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Full-Text Articles in Physical Sciences and Mathematics
Supernova Reverse Shocks: Sic Growth And Isotopic Composition, Ethan A-N. Deneault, Donald D. Clayton, Alexander Heger
Supernova Reverse Shocks: Sic Growth And Isotopic Composition, Ethan A-N. Deneault, Donald D. Clayton, Alexander Heger
Donald D Clayton
We present new mechanisms by which the isotopic compositions of X-type grains of presolar SiC are altered by reverse shocks in Type II supernovae. We address three epochs of reverse shocks: pressure wave from the H envelope near t ¼ 106 s, reverse shock from the presupernova wind near 108–109 s, and reverse shock from the interstellar medium near 1010 s. Using one-dimensional hydrodynamics we show that the first creates a dense shell of Si and C atoms near 106 s in which the SiC surely condenses. The second reverse shock causes precondensed grains to move rapidly forward through decelerated …
Herschel/Pacs Observations Of Young Sources In Taurus: The Far-Infrared Counterpart Of Optical Jets, L Podio, I Kamp, D Flower, C Howard, G Sandell, A Mora, G Aresu, Sean D. Brittain, W.R.F. Dent, C Pinte, G J. White
Herschel/Pacs Observations Of Young Sources In Taurus: The Far-Infrared Counterpart Of Optical Jets, L Podio, I Kamp, D Flower, C Howard, G Sandell, A Mora, G Aresu, Sean D. Brittain, W.R.F. Dent, C Pinte, G J. White
Sean D Brittain
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, …
Detection Of Ch+ Emission From The Disc Around Hd 100546, W F. Thi, F Menard, G Meeus, C. Martin-Zaidi, P Woitke, E Tatulli, M Benisty, I Kamp, I Pascucci, C Pinte, C A. Grady, Sean D. Brittain, G J. White, C D. Howard, G Sandell, C Eiroa
Detection Of Ch+ Emission From The Disc Around Hd 100546, W F. Thi, F Menard, G Meeus, C. Martin-Zaidi, P Woitke, E Tatulli, M Benisty, I Kamp, I Pascucci, C Pinte, C A. Grady, Sean D. Brittain, G J. White, C D. Howard, G Sandell, C Eiroa
Sean D Brittain
Despite its importance in the thermal balance of the gas and in the determination of primeval planetary atmospheres, the chemistry in protoplanetary discs remains poorly constrained with only a handful of detected species. We observed the emission from the disc around the Herbig Be star HD 100546 with the PACS instrument in the spectroscopic mode on board the Herschel Space Telescope as part of the GAS in Protoplanetary Systems (GASPS) programme and used archival data from the DIGIT programme to search for the rotational emission of CH+. We detected in both datasets an emission line centred at 72.16 μm that …
Nature Of The Gas And Dust Around 51 Oph, W F. Thi, F Menard, G Meeus, A Carmona, P Riviere-Marichalar, J C. Augereau, I Kamp, P Woitke, C Pinte, I Mendigutia, C Eiroa, B Montesinos, Sean D. Brittain, W Dent
Nature Of The Gas And Dust Around 51 Oph, W F. Thi, F Menard, G Meeus, A Carmona, P Riviere-Marichalar, J C. Augereau, I Kamp, P Woitke, C Pinte, I Mendigutia, C Eiroa, B Montesinos, Sean D. Brittain, W Dent
Sean D Brittain
Circumstellar disc evolution is paramount for the understanding of planet formation. The GASPS program aims at determining the circumstellar gas and solid mass around ~250 pre-main-sequence Herbig Ae and TTauri stars. We aim to understand the origin and nature of the circumstellar matter orbiting 51 Oph, a young (Myr) luminous B9.5 star. We obtained continuum and line observations with the PACS instrument on board the Herschel Space Observatory and continuum data at 1.2 mm with the IRAM 30m telescope. The SED and line fluxes were modelled using the physico-chemo radiative transfer code ProDiMo. We detected a strong emission by OI …
The Herschel View Of Gas In Protoplanetary Systems (Gasps). First Comparisons With A Large Grid Of Models, C Pinte, P Woitke, F Menard, G Duchene, I Kamp, G Meeus, G Mathews, C D. Howard, C A. Grady, W.-F. Thi, I Tilling, J.-C. Augereau, W.R.F. Dent, J M. Alacid, S Andrews, D R. Ardila, G Aresu, D Barrado, Sean D. Brittain, D R. Ciardi
The Herschel View Of Gas In Protoplanetary Systems (Gasps). First Comparisons With A Large Grid Of Models, C Pinte, P Woitke, F Menard, G Duchene, I Kamp, G Meeus, G Mathews, C D. Howard, C A. Grady, W.-F. Thi, I Tilling, J.-C. Augereau, W.R.F. Dent, J M. Alacid, S Andrews, D R. Ardila, G Aresu, D Barrado, Sean D. Brittain, D R. Ciardi
Sean D Brittain
The Herschel GASPS key program is a survey of the gas phase of protoplanetary discs, targeting 240 objects which cover a large range of ages, spectral types, and disc properties. To interpret this large quantity of data and initiate self-consistent analyses of the gas and dust properties of protoplanetary discs, we have combined the capabilities of the radiative transfer code MCFOST with the gas thermal balance and chemistry code ProDiMo to compute a grid of ≈300 000 disc models (DENT). We present a comparison of the first Herschel/GASPS line and continuum data with the predictions from the DENT grid of …
Gas Lines From The 5-Myr Old Optically Thin Disk Around Hd141569a, W F. Thi, C Pinte, E Pantin, J C. Augereau, G Meeus, F Menard, C Martin-Zaidi, P Woitke, P Riviere-Marichalar, I Kamp, A Carmona, G Sandell, C Eiroa, W Dent, B Montesinos, G Aresu, R Meijerink, M Spaans, G White, D Ardila, J Lebreton, I Mendigutia, Sean D. Brittain
Gas Lines From The 5-Myr Old Optically Thin Disk Around Hd141569a, W F. Thi, C Pinte, E Pantin, J C. Augereau, G Meeus, F Menard, C Martin-Zaidi, P Woitke, P Riviere-Marichalar, I Kamp, A Carmona, G Sandell, C Eiroa, W Dent, B Montesinos, G Aresu, R Meijerink, M Spaans, G White, D Ardila, J Lebreton, I Mendigutia, Sean D. Brittain
Sean D Brittain
At the distance of 99-116 pc, HD141569A is one of the nearest HerbigAe stars that is surrounded by a tenuous disk, probably in transition between a massive primordial disk and a debris disk. We observed the fine-structure lines of OI at 63 and 145 micron and the CII line at 157 micron with the PACS instrument onboard the Herschel Space Telescope as part of the open-time large programme GASPS. We complemented the atomic line observations with archival Spitzer spectroscopic and photometric continuum data, a ground-based VLT-VISIR image at 8.6 micron, and 12CO fundamental ro-vibrational and pure rotational J=3-2 observations. We …
Observations Of Herbig Ae/Be Stars With Herschel/Pacs. The Atomic And Molecular Contents Of Their Protoplanetary Discs, G Meeus, B Montesinos, I Mendigutia, I Kamp, W F. Thi, C Eiroa, C A. Grady, G Mathews, G Sandell, C. Martin-Zaidi, Sean D. Brittain, W.R.F. Dent, C Howard, F Menard, C Pinte, A Roberge, B Vandenbussche, J P. Williams
Observations Of Herbig Ae/Be Stars With Herschel/Pacs. The Atomic And Molecular Contents Of Their Protoplanetary Discs, G Meeus, B Montesinos, I Mendigutia, I Kamp, W F. Thi, C Eiroa, C A. Grady, G Mathews, G Sandell, C. Martin-Zaidi, Sean D. Brittain, W.R.F. Dent, C Howard, F Menard, C Pinte, A Roberge, B Vandenbussche, J P. Williams
Sean D Brittain
We observed a sample of 20 representative Herbig Ae/Be stars and 5 A-type debris discs with PACS onboard Herschel, as part of the GAS in Protoplanetary Systems (GASPS) project. The observations were done in spectroscopic mode, and cover the far-infrared lines of [O i], [C ii], CO, CH+, H2O, and OH. We have a [Oi] 63 μm detection rate of 100% for the Herbig Ae/Be and 0% for the debris discs. The [Oi] 145 μm line is only detected in 25% and CO J = 18–17 in 45% (and fewer cases for higher J transitions) of the Herbig Ae/Be stars, …