Astron. Astrophys. 324, 1036-1045
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A 1.3 mm dust continuum survey of H selected T Tauri
Dieter Nürnberger1 and Rolf Chini2, and Hans Zinnecker3
1Astronomisches Institut der Universität Würzburg,
Am Hubland, D-97074 Würzburg, Germany
2Astronomisches Institut der Ruhr-Universität Bochum,
Univ.-str. 150, D-44780 Bochum, Germany
3Astrophysikalisches Institut Potsdam,
An der Sternwarte 16, D-14482 Potsdam, Germany (email@example.com)
Received 30 May 1996 / Accepted 6 March 1997
We have observed a sample of 32 H selected T Tauri stars in the
Lupus 2 and 3 T association with the facility bolometer at the SEST and
detected cold dust emission at 1.3 mm from 12 of the objects.
For the remaining objects we have derived 3 upper limits
( 40 mJy), which suggest that the cold dust masses are less
than M .
For stellar masses below 0.7 M the mean disk mass (gas + dust)
is approximately 3 of the stellar mass.
The face value detection rate (38 ) of the Lupus stars is very
similar to that of young stars in the Taurus-Auriga association.
Thus, the young stellar population in Lupus seems to have an equal
incidence of circumstellar disks.
In comparison to Taurus-Auriga the low-mass pre-main sequence stars in
Lupus show a lack of disk masses below 3 · 10-3 M
(gas + dust), which in part can be explained by the absence of weak-line
T Tauri stars in our sample.
Both samples show a strong correlation between relative disk mass and
Considering the absolute disk mass of 1.3 mm detected sources in Lupus
we see a tentative decrease with increasing age, too, while there is no
correlation for the Taurus-Auriga sample.
This effect might be due to different modes of star formation: isolated
star formation in Taurus-Auriga versus clustered star formation in
Considering both samples globally none of the 6 stars older than 3 Myr
shows dust emission, which could mean that almost no small dust grains
are left over in the disk at this age.
Furthermore, for both samples we do not see any indication that more massive
stars have more massive disks.
On the contrary, statistical tests suggest that the absolute disk mass as
well as the relative disk mass decreases with increasing stellar mass.
Finally, in order to investigate the age-dependent behaviour of the
spectral energy distribution, we have determined the IR indices IR
between = 2.2 µm and
= 12 25 µm (IRAS) for 11 sources of our
According to the revised IR classification by André & Montmerle (1994)
these objects belong to the IR class II.
Neither a correlation between the infrared indices and the stellar age
nor between the infrared indices and the disk mass could have been found.
Key words: stars: circumstellar matter -
stars: formation -
stars: late-type -
stars: low-mass -
stars: pre-main sequence -
radio continuum: stars
Send offprint requests to: Dieter Nürnberger
*Based on observations obtained with
the SEST at the European Southern Observatory, La Silla, Chile
© European Southern Observatory (ESO) 1997