Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-11-09
Mon.Not.Roy.Astron.Soc.365:1283-1287,2006
Astronomy and Astrophysics
Astrophysics
13 pages, 2 figures. Accepted by MNRAS
Scientific paper
10.1111/j.1365-2966.2005.09825.x
We present 7 mm and 3.5 cm wavelength continuum observations toward the Herbig AeBe star HD169142 performed with the Very Large Array (VLA) with an angular resolution of ~1". We find that this object exhibits strong (~4.4 mJy), unresolved (~1") 7 mm continuum emission, being one of the brightest isolated Herbig AeBe stars ever detected with the VLA at this wavelength. No emission is detected at 3.5 cm continuum, with a 3 sigma upper limit of ~0.08 mJy. From these values, we obtain a spectral index of ~2.5 in the 3.5 cm to 7 mm wavelength range, indicating that the observed flux density at 7mm is most likely dominated by thermal dust emission coming from a circumstellar disc. We use available photometric data from the literature to model the spectral energy distribution (SED) of this object from radio to near-ultraviolet frequencies. The observed SED can be understood in terms of an irradiated accretion disc with low mass accretion rate, 10^{-8} solar masses per year, surrounding a star with an age of ~10 Myr. We infer that the mass of the disc is ~0.04 solar masses, and is populated by dust grains that have grown to a maximum size of 1 mm everywhere, consistent with the lack of silicate emission at 10 microns. These features, as well as indications of settling in the wall at the dust destruction radius, led us to speculate the disc of HD169142 is in an advanced stage of dust evolution, particularly in its inner regions.
Anglada Guillem
Calvet Nuria
Dent William R. F.
Osorio Mauricio
Torrelles Jose Maria
No associations
LandOfFree
The circumstellar disc around the Herbig AeBe star HD169142 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 The circumstellar disc around the Herbig AeBe star HD169142, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The circumstellar disc around the Herbig AeBe star HD169142 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-103716