinary disks. the resonant truncation of these disks will prevent the flow of material from the circumbinary disk to the circumstellar disks. continued accretion of circumstellar disk material without replenishment would rapidly exhaust the circumstellar disks, particularly in the closer binaries. yet many pre-main-sequence binaries show evidence for circumstellar disks, such as mid-infrared excesses and active accretion. whether these disks have surface densities typical of disks around single stars or are depleted is not known. the survival of high surface densities in circum- stellar disks would have implications for binary formation theories, accretion disk dynamics, and planet formation. mid-infrared observations are not sensitive to disk mass, except at the very lowest disk surface densities. observations at longer wave- lengths where dust opacities are low are required. iso observations of continuum emission at 60 um and 120 um are uniquely capable of measuring the masses of circumstellar disks in young binary stars. ground-based submillimeter telescopes cannot achieve the required flux sensitivities. we propose iso observations for a sample of pre-main-sequence binary stars with a range in separation from 1 au to 150 au. we will determine whether binaries with luminous mid-infrared excesses have high-surface- density circumstellar disks. we will map circumstellar disk surface- density as a function of binary separation, testing whether disks are more readily depleted in close binaries. finally, we will establish evo- lutionary timescales to be compared with iso findings for single stars.
Instrument
PHT22
Temporal Coverage
1996-08-04T10:17:54Z/1997-08-06T05:16:58Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the worlds first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
European Space Agency, MATHIEU et al., 1999, 'MASSES OF CIRCUMSTELLAR DISKS IN PRE-MAIN-SEQUENCE BINARY STARS', 1.0, European Space Agency, https://doi.org/10.5270/esa-tezjggy
