output
19912026
Showing 2001 · astro-phShow all

77 papers · 2 filters

astro-ph2001★ 19 cited

Discovery of 16.6 and 25.5 s Pulsations from the Small Magellanic Cloud

R. C. Lamb, D. J. Macomb, T. A. Prince +1

We report the serendipitous detection of two previously unreported pulsars from the direction of the Small Magellanic Cloud, with periods of 16.6 and 25.5 seconds. The detections a…

astro-ph2001

The Pulsar Wind Nebula of G11.2-0.3

M. S. E. Roberts, C. Tam, V. M. Kaspi +4

We present high-resolution radio and X-ray studies of the composite supernova remnant G11.2-0.3. Using archival VLA data, we perform radio spectral tomography to measure for the fi…

astro-ph2001★ 168 cited

Asymmetric Supernovae from Magneto-Centrifugal Jets

J. Craig Wheeler, David L. Meier, James R. Wilson

Strong toroidal magnetic fields generated in stellar collapse can generate magneto-centrifugal jets in analogy to those found in simulations of black hole accretion and explain why…

astro-ph2001

15 Years Going Steady - Timing the Magnetar 1E 1841-045

E. V. Gotthelf, F. P. Gavriil, V. M. Kaspi +2

We report on a long-term monitoring campaign of 1E 1841-045, the 12-s anomalous X-ray pulsar and magnetar candidate at the center of the supernova remnant Kes 73. We have obtained…

astro-ph2001★ 17 cited

Cosmic Microwave Background Anisotropy Measurement From Python V

K. Coble, S. Dodelson, M. Dragovan +5

We analyze observations of the microwave sky made with the Python experiment in its fifth year of operation at the Amundsen-Scott South Pole Station in Antarctica. After modeling t…

astro-ph2001★ 152 cited

Chandra Detection of a TypeII Quasar at z=3.288

Daniel Stern, Edward C. Moran, Alison L. Coil +16

We report on observations of a TypeII quasar at redshift z=3.288, identified as a hard X-ray source in a 185 ks observation with the Chandra X-ray Observatory and as a high-redshif…

astro-ph2001★ 141 cited

Scaling relations of supersonic turbulence in star-forming molecular clouds

Stanislav Boldyrev, Aake Nordlund, Paolo Padoan

We present a direct numerical and analytical study of driven supersonic MHD turbulence that is believed to govern the dynamics of star-forming molecular clouds. We describe statist…

astro-ph2001★ 7 cited

Capabilities of the NASA/IPAC Extragalactic Database (NED) in the Era of a Global Virtual Observatory

Joseph M. Mazzarella, Barry F. Madore, George Helou +1

We review the capabilities of the NASA/IPAC Extragalactic Database (NED, http://ned.ipac.caltech.edu) for information retrieval and knowledge discovery in the context of a globally…

astro-ph2001★ 30 cited

PLANCK: systematic effects induced by periodic fluctuations of arbitrary shape

Aniello Mennella, Marco Bersanelli, Carlo Burigana +4

A fundamental requirement in the new generation of high resolution Cosmic Microwave Background imaging experiments is a strict control of systematic errors that must be kept at mic…

astro-ph2001★ 68 cited

An X-ray Selected Galaxy Cluster at z=1.11 in the Rosat Deep Cluster Survey

S. A. Stanford, B. P. Holden, P. Rosati +4

We report the discovery of an X-ray luminous galaxy cluster at z =1.11. RDCS J0910+5422 was selected as an X-ray cluster candidate in the ROSAT Deep Cluster Survey on the basis of…

astro-ph2001★ 45 cited

Tomographic Separation of Composite Spectra. VIII. The Physical Properties of the Massive Compact Binary in the Triple Star System HD 36486 (delta Orionis A)

James A. Harvin, Douglas R. Gies, William G. Bagnuolo +2

Double-lined spectroscopic orbital elements have recently been found for the central binary in the massive triple, delta Orionis A based on radial velocities from cross-correlation…

astro-ph2001★ 87 cited

Interferometric Mapping of Magnetic Fields in Star-forming Regions II. NGC2024 FIR5

Shih-Ping Lai, Richard M. Crutcher, Jose M. Girart +1

We present the first interferometric polarization maps of the NGC2024 FIR5 molecular core obtained with the BIMA array at approximately 2 arcsec resolution. We measure an average p…

astro-ph2001

X-ray temperature and morphology of z>0.8 clusters of galaxies

B. Holden, S. A. Stanford, P. Rosati +4

We discuss our current progress in studying a sample of z>0.8 clusters of galaxies from the ROSAT Distant Cluster Survey. To date, we have Chandra observations for four of the ten…

astro-ph2001

Detection of an inner torus in the Proto planetary Nebulae OH231.8+4.2

J. -F. Desmurs, C. Sanchez Contreras, V. Bujarrabal +2

We performed the first VLBI observations of the SiO v=1 and v=2 J=1--0 masers in a Proto Planetary Nebula OH 231.8+4.2 (also known as the Rotten Egg nebula), at milliarcsecond reso…

astro-ph2001★ 153 cited

Optical and Near-IR Imaging of Ultra Steep Spectrum Radio Sources - The K-z diagram of radio and optically selected galaxies

Carlos De Breuck, Wil van Breugel, Adam Stanford +3

We present optical and/or near-IR images of 128 ultra steep spectrum (USS) radio sources. Roughly half of the objects are identified in the optical images (R <~ 24), while in the n…

astro-ph2001★ 332 cited

The Distance to SN 1999em in NGC 1637 from the Expanding Photosphere Method

Douglas C. Leonard, Alexei V. Filippenko, Elinor L. Gates +13

We present 30 optical spectra and 49 photometric epochs sampling the first 517 days after discovery of supernova (SN) 1999em, and derive its distance through the expanding photosph…

astro-ph2001★ 35 cited

Total linear polarization in the OH maser W75N: VLBA polarization structure

V. I. Slysh, V. Migenes, I. E. Val'tts +5

W75N is a star-forming region containing various ultracompact HII regions and OH, water, and methanol maser emission. Our VLBA map shows that the OH masers are located in a thin di…

astro-ph2001★ 26 cited

Low mass T Tauri and young brown dwarf candidates in the Chamaeleon II dark cloud found by DENIS

My Ha Vuong, Laurent Cambresy, Nicolas Epchtein

We define a sample designed to select low-mass T Tauri stars and young brown dwarfs using DENIS data in the Chamaeleon II molecular cloud. We use a star count method to construct a…

astro-ph2001★ 66 cited

Optical/Near-Infrared Imaging of Infrared-Excess Palomar-Green QSOs

Jason A. Surace, David B. Sanders, Aaron S. Evans

Ground-based high spatial-resolution (FWHM < 0.3-0.8") optical and near-infrared imaging (0.4-2.2um) is presented for a complete sample of optically selected Palomar-Green QSOs wit…

astro-ph2001★ 46 cited

Precise Chandra Localization of the Soft Gamma-ray Repeater SGR 1806-20

D. L. Kaplan, D. W. Fox, S. R. Kulkarni +3

We present observations of the Soft Gamma-ray Repeater SGR 1806-20 taken with the Chandra X-ray Observatory. We identify the X-ray counterpart of SGR 1806-20 based on detection of…

astro-ph2001★ 3 cited

The Formation and Evolution of Planetary Systems: SIRTF Legacy Science in the VLT Era

M. R. Meyer, D. Backman, S. V. W. Beckwith +20

We will utilize the sensitivity of SIRTF through the Legacy Science Program to carry out spectrophotometric observations of solar-type stars aimed at (1) defining the timescales ov…

astro-ph2001★ 226 cited

On the Threshold of the Reionization Epoch

S. G. Djorgovski, S. M. Castro, D. Stern +1

Discovery of the cosmic reionization epoch would represent a significant milestone in cosmology. We present Keck spectroscopy of the quasar SDSS 1044-0125, at z = 5.73. The spectru…

astro-ph2001★ 16 cited

Exploration of Parameter Spaces in a Virtual Observatory

S. G. Djorgovski, A. Mahabal, R. Brunner +5

Like every other field of intellectual endeavor, astronomy is being revolutionised by the advances in information technology. There is an ongoing exponential growth in the volume,…

astro-ph2001★ 31 cited

Orientation and Speed of the Parsec-Scale Jet in NGC4261 (3C270)

B. Glenn Piner, Dayton L. Jones, Ann E. Wehrle

NGC4261 (3C270) is an elliptical galaxy containing a 300-parsec scale nuclear disk of gas and dust imaged by the Hubble Space Telescope (HST), around a central supermassive black h…