ISO spectroscopy of circumstellar dust in 14 Herbig Ae/Be systems: Towards an understanding of dust processing

By G. Meeus, L. Waters, J. Bouwman, M. V. D. Ancker, C. Waelkens, K. Malfait. 2000

469 citations recorded by the source corpus.

We present Infrared Space Observatory (ISO) spectra of fourteen isolated Herbig Ae/Be (HAEBE) stars, to study the characteristics of their circumstellar dust. These spectra show large star-to-star differences, in the emission features of both carbon-rich and oxygen-rich dust grains. The IR spectra were combined with photometric data ranging from the UV through the optical into the sub-mm region. We defined two key groups, based upon the spectral shape of the infrared region. The derived results can be summarized as follows: (1) the continuum of the IR to sub-mm region of all stars can be reconstructed by the sum of a power-law and a cool component, which can be represented by a black body. Possible locations for these components are an optically thick, geometrically thin disc (power-law component) and an optically thin flared region (black body); (2) all stars have a substantial amount of cold dust around them, independent of the amount of mid-IR excess they show; (3) also the near-IR excess is unrelated to the mid-IR excess, indicating different composition/location of the emitting material; (4) remarkably, some sources lack the silicate bands; (5) apart from amorphous silicates, we find evidence for crystalline silicates in several stars, some of which are new detections; (6) PAH bands are present in at least 50% of our sample, and their appearance is slightly different from PAHs in the ISM; (7) PAH bands are, with one exception, not present in sources which only show a power-law continuum in the IR; their presence is unrelated to the presence of the silicate bands; (8) the dust in HAEBE stars shows strong evidence for coagulation; this dust processing is unrelated to any of the central star properties (such as age, spectral type and activity).

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/f47b3e10a3583bbba84300ec877d7443e443ee1d

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In Astronomy and Astrophysics

1. C. Dullemond
2. S. Andrews
3. D. Wilner
4. Jonathan P. Williams
5. T. Birnstiel
6. A. Hughes
7. C. Qi
8. L. Hartmann

In Instrumentation

1. S. Andrews
2. D. Wilner
3. C. Dullemond
4. A. Hughes
5. T. Birnstiel
6. Xue-Ning Bai
7. C. Qi
8. Andrea Isella

Citations in the corpus

• Size-sorting dust grains in the surface layers of protoplanetary disks (2008, unknown): “These features have been studied in great detail with the Infrared Space Observatory (ISO; e.g. Meeus et al. 2001; Bouwman 2001), with ground-based instruments (van Boekel et al. 2003; Honda et al. 2003) and with the Spitzer Space Telescope (e.g. Apai et al. 2005; Kessler-Silacci et al. 2006;…”
• A SPITZER SURVEY OF MID-INFRARED MOLECULAR EMISSION FROM PROTOPLANETARY DISKS. I. DETECTION RATES (2010, background): “Why have these complex infrared emission spectra not previously been seen (e.g., Meeus et al. 2001; Kessler-Silacci et al. 2006)?”
• ISO Spectroscopy of Gas and Dust: From Molecular Clouds to Protoplanetary Disks (2004, background): “Meeus et al. (2001) divided the isolated Herbig Ae star ISO spectra into two groups: those with a rising SED (Group I) and those with a flat continuum (Group II).”
• STRUCTURES IN THE PROTOPLANETARY DISK OF HD142527 SEEN IN POLARIZED SCATTERED LIGHT (2013, background): “HD142527 is an F-type Herbig Ae/Be star (Waelkens et al. 1996; Malfait et al. 1998) that has been classified as group Ia (Meeus et al. 2001), meaning that its spectral energy disribution rises in the mid-infrared and also shows a 10 μm silicate emission feature.”
• Passive Irradiated Circumstellar Disks with an Inner Hole (2001, background): “…values of for AFNIR/F*stars (hovering around 0.17) agree well with those observed in four HAe stars by Natta et al. (2001), which range between 0.12 and 0.25, respectively, and by Meeus et al. (2001) in a sample of 14 HAe stars, where variesFNIR/F*between 0.06 and 0.3 for the group I sources.”
• Keplerian discs around post-AGB stars: a common phenomenon? (2006, methodology): “Meeus et al. (2001) classified a sample of 14 isolated HAEBE sample stars into two groups, based on the shape of the SED.”
• Triggered massive-star formation on the borders of Galactic H II regions I. A search for "collect and collapse" candidates (2004, unknown): “Most present a continuum emission increasing with wavelength; some exhibit a strong silicate emission near 10 µm, others PAH emission bands (Bouwman et al. 2001; Meeus et al. 2001).”
• Resolving the inner dust disks surrounding LkCa 15 and MWC 480 at mm wavelengths (2006, result): “This explanation agrees with the classification of MWC 480 as a group II star (Meeus et al. 2001; Acke & van den Ancker 2004).”
• Accretion disks in luminous young stellar objects (2015, background): “The dominance of circumstellar dust emission is the base for the group I/II subdivision among this class (Meeus et al., 2001).”
• From molecular cores to planet-forming disks: An SIRTF legacy program (2003, background): “Indeed, one of the major results from the SWS instrument onISO is that solid-state evolution of grain minerals occurs in disks around pre–main-sequence stars (Meeus et al. 2001).”
• A Survey and Analysis of Spitzer Infrared Spectrograph Spectra of T Tauri Stars in Taurus (2006, background): “PAH emission is typical for the more massive counterparts of T Tauri stars, the Herbig Ae/Be stars (see, e.g., Meeus et al. 2001), and their absence in the circumstellar environment of lower mass Fig.”
• The molecular composition of the planet-forming regions of protoplanetary disks across the luminosity regime (2015, background): “Disks around Herbig Ae/Be stars have been classified into groups based on the shapes of their SED at mid-IR wavelengths (Meeus et al. 2001).”
• Sub-arcsec imaging of the AB Aur molecular disk and envelope at millimeter wavelengths: a non Keplerian disk (2005, methodology): “AB Auriga has been also observed in MID-IR spectroscopy with ISO (Meeus et al. 2001; Bouwman et al. 2000).”
• The shape of the inner rim in proto-planetary disks (2005, background): “…Dullemond and Dominik (2004), who propose that the classification of Herbig Ae stars in two groups, based on the shape of the far-infrared excess (Meeus et al. 2001), can be interpreted as differences between objects where the outer disk emerges from the shadow of the inner rim and objects where…”
• A Three-dimensional View of Turbulence: Constraints on Turbulent Motions in the HD 163296 Protoplanetary Disk Using DCO+ (2017, background): “…for α ∼ 10−4 (Mulders & Dominik 2012; Pinte et al. 2016) and settling has been inferred in the disk around HD 163296 from its diminished infrared excess (Meeus et al. 2001; Juhász et al. 2010), although these infrared measures are more sensitive to the inner disk, while our ALMA constraints apply…”
• The origin of crystalline silicates in the Herbig Be star HD 100546 and in comet Hale-Bopp (2003, methodology): “In a series of papers, we have studied the dust emission from HAEBE stars (Waelkens et al. 1996; Malfait et al. 1998; Malfait et al. 1999, van den Ancker et al. 2000, 2001; Bouwman et al. 2000, 2001; Meeus et al. 2001), focusing on the mineralogical composition of the dust.”
• CO emission from discs around isolated HAeBe and Vega-excess stars (2005, unknown): “References: B99: Beskrovnaya et al., (1999); CWD98: Coulson et al. (1998); D03: Dominik et al. (2003); DC98: Dunkin & Crawford (1998); F96: Fekel et al. (1996); G00: Greaves et al. (2000); J01: Jayawardhana et al. (2001); K02: Kalas et al. (2002); K97: Kastner et al. (1997); L02: Lisse et al., (2002”