EDP Sciences
Free Access
Issue
A&A
Volume 557, September 2013
Article Number A104
Number of page(s) 20
Section Interstellar and circumstellar matter
DOI https://doi.org/10.1051/0004-6361/201322015
Published online 11 September 2013

Online material

Appendix A: Additional 30 m-telescope CO data

In this Appendix, we show our 30 m telescope data of RV Tau, U Mon, and R Sge, which are the only objects of our northern sample that were not detected. Wide spectral bands are shown, centered on the stellar velocity expected from optical observations. See a summary of the observational parameters in Sect. 2 and Table 3.

thumbnail Fig. A.1

30 m telescope observations of RV Tau. No line is detected.

Open with DEXTER

thumbnail Fig. A.2

30 m telescope observations of U Mon. No line is detected.

Open with DEXTER

thumbnail Fig. A.3

30 m telescope observations of R Sge. No line is detected.

Open with DEXTER

Appendix B: APEX observations of southern sources: spectra and disk mass estimates

We have also observed southern post-AGB stars using APEX in the 12CO J = 3−2 and J = 2−1 transitions, the source sample is given in Table 2 (we give the same parameters as in Table 1 for the northern sources). Because of the lack of 13CO observations and the poorer quality of the data, which include spectra dominated by interstellar (IS) contamination, these results are not analyzed with the same detail as those of northern sources. When strong IS contamination is present, it is even impossible to give a reasonable upper limit to the post-AGB source emission, since the IS contribution can be very intense, both positive and negative, and practically impossible to predict. The observational procedure is described in Sect. 3.2, and a summary of the line parameters is given in Table 4 (similar to that given in Table 3), and the observed profiles are given in Figs. B.1 to B.10.

To derive mass values for the disk in the detected sources, we first compared the mass values derived from the 13CO J = 1−0 integrated main-beam temperatures (our best estimates, in Table 5) with those derived from 12CO J = 2−1 (very probably underestimates), in both cases following the method described in Sect. 5. We have not considered the mass derived for R Sct and IRAS 20056+1834, in which the contribution of an additional component, probably in expansion, is largely dominant. The result is shown in Fig. B.11, the mass values derived from 12CO J = 2−1 are approximately ten times lower than those obtained from 13CO J = 1−0, which are the best estimates. We will accordingly estimate the mass of the southern sources from their 12CO J = 2−1 intensities (also considering SEST observations of IRAS 08544-4431 by Maas et al. 2003) and correct them by a factor 10. In the calculation of the disk mass values from the SEST and APEX data, we consider that the APEX beam solid angle (at 230 GHz) is about 4.7 times greater than that of the 30 m telescope and that the beam of the SEST is about 4 times greater. The (uncertain) mass estimates derived in this way for our four detected southern sources are given in Table 5 (last four lines).

thumbnail Fig. B.1

APEX observations of AR Pup. No circumstellar line is detected; only a narrow interstellar feature is found.

Open with DEXTER

thumbnail Fig. B.2

APEX observations of IRAS 08544-4431. 12CO J = 3−2 is detected (see previous data by Maas et al. 2003).

Open with DEXTER

thumbnail Fig. B.3

APEX observations of IW Car. Both lines are detected.

Open with DEXTER

thumbnail Fig. B.4

APEX observations of IRAS 10174-5704. Strong interstellar contamination at the relevant velocities prevents any conclusion on the emission from our source.

Open with DEXTER

thumbnail Fig. B.5

APEX observations of IRAS 10456-5712. Strong interstellar contamination at the relevant velocities prevents any conclusion on the emission from our source.

Open with DEXTER

thumbnail Fig. B.6

APEX observations of HD 95767. Emission is detected in J = 3−2, at the velocity found from optical spectroscopy, and tentatively in J = 2−1.

Open with DEXTER

thumbnail Fig. B.7

APEX observations of RU Cen. No circumstellar line is detected.

Open with DEXTER

thumbnail Fig. B.8

APEX observations of HD 108015. 12CO J = 2−1 is detected.

Open with DEXTER

thumbnail Fig. B.9

APEX observations of IRAS 15469-5311. Strong interstellar contamination at the relevant velocities prevents any conclusion on the emission from our source.

Open with DEXTER

thumbnail Fig. B.10

APEX observations of IRAS 15556-5444. Strong interstellar contamination at the relevant velocities prevents any conclusion on the emission from our source.

Open with DEXTER

thumbnail Fig. B.11

Relation between the mass values (M) derived respectively from 13CO J = 1−0 and 12CO J = 2−1 30 m telescope data for the objects in which both determinations can be performed (Sect. 5). Results from 13CO J = 1−0 are expected to be the most accurate ones and those from 12CO J = 2−1 are underestimates. The continuous line represents a factor of ten between both estimates, and the other lines represent deviations of a 10% from this ratio.

Open with DEXTER


© ESO, 2013

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.