Search Publications
The art of fitting p-mode spectra. I. Maximum likelihood estimation
Appourchaux, T.; Gizon, L.; Rabello-Soares, M. -C.
In this article we present our state of the art of fitting helioseismic p-mode spectra. We give a step by step recipe for fitting the spectra: statistics of the spectra both for spatially unresolved and resolved data, the use of Maximum Likelihood estimates, the statistics of the p-mode parameters, the use of Monte-Carlo simulation and the signifi…
Dust Emission and Molecular Depletion in L1498
Langer, W. D.; Velusamy, T.; Willacy, K.
We present 100 and 200 µm ISOPHOT observations of the dense core L1498. We have mapped the central core by using ΔI200=I200-I100/Θ, where ΔI200 is a measure of the emission from the cold dust and Θ=I100/I200 in the outer regions. The dust continuum emission provides informatio…
Steps toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. XIII. Ultraviolet Observations of the Broad-Line Radio Galaxy 3C 390.3
Shull, J. M.; Malkan, M. A.; Martin, P. G. +44 more
As part of an extensive multiwavelength monitoring campaign, the International Ultraviolet Explorer satellite was used to observe the broad-line radio galaxy 3C 390.3 during the period 1994 December 31-1996 March 5. Spectra were obtained every 6-10 days. The UV continuum varied by a factor of 7 through the campaign, while the broad emission lines …
Deep Hubble Space Telescope Observations of Star Clusters in NGC 1275
Ballester, Gilda E.; Crisp, David; Grillmair, Carl J. +15 more
We present an analysis of compact star clusters in deep Hubble Space Telescope Wide Field Planetary Camera 2 images of NGC 1275. B- and R-band photometry of roughly 3000 clusters shows a bimodality in the B - R colors, suggesting that distinct old and young cluster populations are present. The small spread in the colors of the blue clusters is con…
HST Planetary Camera images of quasar host galaxies
Boksenberg, A.; Macchetto, F. D.; Crane, P. +6 more
We present Hubble Space Telescope (HST) images of seven low-redshift quasars (six taken with the Planetary Camera, one with the Wide Field Camera). These complete the sample of 14 quasars observed by the Faint Object Camera Investigation Definition Team (FOC IDT). Following subtraction of the quasar nuclear light, host galaxies can be seen in all …
ISO-SWS observations of infrared absorption bands of the diffuse interstellar medium: The 6.2 MU M feature of aromatic compounds
de Graauw, Th.; Morris, P. W.; van Dishoeck, E. F. +8 more
We present ISO-SWS spectroscopy of eight strong infrared sources with large extinction through the diffuse interstellar medium. These are five late-type Wolf-Rayet stars, the blue hypergiant Cyg OB2 #12 and the Galactic Center Sources 3 and 4. The spectra show a number of absorption features that can be ascribed to interstellar dust and gas. Featu…
Overexpanding coronal mass ejections at high heliographic latitudes: Observations and simulations
McComas, D. J.; Riley, Pete; Gosling, J. T. +1 more
Ulysses observations reveal that most coronal mass ejections (CMEs) observed in the solar wind far from the Sun at high heliographic latitudes have large radial widths and are still expanding as they pass the spacecraft. CME radial widths ranging between 0.5 and 2.5 AU have been observed at heliocentric distances between 1.4 and 4.6 AU and at lati…
A model of solar total and spectral irradiance variations
Solanki, S. K.; Unruh, Y. C.; Fligge, M. +2 more
We model solar spectral irradiance variations under the assumption that they are produced by sunspots and faculae alone. The model is based on three components, i.e. quiet Sun, assumed to be temporally invariant, sunspots and faculae whose temporal variations are mimicked using time series of sunspot areas and Mg II core-to-wing ratios. The detail…
Emission Features and Source Counts of Galaxies in the Mid-Infrared
Xu, Cong; Ashby, Matthew L. N.; Shupe, David L. +6 more
In this work we incorporate the newest Infrared Space Observatory (ISO) results on the mid-infrared spectral energy distributions (MIR SEDs) of galaxies into models for the number counts and redshift distributions of MIR surveys. A three-component model, with empirically determined MIR SED templates of (1) a cirrus/photodissociation region compone…
Optical Structure and Colors of Faint Compact Narrow Emission-Line Galaxies
Bershady, Matthew A.; Koo, David C.; Simard, Luc +2 more
We present the results of Hubble Space Telescope Wide Field Planetary Camera imaging in V606 and I814 of five compact narrow emission line galaxies (CNELGs) and four slightly more extended faint blue galaxies (FBGs) with 20.3<=B<=22.4 and redshifts z~0.22-0.66. Half-light radii are measured to span from 0.14" to 0.67", …