A spectro-astrometric study of southern pre-main sequence stars - binaries, outflows, and disc structure down to AU scales

Details A spectro-astrometric study of southern pre-main sequence stars - binaries, outflows, and disc structure down to AU scales A spectro-astrometric study of southern pre-main sequence stars - binaries, outflows, and disc structure down to AU scales

2002-10-25

arxiv.org/abs/astro-ph/0210559v2

Astron.Astrophys.397:675-692,2003; Astron.Astrophys.401:655-656,2003

Astronomy and Astrophysics

Astrophysics

18 pages including 10 figures, accepted for publication in Astronomy and Astrophysics

Scientific paper

10.1051/0004-6361:20021544

We present spectro-astrometric observations for 28 southern pre-main sequence (PMS) stars and investigate their circumstellar environment down to AU scales. The structures detected in the ``position spectra'' include: (1) almost all the known binary companions in our sample (Sz 68, Sz 41, HO Lup, VW Cha, S CrA, AS 205), (2) companion candidates which have not been detected by infrared speckle techniques (T CrA, MWC 300), (3) monopolar and bipolar jets (AS 353A, CS Cha), (4) a combination of jets and a bow shock (VV CrA), and (5) a combination of a jet and stellar companion (R CrA). Results in known binaries show that this technique is capable of detecting binaries with separations down to ~10 milliarcsec. Both components in each binary appear to have strikingly similar profiles in H-alpha emission, indicating a similarity of circumstellar activity (mass accretion and/or a wind), and supporting the scenario of core fragmentation for the mechanism of binary formation. The bipolar H-alpha jet in CS Cha has a spatial scale of ~1.5 AU, similar to that previously observed in RU Lup, and likely be heated by a mechanism other than shocks. From the spatial scale, velocity, and H-alpha luminosity, we estimate the mean hydrogen density in the AU-scale bipolar flows to be > 10^7 cm^-3. The bipolar geometry in these jets can be explained by the presence of a disc gap/hole at AU scales, which could be induced by a gas-giant planet at the ice condensation radius.

Affiliated with

Also associated with

No associations

Rating

A spectro-astrometric study of southern pre-main sequence stars - binaries, outflows, and disc structure down to AU scales 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 A spectro-astrometric study of southern pre-main sequence stars - binaries, outflows, and disc structure down to AU scales, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A spectro-astrometric study of southern pre-main sequence stars - binaries, outflows, and disc structure down to AU scales will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-613925