Showing 1998Show all

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astro-ph1998★ 17 cited

The Submillimeter Frontier: A Space Science Imperative

John C. Mather, S. Harvey Moseley, David Leisawitz +8

A major goal of modern astrophysics is to understand the processes by which the universe evolved from its initial simplicity, as seen in measurements of the Cosmic Microwave Backgr…

astro-ph1998★ 4 cited

BL Lac Objects and Blazars: Past, Present, and Future

C. Megan Urry

The past 20 years have seen phenomenal progress in our understanding of BL Lac objects. They form part of the blazar class, which are radio-loud AGN whose relativistic jets are ali…

astro-ph1998★ 1 cited

Calibrating UV Emissivity And Dust Absorption At z \approx 3

Gerhardt R. Meurer, Timothy M. Heckman, Daniela Calzetti

We detail a technique for estimating the UV extinction and luminosity of UV selected galaxies using UV quantities alone. The technique is based on a tight correlation between the r…

astro-ph1998★ 2 cited

Astronomical Archives of the Future: A Virtual Observatory

A. S. Szalay, R. J. Brunner

Astronomy is entering a new era as multiple, large area, digital sky surveys are in production. The resulting datasets are truly remarkable in their own right; however, a revolutio…

astro-ph1998★ 42 cited

An X-ray and Optical Investigation of the Starburst-driven Superwind in the Galaxy Merger Arp 299

T. M. Heckman, L. Armus, K. A. Weaver +1

We present a detailed investigation of the X-ray and optical properties of the starburst-merger system Arp299 (NGC 3690, Mrk 171), with an emphasis on its spectacular gaseous nebul…

astro-ph1998★ 2 cited

Galactic and Accretion Disk Dynamos

Ethan T. Vishniac

Dynamos in astrophysical disks are usually explained in terms of the standard alpha-omega mean field dynamo model where the local helicity generates a radial field component from a…

cond-mat.supr-con1998★ 21 cited

Quasiparticle spectra in the vicinity of a d-wave vortex

M. Franz, Z. Tesanovic

We discuss the evolution of the local quasiparticle spectral density and the related tunneling conductance measurable by the scanning tunneling microscope, as a function of distanc…

hep-ph1998★ 99 cited

Strongly Interacting Neutrinos and the Highest Energy Cosmic Rays

G. Domokos, S. Kovesi-Domokos

Cosmic rays of energies larger than the Greisen-Zatsepin-Kuzmin (GZK) cutoff may be neutrinos if they acquire strong interactions due to a ``precocious unification'' of forces. A s…

astro-ph1998★ 29 cited

A Polarimetric Search for Hidden Quasars in Three Radio Selected Ultraluminous Infrared Galaxies

Hien D. Tran, M. S. Brotherton, S. A. Stanford +4

We have carried out a spectropolarimetric search for hidden broad-line quasars in three ultraluminous infrared galaxies (ULIRGs) discovered in the positional correlations between s…

astro-ph1998★ 36 cited

The Statistical Approach to Quantifying Galaxy Evolution

R. J. Brunner, A. J. Connolly, A. S. Szalay

Studies of the distribution and evolution of galaxies are of fundamental importance to modern cosmology; these studies, however, are hampered by the complexity of the competing eff…

astro-ph1998

VLT and HST observations of a candidate high redshift elliptical galaxy in the Hubble Deep Field South

M. Stiavelli, T. Treu, C. M. Carollo +8

The combined use of the ESO Very Large Telescope (VLT) UT1 Science Verification (SV) images and of the Hubble Space Telescope (HST) Hubble Deep Field South observations allows us t…

astro-ph1998★ 104 cited

The Ratio of Ortho- to Para-H2 in Photodissociation Regions

Amiel Sternberg, David A. Neufeld

We discuss the ratio of ortho- to para-H2 in photodissociation regions (PDRs). We draw attention to an apparent confusion in the literature between the ortho-to-para ratio of molec…

hep-ph1998★ 26 cited

Heavy Majorana neutrinos in e+e- colliders

G. Cvetic, C. S. Kim, C. W. Kim

We investigate possibilities for detecting heavy Majorana neutrinos ('s) in at LEP200 and future Linear Colliders. We concentrate on the processes where the pairs of in…

cond-mat.mtrl-sci1998★ 55 cited

Anisotropic spin freezing in the S=1/2 zigzag ladder compound SrCuO2

I. A. Zaliznyak, C. Broholm, M. Kibune +2

Using magnetic neutron scattering we characterize an unusual low temperature phase in orthorhombic SrCuO2. The material contains zigzag spin ladders formed by pairs of S=1/2 chains…

astro-ph1998★ 49 cited

New High-Redshift Radio Galaxies from the MIT-Green Bank Catalog

Daniel Stern, Arjun Dey, Hyron Spinrad +4

We present optical identifications and redshifts for seventeen new high-redshift radio sources. Fifteen of these sources are radio galaxies; the remaining two are high-redshift, st…

gr-qc1998★ 58 cited

Mass Quantization of the Schwarzschild Black Hole

Cenalo Vaz, Louis Witten

We examine the Wheeler-DeWitt equaton for a static, eternal Schwarzschild black hole in Kucha\v r-Brown variables and obtain its energy eigenstates. Consistent solutions vanish in…

astro-ph1998★ 115 cited

Nuclear Disks of Gas and Dust in Early Type Galaxies and the Hunt for Massive Black Holes: Hubble Space Telescope Observations of NGC 6251

Laura Ferrarese, Holland Ford

We discuss Hubble Space Telescope optical images and spectra of NGC 6251, a giant E2 galaxy and powerful radio source at a distance of 106 Mpc (for H_0 = 70 km/s/Mpc). The galaxy i…

astro-ph1998★ 1 cited

The Far Ultraviolet Spectroscopic Explorer: Mission Overview and Prospects for Studies of the Interstellar Medium and High Velocity Clouds

Kenneth R. Sembach

The Far Ultraviolet Spectroscopic Explorer (FUSE) is a NASA astronomy mission that will explore the 905-1187 A wavelength region at high spectral resolution. Funded by NASA's Explo…

astro-ph1998

Highly Ionized High Velocity Clouds

Kenneth R. Sembach, Blair D. Savage, Limin Lu +1

We have recently used the Hubble Space Telescope to study a pair of high velocity clouds in the direction of Mrk 509 that have unusual ionization properties. They exhibit strong CI…

astro-ph1998★ 26 cited

The Closest Damped Lyman Alpha System

Eric D. Miller, Patricia M. Knezek, Joel N. Bregman

A difficulty of studying damped Lyman alpha systems is that they are distant, so one knows little about the interstellar medium of the galaxy. Here we report upon a damped Lyman al…

astro-ph1998★ 49 cited

Formation of Interstellar Ices Behind shock Waves

Edwin A. Bergin, David A. Neufeld, Gary J. Melnick

We have used a coupled dynamical and chemical model to examine the chemical changes induced by the passage of an interstellar shock in well shielded regions. Using this model we de…

astro-ph1998★ 19 cited

On the Structure and Morphology of the `Diffuse Ionized Medium' in Star-Forming Galaxies

Jing Wang, Timothy Heckman, Matthew Lehnert

Deep H images of a sample of nearby late-type spiral galaxies have been analyzed to characterize the morphology and energetic significance of the ``Diffuse Ionized Medium'' (DIM…

math.AT1998★ 1 cited

Phantom maps and chromatic phantom maps

J. Daniel Christensen, Mark Hovey

In the first part, we determine conditions on spectra X and Y under which either every map from X to Y is phantom, or no nonzero maps are. We also address the question of whether s…

astro-ph1998★ 95 cited

The Evolution of Dust Opacity in Galaxies

D. Calzetti, T. M. Heckman

(Abridged) We investigate the evolution of the opacity of galaxies as a function of redshift, using simple assumptions about the metal and dust enrichment of the gas and the distri…