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Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
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
Publications
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 …
Accretion Variability Of Herbig Ae/Be Stars Observed By X-Shooter Hd 31648 And Hd 163296, I Mendigutia, Sean D. Brittain, C Eiroa, G Meeus, B Montesinos, A Mora, J Muzerolle, R D. Oudmaijer, E Rigliaco
Accretion Variability Of Herbig Ae/Be Stars Observed By X-Shooter Hd 31648 And Hd 163296, I Mendigutia, Sean D. Brittain, C Eiroa, G Meeus, B Montesinos, A Mora, J Muzerolle, R D. Oudmaijer, E Rigliaco
Publications
This work presents X-Shooter/Very Large Telescope spectra of the prototypical, isolated Herbig Ae stars HD 31648 (MWC 480) and HD 163296 over five epochs separated by timescales ranging from days to months. Each spectrum spans over a wide wavelength range covering from 310 to 2475 nm. We have monitored the continuum excess in the Balmer region of the spectra and the luminosity of 12 ultraviolet, optical, and near-infrared spectral lines that are commonly used as accretion tracers for T Tauri stars. The observed strengths of the Balmer excesses have been reproduced from a magnetospheric accretion shock model, providing a mean …
The Unusual Protoplanetary Disk Around The T Tauri Star Et Chamaeleontis, P Woitke, B Riaz, G Duchene, I Pascucci, A Ran Lyo, W.R.F. Dent, N Phillips, W F. Thi, F Menard, G J. Herczeg, E Bergin, A Brown, A Mora, I Kamp, G Aresu, Sean D. Brittain, I De Gregorio-Monsalvo, G Sandell
The Unusual Protoplanetary Disk Around The T Tauri Star Et Chamaeleontis, P Woitke, B Riaz, G Duchene, I Pascucci, A Ran Lyo, W.R.F. Dent, N Phillips, W F. Thi, F Menard, G J. Herczeg, E Bergin, A Brown, A Mora, I Kamp, G Aresu, Sean D. Brittain, I De Gregorio-Monsalvo, G Sandell
Publications
We present new continuum and line observations, along with modelling, of the faint (6−8) Myr old T Tauri star ETCha belonging to the η Chamaeleontis cluster. We have acquired Herschel/PACS photometric fluxes at 70 μm and 160 μm, as well as a detection of the [OI] 63 μm fine-structure line in emission, and derived upper limits for some other far-IR OI, CII, CO and o-H2O lines. These observations were carried out in the frame of the open time key programme GASPS, where ETCha was selected as one of the science demonstration phase targets. The Herschel data is complemented by new …
Gas In The Protoplanetary Disc Of Hd 169142: Herschel's View, G Meeus, C Pinte, P Woitke, B Montesinos, I Mendigutia, P Riviere-Marichalar, C Eiroa, G S. Mathews, B Vandenbussche, C D. Howard, A Roberge, G Sandell, G Duchene, F Menard, C A. Grady, W.R.F. Dent, I Kamp, J C. Augereau, W F. Thi, I Tilling, J M. Alacid, S Andrews, D R. Ardila, G Aresu, D Barrado, Sean D. Brittain
Gas In The Protoplanetary Disc Of Hd 169142: Herschel's View, G Meeus, C Pinte, P Woitke, B Montesinos, I Mendigutia, P Riviere-Marichalar, C Eiroa, G S. Mathews, B Vandenbussche, C D. Howard, A Roberge, G Sandell, G Duchene, F Menard, C A. Grady, W.R.F. Dent, I Kamp, J C. Augereau, W F. Thi, I Tilling, J M. Alacid, S Andrews, D R. Ardila, G Aresu, D Barrado, Sean D. Brittain
Publications
In an effort to simultaneously study the gas and dust components of the disc surrounding the young Herbig Ae star HD 169142, we present far-IR observations obtained with the PACS instrument onboard the Herschel Space Observatory. This work is part of the open time key program GASPS, which is aimed at studying the evolution of protoplanetary discs. To constrain the gas properties in the outer disc, we observed the star at several key gas-lines, including [OI] 63.2 and 145.5 mum, [CII] 157.7 mum, CO 72.8 and 90.2 mum, and o-H2O 78.7 and 179.5 mum. We only detect the [OI] 63.2 …
Warm Gas In The Inner Disks Around Young Intermediate-Mass Stars, Sean D. Brittain, Theodore Simon, Joan R. Najita, Terrence W. Rettig
Warm Gas In The Inner Disks Around Young Intermediate-Mass Stars, Sean D. Brittain, Theodore Simon, Joan R. Najita, Terrence W. Rettig
Publications
The characterization of gas in the inner disks around young stars is of particular interest because of its connection to planet formation. In order to study the gas in inner disks, we have obtained high-resolution K- and M-band spectroscopy of 14 intermediate-mass young stars. In sources that have optically thick inner disks, i.e., E(K-L)>1, our detection rate of the rovibrational CO transitions is 100%, and the gas is thermally excited. Of the five sources that do not have optically thick inner disks, we only detect the rovibrational CO transitions from HD 141569. In this case, we show that the …
Dust Stratification In Young Circumstellar Disks, Terrence Rettig, Sean D. Brittain, Theodore Simon, Erika Gibb, Dinshaw S. Balsara, David A. Tilley, Craig Kulesa
Dust Stratification In Young Circumstellar Disks, Terrence Rettig, Sean D. Brittain, Theodore Simon, Erika Gibb, Dinshaw S. Balsara, David A. Tilley, Craig Kulesa
Publications
We present high-resolution infrared spectra of four YSOs (T Tau N, T Tau S, RNO 91, and HL Tau). The spectra exhibit narrow absorption lines of 12CO, 13CO, and C18O, as well as broad emission lines of gas-phase 12CO. The narrow absorption lines of CO are shown to originate from the colder circumstellar gas. We find that the line-of-sight gas column densities resulting from the CO absorption lines are much higher than expected for the measured extinction for each source and suggest the gas/dust ratio is measuring the dust settling and/or grain coagulation in these extended disks. We provide a …
Co Line Emission And Absorption From The Hl Tauri Disk-Where Is All The Dust?, Sean D. Brittain, Terrence W. Rettig, Theodore Simon, Craig Kulesa
Co Line Emission And Absorption From The Hl Tauri Disk-Where Is All The Dust?, Sean D. Brittain, Terrence W. Rettig, Theodore Simon, Craig Kulesa
Publications
We present high-resolution infrared spectra of HL Tau, a heavily embedded young star. The spectra exhibit broad emission lines of 12CO gas-phase molecules, as well as narrow absorption lines of 12CO, 13CO, and C18O. The broad emission lines of vibrationally excited 12CO are dominated by the hot (T ~ 1500 K) inner disk. The narrow absorption lines of CO are found to originate from the circumstellar gas at a temperature of ~100 K. The 12CO column density for this cooler material [(7.5 ± 0.2) × 1018 cm-2] indicates a large column of absorbing gas along the line of sight. In …