Related papers: Evolution of the dust/gas environment around Herbi…
We present optical spectra of 45 intermediate mass Herbig Ae/Be stars. Together with the multi-epoch spectroscopic and photometric data compiled for a large sample of these stars and ages estimated for individual stars by using pre-main…
The recent findings of gas giant planets around young A-type stars suggest that disks surrounding Herbig Ae/Be stars will develop planetary systems. An interesting case is HD142527, for which previous observations revealed a complex…
We present new multi-wavelength millimeter interferometric observations of the Herbig Ae star HD 163296 obtained with the IRAM/PBI, SMA and VLA arrays both in continuum and in the 12CO, 13CO and C18O emission lines. Gas and dust properties…
We present detailed model fits to observations of the disc around the Herbig Ae star HD 163296. This well-studied object has an age of ~ 4 Myr, with evidence of a circumstellar disc extending out to ~ 540AU. We use the radiation…
We investigate the physical structure of the gas component of the disk around the pre-main-sequence star HD169142. The 13CO and C18O J=2-1 line emission is observed from the disk with 1.4'' resolution using the Submillimeter Array. We adopt…
Aims: To calculate chemistry and gas temperature of evolving protoplanetary disks with decreasing mass or dust settling, and to explore the sensitivity of gas-phase tracers. Methods: The density and dust temperature profiles for a range of…
The spectral shape of IR emission from Herbig Ae/Be stars has been invoked as evidence for accretion disks around high-mass protostars. Instead, we present here models based on spherical envelopes with $r^{-1.5}$ dust density profile that…
12CO and 13CO lines, as well as a mm-wave continuum, have been observed for a sample of 22 OH/IR stars in directions within 2 degrees of the Galactic Centre. Photometry data have been gathered from the literature to construct SEDs and to…
[abridged]CO rovibrational lines are efficient probes of warm molecular gas and can give unique insights into the inner 10 AU of proto-planetary disks. Recent studies have found a relation between the ratio of lines originating from the…
We report Submillimeter Array (SMA) observations of CO (J=2--1, 3--2 and 6--5) and its isotopologues (13CO J=2--1, C18O J=2--1 and C17O J=3--2) in the disk around the Herbig Ae star HD 163296 at ~2" (250 AU) resolution, and interpret these…
Herbig Ae/Be stars lie in the mass range between low and high mass young stars, and therefore offer a unique opportunity to observe any changes in the formation processes that may occur across this boundary. This paper presents medium…
We investigate the structure and kinematics of the circumstellar disk around the Herbig Ae star MWC 758 using high resolution observations of the 12CO (3-2) and dust continuum emission at the wavelengths of 0.87 and 3.3 mm. We find that the…
Young stars with masses 2-8 Suns, called the Herbig Ae and Be stars, often show a near-infrared excess too large to explain with a hydrostatically-supported circumstellar disk of gas and dust. At the same time the accretion flow carrying…
We completed a search for circumstellar disks around Herbig Be stars using the NRAO Very Large Array (VLA) and the IRAM Plateau de Bure (PdB) interferometers. We present our new VLA and PdBI data for the three objects MWC 297, Z CMa, and…
Accretion rates from disks around pre-main sequence stars are of importance for our understanding of planetary formation and disk evolution. We provide in this paper estimates of the mass accretion rates in the disks around a large sample…
Aims: The aim of this work is to study the structure of the protoplanetary disk surrounding the Herbig Ae star HD 163296. Methods: We have used high-resolution and high-sensitivity ALMA observations of the CO(3-2) emission line and the…
We report on the discovery of correlations between dust and CO gas tracers of the 0.1-10 au region in planet-forming disks around young intermediate-mass stars. The abundance of refractory elements on stellar photospheres decreases as the…
The disc around the Herbig Ae/Be star HD 100546 is one of the most extensively studied discs in the southern sky. Although there is a wealth of information about its dust content and composition, not much is known about its gas and large…
We have carried out a study of the early type stars in nearby OB associations spanning an age range of $\sim$ 3 to 16 Myr, with the aim of determining the fraction of stars which belong to the Herbig Ae/Be class. We studied the B, A, and F…
We have acquired sub-millimeter observations of 33 fields containing 37 Herbig Ae/Be (HAEBE) stars or potential HAEBE stars, including SCUBA maps of all but two of these stars. Nine target stars show extended dust emission. The other 18 are…