scholarly journals Dust grain growth and settling in initial gaseous giant protoplanets

2012 ◽  
Vol 64 (7) ◽  
pp. 641-648 ◽  
Author(s):  
G. C. Paul ◽  
S. Datta ◽  
J. N. Pramanik ◽  
M. M. Rahman
Keyword(s):  
Grain Growth ◽  
Dust Grain ◽  
Dust Grain Growth

scholarly journals A systematic metallicity study of DustPedia galaxies reveals evolution in the dust-to-metal ratios

2019 ◽  
Vol 623 ◽  
pp. A5 ◽  
Author(s):  
P. De Vis ◽  
A. Jones ◽  
S. Viaene ◽  
V. Casasola ◽  
C. J. R. Clark ◽  
...  
Keyword(s):  
Star Formation ◽  
Grain Growth ◽  
Stellar Mass ◽  
Mass Ratio ◽  
Local Conditions ◽  
Metal Ratio ◽  
Stellar Masses ◽  
Dust Grain ◽  
Dust Grain Growth ◽  
Metal Ratios

Observations of evolution in the dust-to-metal ratio allow us to constrain the dominant dust processing mechanisms. In this work, we present a study of the dust-to-metal and dust-to-gas ratios in a sub-sample of ~500 DustPedia galaxies. Using literature and MUSE emission line fluxes, we derived gas-phase metallicities (oxygen abundances) for over 10 000 individual regions and determine characteristic metallicities for each galaxy. We study how the relative dust, gas, and metal contents of galaxies evolve by using metallicity and gas fraction as proxies for evolutionary state. The global oxygen abundance and nitrogen-to-oxygen ratio are found to increase monotonically as galaxies evolve. Additionally, unevolved galaxies (gas fraction >60%, metallicity 12 + log(O∕H) < 8.2) have dust-to-metal ratios that are about a factor of 2.1 lower (a factor of six lower for galaxies with gas fraction >80%) than the typical dust-to-metal ratio (Md∕MZ ~ 0.214) for more evolved sources. However, for high gas fractions, the scatter is larger due to larger observational uncertainties as well as a potential dependence of the dust grain growth timescale and supernova dust yield on local conditions and star formation histories. We find chemical evolution models with a strong contribution from dust grain growth describe these observations reasonably well. The dust-to-metal ratio is also found to be lower for low stellar masses and high specific star formation rates (with the exception of some sources undergoing a starburst). Finally, the metallicity gradient correlates weakly with the HI-to-stellar mass ratio, the effective radius and the dust-to-stellar mass ratio, but not with stellar mass.

scholarly journals Evidence for Dust Grain Growth in Young Circumstellar Disks

Science ◽  
2001 ◽  
Vol 292 (5522) ◽  
pp. 1686-1689 ◽  
Author(s):  
H. B. Throop
Keyword(s):  
Grain Growth ◽  
Circumstellar Disks ◽  
Dust Grain ◽  
Dust Grain Growth

scholarly journals Dust grain growth in the interstellar medium of 5 < z < 6.5 quasars

2010 ◽  
Vol 522 ◽  
pp. A15 ◽  
Author(s):  
M. J. Michałowski ◽  
E. J. Murphy ◽  
J. Hjorth ◽  
D. Watson ◽  
C. Gall ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Grain Growth ◽  
Dust Grain ◽  
Dust Grain Growth

Dust evolution in galaxies at z > 7

2019 ◽  
Vol 15 (S341) ◽  
pp. 312-313
Author(s):  
Tsutomu T. Takeuchi ◽  
Ryosuke S. Asano ◽  
Sayaka Nagasaki ◽  
Takaya Nozawa ◽  
Yoichi Tamura ◽  
...  
Keyword(s):  
Grain Growth ◽  
Stellar Mass ◽  
Dust Production ◽  
Huge Amount ◽  
Dust Mass ◽  
Dust Destruction ◽  
Dust Grain ◽  
Dust Evolution ◽  
Dust Grain Growth ◽  
The Universe

AbstractRecently huge amount of dust Mdust ≃ 106−7M⊙ in galaxies at z = 7–8 has been discovered by ALMA observations. The suggested timescale of the dust production was a few–several×108 yr, while the stellar mass was several × 109M⊙. This amount of dust cannot be easily explained only by a supply from supernovae if we consider the dust destruction by reverse shocks. We propose that these values can be consistently explained if we take into account the grain growth in the interstellar medium (ISM). This scenario successfully reproduces the evolution of the dust mass, as well as the SFR, and stellar mass simultaneously. We conclude that even at such an early epoch of the Universe, the dust grain growth in the ISM plays a significant role in galaxies.

scholarly journals ALMA Observations of Polarized Emission toward the CW Tau and DG Tau Protoplanetary Disks: Constraints on Dust Grain Growth and Settling

2018 ◽  
Vol 865 (2) ◽  
pp. L12 ◽  
Author(s):  
Francesca Bacciotti ◽  
Josep Miquel Girart ◽  
Marco Padovani ◽  
Linda Podio ◽  
Rosita Paladino ◽  
...  
Keyword(s):  
Grain Growth ◽  
Protoplanetary Disks ◽  
Polarized Emission ◽  
Dust Grain ◽  
Dust Grain Growth

scholarly journals Dust grain growth and the formation of the extremely primitive star SDSS J102915+172927

2014 ◽  
Vol 439 (3) ◽  
pp. 3121-3127 ◽  
Author(s):  
Gen Chiaki ◽  
Raffaella Schneider ◽  
Takaya Nozawa ◽  
Kazuyuki Omukai ◽  
Marco Limongi ◽  
...  
Keyword(s):  
Grain Growth ◽  
Dust Grain ◽  
Dust Grain Growth

scholarly journals Dust grain growth inρ-Ophiuchi protoplanetary disks

2010 ◽  
Vol 521 ◽  
pp. A66 ◽  
Author(s):  
L. Ricci ◽  
L. Testi ◽  
A. Natta ◽  
K. J. Brooks
Keyword(s):  
Grain Growth ◽  
Protoplanetary Disks ◽  
Dust Grain ◽  
Dust Grain Growth

scholarly journals Low dust emissivities and radial variations in the envelopes of Class 0 protostars: possible signature of early grain growth

2019 ◽  
Vol 632 ◽  
pp. A5 ◽  
Author(s):  
M. Galametz ◽  
A. J. Maury ◽  
V. Valdivia ◽  
L. Testi ◽  
A. Belloche ◽  
...  
Keyword(s):  
Grain Size ◽  
Star Formation ◽  
Grain Growth ◽  
Central Region ◽  
Radial Gradient ◽  
Central Regions ◽  
Dust Composition ◽  
Dust Grain ◽  
Early Phases ◽  
Inner Envelope

Context. Analyzing the properties of dust and its evolution in the early phases of star formation is crucial to put constraints on the collapse and accretion processes as well as on the pristine properties of planet-forming seeds. Aims. In this paper, we aim to investigate the variations of the dust grain size in the envelopes of the youngest protostars. Methods. We analyzed Plateau de Bure interferometric observations at 1.3 and 3.2 mm for 12 Class 0 protostars obtained as part of the CALYPSO survey. We performed our analysis in the visibility domain and derived dust emissivity index (β1−3mm) profiles as a function of the envelope radius at 200–2000 au scales. Results. Most of the protostellar envelopes show low dust emissivity indices decreasing toward the central regions. The decreasing trend remains after correction of the (potentially optically thick) central region emission, with surprisingly low β1−3mm < 1 values across most of the envelope radii of NGC 1333-IRAS 4A, NGC 1333-IRAS 4B, SVS13B, and Serpens-SMM4. Conclusions. We discuss the various processes that could explain such low and varying dust emissivity indices at envelope radii 200–2000 au. Our observations of extremely low dust emissivity indices could trace the presence of large (millimeter-size) grains in Class 0 envelopes, in which case our results would point to a radial increase of the dust grain size toward the inner envelope regions. While it is expected that large grains in young protostellar envelopes could be built via grain growth and coagulation, we stress that the typical timescales required to build millimeter grains in current coagulation models are at odds with the youth of our Class 0 protostars. Additional variations in the dust composition could also partly contribute to the low β1−3mm we observe. We find that the steepness of the β1−3mm radial gradient depends strongly on the envelope mass, which might favor a scenario in which large grains are built in high-density protostellar disks and transported to the intermediate envelope radii, for example with the help of outflows and winds.

scholarly journals The time evolution of dusty protoplanetary disc radii: observed and physical radii differ

2019 ◽  
Vol 486 (4) ◽  
pp. 4829-4844 ◽  
Author(s):  
Giovanni P Rosotti ◽  
Marco Tazzari ◽  
Richard A Booth ◽  
Leonardo Testi ◽  
Giuseppe Lodato ◽  
...  
Keyword(s):  
Outer Part ◽  
Theoretical Models ◽  
Outer Edge ◽  
Continuum Emission ◽  
Multiple Star ◽  
Star Forming ◽  
Star Forming Regions ◽  
Dust Distribution ◽  
Dust Grain ◽  
Dust Grain Growth

ABSTRACT Protoplanetary disc surveys conducted with Atacama Large Millimetre Array (ALMA) are measuring disc radii in multiple star-forming regions. The disc radius is a fundamental quantity to diagnose whether discs undergo viscous spreading, discriminating between viscosity or angular momentum removal by winds as drivers of disc evolution. Observationally, however, the sub-mm continuum emission is dominated by the dust, which also drifts inwards, complicating the picture. In this paper we investigate, using theoretical models of dust grain growth and radial drift, how the radii of dusty viscous protoplanetary discs evolve with time. Despite the existence of a sharp outer edge in the dust distribution, we find that the radius enclosing most of the dust mass increases with time, closely following the evolution of the gas radius. This behaviour arises because, although dust initially grows and drifts rapidly on to the star, the residual dust retained on Myr time-scales is relatively well coupled to the gas. Observing the expansion of the dust disc requires using definitions based on high fractions of the disc flux (e.g. 95 per cent) and very long integrations with ALMA, because the dust grains in the outer part of the disc are small and have a low sub-mm opacity. We show that existing surveys lack the sensitivity to detect viscous spreading. The disc radii they measure do not trace the mass radius or the sharp outer edge in the dust distribution, but the outer limit of where the grains have significant sub-mm opacity. We predict that these observed radii should shrink with time.

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