Debris disks around stars in the NIKA2 era

Lestrade, J. F.; Augereau, J.-C.; Booth, Mark; Adam, R.; Ade, Peter A. R.; André, P.; Andrianasolo, A.; Aussel, H.; Beelen, Anita; Benoı̂t, A.; Bideaud, A.; Bourrion, O.; Calvo, M.; Catalano, A.; Comis, B.; Petris, M. De; Désert, F.‐X.; Doyle, S.; Driessen, E. F. C.; Gómez, A.; Goupy, J.; Holland, W. S.; Kéruzoré, F.; Krämer, C.; Ladjelate, B.; Lagache, G.; Leclercq, S.; Lefèvre, Charlène; Macías-Pérez, J. F.; Mauskopf, Philip Daniel; Mayet, F.; Monfardini, A.; Perotto, L.; Pisano, G.; Revéret, V.; Ritacco, A.; Romero, C.; Roussel, H.; Ruppin, F.; Schuster, K.; Shu, S.; Sievers, A.; Tucker, C.; Zylka, R.

doi:10.1051/epjconf/202022800015

Cited by 4 publications

(7 citation statements)

References 19 publications

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“…Eventually, the overabundance of particles of selected sizes -if compared to a grain size distribution resulting from an ideal collisional cascade -may become observable as a result of collision events in debris discs. Here, one would expect a change of the slope of the spectral energy distribution in the wavelength region in which grains of that specific size emit most efficiently (for a potential observation of this phenomenon see Lestrade et al 2020).…”

Section: Results In the Context Of Protoplanetary And Debris Disc Obs...mentioning

confidence: 99%

Sub-mm/mm optical properties of real protoplanetary matter derived from Rosetta/MIRO observations of comet 67P

Burger

Glißmann

Lethuillier

et al. 2022

Monthly Notices of the Royal Astronomical Society

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Optical properties are required for the correct understanding and modelling of protoplanetary and debris discs. By assuming that comets are the most pristine bodies in the solar system, our goal is to derive optical constants of real protoplanetary material. We determine the complex index of refraction of the near-surface material of comet 67P/Churyumov-Gerasimenko by fitting the sub-millimetre/millimetre observations of the thermal emission of the comet’s sub-surface made by the Microwave Instrument for the Rosetta Orbiter (MIRO) with synthetic temperatures derived from a thermophysical model and radiative-transfer models. According to the two major formation scenarios of comets, we model the sub-surface layers to consist of pebbles as well as of homogeneously packed dust grains. In the case of a homogeneous dusty surface material, we find a solution for the length-absorption coefficient of α ≈ 0.22 cm−1 for a wavelength of 1.594 mm and α ≥ 3.84 cm−1 for a wavelength of 0.533 mm and a constant thermal conductivity of 0.006 Wm−1K−1. For the pebble scenario, we find for the pebbles and a wavelength of 1.594 mm a complex refractive index of n = (1.074 − 1.256) + i (2.580 − 7.431) · 10−3 for pebble radii between 1 mm and 6 mm. Taking into account other constraints, our results point towards a pebble makeup of the cometary sub-surface with pebble radii between 3 mm and 6 mm. The derived real part of the refractive index is used to constrain the composition of the pebbles and their volume filling factor. The optical and physical properties are discussed in the context of protoplanetary and debris disc observations.

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Section: Results In the Context Of Protoplanetary And Debris Disc Obs...mentioning

confidence: 99%

Sub-mm/mm optical properties of real protoplanetary matter derived from Rosetta/MIRO observations of comet 67P

Burger

Glißmann

Lethuillier

et al. 2022

Monthly Notices of the Royal Astronomical Society

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“…Furthermore, for the particular case of debris disks around HD107146, referenced in Sect. 1, a local decrease in the long wavelength regime of the SED ranging from 800 µm to 6 mm has been observed (Lestrade et al 2020). A possible explanation for this finding is to link it to the peculiarities of the grain size distribution, where the deep depletion of the abundance of grains in the size range of hundreds of micrometers coincides with the characteristic grain size for strongly absorbing materials (∼ approximately ranging from 100 to 1000 µm; Backman & Paresce 1993).…”

Section: Broken Power Law Grain Size Distributionmentioning

confidence: 91%

“…Narrow belt's fractional width ∆R/R ∼ 0.17 (a) (Lestrade & Thilliez 2015) Broad belt's fractional width ∆R/R ∼ 1.20 (b) (Marino et al 2020) Distance d 7.7 pc (Mamajek 2012) Radial density distribution n (r) n (r) ∝ r −1.5 (Krivov et al 2006) Dust composition and bulk density Astrosil and 3.5 g cm −3 (Draine 2003) Minimum grain radius a min a bo (c) (Kirchschlager & Wolf 2013) or 0.264 µm (Kim et al 2018) Maximum grain radius a max 10 cm (Lestrade et al 2020) Notes. (a,b,c) See Table 2.…”

Section: Parameter Valuementioning

confidence: 99%

“…Consequently, the presence of overabundant or underabundant particle sizes at these wavelengths potentially leaves an observable imprint in the SED. For example, the recent NIKA2 observation of HD 107146 indicates a break at the far-IR and sub-millimeter/millimeter wavelength regimes (Lestrade et al 2020), which is further supported by supplementary observations, possibly showing a change in the slope of the SED (e.g., Holland et al 2017;Ricci et al 2015b). In this particular case, the spatial distribution of dust in this debris disk system cannot be a reason for this break at long wavelength because HD 107146 is observed as a narrow belt system (Marino et al 2018).…”

Section: Parameter Valuementioning

confidence: 99%

“…Furthermore, using Mie theory, silicate or ice grains comparable to this size are hardly affected by the stellar radiation pressure in debris disks around a solartype star (Cataldi 2016). We adopted a maximum grain radius of 10 cm (Lestrade et al 2020;Pawellek et al 2021) to analyze the dust continuum up to a wavelength of a few millimeters (e.g., ATCA Survey; Ricci et al 2015b). We note that the contribution of larger grains to the net flux is negligible when considering a steep grain size distribution.…”

Section: Model Parameters Of Debris Disk Systemmentioning

confidence: 99%

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Impact of discontinuous grain size distributions on the spectral energy distribution of debris disks

Kim,

Wolf

2024

A&A

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The collisional evolution of debris disks is expected to cause the characteristic wavy pattern, that is, an under- or overabundance of particles of specific sizes, of grain size distributions. This perturbed grain size distribution potentially leaves characteristic patterns in the spectral energy distribution (SED) of the disk system. We aim to quantify and understand the specific influence of discontinuous particle size distributions on the appearance of debris disks. For this purpose, we considered dust emission models based on two different grain size distributions, namely, one with a single power law and one with a broken power law. In particular, our study is focused on the impact of an overabundance of small grains and an underabundance of medium-sized grains on the far-IR and (sub-)millimeter regime on the dust reemission radiation and the potential to constrain discontinuities in the grain size distribution from (sub-)millimeter photometric measurements of debris disks. We compared the spectral index alpha ($F_ nu alpha $) in the case of a continuous grain size distribution with that of a discontinuous grain size distribution. We performed this comparison for central stars with different spectral types and two different disk structures (e.g., slim and broad debris dust rings). Within the considered parameter space, we found a characteristic difference between the spectral slopes of the SED in the different scenarios. In particular, the overabundance of small grains resulting from collisional events and thus parameters defining the outcome of disk events in debris disks is potentially observable by comparison with the SED corresponding to a grain size distribution resulting from an ideal collisional cascade. More specifically, the overabundance of small grains leads to a steeper slope in the far-IR and sub-millimeter regime, while the spectral index in the millimeter regime is hardly affected. On the other hand, the underabundance of medium-sized grains results in a slight steepening of the far-IR slope of the SED, but its primary effect is on the millimeter slope of the SED, causing it to become shallower. We also found that the impact of an overabundance of small dust particles is more pronounced than that of an underabundance of medium-sized dust particles. We also found that the difference between the spectral indices for the two different grain size distributions is largest for debris disks around brighter central stars and broader disks. However, the impact of the considered spatial distributions described by the fractional width of the disk system is weak. Our results also show that the dust composition is not the sole physical mechanism responsible for the spectral inversion observed in the far-IR to millimeter part of the SED of debris disk systems. Furthermore, the location of the spectral break is placed at different wavelength regimes if the grain size distribution is considered as a function of blowout size and stellar type.

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Development and application of metamaterial-based half-wave plates for the NIKA and NIKA2 polarimeters

Pisano

Ritacco

Monfardini

et al. 2022

A&A

Self Cite

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Context. Large field-of-view imaging and polarimetry instruments operating at millimetre and sub-millimetre wavelengths are fundamental tools to understand the role of magnetic fields in channelling filament material into prestellar cores, providing unique insight in the physics of galactic star-forming regions. Among other topics, at extra-galactic scales, polarisation observations of Active Galactic Nuclei (AGNs) will allow us to constrain the possible physical conditions of the emitting plasma from the jets and/or explore the physics of dust inside supernova remnants. The kilo-pixel New IRAM KIDs Array 2 (NIKA2) camera, installed today at the Institut de Radioastronomie Millimétrique (IRAM) 30-m telescope, represents one of the best tools available to astronomers to produce simultaneous intensity and polarimetry maps over large fields at 260 GHz (1.15 mm). Aims. The polarisation measurement, in NIKA and NIKA2, is achieved by rapidly modulating the total incoming polarisation. In the end, this allows one to safely isolate the small science signal from the large, un-polarised, and strongly variable, atmospheric background. Methods. The polarisation modulation is achieved by inserting a fast rotating half-wave plate (HWP) in the optical beam. In order to allow wide field-of-view observations, the plate has to be large, with a diameter of 250 mm. The modulation of the polarised signal at 12 Hz also requires the waveplate to be sufficiently light. In addition, this key optical element has to exhibit optimal electromagnetic characteristics in terms of transmission and differential phase-shift. For this purpose, three metamaterial HWPs have been developed using the mesh-filter technology. The knowledge acquired in developing the first two single-band HWPs was used to achieve the more challenging performance requirements of the last dual-band HWP. The first and the third waveplates met the requirements for both the NIKA and NIKA2 instruments. Results. We first illustrate the design, the technical developments, the fabrication, and laboratory characterisation of the three mesh-HWPs. The deployment of two such elements in the NIKA and NIKA2 instruments at the 30-metre telescope is then described. We conclude with representative examples of astrophysical maps integrating polarimetry.

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Debris disks around stars in the NIKA2 era

Cited by 4 publications

References 19 publications

Sub-mm/mm optical properties of real protoplanetary matter derived from Rosetta/MIRO observations of comet 67P

Sub-mm/mm optical properties of real protoplanetary matter derived from Rosetta/MIRO observations of comet 67P

Impact of discontinuous grain size distributions on the spectral energy distribution of debris disks

Development and application of metamaterial-based half-wave plates for the NIKA and NIKA2 polarimeters

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