Gas density drops inside dust cavities of transitional disks around young stars observed with ALMA

By N. Marel, E. Dishoeck, Simon Bruderer, L. P'erez, Andrea Isella Leiden Observatory, Mpe Garching, Nrao Socorro, R. University. 2015

135 citations recorded by the source corpus.

Transitional disks with large dust cavities are important laboratories to study planet formation and disk evolution. Cold gas may still be present inside these cavities, but the quantification of this gas is challenging. The gas content is important to constrain the origin of the dust cavity. We use Atacama Large Millimeter/submillimeter Array (ALMA) observations of 12CO 6--5 and 690 GHz (Band 9) continuum of five well-studied transitional disks. In addition, we analyze previously published Band 7 observations of a disk in 12CO 3--2 line and 345 GHz continuum. The observations are used to set constraints on the gas and dust surface density profiles, in particular the drop delta-gas of the gas density inside the dust cavity. The physical-chemical modeling code DALI is used to analyze the gas and dust images simultaneously. We model SR21, HD135344B, LkCa15, SR24S and RXJ1615-3255 (Band 9) and J1604-2130 (Band 7). The SED and continuum visibility curve constrain the dust surface density. Subsequently, the same model is used to calculate the 12CO emission, which is compared with the observations through spectra and intensity cuts. The amount of gas inside the cavity is quantified by varying the delta-gas parameter. Model fits to the dust and gas indicate that gas is still present inside the dust cavity for all disks but at a reduced level. The gas surface density drops inside the cavity by at least a factor 10, whereas the dust density drops by at least a factor 1000. Disk masses are comparable with previous estimates from the literature, cavity radii are found to be smaller than in the 345 GHz SubMillimeter Array (SMA) data. The derived gas surface density profiles suggest clearing of the cavity by one or more companions in all cases, trapping the millimeter-sized dust at the edge of the cavity.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/f1374c578ba42bc39aae66f6453e90946030dfb0

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. S. Andrews
2. Jonathan P. Williams
3. D. Wilner
4. G. Herczeg
5. L. Testi
6. A. Natta
7. Simon Bruderer
8. L. Hartmann

In Instrumentation

1. S. Andrews
2. Jonathan P. Williams
3. L. Testi
4. A. Natta
5. G. Herczeg
6. L. Hartmann
7. E. Dishoeck
8. J. Carpenter

Citations in the corpus

• Volatile carbon locking and release in protoplanetary disks. A study of TW Hya and HD 100546 (2016, background): “…magnitude more deficient than gas, have been found in ALMA studies of several transitional disks around Herbig Ae/Be stars (e.g. Bruderer et al. 2014; Zhang et al. 2014; van der Marel et al. 2015), and no doubt high spatial resolution observations of TW Hya will soon shed more light on the matter.”
• Resolved gas cavities in transitional disks inferred from CO isotopologs with ALMA (2015, methodology): “…are sufficiently empty so that 12CO becomes optically thin inside the dust cavity, and it was found that the gas cavity radius is indeed smaller than the dust cavity (Bruderer et al. 2014; Zhang et al. 2014; van der Marel et al. 2015b), consistent with predictions for the planet-disk interaction.”
• ALMA SURVEY OF LUPUS PROTOPLANETARY DISKS. I. DUST AND GAS MASSES (2016, background): “The gas emission is clearly present inside the dust cavities of the resolved TDs (Figure B1), consistent with previous TD observations (Mathews et al. 2012; van der Marel et al. 2013; Casassus et al. 2013; Bruderer et al. 2014; Zhang et al. 2014; van der Marel et al. 2015).”
• Multiple Disk Gaps and Rings Generated by a Single Super-Earth (2017, background): “Dust rings have been detected (e.g., Zhang et al. 2014; Hashimoto et al. 2015; van der Marel et al. 2015; Dong et al. 2017).”
• Accretion onto Pre-Main-Sequence Stars (2016, background): “Recent high-resolution Atacama Large Millimeter Array (ALMA) studies have suggested that the gas interior to the dusty region is depleted (van der Marel et al. 2015) by at least an order of magnitude, and in some cases by factors of more than 102–104 (van der Marel et al. 2016); however, such…”