Search Publications
Radio Emission from Galaxies in the Hubble Deep Field
Fomalont, E. B.; Windhorst, R. A.; Richards, E. A. +2 more
We report on sensitive radio observations made with the VLA at 8.5 GHz centered on the Hubble Deep Field (HDF). We collected data in the A, CnB, C, DnC, and D configurations corresponding to angular resolutions ranging from 0.3" to 10". We detected 29 radio sources in a complete sample within 4.6‧ of the HDF center and above a flux density limit o…
The distribution of nearby stars in phase space mapped by Hipparcos. I. The potential well and local dynamical mass
Pichon, C.; Creze, M.; Chereul, E. +1 more
Hipparcos data provide the first, volume limited and absolute magnitude limited homogeneous tracer of stellar density and velocity distributions in the solar neighbourhood. The density of A-type stars more luminous than M_v=2. 5 can be accurately mapped within a sphere of 125 pc radius, while proper motions in galactic latitude provide the vertica…
The TYCHO Reference Catalogue
Makarov, V. V.; Lindegren, L.; Bastian, U. +5 more
The Tycho Reference Catalogue\ (TRC) contains high-quality positions and proper motions for 990 182\ stars of the Tycho Catalogue. The proper motions were derived from Tycho positions and Astrographic Catalogue\ positions reduced to the Hipparcos system. The median accuracy of the TRC position components is 40 mas at J1991.25. The median precision…
First Solar EUV Irradiances Obtained from SOHO by the CELIAS/SEM
Wurz, P.; Klecker, B.; Möbius, E. +10 more
The first results obtained with the Solar EUV Monitor (SEM), part of the Charge, Element, and Isotope Analysis System (CELIAS) instrument, aboard the SOlar and Heliospheric Observatory (SOHO) satellite are presented. The instrument monitors the full-disk absolute value of the solar Heii irradiance at 30.4 nm, and the full-disk absolute solar irrad…
Minimum and Maximum Variance Analysis
Sonnerup, Bengt U. Ö.; Scheible, Maureen
Faint Submillimeter Galaxies: Hubble Space Telescope Morphologies and Colors
Kneib, J. -P.; Ivison, R. J.; Smail, Ian +1 more
We present deep optical imaging from the Hubble Space Telescope (HST) and from the ground for galaxies selected from the first submillimeter survey of the distant universe. Our survey comprises 850 µm continuum maps of seven massive lensing clusters and covers a total area of 0.01 deg2 to 1 σ noise levels of <=2 mJy beam-1…
On Quasar Masses and Quasar Host Galaxies
Laor, Ari
The mass of massive black holes in quasar cores can be deduced by using the typical velocities of Hβ-emitting clouds in the broad-line region and by the size of this region. However, this estimate depends on various assumptions and is susceptible to large systematic errors. The Hβ-deduced black hole mass in a sample of 14 bright quasars is found h…
Classical monopoles: Newton, NUT space, gravomagnetic lensing, and atomic spectra
Lynden-Bell, D.; Nouri-Zonoz, M.
This article reviews the dynamics and observational signatures of particles interacting with monopoles, beginning with a scholium in Newton'sPrincipia. The orbits of particles in the field of a gravomagnetic monopole, the gravitational analog of a magnetic monopole, lie on cones; when the cones are slit open and flattened, the orbits are the ellip…
Observations of Correlated White-Light and Extreme-Ultraviolet Jets from Polar Coronal Holes
Llebaria, A.; St. Cyr, O. C.; Michels, D. J. +7 more
Time-lapse sequences of white-light images recorded with the Large Angle Spectrometric Coronagraph (LASCO) on the Solar and Heliospheric Observatory (SOHO) frequently show long, narrow structures moving outward over the Sun's polar regions at high apparent speeds. By comparing the LASCO observations with Fe XII λ195 spectroheliograms made with the…
HIPPARCOS observations of pre-main-sequence stars
Bastian, U.; Krautter, J.; Rucinski, S. M. +2 more
We present first results of Hipparcos observations of nearby low-mass pre-main-sequence (PMS) stars (TTauri and Herbig Ae/Be stars). The data obtained by Hipparcos allow us to derive weighted mean parallaxes for three major nearby star-forming regions (SFRs), Lupus, Chamaeleon I and Taurus-Auriga. Furthermore, results on the isolated objects AB Do…