A5061825757- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Molecular Spectroscopy and Structure
- Astronomy and Astrophysical Research
- Atmospheric Ozone and Climate
- Astrophysical Phenomena and Observations
- Spectroscopy and Laser Applications
- Space Exploration and Technology
- Astronomical Observations and Instrumentation
- Atomic and Molecular Physics
- History and Developments in Astronomy
- Adaptive optics and wavefront sensing
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- Calibration and Measurement Techniques
- Gamma-ray bursts and supernovae
- Advanced Combustion Engine Technologies
- Planetary Science and Exploration
- CCD and CMOS Imaging Sensors
- Superconducting and THz Device Technology
- Advanced Chemical Physics Studies
- Plasma Diagnostics and Applications
- Plasma and Flow Control in Aerodynamics
- Bee Products Chemical Analysis
University of Hawaii at Hilo
1994-2024
University of Hawaiʻi at Mānoa
2021-2024
University of Hawaii System
2020
Ames Research Center
2007-2018
Max Planck Society
2015
Max Planck Institute for Radio Astronomy
2015
Universities Space Research Association
2001-2014
Goddard Space Flight Center
2010
University of Helsinki
1982-2008
Joint Research Centre
2007-2008
The Stratospheric Observatory For Infrared Astronomy (SOFIA) is an airborne observatory consisting of a specially modified Boeing 747SP with 2.7 m telescope, flying at altitudes as high 13.7 km (45,000 ft). Designed to observe wavelengths from 0.3 μm 1.6 mm, SOFIA operates above 99.8% the water vapor that obscures much infrared and submillimeter. has seven science instruments under development, including occultation photometer, near-, mid-, far-infrared cameras, spectrometers, heterodyne...
We present λ1.3 mm CARMA observations of dust polarization toward 30 star-forming cores and 8 regions from the TADPOL survey. show maps all sources, compare ~2.5" resolution with ~20" single-dish submillimeter telescopes. Here we do not attempt to interpret detailed B-field morphology each object. Rather, use average orientations derive conclusions in a statistical sense ensemble bearing mind that these can be quite uncertain. discuss three main findings: (1) A subset sources have consistent...
Molecular line surveys and fully sampled spectral maps at 1.3 0.87 mm are used to examine the physical chemical characteristics of extreme Class I sources IRAS 4A 4B in L1450/NGC 1333 molecular cloud complex. A very well collimated, jetlike outflow emanates from 4A, with a dynamical age few thousand years. Symmetric, clumpy structure along lobes suggests that there is considerable variability mass-loss rate or wind velocity even this young age. emission lines toward observed be weak range...
We present wide-field near-infrared (IR) images of the DR21/W75 high-mass star-forming region, obtained with Wide Field Camera (WFCAM) on United Kingdom Infrared Telescope. Broad-band JHK and narrow-band H2 1-0S(1) are compared to archival mid-IR from Spitzer Space Telescope, 850-μm dust-continuum maps Submillimeter Common User Bolometer Array (SCUBA). Together these data give a complete picture dynamic star formation across this extensive which includes at least four separate sites in...
We observed a sample of 20 representative Herbig Ae/Be stars and 5 A-type debris discs with PACS onboard Herschel, as part the GAS in Protoplanetary Systems (GASPS) project. The observations were done spectroscopic mode, cover far-infrared lines [O i], [C ii], CO, CH+, H2O, OH. have i] 63 μm detection rate 100% for 0% discs. 145 line is only detected 25% CO J = 18–17 45% (and fewer cases higher transitions) stars, while ii] 157 μm, we often find spatially variable background contamination....
We describe a large-scale far-infrared line and continuum survey of protoplanetary disk through to young debris systems carried out using the ACS instrument on Herschel Space Observatory. This Open Time Key program, known as GASPS (Gas Survey Protoplanetary Systems), targeted ∼250 stars in narrow wavelength regions covering [OI] fine structure at 63 μm brightest such objects. A subset targets were also surveyed [OI]145 μm, [CII] 157 well several transitions H2O high-excitation CO lines...
view Abstract Citations (160) References (46) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Distribution of Molecules in the Core OMC-1 Sutton, E. C. ; Peng, R. Danchi, W. Jaminet, P. A. Sandell, G. Russell, We have surveyed molecular line emission from five positions near core Orion cloud OMC-1, vicinity Orion-KL, with 14 sec spatial resolution. frequency coverage survey was 334 to 343 GHz. A maximum entropy analysis has been used deconvolve...
We present large (13' × 18') and sensitive continuum maps at 850 450 μm of the NGC 1333 star formation region. identify 33 submillimeter sources, some which are extended may contain multiple condensations. Very few sources have optical or near-IR counterparts. In addition to previously known bright class 0 this survey suggests that many fainter also likely be very young low-mass protostars. find several dust ridges shells formed by outflows in cloud, two cases we protostellar whose is been...
view Abstract Citations (192) References (16) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Submillimeter Measurements of T Tauri and FU Orionis Stars Weintraub, David A. ; Sandell, G. Duncan, W. D. Millimeter submillimeter detections 12 low-mass, premain-sequence stars are reported: nine stars, one SU Aurigae star, two stars. The submm spectra found to be less steep than that expected from optically thin thermal dust emission. emissivity index, beta, is...
Water is key in the evolution of protoplanetary disks and formation comets icy/water planets. While high excitation water lines originating hot inner disk have been detected several T Tauri stars (TTSs), vapor from outer disk, where most ice reservoir stored, was only reported closeby TTS TW Hya. We present spectrally resolved Herschel/HIFI observations young DG Tau ortho- para- ground-state transitions at 557, 1113 GHz. The show a narrow double-peaked profile, consistent with an origin are...
We present high signal-to-noise, moderate spectral resolution (R ~ 2000-2500) near-infrared (0.8-5.0 micron) spectroscopy of the nearby T Tauri star TW Hya. By comparing spectrum and equivalent widths several atomic molecular features with those for stars in IRTF library, we revise type to M2.5V, which is later than usually adopted (K7V). This implies a substantially cooler stellar temperature previously assumed. Comparison various pre-main sequence models suggests that Hya only ~3 Myr old;...
HD 100546 is a well-studied Herbig Be star-disk system that likely hosts close-in companion with compelling observational evidence for an embedded protoplanet at 68 AU. We present Atacama Large Millimeter/Submillimeter Array observations of the disk which resolve gas and dust structure (sub)millimeter wavelengths. The CO emission (at 345.795 GHz) originates from extensive molecular (390 ± 20 AU in radius) whereas continuum more compact (230 radius), suggesting radial drift millimeter-sized...
Theoretical models of star formation make predictions about the density and velocity structure envelopes surrounding isolated, low-mass young stars. This paper tests such through high-quality submillimeter continuum imaging four embedded stellar objects in Taurus previously obtained molecular-line data. Observations carried out with Submillimeter Continuum Bolometer Array on James Clerk Maxwell Telescope at 850 450 μm L1489 IRS, L1535 L1527 TMC 1 reveal ~2000 AU elongated structures extended...
On the basis of analysis new submillimeter maps a sample most known FU Orionis stars, we confirm that these stars are extremely young, more similar to Class I protostars than II T Tauri stars. The reveal have accretion disks larger and contain an order magnitude mass those but comparable in seen around sources. sufficiently massive act as reservoirs material for replenishing after eruptions, which large amounts believed fall onto underlying We identified number surrounded by extended cloud...
This paper is the first attempt to establish a set of secondary calibrators for submillimetre continuum photometry. In total we include photometry on 21 sources (ultracompact H II regions, compact bipolar outflow and protoplanetaries). These are all calibrated relative Mars Uranus, which primary standards. Data given major atmospheric windows in (sub)millimetre regime standard broad-band filters used commonuser bolometer UKT14, i.e. 2, 1.3 1.1 mm, 800, 450 350 µm. For most sources, some data...
view Abstract Citations (131) References (22) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS NGC 1333 IRAS 4: A Very Young, Low-Luminosity Binary System Sandell, Goran ; Aspin, Colin Duncan, William D. Russell, Adrian P. G. Robson, E. I. 4 is a cold, low luminosity source in the active star formation region 1333. The present sub-mm photometry and high spatial resolution 800- 450-micron maps resolve this into binary system whose components are separated by...
We present deep images of dust continuum emission at 450, 800, and 850 μm the dark cloud LDN 1689N, which harbors low-mass young stellar objects (YSOs) IRAS 16293-2422 A B (I16293A I16293B) cold prestellar object I16293E. Toward positions I16293A I16293E we also obtained spectra CO-isotopomers submillimeter observations chemically related molecules with high critical densities (HCO+, H13CO+, DCO+, H2O, HDO, H2D+). report detection HDO 101-000 H2O 110-101 ground-state transitions as broad...
We present detailed model fits to observations of the disc around Herbig Ae star HD 163296. This well-studied object has an age ~ 4 Myr, with evidence a circumstellar extending out 540AU. use radiation thermo-chemical code ProDiMo gas and dust in 163296, attempt determine properties by fitting observational line continuum data. These include new Herschel/PACS obtained as part open-time key program GASPS (Gas Protoplanetary Systems), consisting detection [OI]63mic upper limits for several...
We present new continuum and line observations, along with modelling, of the faint (6-8) Myr old T Tauri star ET Cha belonging to eta Chamaeleontis cluster. have acquired HERSCHEL/PACS photometric fluxes at 70 mic 160 mic, as well a detection [OI] 63 fine-structure in emission, derived upper limits for some other far-IR OI, CII, CO o-H2O lines. The HERSCHEL data is complemented by ANDICAM B-K photometry, HST/COS HST/STIS UV-observations, non-detection J=3-2 APEX, re-analysis UCLES...
We have acquired sub-millimeter observations of 33 fields containing 37 Herbig Ae/Be (HAEBE) stars or potential HAEBE stars, including SCUBA maps all but two these stars. Nine target show extended dust emission. The other 18 are unresolved, suggesting that the envelopes disks around less than a few arcseconds in angular size. In several cases we find strongest emission originates from younger, heavily embedded sources rather star, which means previous models must be viewed with caution....
The Herschel Space Observatory was used to observe ~ 120 pre-main-sequence stars in Taurus as part of the GASPS Open Time Key project. PACS measure continuum well several gas tracers such [OI] 63 \mu m, 145 [CII] 158 OH, H2O and CO. strongest line seen is at m. We find a clear correlation between strength m for disk sources. In outflow sources, emission can be up 20 times stronger than suggesting that dominated by outflow. tight sources suggests arises from inner ($<$ 50 AU) lower surface...
Despite its importance in the thermal-balance of gas and determination primeval planetary atmospheres, chemistry protoplanetary discs remains poorly constrained with only a handful detected species. We observed emission from disc around Herbig Be star HD 100546 PACS instrument spectroscopic mode on board Herschel Space Telescope as part Gas Protoplanetary Systems (GASPS) programme used archival data DIGIT to search for rotational CH+. both datasets an line centred at 72.16 micron that most...
Planets are formed in disks around young stars. With an age of ~10 Myr, TW Hya is one the nearest T Tauri stars that still surrounded by a relatively massive disk. In addition large number molecules has been found disk, making perfect test case survey with <i>Herschel<i/>–PACS to directly study their gaseous component. We aim constrain gas and dust mass circumstellar disk Hya. observed fine-structure lines [O i] [C ii] as part open-time program GASPS. complement this continuum data...
Line spectra of 68 Taurus T Tauri stars were obtained with the Herschel-PACS (Photodetector Array Camera & Spectrometer) instrument as part GASPS (Gas Evolution in Protoplanetary Systems) survey protoplanetary discs. A careful examination line scans centred on [OI] 63.18 microns fine-structure unveiled a at 63.32 micron some these spectra. We identify this transition ortho-water. It is detected confidently (i.e., >3 sigma) eight sources, i.e., 24% sub-sample gas-rich Several statistical...