Search Publications
A Morphological and Multicolor Survey for Faint QSOS in the Groth-Westphal Strip
Anderson, Scott F.; Beck-Winchatz, Bernhard
Quasars that are representative of the populous faint end of the luminosity function are frustratingly dim, with m~24 at intermediate redshift; moreover, ground-based surveys for such faint QSOs suffer substantial morphological contamination by compact galaxies with similar colors. In order to establish a more reliable ultrafaint QSO sample, we us…
HUBBLE SPACE TELESCOPE View of the Heart of Ursa Minor
Battinelli, Paolo; Demers, Serge
Hubble Space Telescope F606W observations to 26th magnitude are used to investigate the stellar distribution in the center of the Ursa Minor dwarf spheroidal galaxy. The central surface density is found to be low, less than 700 stars arcmin^-2, with no sign of a pronounced cusp. The maximum of the surface density is not found at our adopted center…
Latitudinal and radial variation of >2 GeV/n protons and α-particles in the northern heliosphere: ulysses cospin/ket and neutron monitor network observations
Kunow, H.; Bothmer, V.; Wibberenz, G. +10 more
Ulysses, launched in October 1990, crossed in December 1997 the heliographic equator and completed its first out of ecliptic orbit. During the time period from February 1995 to November 1997 solar activity was low and the spacecraft scanned the latitude range from 80° N to the heliographic equator. The Kiel Electron Telescope on-board Ulysses meas…
Laboratory Studies of Alkali Metal Filter Deposition, Ultraviolet Transmission, and Visible Blocking
Trauger, John T.; Vincent, Mark B.; Clarke, John T. +4 more
Far-ultraviolet alkali metal or Wood s filters have been produced and tested supporting the production of a flight filter for the Wide Field Planetary Camera 2 on the Hubble Space Telescope. Sodium layers 0.5 1- m thick transmit up to 40% in the ultraviolet while efficiently blocking visible wavelengths. The prevention of visible pinholes is assis…
Jovian electron modulations by the solar wind interaction with the magnetosphere
Misawa, H.; Tsuchiya, F.; Morioka, A.
Variations of energetic electrons released from the Jovian magnetosphere are investigated in detail by using data from three spacecraft, Pioneer 10, 11, and Ulysses. Analyses with the three spacecraft data confirmed that the Jovian electrons are modulated by the dynamic pressure of the solar wind at the position of Jupiter. It is also found that t…
The Cassini-Huygens ACP experiment and exobiological implications
Israel, G.; Coll, P.; Raulin, F. +3 more
Since the discovery of its dense nitrogen atmosphere Titan, the largest satellite of Saturn has always been the subject of a strong interest by the scientific community of the exobiologists. The main reason is that Titan's atmosphere is believed to be over geologic time a permanent source of N- containing organic molecules (mostly nitriles) and of…
ISO Spectroscopy of Ultraluminous Infrared Galaxies
Lutz, D.; Genzel, R.; Sturm, E. +5 more
Spectroscopy from the Infrared Space Observatory ISO has for the first timeprovided the sensitivity to exploit the diagnostic power ofmid-infrared fine structure lines and PAH features for the study ofultraluminous infrared galaxies (LIR >1012L⊙). We report on observations obtainedwith SWS, ISOPHOT-S, and the CV…
Working Group 1 Report: Solar Wind Models from the Sun to 1 AU: Constraints by "in situ" and Remote Sensing Measurements
Marsch, E.; Leer, E.
The goal of Working Group 1 was to discuss constraints on solar wind models. The topics for discussion, outlined by Eckart Marsch in his introduction, were: (1) what heats the corona, (2) what is the role of waves, (3) what determines the solar wind mass flux, (4) can stationary, multi-fluid models describe the fast and slow solar wind, or (5) do …
Near infrared observations of quasars with extended ionized envelopes
Durret, F.; Petitjean, P.; Márquez, I.
We have observed a sample of 15 and 8 quasars with redshifts between 0.11 and 0.87 (mean value 0.38) in the J and K' bands respectively. Eleven of the quasars were previously known to be associated with extended emission line regions. After deconvolution of the image, substraction of the PSF when possible, and identification of companions with the…
High Resolution WFPC2 Imaging of IRAS 09104 + 4109
Armus, L.; Soifer, B. T.; Neugebauer, G.
With a infrared luminosity of nearly 10^13 Lsuns, IRAS 09104+4109 is the most luminous galaxy with z<0.5 in the IRAS All Sky Survey. A radio-loud Seyfert 2 type optical spectrum, a cD host galaxy in a rich cluster, and a massive cooling flow make IRAS 09104+4109 unique among ultraluminous infrared galaxies. Cannibalized cluster members and the …