Search Publications
Modeling far-infrared emission from the HII region S125
Emery, R. J.; Aannestad, P. A.
We present ISO-LWS 45-180 mu m spectral observations at 17 positions in the HII region S125. We model, as one integrated region, the far-IR continuum emission as well as the observed emissions in the radio continuum and in the 21 cm line, comparing two different model density distributions and several silicate-carbon dust models. The dust in the H…
The Optical Spectroscopic Evolution of V1974 Cygni (Nova Cygni 1992)
Garnavich, Peter M.; Noriega-Crespo, Alberto; Moro-Martín, Amaya
Optical observations of V1974 Cygni (Nova Cygni 1992) spanning a 4 yr period have been used to study its spectroscopic evolution. The data cover a wavelength range from ~3200-8000 Å and follow the nebular evolutionary phase of the ejecta. We have modeled the integrated fluxes by means of the photoionization code CLOUDY. The models were run at a fi…
Millimeter Continuum Image of the Circumstellar Disk around the Young Star Haro 6-5B
Tamura, Motohide; Kawabe, Ryohei; Momose, Munetake +4 more
Aperture synthesis observations of dust continuum emission at 2 mm from the class I object Haro 6-5B, made with the Nobeyama Millimeter Array, are presented. A disklike structure that coincides with the dark lane in the visible and near-infrared images is clearly resolved with a small synthesized beam of 1.33"×1.21" with its position angle (P.A.) …
Propagation of electromagnetic waves in the lower ionosphere of Titan
Rodrigo, R.; López-Moreno, J. J.; Molina-Cuberos, G. J. +6 more
Towards the end of 2004 during the descent of the HUYGENS probe the Permittivity, Wave and Altimetry instrument (PWA) as part of the HASI experiment will investigate electrical properties and electric field fluctuations in the atmosphere of Titan below 170 km. We have modelled the propagation of low frequency electromagnetic waves in the lower ion…
Energy Distribution of Solar Oscillation Modes Inferred from Space-based Measurements
Korzennik, S. G.; Rabello-Soares, M. C.; Tarbell, T. D. +3 more
We have measured the energy distribution of solar p- and f-mode oscillations of angular degree and temporal frequency in the range 100<l<800 and 2<ν(mHz)<4 using helioseismology data from the Solar Oscillations Investigation-Michelson Doppler Imager instrument on the Solar and Heliospheric Observatory satellite. At temporal frequency ν…
Proton transport through self-generated waves in impulsive flares
Vainio, R.; Kocharov, L.
Energetic proton transport through self-generated Alfvén waves in impulsive (gamma -ray) flares is studied using the method of Monte Carlo simulations. Protons are traced inside a flux tube after they are released from a point source located inside the loop until they hit the boundary of the 1-D simulation box and escape. As they stream from the s…
The field of NGC 6397 as a test for Galactic models
Degl'Innocenti, S.; Piotto, G.; Castellani, V. +1 more
Taking advantage of recent Hubble Space Telescope (HST) data for field stars in the region of the Galactic globular cluster NGC 6397, we tested the predictions of several Galactic models with star counts reaching a largely unexplored range of magnitudes, down to V~26.5. After updating the input stellar (V-I) colours, we found that the two-componen…
A Search for Interstellar CH2 toward HD 154368 and ζ Ophiuchi
Smith, Andrew M.; Bruhweiler, Frederick C.; Lyu, Cheng-Hsuan
We have searched for molecular CH2 in the interstellar gas in the line of sight to HD 154368 and ζ Oph to constrain further the gas-phase chemistry of carbon-bearing molecules in the cool, translucent clouds toward these stars. We report tentative detection of CH2 in the interstellar spectra of both stars. In ζ Oph, slight de…
Analysis of Stars Common to the IRAS and Hipparcos Surveys
Knapp, G. R.; Ivezić, Željko; Knauer, Timothy G.
For about 11,000 stars observed in the Hipparcos Survey and detected by IRAS, we calculate bolometric luminosities by integrating their spectral energy distributions from the B band to far-IR wavelengths. We present an analysis of the dependence of dust emission on spectral type and of the correlations between luminosity and dust emission for abou…
Multi-scale temporal features of the 14 July 2000 meter- wavelength dynamic radio spectrum compared with TRACE data
Grechnev, V. V.; Chertok, I. M.; Nightingale, R. W. +5 more
The 14 July 2000 (`Bastille Day') eruptive and geoeffective flare event was observed by the digital IZMIRAN radio spectrograph in the frequency range of 25-270 MHz. This instrument allowed the analysis of various features of the dynamic radio spectrum and their comparison with other observational data, in particular with development of a spectacul…