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High-resolution study of the young stellar objects in Mon R2 IRS 3
Weigelt, G.; Schertl, D.; Preibisch, T. +1 more
We present a bispectrum speckle interferometry study of the embedded young stellar objects in Mon R2 IRS 3 in the near-infrared H and K bands. Our images with a resolution of 75 mas (cor 62 AU) show a close triple system surrounded by strong diffuse nebulosity and three additional infrared sources (K magnitudes ~ 11.8-13.7) within 3'' of the brigh…
HST Multicolor (255-1042 nm) Photometry of Saturn's Main Rings. I: Radial Profiles, Phase and Opening Angle Variations, and Regional Spectra
French, Richard G.; Dones, Luke; Cuzzi, Jeffrey N.
The main rings of Saturn were observed with the Planetary Camera of the WFPC2 instrument on the Hubble Space Telescope (HST) from September 1996 to December 2000 as the ring opening angle to Earth and Sun increased from 4° to 24°, with a spread of phase angles between 0.3° and 6° at each opening angle. The rings were routinely observed in the five…
Ionospheric and dayglow responses to the radiative phase of the Bastille Day flare
Mariska, J. T.; Warren, H. P.; Judge, D. L. +11 more
The Sun's Bastille Day flare on July 14, 2000 produced a variety of geoeffective events. This solar eruption consisted of an X-class flare followed by a coronal mass ejection that produced a major geomagnetic storm. We have undertaken a study of this event beginning with an analysis of the effects of the radiative phase of the flare on the dayglow…
Accurate Stellar Population Studies from Multiband Photometric Observations
Kirshner, Robert P.; Panagia, Nino; Romaniello, Martino +1 more
We present a new technique based on multiband near-ultraviolet and optical photometry to measure both the stellar intrinsic properties, i.e., luminosity and effective temperature, and the interstellar dust extinction along the line of sight to hundreds of stars per square arcminute. The yield is twofold. On the one hand, the resulting reddening ma…
Observations of the Hubble Deep Field South with the Infrared Space Observatory - I. Observations, data reduction and mid-infrared source counts
Oliver, Seb; Elbaz, David; Franceschini, Alberto +14 more
We present results from a deep mid-infrared survey of the Hubble Deep Field South (HDF-S) region performed at 6.7 and 15µm with the ISOCAM instrument on board the Infrared Space Observatory (ISO ). The final map in each band was constructed by the co-addition of four independent rasters, registered using bright sources securely detected in a…
Balmer lines emission region in NGC 3516: Kinematical and physical properties
Jovanović, P.; Popović, L. Č.; Mediavilla, E. G. +1 more
We have studied the Balmer line shapes of NGC 3516 in order to find the structure of central Emission Line Region (ELR) and the physical parameters of the emitting plasma. The shapes of these broad emission lines show evidences of a multicomponent origin and also features which could be identified as the peaks of a rotating disc. We have proposed …
Chemical Evolution of the Circumstellar Envelopes of Carbon-rich Post-Asymptotic Giant Branch Objects
Cernicharo, J.; Goicoechea, J. R.; Herpin, F. +1 more
We have observed, with the 30 m IRAM telescope, the Caltech Submillimeter Observatory telescope, and the Infrared Space Observatory (ISO) satellite,3 the rotational lines of CO at millimeter, submillimeter, and far-IR wavelengths in the direction of carbon-rich stellar objects at different stages of evolution: CRL 2688 (a very young proto-planetar…
The spectroscopic orbits and the geometrical configuration of the symbiotic binary AR Pavonis
Mikołajewska, J.; Quiroga, C.; Brandi, E. +2 more
We analyze optical and near infrared spectra of intermediate and high resolution of the eclipsing symbiotic system AR Pavonis. We have obtained the radial velocity curves for the red and the hot component from the M-giant absorption lines and from the wings of Hα , Hβ and He II lambda 4686 emission profiles, respectively. From the orbital elements…
On the detectability of distant Compton-thick obscured quasars
Fabian, A. C.; Crawford, C. S.; Wilman, R. J.
Chandra and XMM-Newton have resolved the 2-8keV X-ray background (XRB) into point sources. Many of the fainter sources are obscured active galactic nuclei (AGN) with column densities in the range of 1022-1023cm-2, some of which have quasar-like luminosities. According to obscuration models, the XRB above 8keV is do…
Resolving the 47 Tucanae Distance Problem
Salaris, Maurizio; Kilkenny, David; van Wyk, Francois +1 more
We present new B-, V-, and I-band photometry for a sample of 43 local subdwarfs with Hipparcos parallax errors less than 13%, in the metallicity range -1.0<[Fe/H]<-0.3, which we use to perform main-sequence (MS) fitting to the Galactic globular cluster 47 Tuc. This sample is many times larger than those used in previous MS-fitting studies an…