output
19922026
researchers with a paper here
collaborating institutions
Showing 1997Show all

37 papers · 1 filter

astro-ph1997★ 54 cited

On the Origin of Broad Fe K alpha and Hi H alpha Lines in AGN

J. W. Sulentic, P. Marziani, T. Zwitter +2

We examine the properties of the Fe emission lines that arise near 6.4 keV in the ASCA spectra of AGN. Our emphasis is on the Seyfert 1 galaxies where broad and apparently complex…

astro-ph1997★ 12 cited

UBVRI photometry and spectroscopy of the young open cluster Haffner 18

Ulisse Munari, Giovanni Carraro, Roberto Barbon

UBVRI CCD photometry of a field centered on the young open cluster Haffner~18 is presented and discussed. Spectroscopic classification of seven s…

astro-ph1997★ 2.5k cited

Discovery of a Supernova Explosion at Half the Age of the Universe and its Cosmological Implications

S. Perlmutter, G. Aldering, M. Della Valle +20

The ultimate fate of the universe, infinite expansion or a big crunch, can be determined by measuring the redshifts, apparent brightnesses, and intrinsic luminosities of very dista…

astro-ph1997★ 7 cited

Balmer Line Variations in the Radio-Loud AGN PG 1512+370

P. Romano, P. Marziani, D. Dultzin-Hacyan

We present spectroscopic observations of the quasar PG~1512+370, covering the Hbeta line spectral range and collected at moderate resolution (2-7 A FWHM) from 1988 to 1996. The obs…

astro-ph1997★ 113 cited

DY/DZ from fine structure in the Main Sequence based on Hipparcos parallaxes

B. E. J. Pagel, L. Portinari

The slope Delta Y/Delta Z is a quantity of interest in relation to stellar evolution, the initial mass function and the determination of the primordial helium abundance. In this pa…

astro-ph1997★ 237 cited

Multiwavelength Observations of a Dramatic High Energy Flare in the Blazar 3C 279

A. E. Wehrle, E. Pian, C. M. Urry +3

The blazar 3C 279, one of the brightest identified extragalactic objects in the gamma-ray sky, underwent a flare of a factor 10 amplitude in gamma-rays towards the end of a 3-week…