The<i>Herschel</i>view of GAS in Protoplanetary Systems (GASPS)

Pinte, C.; Woitke, P.; Ménard, F.; Duchêne, Gaspard; Kamp, I.; Meeus, G.; Mathews, Geoffrey S.; Howard, Christian D.; Grady, C. A.; Thi, Wing-Fai; Tilling, I.; Augereau, J.-C.; Dent, W. R. F.; Alacid, J. M.; Andrews, Sean M.; Ardila, D. R.; Aresu, G.; Barrado, D.; Brittain, S.; Ciardi, David R.; Danchi, W. C.; Eiroa, C.; Fedele, D.; Gregorio-Monsalvo, I. de; Heras, A. M.; Huélamo, N.; Krivov, A. V.; Lebreton, J.; Liseau, R.; Martin-Zaidi, C.; Mendigutía, I.; Montesinos, B.; Mora, A.; Morales-Calderón, M.; Nomura, Hideko; Pantin, E.; Pascucci, Ilaria; Phillips, Neil; Podio, L.; Poelman, D. R.; Ramsay, Suzanne; Riaz, B.; Rice, Ken; Riviére-Marichalar, P.; Roberge, Aki; Sandell, G.; Solano, E.; Vandenbussche, B.; Walker, H. J.; Williams, Jonathan P.; White, G. J.; Wright, G. S.

doi:10.1051/0004-6361/201014591

Cited by 23 publications

(8 citation statements)

References 24 publications

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“…In Figure 5, bottom panel, we plot the [O I] 63 µm line flux as a function of the UV luminosity (calculated as lower limits from atmosphere models in the range of 1150-2430 Å). For HAe stars, there is a correlation between the [O I] 63 µm flux and the UV luminosity, as reported earlier for a limited sample in Pinte et al (2010) and supported by disc models in Kamp et al (2011) can be a consequence of an increase in OH photo-dissociation in the disc surface and/or close to the star, therefore a PDR emission result from the UV irradiation of the outflow. In addition, the data presented in this paper -enhanced [O I], [C II] and CO lines, as well as the presence of water lines-show clear evidence for emission from the shocked material due to the presence of the outflow, which can add up to the [O I] emission from the disc.…”

Section: [O I] and [C Ii]supporting

confidence: 81%

Herschel observations of the circumstellar environments of the Herbig Be stars R Mon and PDS 27

Jiménez-Donaire

Meeus

Karska

et al. 2017

A&A

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Context. The circumstellar environment of Herbig Be stars in the far-infrared is poorly characterised, mainly because they are often embedded and rather distant. The analysis of far-infrared spectroscopy allows us to make a major step forward by covering multiple rotational lines of molecules, e.g. CO, that are useful probes of physical conditions of the gas. Aims. To characterise the gas and dust in the disc and environment of Herbig Be stars, and to compare the results with those of their lower-mass counterparts, the Herbig Ae stars. Methods. We report and analyse far-infrared observations of two Herbig Be stars, R Mon and PDS 27, obtained with Herschel's instruments PACS and SPIRE. We construct spectral energy distributions and derive the infrared excess. We extract line fluxes from the PACS and SPIRE spectra and construct rotational diagrams in order to estimate the excitation temperature of the gas. We derive CO, [O I] and [C I] luminosities to determine physical conditions of the gas, as well as the dominant cooling mechanism. Results. We confirm that the Herbig Be stars are surrounded by remnants from their parental clouds, with an IR excess that mainly originates in a disc. In R Mon we detect [O I], [C I], [C II], CO (26 transitions), water and OH, while in PDS 27 we only detect [C I] and CO (8 transitions). We attribute the absence of OH and water in PDS 27 to UV photo-dissociation and photo-evaporation. From the rotational diagrams, we find several components for CO: we derive T rot 949±90 K, 358±20 K & 77±12 K for R Mon, 96±12 K & 31±4 K for PDS 27 and 25±8 K & 27±6 K for their respective compact neighbours. The forsterite feature at 69 µm was not detected in either of the sources, probably due to the lack of (warm) crystalline dust in a flat disc. We find that cooling by molecules is dominant in the Herbig Be stars, while this is not the case in Herbig Ae stars where cooling by [O I] dominates. Moreover, we show that in the Herbig Be star R Mon, outflow shocks are the dominant gas heating mechanism, while in Herbig Ae stars this is stellar. Conclusions. The outflow of R Mon contributes to the observed line emission by heating the gas, both in the central spaxel/beam covering the disc and the immediate surroundings, as well as in those spaxels/beams covering the parabolic shell around it. PDS 27, a B2 star, has dispersed a large part of its gas content and/or destroyed molecules; this is likely given its intense UV field.

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Section: [O I] and [C Ii]supporting

confidence: 81%

Herschel observations of the circumstellar environments of the Herbig Be stars R Mon and PDS 27

Jiménez-Donaire

Meeus

Karska

et al. 2017

A&A

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“…Results from some subsets of the GASPS study have been presented in previous papers. A summary of the 'science demonstration' observations of a small number of targets was given in Mathews et al (2010), and a comparison of these data with a broad grid of disk models was shown by Pinte et al (2010) In most of the older gas-poor systems the lines were not detected, however, the far-IR photome-try has been used to improve the SEDs and dust modeling (Donaldson et al 2012;Lebreton et al 2012).…”

Section: First Resultsmentioning

confidence: 99%

GASPS—A Herschel Survey of Gas and Dust in Protoplanetary Disks: Summary and Initial Statistics

Dent¹,

Thi²,

Kamp³

et al. 2013

Publications of the Astronomical Society of the Pacific

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We describe a large-scale far-infrared line and continuum survey of protoplanetary disk through to young debris disk systems carried out using the PACS instrument on the Herschel Space Observatory. This Open Time Key Program, known as GASPS (Gas Survey of Protoplanetary Systems), targeted ∼250 young stars in narrow wavelength regions covering the [OI] fine structure line at 63µm, the brightest far-infrared line in such objects. A subset of the brightest targets were also surveyed in [OI] 145µm, [CII] at 157µm, as well as several transitions of H 2 O and high-excitation CO lines at selected wavelengths between 78 and 180µm. Additionally, GASPS included continuum photometry at 70, 100 and 160µm, around the peak of the dust emission. The targets were SED Class II-III T Tauri stars and debris disks from 7 nearby young associations, along with a comparable sample of isolated Herbig AeBe stars. The aim was to study the global gas and dust content in a wide sample of circumstellar disks, combining the results with models in a systematic way. In this overview paper we review the scientific aims, target selection and observing strategy. We summarise some of the initial results, showing line identifications, listing the detections, and giving a first statistical study of line detectability.The [OI] line at 63µm was the brightest line seen in almost all objects, by a factor of ∼ 10. Overall [OI]63µm detection rates were 49%, with 100% of HAeBe stars and 43% of T Tauri stars detected. A comparison with published disk dust masses (derived mainly from sub-mm continuum, assuming standard values of the mm mass opacity) shows a dust mass threshold for [OI]63µm detection of ∼ 10 −5 M . Normalising to a distance of 140pc, 84% of objects with dust masses ≥ 10 −5 M can be detected in this line in the present survey, along with 32% of those of mass 10 −6 − 10 −5 M , and only a very small number of unusual objects with lower masses. This is consistent with models with a moderate UV excess and disk flaring. For a given disk mass, [OI] detectability is lower for M stars compared with earlier spectral types. Both the continuum and line emission was, in most systems, spatially and spectrally unresolved and centred on the star, suggesting emission in most cases was from the disk. Approximately 10 objects showed resolved emission, most likely from outflows.In the GASPS sample, [OI] detection rates in T Tauri associations in the 0.3-4Myr age range were ∼50%. For each association in the 5-20Myr age range, ∼2 stars remain detectable in [OI]63µm, and no systems were detected in associations with age >20Myr. Comparing with the total number of young stars in each association, and assuming a ISM-like gas/dust ratio, this indicates that ∼18% of stars retain a gas-rich disk of total mass 1M Jupiter for 1-4Myr, 1-7% keep such disks for 5-10Myr, but none are detected beyond 10-20Myr.The brightest [OI] objects from GASPS were also observed in [OI]145µm, [CII]157µm and CO J=18-17, with detection rates of 20-40%. Detection of the [CII] line was not corr...

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“…To understand how much the disk can contribute to the extended [O i] and [C ii] atomic lines and to the unresolved molecular emission, we compare observed line fluxes and ratios with predictions from the DENT grid of disk models Pinte et al 2010;Kamp et al 2011). The DENT grid consists of 300 000 disk models spanning a large range of parameters defining the source (mass, M * , temperature, T e f f , luminosity, L * , UV excess) and the disk (disk gas mass, gas-to-dust ratio, inner and outer disk radius, R in , R out , surface density, flaring, dust grain size distribution, dust settling, disk inclination) properties.…”

Section: Emission From Disksmentioning

confidence: 99%

Herschel/PACS observations of young sources in Taurus: the far-infrared counterpart of optical jets

Podio

Kamp²,

Flower

et al. 2012

A&A

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108

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Context. Observations of the atomic and molecular line emission associated with jets and outflows emitted by young stellar objects provide sensitive diagnostics of the excitation conditions, and can be used to trace the various evolutionary stages they pass through as they evolve to become main sequence stars. Aims. To understand the relevance of atomic and molecular cooling in shocks, and how accretion and ejection efficiency evolves with the evolutionary state of the sources, we will study the far-infrared counterparts of bright optical jets associated with Class I and II sources in Taurus (T Tau, DG Tau A, DG Tau B, FS Tau A+B, and RW Aur). Results. All of the targets are associated with extended emission in the atomic lines; in particular, the strong [O i] 63 μm emission is correlated with the direction of the optical jet/mm-outflow. The line ratios suggest that the atomic lines can be excited in fast dissociative J-shocks occurring along the jet. The molecular emission, on the contrary, originates from a compact region, that is spatially and spectrally unresolved, and lines from highly excited levels are detected (e.g., the o-H 2 O 8 18 -7 07 line, and the CO J = 36−35 line). Disk models are unable to explain the brightness of the observed lines (CO and H 2 O line fluxes up to 10 −15 −6 × 10 −16 W m −2 ). Slow C-or J-shocks with high pre-shock densities reproduce the observed H 2 O and high-J CO lines; however, the disk and/or UV-heated outflow cavities may contribute to the observed emission. Conclusions. Similarly to Class 0 sources, the FIR emission associated with Class I and II jet-sources is likely to be shock-excited. Methods. We have analysedWhile the cooling is dominated by CO and H 2 O lines in Class 0 sources, [O i] becomes an important coolant as the source evolves and the environment is cleared. The cooling and mass loss rates estimated for Class II and I sources are one to four orders of magnitude lower than for Class 0 sources. This provides strong evidence to indicate that the outflow activity decreases as the source evolves.

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TheHerschelview of GAS in Protoplanetary Systems (GASPS)

Cited by 23 publications

References 24 publications

Herschel observations of the circumstellar environments of the Herbig Be stars R Mon and PDS 27

Herschel observations of the circumstellar environments of the Herbig Be stars R Mon and PDS 27

GASPS—A Herschel Survey of Gas and Dust in Protoplanetary Disks: Summary and Initial Statistics

Herschel/PACS observations of young sources in Taurus: the far-infrared counterpart of optical jets

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