Page 1. Revista Brasileira de Ensino de Fısica, v. 34, n. 1, 1702 (2012) www.sbfisica.org.br Velo... more Page 1. Revista Brasileira de Ensino de Fısica, v. 34, n. 1, 1702 (2012) www.sbfisica.org.br Velocidade do som no ar e efeito Doppler em um único experimento (Sound speed in air and Doppler effect in a single experiment) ...
971 SOUTHERN HEMISPHERE SOLAR RADIO HELIOGRAPH HS Sawant1, F. С. R. Fernandes1, J. А. С. F. Neri1... more 971 SOUTHERN HEMISPHERE SOLAR RADIO HELIOGRAPH HS Sawant1, F. С. R. Fernandes1, J. А. С. F. Neri1, JR Cecatto1, С. Faria1, S. Stephany1, RR Rosa1, M. С Andrade1, E. Ludke2, К. R. Subramanian3, R. Ramesh3, MS Sundrarajan3, MR Sanka ...
We present 1.3 and 3.6 cm radio continuum images and a HCO + spectrum of the massive star forming... more We present 1.3 and 3.6 cm radio continuum images and a HCO + spectrum of the massive star forming region G75.78+0.34 obtained with the Very Large Array (VLA) and with the Berkley Illinois Maryland Association (BIMA) interferometer. Three structures were detected in the continuum emission: one associated to the well known cometary H II region, plus two more compact structures located at 6 ′′ east and at 2 ′′ south of cometary H II region. Using the total flux and intensity peak we estimated an electron density of ≈1.5×10 4 cm −3 , an emission measure of ≈6×10 7 cm −6 pc, a mass of ionized gas of ≈ 3 M ⊙ and a diameter of 0.05 pc for the cometary H II region, being typical values for an ultracompact H II region. The HCO + emission is probably originated from the molecular outflows previously observed in HCN and CO.
In this paper, I have analysed the subarcsecond polarization structure of two high-z compact stee... more In this paper, I have analysed the subarcsecond polarization structure of two high-z compact steep-spectrum quasars. Morphology suggests that the jets are interacting strongly with intergalactic medium. Models of bending by ram pressure equilibrium in a cooling flow and alignment of magnetic field lines by jet-IGM shock suggest that the CSS jets are light, supersonic and mildly relativistic. Particle energy index variations along the jet suggests replenishment triggered by such interactions.
The attainment of high-fidelity images obtained with Very Long Baseline Techniques and earth-rota... more The attainment of high-fidelity images obtained with Very Long Baseline Techniques and earth-rotation synthesis is the main observational quest to study the physical properties of cosmic radio sources for various astrophysical and cosmological purposes. In this paper, I present a method to combine individual array observations in radio continuum mode at 4995 GHz which is successful when obtaining enhanced images of radio sources. The data combining techniques explained here allow to produce synthesis array images which show details which cannot be obtained by standard data processing and observational techniques with individual arrays.
Monthly Notices of The Royal Astronomical Society, 2010
We present images for the 3.5 mm continuum and HCN (J=1–0) hyperfine line emission from the surro... more We present images for the 3.5 mm continuum and HCN (J=1–0) hyperfine line emission from the surroundings of the H ii regions G75.78+0.34 and G75.77+0.34 obtained with the Berkeley Illinois Maryland Association (BIMA) interferometer using the D configuration at a spatial resolution of ∼18 arcsec and spectral sampling of 0.34 km s−1. The continuum emission of both objects is dominated by free–free emission from the ionized gas surrounding the exciting stars. Dust emission may contribute only a small fraction of the 3.5 mm continuum from G75.78+0.34 and is negligible for G75.77+0.34. The high spectral resolution reached by BIMA allowed us to separate the emission from each hyperfine transition (F=1–1, 2–1 and 0–1), as well as to construct velocity channel maps along each emission-line profile. The HCN flux distributions are similar to those observed for the CO emission but with some knots of high intensities indicating that the HCN traces high-density clouds not seen in CO. The HCN hyperfine line ratios for both H ii regions differ from those predicted theoretically for local thermodynamic equilibrium, probably due to scattering of radiation processes. The velocity channels show that the HCN emission of G75.78+0.34 follows the bipolar molecular outflows previously observed in CO. For G75.77+0.34, the outflowing gas contributes only a small fraction of the HCN emission.
We present recent radio interferometer measurements of the OH 1612 MHz maser emission from the OH... more We present recent radio interferometer measurements of the OH 1612 MHz maser emission from the OH/IR sources OH0.9+1.3 and OH357.31 obtained with the enhanced MERLIN. Some preliminary results are briefly discussed. These results are part of an on-going observational campaign to obtain the best radio maps of bright OH/IR stars with MERLIN, VLA and VLBA, in order to understand the nature and dynamics of their circumstellar matter and evolution.
Monthly Notices of The Royal Astronomical Society, 2010
We present images for the 3.5 mm continuum and HCN(J=1-0) hyperfine line emission from the surrou... more We present images for the 3.5 mm continuum and HCN(J=1-0) hyperfine line emission from the surroundings of the HII regions G75.78+0.34 and G75.77+0.34 obtained with the Berkeley Illinois Maryland Association (BIMA) interferometer using the D configuration at a spatial resolution of 18 arcsec and spectral sampling of 0.34 km/s. The continuum emission of both objects is dominated by free-free emission from the ionized gas surrounding the exciting stars. Dust emission may contribute only a small fraction of the 3.5 mm continuum from G75.78+0.34 and is negligible for G75.77+0.34. The high spectral resolution reached by BIMA allowed us to separate the emission from each hyperfine transition (F=1-1, F=2-1 and F=0-1), as well as to construct velocity channel maps along each emission-line profile. The HCN flux distributions are similar to those observed for the CO emission, but with some knots of high intensities indicating that the HCN traces high density clouds not seen in CO. The HCN hyperfine line ratios for both HII regions differ from those predicted theoretically for Local Thermodynamic Equilibrium (LTE), probably due to scattering of radiation processes. The velocity channels shows that the HCN emission of G75.78+0.34 follows the bipolar molecular outflows previously observed in CO. For G75.77+0.34, the outflowing gas contributes only a small fraction of the HCN emission.
Revista Mexicana De Astronomia Y Astrofisica, 1990
Detailed slit spectrophotometry in the range 3700 - 7200 Å is presented for the nucleus and seven... more Detailed slit spectrophotometry in the range 3700 - 7200 Å is presented for the nucleus and seven different positions in NGC 5253. Population synthesis models show that NGC 5253 is highly composed in age and characterized by a strong gradient in the sense that the blue components become not only stronger but younger towards the center. The old population substratum is metal deficient [Z/Z0] < -0.5. A similar abundance is derived for the gas with no spatial variations.
In this paper, I present construction details of a spectrophotometric assay operating in visual a... more In this paper, I present construction details of a spectrophotometric assay operating in visual and ultraviolet wavelengths at a very low cost. The equipment is intended to be used by first or second-year undergraduate students in health sciences during practical activities of methods in analytical chemistry, physical chemistry or biophysics. The experimental learning of fundamental spectrophotometric techniques and the quantitative determination of the Lambert-Beer law, which cannot be done with commercial UV spectrophotometers, is easily attained with the apparatus. Experimental examples in biophysics teaching labs are briefly discussed.
Page 1. Revista Brasileira de Ensino de Fısica, v. 34, n. 1, 1702 (2012) www.sbfisica.org.br Velo... more Page 1. Revista Brasileira de Ensino de Fısica, v. 34, n. 1, 1702 (2012) www.sbfisica.org.br Velocidade do som no ar e efeito Doppler em um único experimento (Sound speed in air and Doppler effect in a single experiment) ...
971 SOUTHERN HEMISPHERE SOLAR RADIO HELIOGRAPH HS Sawant1, F. С. R. Fernandes1, J. А. С. F. Neri1... more 971 SOUTHERN HEMISPHERE SOLAR RADIO HELIOGRAPH HS Sawant1, F. С. R. Fernandes1, J. А. С. F. Neri1, JR Cecatto1, С. Faria1, S. Stephany1, RR Rosa1, M. С Andrade1, E. Ludke2, К. R. Subramanian3, R. Ramesh3, MS Sundrarajan3, MR Sanka ...
We present 1.3 and 3.6 cm radio continuum images and a HCO + spectrum of the massive star forming... more We present 1.3 and 3.6 cm radio continuum images and a HCO + spectrum of the massive star forming region G75.78+0.34 obtained with the Very Large Array (VLA) and with the Berkley Illinois Maryland Association (BIMA) interferometer. Three structures were detected in the continuum emission: one associated to the well known cometary H II region, plus two more compact structures located at 6 ′′ east and at 2 ′′ south of cometary H II region. Using the total flux and intensity peak we estimated an electron density of ≈1.5×10 4 cm −3 , an emission measure of ≈6×10 7 cm −6 pc, a mass of ionized gas of ≈ 3 M ⊙ and a diameter of 0.05 pc for the cometary H II region, being typical values for an ultracompact H II region. The HCO + emission is probably originated from the molecular outflows previously observed in HCN and CO.
In this paper, I have analysed the subarcsecond polarization structure of two high-z compact stee... more In this paper, I have analysed the subarcsecond polarization structure of two high-z compact steep-spectrum quasars. Morphology suggests that the jets are interacting strongly with intergalactic medium. Models of bending by ram pressure equilibrium in a cooling flow and alignment of magnetic field lines by jet-IGM shock suggest that the CSS jets are light, supersonic and mildly relativistic. Particle energy index variations along the jet suggests replenishment triggered by such interactions.
The attainment of high-fidelity images obtained with Very Long Baseline Techniques and earth-rota... more The attainment of high-fidelity images obtained with Very Long Baseline Techniques and earth-rotation synthesis is the main observational quest to study the physical properties of cosmic radio sources for various astrophysical and cosmological purposes. In this paper, I present a method to combine individual array observations in radio continuum mode at 4995 GHz which is successful when obtaining enhanced images of radio sources. The data combining techniques explained here allow to produce synthesis array images which show details which cannot be obtained by standard data processing and observational techniques with individual arrays.
Monthly Notices of The Royal Astronomical Society, 2010
We present images for the 3.5 mm continuum and HCN (J=1–0) hyperfine line emission from the surro... more We present images for the 3.5 mm continuum and HCN (J=1–0) hyperfine line emission from the surroundings of the H ii regions G75.78+0.34 and G75.77+0.34 obtained with the Berkeley Illinois Maryland Association (BIMA) interferometer using the D configuration at a spatial resolution of ∼18 arcsec and spectral sampling of 0.34 km s−1. The continuum emission of both objects is dominated by free–free emission from the ionized gas surrounding the exciting stars. Dust emission may contribute only a small fraction of the 3.5 mm continuum from G75.78+0.34 and is negligible for G75.77+0.34. The high spectral resolution reached by BIMA allowed us to separate the emission from each hyperfine transition (F=1–1, 2–1 and 0–1), as well as to construct velocity channel maps along each emission-line profile. The HCN flux distributions are similar to those observed for the CO emission but with some knots of high intensities indicating that the HCN traces high-density clouds not seen in CO. The HCN hyperfine line ratios for both H ii regions differ from those predicted theoretically for local thermodynamic equilibrium, probably due to scattering of radiation processes. The velocity channels show that the HCN emission of G75.78+0.34 follows the bipolar molecular outflows previously observed in CO. For G75.77+0.34, the outflowing gas contributes only a small fraction of the HCN emission.
We present recent radio interferometer measurements of the OH 1612 MHz maser emission from the OH... more We present recent radio interferometer measurements of the OH 1612 MHz maser emission from the OH/IR sources OH0.9+1.3 and OH357.31 obtained with the enhanced MERLIN. Some preliminary results are briefly discussed. These results are part of an on-going observational campaign to obtain the best radio maps of bright OH/IR stars with MERLIN, VLA and VLBA, in order to understand the nature and dynamics of their circumstellar matter and evolution.
Monthly Notices of The Royal Astronomical Society, 2010
We present images for the 3.5 mm continuum and HCN(J=1-0) hyperfine line emission from the surrou... more We present images for the 3.5 mm continuum and HCN(J=1-0) hyperfine line emission from the surroundings of the HII regions G75.78+0.34 and G75.77+0.34 obtained with the Berkeley Illinois Maryland Association (BIMA) interferometer using the D configuration at a spatial resolution of 18 arcsec and spectral sampling of 0.34 km/s. The continuum emission of both objects is dominated by free-free emission from the ionized gas surrounding the exciting stars. Dust emission may contribute only a small fraction of the 3.5 mm continuum from G75.78+0.34 and is negligible for G75.77+0.34. The high spectral resolution reached by BIMA allowed us to separate the emission from each hyperfine transition (F=1-1, F=2-1 and F=0-1), as well as to construct velocity channel maps along each emission-line profile. The HCN flux distributions are similar to those observed for the CO emission, but with some knots of high intensities indicating that the HCN traces high density clouds not seen in CO. The HCN hyperfine line ratios for both HII regions differ from those predicted theoretically for Local Thermodynamic Equilibrium (LTE), probably due to scattering of radiation processes. The velocity channels shows that the HCN emission of G75.78+0.34 follows the bipolar molecular outflows previously observed in CO. For G75.77+0.34, the outflowing gas contributes only a small fraction of the HCN emission.
Revista Mexicana De Astronomia Y Astrofisica, 1990
Detailed slit spectrophotometry in the range 3700 - 7200 Å is presented for the nucleus and seven... more Detailed slit spectrophotometry in the range 3700 - 7200 Å is presented for the nucleus and seven different positions in NGC 5253. Population synthesis models show that NGC 5253 is highly composed in age and characterized by a strong gradient in the sense that the blue components become not only stronger but younger towards the center. The old population substratum is metal deficient [Z/Z0] < -0.5. A similar abundance is derived for the gas with no spatial variations.
In this paper, I present construction details of a spectrophotometric assay operating in visual a... more In this paper, I present construction details of a spectrophotometric assay operating in visual and ultraviolet wavelengths at a very low cost. The equipment is intended to be used by first or second-year undergraduate students in health sciences during practical activities of methods in analytical chemistry, physical chemistry or biophysics. The experimental learning of fundamental spectrophotometric techniques and the quantitative determination of the Lambert-Beer law, which cannot be done with commercial UV spectrophotometers, is easily attained with the apparatus. Experimental examples in biophysics teaching labs are briefly discussed.
Uploads
Papers by Everton Lüdke