A5029536670- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Scientific Research and Discoveries
- Solar and Space Plasma Dynamics
- Ultrasound and Hyperthermia Applications
- Coronary Interventions and Diagnostics
- Pulsars and Gravitational Waves Research
- History and Developments in Astronomy
- Venous Thromboembolism Diagnosis and Management
- Computer Graphics and Visualization Techniques
- Radio Astronomy Observations and Technology
- Fluid Dynamics and Turbulent Flows
- Heart Failure Treatment and Management
- Atmospheric Ozone and Climate
- Cardiac Imaging and Diagnostics
- Regional Development and Policy
- Historical and Architectural Studies
- Atrial Fibrillation Management and Outcomes
Universidad Nacional Autónoma de México
2012-2022
Universidad Autónoma de Baja California
2003-2020
Technische Universität Braunschweig
2012-2013
Ensenada Institute of Technology
2011-2012
Rochester Institute of Technology
2011
Krankenhaus vom Roten Kreuz
2010
Netherlands Institute for Radio Astronomy
2010
University Medical Center Hamburg-Eppendorf
1997-2008
Universität Hamburg
1997-2008
HTW Berlin - University of Applied Sciences
2007-2008
We have investigated the rapid variations of BL Lac object S5 0716+714 in radio, optical, ultraviolet, and x-ray regimes. Several simultaneous multifrequency campaigns been carried out. Here we describe complete analysis a four-week monitoring campaign at three radio optical frequency bands, optical-UV optical-x-ray observations, correlations between changes on longer time scales. also investigate polarization properties regime. The major observational results are high duty cycle variability...
We present a flexible interactive 3D morpho-kinematical modeling application for astrophysics. Compared to other systems, our reduces the restrictions on physical assumptions, data type, and amount that is required reconstruction of an object's morphology. It one first publicly available tools apply graphics astrophysical modeling. The tool allows astrophysicists provide priori knowledge about object by interactively defining structural elements. By direct comparison model prediction with...
(abbreviated) We aim to study the inner wind of well-known AGB star CW Leo. Different diagnostics probing different geometrical scales have pointed toward a non-homogeneous mass-loss process: dust clumps are observed at milli-arcsec scale, bipolar structure is seen arcsecond-scale and multi-concentric shells detected beyond 1". present first ALMA Cycle 0 band 9 data around 650 GHz. The full-resolution spatial resolution 0".42x0".24, allowing us morpho-kinematical within ~6". Results: 25...
Shadows behind neutral clumps in photoionized regions can have a core surrounded by gas that is the diffuse flux produced nebula. We present simple analytic model describing configuration of such shadows. also numerical gasdynamic simulations relaxation to final, steady state. These models clear applications (e.g., cometary knots Helix Nebula) but be applied other astrophysical contexts.
BACKGROUND Previous studies have shown the feasibility of peripheral arterial ultrasound angioplasty. METHODS AND RESULTS In this report, we describe use percutaneous therapeutic for coronary vitro, 11 postmortem, atherosclerotically occluded arteries were obtained to assess catheter-delivered recanalization as well assessment size particulate debris. Clinically, angioplasty was performed in 19 patients (mean age, 56 years) safety and treatment obstructive atherosclerosis. Three with...
New observations using narrow band imaging, long-slit spectroscopy and MERLIN of the nuclear region Seyfert galaxy NGC~4051 have been made. An edge brightened, triangular ionized gas extending 420 pc from centre has detected. Long-slit spectra this ionised gas, taken at 1.5\arcsec\ core, show \oiii\ emission line to consist two velocity components, both blue-shifted systemic radial velocity, with widths 140\kms\ separated by 120\kms. This is co-spatial weak extended radio suggestive a...
The 3-D and kinematic structure of the Eskimo nebula, NGC 2392, has been notoriously difficult to interpret in detail given its complex morphology, multiple components nearly pole-on orientation along line sight. We present a comprehensive, spatially resolved, high resolution, long-slit spectroscopic mapping planetary nebula. data consist 21 echelle spectra tightly spaced over bipolar jets. This set allows us construct velocity-resolved [NII] channel map nebula with resolution 10 km/s that...
The extremely luminous supernova 2006gy (SN 2006gy) is among the most energetic ever observed. peak brightness was 100 times that of a typical and it spent an unheard 250 days at magnitude -19 or brighter. Efforts to describe SN have pushed boundaries current theory. In this work we aspire simultaneously reproduce photometric spectroscopic observations using quark nova model. This analysis considers explosion massive star followed later by detonation neutron star. We lay out detailed model...
We investigate, using the modelling code shape, three-dimensional structure of bipolar Homunculus nebula surrounding Eta Carinae as mapped by new ESO Very Large Telescope/X-Shooter observations H2 λ = 2.121 25 μm emission line. Our results reveal for first time important deviations from axisymmetric morphology: (1) circumpolar trenches in each lobe positioned point symmetrically centre and (2) off-planar protrusions equatorial region at longitudinal (∼55°) latitudinal (10°-20°) distances...
Context. Complex bipolar shapes can be generated either as a planetary nebula or symbiotic system. The origin of the material ionised by white dwarf is very different in these two scenarios, and it complicates understanding morphologies nebulae. Aims. physical properties, structure, dynamics nebulae, M 2-9, Mz 3, Hen 2-104, are investigated detail with aim their nature, shaping mechanisms, evolutionary history. Methods. Long-slit optical echelle spectra used to investigate morpho-kinematics...
Red novae are optical transients erupting at luminosities typically higher than those of classical novae. Their outbursts believed to be caused by stellar mergers. We present millimeter/submillimeter-wave observations with ALMA and SMA the three best known Galactic red novae, V4332 Sgr, V1309 Sco, V838 Mon. The were taken 22, 8, 14 yr after their respective eruptions reveal presence molecular gas excitation temperatures 35-200 K. displays emission in rotational transitions very broad lines...
We explore the formation of multipolar structures in planetary and pre-planetary nebulae from interaction a fast post-AGB wind with highly inhomogeneous filamentary shell structure assumed to form during final phase high density wind. The simulations were performed new hydrodynamics code integrated interactive framework astrophysical modeling package SHAPE. In contrast conventional software, does not require any programming intervention by user for setting up or controlling code....
Context. Despite numerous and detailed studies of the jets active galactic nuclei (AGN) on pc-scales, many questions are still debated. The physical nature jet components is one most prominent unsolved problems, as launching mechanism in AGN. quasar 1308+326 (z = 0.997) allows us to study overall properties its detail derive a more understanding origin general. long-term data provided by Monitoring Of Jets Active with Very Long Baseline Array (VLBA) experiments (MOJAVE)⋆⋆ survey permit trace...
CK Vul is the remnant of an energetic eruption known as Nova 1670 that thought to be caused by a stellar merger. The composed (1) large hourglass nebula recombining gas (of 71\arcsec size), very similar some classical planetary and pre-planetary nebulae (PPNe), (2) much smaller cooler inner prominent in millimeter-wave emission from molecules. We investigate three-dimensional spatio-kinematic structure both components. analysis yields revised distance object >2.6 kpc, at least 3.7 times...
We perform numerical simulations to investigate the stellar wind from interacting binary stars. Our aim is find analytical formulae describing outflow structure. In each system more massive star in asymptotic giant branch and its driven by a combination of pulsations surface layers radiation pressure on dust, while less main sequence. Time averages density velocity are calculated plotted as profiles against distance centre mass colatitude angle. that lost mainly through outer Lagrangian...
The system of cometary knots in the Helix planetary nebula (NGC 7293) has been systematically observed using ground-based images and long-slit, high-resolution spectroscopy. CCD [N ii] 6584-Å line, taken with ESO NTT, are used to determine spatial distribution knots; [O iii] 5007-Å line distinguish their position within on basis absorption central 5007-Å-emitting zone nebula. kinematics 50 brighter tails were studied primarily Manchester Echelle Spectrograph (MES) as well NTT EMMI...
NGC 6337 is a member of the rare group planetary nebulae where close binary nucleus has been identified. The nebula's morphology and emission line profiles are both unusual, particularly latter. We present thorough mapping spatially resolved, long-slit echelle spectra obtained over nebula that allows detailed characterization its complex kinematics. This information, together with narrowband imagery, used to produce three-dimensional (3D) model using code SHAPE. 3D yields slowly expanding...
We study the kinematical and brightness evolution of emission line clouds in narrow region (NLR) Seyfert galaxies during passage a jet. derive critical density above which cloud remains radiative after compression by jet cocoon. The depends mainly on cocoon pressure. Super-critical increase brightness, while sub-critical generally are highly overheated reducing their luminosity below that inter-cloud medium. Due to pressure stratification bow-shock jet, cylindrical structure nested shells...
Journal Article Chrome congestive heart failure: Catheter-delivered high intensity, low frequency ultrasound induces vasodilation in vivo Get access W. STEFFEN, STEFFEN From the Divisions of Cardiology and Anatomic Pathology, Cedars Sinai Medical Center8700 Beverly Boulevard, Los Angeles, CA, 90048, U.S.A. Correspondence: Robert J. Siegel, MD, FACC, Division Rm 5314, 8700 CA. Search for other works by this author on: Oxford Academic PubMed Google Scholar D. CUMBERLAND, CUMBERLAND P. GAINES,...
In this paper we explore the dynamics of ionization bounded planetary nebulae after termination fast stellar wind.When wind becomes negligible, hot, shocked bubble depressurizes and thermal pressure photoionized region, at inner edge swept-up shell, dominant.At stage shell tends to fragment creating clumps with comet-like tails long, trails in between, while material expands back towards central stars as a rarefaction wave.Once that gas fills cavity, it develops kinematical pattern...