A5064775938- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Physics of Superconductivity and Magnetism
- Astro and Planetary Science
- Galaxies: Formation, Evolution, Phenomena
- Calibration and Measurement Techniques
- Fuel Cells and Related Materials
- History and Developments in Astronomy
- Astrophysical Phenomena and Observations
- Electrocatalysts for Energy Conversion
- Analytical Chemistry and Sensors
- Gamma-ray bursts and supernovae
- Magnetic properties of thin films
- Advancements in Solid Oxide Fuel Cells
- Oil and Gas Production Techniques
- Reservoir Engineering and Simulation Methods
- Nuclear Physics and Applications
- Hydraulic Fracturing and Reservoir Analysis
- Scientific Research and Discoveries
- CCD and CMOS Imaging Sensors
- Optical Coatings and Gratings
- Spectroscopy and Laser Applications
BP (United States)
2025
San Diego Supercomputer Center
2024
University of California, San Diego
2024
Instituto de Astrofísica de Canarias
2011-2023
Universidad de La Laguna
2007-2022
Dartmouth–Hitchcock Medical Center
2013
Eisai (United States)
2013
Texas Oncology
2013
Université Libre de Bruxelles
2013
Institut Jules Bordet
2013
We have pursued two different methods to analyze the old stellar population near Galactic plane, using data from 2MASS survey. The first method is based on isolation of red clump giant in color-magnitude diagrams and inversion its star counts obtain directly density distribution along line sight. second fits parameters a disc model 820 regions. Results both independent are consistent with each other. qualitative conclusions that well fitted by an exponential galactocentric distance height....
In this paper we present the first comprehensive results extracted from spectroscopic campaigns carried out by EXPORT (EXoPlanetary Observational Research Team) consortium. During 1998-1999, an intensive observational effort in framework of origin and evolution protoplanetary systems order to obtain clues on evolutionary path early stages pre-main sequence stars with planets already formed. The spectral types 70 stars, projected rotational velocities, , 45 mainly Vega-type sequence, have...
We present contemporaneous optical and infrared (IR) photometric observations of the Type IIn SN 1998S covering period between 11 146 d after discovery. The IR data constitute first ever light curves a supernova. use blackbody spline fits to photometry examine luminosity evolution. During 2–3 months, is dominated by release shock-deposited energy in ejecta. After ∼100 powered mostly deposition radioactive decay from 0.15±0.05 M⊙ 56Ni which was produced explosion. also report discovery an...
Context.Over the last decade a series of results have lent support to hypothesis existence long thin bar in Milky Way with half-length 4.5 kpc and position angle around 45°. This is apparently very different structure from triaxial bulge Galaxy.
We have compiled the near infrared Point Source Catalogue (PSC) towards Magellanic Clouds (MCs) extracted from data obtained with Deep Near Infrared Survey of Southern Sky – DENIS (Epchtein et al. 1997). The catalogue covers an area square degrees centered on , for Large Cloud (LMC) and Small (SMC) at epoch J2000. It contains about sources LMC SMC each detected in least 2 3 photometric bands involved survey (I, J, Ks). are true members Clouds, respectively consist mainly red giants,...
We present near-infrared colour-magnitude diagrams and star counts for a number of regions along the Galactic plane. It is shown that l=27°, b=0° line sight there feature at 5.7±0.7 kpc with density stars least factor 2 probably more than 5 times disc same position. This forms distinct clump on an H versus J−H diagram seen all longitudes from bulge to about l=28°, but no longitude greater this. The distance l=20° 0.5 further by l=10° it has merged with, or become, bulge. Given l=27° l=21°...
Analysis of polarized copper K-edge extended x-ray-absorption fine-structure (EXAFS) measurements on ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$ for temperatures 10\ensuremath{\le}${\mathit{T}}_{\mathrm{nom}}$\ensuremath{\le}105 K indicates that the axial oxygen moves in a double-well potential which softens within fluctuation region associated with onset superconductivity this material. This follows from coupling between phonons derived and superconducting order parameter. The...
For a complete understanding of the physical processes causing photometric variability pre-main sequence systems, simultaneous optical and near-IR observations are required to disentangle emission from stars that their associated circumstellar disks. Data this sort extremely rare little systematic work has been reported date. The presented in paper is attempt direction. It presents an analysis 18 Herbig Ae/Be T Tauri which were observed October 98 by EXPORT collaboration. time difference...
This paper presents optical UBVRI broadband photo-polarimetry of the EXPORT sample obtained at 2.5 m Nordic Optical Telescope. The database consists multi-epoch 68 pre-main-sequence and main-sequence stars. An investigation polarization variability indicates that 22 objects are variable 3σ level in our data. All these pre-main sequence stars, consisting both T Tauri Herbig Ae/Be while main sequence, Vega type post-T not variable. properties sources mostly indicative UXOR-type behaviour; show...
Recent GLIMPSE data have further confirmed the hypothesis of existence an in-plane long bar different from bulge Milky Way with same characteristics as emphasized some years ago by our team. In this paper, we present two new analyses that corroborate recent and earlier claims concerning in Galaxy a flat approximate dimensions 7.8 kpc x 1.2 0.2 position angle approximately 43 deg.: 1) star counts 2MASS All-Sky Release MSX data, which give excess plane region along 0
Context. Over the past decade there have been a series of results supporting hypothesis existence long thin bar in Milky Way with half-length 4.5 kpc and position angle around 45°. This is apparently very different structure from triaxial bulge Galaxy, which thicker shorter dominates star counts at .
We present a study of the stellar parameters, distances and spectral energy distributions (SEDs) HD 34282 141569, two pre-main sequence Herbig AeBe stars. Both objects have been reported to show "anomalous positions" in HR diagram sense that they appear below main sequence. A significant result this work is both stars are metal-deficient. The Hipparcos distance very uncertain current places star at expected evolutionary position diagram, i.e. as PMS star. for 141569 found matches distance,...
An absolute calibration of the DENIS photometric system is presented. It includes determination overall transmission profiles in 3 bands, namely i, J and Ks, combining contributions from atmosphere, telescope mirrors, instrument lenses dichroics, filters, detectors. From these normalized profiles, isophotal effective wavelengths are computed, using same synthetic Vega spectrum as that used to support many other ground-based spaceborne systems. Flux densities at zero magnitude derived...
The vertical distribution of K giants stars is analyzed using 2MASS data and a semiempirical method extracting stellar densities from the colour–magnitude diagrams. density red clump giant can be described by double exponential, with scaleheights 268.81 ± 12.65 pc 1061.9 52.16 pc. These values are in agreement expected for thin thick disc components Milky Way. For disc, radial scalelength also obtained, value hR = 3.04 0.11 kpc.
Star counts from the Two-Micron Galactic Survey are used to determine nature of peaks for 35° > l 15° in plane 2-μm surface-brightness maps. Low extinction by itself is demonstrated be insufficient explain peaks. The peak at = 33° shown have a different luminosity function those 21° and 27°, latter being almost certainly caused very luminous, massive young stars. By far most likely explanation that they associated with star formation region near end bar. A simple model which includes bar...
We demonstrate the fabrication of acoustically engineered diamond nanoparticles-based metamaterials and their internal microstructure characterization using x-ray microcomputed tomography (XμCT). The state-of-the-art technique based on radiation force ultrasound standing (or stationary) waves in a rectangular chamber is utilized to pattern clusters 5-nm-diameter nanoparticles parallel planes within three-dimensional (3D) matrix epoxy before solidification. Gradually, periodic becomes...
Context: In our Paper I, by using statistical deconvolution methods, extended kinematics maps of Gaia-DR2 data have been produced in a range heliocentric distances that are factor two to three larger than those analyzed previously the Gaia Collaboration with same data. It added Galactocentric between 13 kpc and 20 previous maps. Aims: Here, we investigate dynamical effects different mechanisms can explain radial vertical components these kinematic maps, including decomposition bending...
A mixed‐potential sensor was constructed and its response to reducing gases in an oxygen containing stream measured at T = 550 600°C. The maximum for negligible methane; other followed the trend methane < propane CO, propylene hydrogen. mixed potentials developed Au Pt electrodes were also independently monitored with respect air‐reference electrodes. potential electrode always higher (more negative) than that irrespective of type gas used. polarization curves two during reduction measured....
We have determined the structure of newly discovered electron-doped superconductor ${\mathrm{Nd}}_{1.85}$${\mathrm{Ce}}_{0.15}$${\mathrm{CuO}}_{4\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ at 11 and 300 K using high-resolution neutron-powder-diffraction techniques. Both nonsuperconducting oxygenated superconducting Zr-gettered (${T}_{c}$=24 with shielding Meissner fractions 30 16% 5 K, respectively) samples were investigated to study effect Zr gettering on crystal oxygen...
CONTEXT. The maximum size of the Galactic stellar disk is not yet known. Some studies have suggested an abrupt drop-off density at Galactocentric distances $R\gtrsim 15$ kpc, which means that in practice no stars or only very few them should be found beyond this limit. However, Milky Way plane are detected larger distances. In addition to halo component, star counts placed end 20 although has been spectroscopically confirmed so far. AIMS. Here, we aim confirm presence up much METHODS. With...