344 research outputs found
L1551NE - Discovery of a Binary Companion
L1551NE is a very young (class 0 or I) low-mass protostar located close to
the well-studied L1551 IRS5. We present here evidence, from 1.3mm continuum
interferometric observations at ~1'' resolution, for a binary companion to
L1551NE. The companion, whose 1.3mm flux density is ~1/3 that of the primary
component, is located 1.43'' (~230 A.U. at 160pc) to the southeast. The
millimeterwave emission from the primary component may have been just barely
resolved, with deconvolved size ~0.82"x0.70" (~131x112 A.U.). The companion
emission was unresolved (<100 A.U.). The pair is embedded within a flattened
circum-binary envelope of size ~5.4'' x 2.3'' (~860 x 370 A.U.). The masses of
the three components (i.e. from the cicumstellar material of the primary star
and its companion, and the envelope) are approximately 0.044, 0.014 and 0.023
Mo respectively.Comment: 8 pages, 1 figur
The compact far infrared emission from the young stellar object IRAS 16293-2422
High resolution far IR observations at 50 and 100 microns were made of the young stellar object (YSO), IRAS 16293-2422. The observations are part of a systematic high resolution study of nearby YSO's. The purpose is to obtain resolution in the far IR comparable to that at other wavelengths. Until recently, the high resolution that has been available in the far IR has been from either IRAS (angular resolution of approx 4 min) or the KAO using standard FIR photometry (approx 35 sec). With scanning techniques, it is possible to obtain 10 sec resolution on bright sources. Such a resolution is necessary to better determine the physical conditions of the YSO, and to compare with model of star formation. In order to better constrain the models for the source, the YSO was observed at both 50 and 100 microns on several flights in 1988 April from the KAO. Estimates are presented of the size both along the major and minor axis of the disk, as well as estimates of the dust temperature and 100 micron opacity for the YSO
Star Formation in the Northern Cloud Complex of NGC 2264
We have made continuum and spectral line observations of several outflow
sources in the Mon OB1 dark cloud (NGC 2264) using the Heinrich Hertz Telescope
(HHT) and ARO 12m millimeter-wave telescope. This study explores the kinematics
and outflow energetics of the young stellar systems observed and assesses the
impact star formation is having on the surrounding cloud environment. Our data
set incorporates 12CO(3-2), 13CO(3-2), and 12CO(1-0) observations of outflows
associated with the sources IRAS 06382+1017 and IRAS 06381+1039, known as IRAS
25 and 27, respectively, in the northern cloud complex. Complementary 870
micron continuum maps were made with the HHT 19 channel bolometer array. Our
results indicate that there is a weak (approximately less than 0.5%) coupling
between outflow kinetic energy and turbulent energy of the cloud. An analysis
of the energy balance in the IRAS 25 and 27 cores suggests they are maintaining
their dynamical integrity except where outflowing material directly interacts
with the core, such as along the outflow axes.Comment: 28 pages including 6 figures, to be published in ApJ 01 July 2006,
v645, 1 issu
Non-Intrusive Load Monitoring Assessment: Literature Review and Laboratory Protocol
To evaluate the accuracy of NILM technologies, a literature review was conducted to identify any test protocols or standardized testing approaches currently in use. The literature review indicated that no consistent conventions were currently in place for measuring the accuracy of these technologies. Consequently, PNNL developed a testing protocol and metrics to provide the basis for quantifying and analyzing the accuracy of commercially available NILM technologies. This report discusses the results of the literature review and the proposed test protocol and metrics in more detail
Results of the engineering run of the coherent neutrino nucleus interaction experiment (CONNIE)
The CONNIE detector prototype is operating at a distance of 30 m from the core of a 3.8 GWth nuclear reactor with the goal of establishing Charge-Coupled Devices (CCD) as a new technology for the detection of coherent elastic neutrino-nucleus scattering. We report on the results of the engineering run with an active mass of 4 g of silicon. The CCD array is described, and the performance observed during the first year is discussed. A compact passive shield was deployed around the detector, producing an order of magnitude reduction in the background rate. The remaining background observed during the run was stable, and dominated by internal contamination in the detector packaging materials. The in-situ calibration of the detector using X-ray lines from fluorescence demonstrates good stability of the readout system. The event rates with the reactor ON and OFF are compared, and no excess is observed coming from nuclear fission at the power plant. The upper limit for the neutrino event rate is set two orders of magnitude above the expectations for the standard model. The results demonstrate the cryogenic CCD-based detector can be remotely operated at the reactor site with stable noise below2 e RMS and stable background rates. The success of the engineering test provides a clear path for the upgraded 100 g detector to be deployed during 2016.Fil: Aguilar Arevalo, A.. Universidad Nacional Autónoma de México; MéxicoFil: Bertou, Xavier Pierre Louis. Comisión Nacional de Energía Atómica; Argentina. Comisión Nacional de Energía Atómica. Fundación José A. Balseiro; ArgentinaFil: Bonifazi, C.. Universidade Federal do Rio de Janeiro; BrasilFil: Butner, M.. Fermi National Accelerator Laboratory; Estados UnidosFil: Cancelo, G.. Fermi National Accelerator Laboratory; Estados UnidosFil: Castañeda Vazquez, A.. Universidad Nacional Autónoma de México; MéxicoFil: Cervantes Vergara, B.. Universidad Nacional Autónoma de México; MéxicoFil: Chavez, C. R.. Universidad Nacional de Asunción; ParaguayFil: Da Motta, H.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: D'Olivo, J. C.. Universidad Nacional Autónoma de México; MéxicoFil: Dos Anjos, J.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Estrada, J.. Fermi National Accelerator Laboratory; Estados UnidosFil: Fernández Moroni, Guillermo. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto ; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ford, R.. Fermi National Accelerator Laboratory; Estados UnidosFil: Foguel, A.. Centro Brasileiro de Pesquisas Físicas; Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Hernandez Torres, K. P.. Universidad Nacional Autónoma de México; MéxicoFil: Izraelevitch, F.. Fermi National Accelerator Laboratory; Estados UnidosFil: Kavner, A.. University of Michigan; Estados UnidosFil: Kilminster, B.. Universitat Zurich; SuizaFil: Kuk, K.. Fermi National Accelerator Laboratory; Estados UnidosFil: Lima Jr, H. P.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Makler, M.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Molina, J.. Universidad Nacional de Asunción; ParaguayFil: Moreno Granados, G.. Universidad Nacional Autónoma de México; MéxicoFil: Moro, Juan Manuel. Universidad Nacional del Sur. Departamento de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Paolini, Eduardo Emilio. Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto ; ArgentinaFil: Sofo Haro, Miguel Francisco. Comision Nacional de Energia Atomica. Gerencia D/area de Energia Nuclear; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tiffenberg, Javier Sebastian. Fermi National Accelerator Laboratory; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Trillaud, F.. Universidad Nacional Autónoma de México; MéxicoFil: Wagner, S.. Centro Brasileiro de Pesquisas Físicas; Brasil. Pontificia Universidade Católica do Rio Grande do Sul; Brasi
A Sub-millimeterwave ``Flare'' from GG Tau?
We have monitored the millimeter and submillimeter emission from the young
stellar object GG Tau, a T Tauri binary system surrounded by a massive
circumbinary disk. We find that between 1992 and 1994, the flux has increased
significantly at 800, 1100, and 1300 microns, resulting in a steepening of the
observed spectral energy distribution at those wavelengths. Such an increase
appears consistent with a modest increase in disk luminosity (a factor of two).
The increase in the effective disk temperature might arise from a slight change
in the disk heating processes. Alternatively, the flux increase may reflect a
sudden change in the underlying dust optical properties.Comment: 15 pages, AASTex v.4.0 format, four postscript figures, four tables,
to appear in The Astrophysical Journa
Harm reduction and abstinence-based models for treatment of substance use disorders during the COVID-19 pandemic : a global perspective
M.F. is an employee of the US Federal Government and is supported by National Institutes of Health (NIH) intramural funding (ZIA-DA000635 and ZIA-AA000218), outside of this research.The COVID-19 pandemic has significantly affected treatment services for people with substance use disorders (SUDs). Based on the perspectives of service providers from eight countries, we discuss the impact of the pandemic on SUD treatment services. Although many countries quickly adapted in provision of harm reduction services by changes in policy and service delivery, some went into a forced abstinence-based strategy. Similarly, disruption of abstinence-based approaches such as therapeutic communities has been reported. Global awareness is crucial for responsible management of SUDs during the pandemic, and the development of international health policy guidelines is an urgent need in this area.Publisher PDFPeer reviewe
Tri-Cities Index of Innovation and Technology
In 2001 and 2004, the Economic Development Office of Pacific Northwest National Laboratory published companion reports to the Washington Technology Center Index studies that provided additional information on the Tri-Cities (Kennewick-Richland-Pasco) area of the state, its technology businesses, and important advantages that the Tri-Cities have as places to live and do business. These reports also compared the Tri-Cities area to other technology-based metropolitan areas in the Pacific Northwest and nation along critical dimensions known to be important to technology firms. This report updates the material in these earlier reports, and highlights a growing Tri-Cities metropolitan area
Inferences from the kinematic properties of 6.7 GHz methanol masers
Context. It is now well established that the strong and widespread 6.7 GHz
methanol masers are associated with young high mass stars. A still
unsolved question is where in the circumstellar environment the masers
arise.
Aims.We address this question by considering an ensemble of rest frame
maser velocities of 337 maser features.
Methods. The CS(2-1) spectra of 63 methanol maser sources were used to derive
systemic velocities and velocity dispersion of the thermal gas. Using
the systemic velocities and the velocities of the 337 maser features
in the 63 sources, a single distribution of rest frame maser
velocities was constructed. This distribution as well as other
kinematic information about the masers are used to evaluate four
proposed scenarios for where the masers might arise in the
circumstellar environment.
Results.It is shown that kinematically the masers are not associated with hot
cores. We also argue that the scenario in which the masers are
associated with an external generated planar shock that propagates into
a rotating core cannot explain the observed kinematic properties of the
masers. It was found that a simple Keplerian-like disk model is consistent
with the observed distribution of rest frame maser
velocities. Although outflows have the potential to explain the data,
it was not possible to fully test this possibility due to the diverse
nature of outflows
The JCMT Legacy Survey of the Gould Belt: a first look at Orion B with HARP
‘The definitive version is available at www3.interscience.wiley.com '. Copyright Royal Astronomical Society.The Gould Belt Legacy Survey will survey nearby star-forming regions (within 500 pc), using Heterodyne Array Receiver Programme (HARP), Submillimetre Common-User Bolometer Array 2 and Polarimeter 2 on the James Clerk Maxwell Telescope. This paper describes the initial data obtained using HARP to observe 12CO, 13CO and C18O J= 3 → 2 towards two regions in Orion B, NGC 2024 and NGC 2071. We describe the physical characteristics of the two clouds, calculating temperatures and opacities utilizing all the three isotopologues. We find good agreement between temperatures calculated from CO and from dust emission in the dense, energetic regions. We determine the mass and energetics of the clouds, and of the high-velocity material seen in 12CO emission, and compare the relative energetics of the high- and low-velocity material in the two clouds. We present a clumpfind analysis of the 13CO condensations. The slope of the condensation mass functions, at the high-mass ends, is similar to the slope of the initial mass function.Peer reviewe
- …