Science Archives Publication System

Trigonometric Parallaxes and a Kinematically Adjusted Distance Scale for OB Associations

DOI: 10.1134/1.1336863 Bibcode: 2001AstL...27...58D

Dambis, A. K.; Rastorguev, A. S.; Mel'Nik, A. M.

By directly comparing the photometric distances of Blaha and Humphreys (1989) (BH) to OB associations and field stars with the corresponding Hipparcos trigonometric parallaxes, we show that the BH distance scale is overestimated, on average, by 10-20%. This result is independently corroborated by applying the rigorous statistical-parallax method a…

2001 • Astronomy Letters

Hipparcos 48

On the metal abundance in the core of M 87

DOI: 10.1051/0004-6361:20010871 Bibcode: 2001A&A...375L..14M

Molendi, S.; Gastaldello, F.

We revisit the XMM-Newton observation of M 87 to make a new and more detailed measurement of the metal abundance profile. After having verified that spectral fits with single temperature models show a dramatic abundance drop within 1 arcmin of the cluster core, we show that more appropriate models, which include a multi-temperature component to ac…

2001 • Astronomy and Astrophysics

XMM-Newton 48

First results from the Cluster wideband plasma wave investigation

DOI: 10.5194/angeo-19-1259-2001 Bibcode: 2001AnGeo..19.1259G

Gurnett, D. A.; Persoon, A. M.; Pickett, J. S. +9 more

In this report we present the first results from the Cluster wideband plasma wave investigation. The four Cluster spacecraft were successfully placed in closely spaced, high-inclination eccentric orbits around the Earth during two separate launches in July August 2000. Each spacecraft includes a wideband plasma wave instrument designed to provide …

2001 • Annales Geophysicae

Cluster 48

Reconciliation of the Surface Brightness Fluctuation and Type Ia Supernova Distance Scales

DOI: 10.1086/322342 Bibcode: 2001ApJ...559..584A

Riess, Adam G.; Ajhar, Edward A.; Schmidt, Brian P. +2 more

We present Hubble Space Telescope measurements of surface brightness fluctuation (SBF) distances to early-type galaxies that have hosted Type Ia supernovae (SNe Ia). The agreement in the relative SBF and SN Ia multicolor light-curve shape and delta-m₁₅ distances is excellent. There is no systematic scale error with distance, and previou…

2001 • The Astrophysical Journal

eHST 48

New Measurements of the Winds of Uranus

DOI: 10.1006/icar.2001.6689 Bibcode: 2001Icar..153..229H

Karkoschka, E.; Hammel, H. B.; de Pater, I. +2 more

Hubble Space Telescope imaging of Uranus in 1994, 1997, 1998, and 2000 revealed 13 cloud features, allowing the first measurements of wind velocities at northern latitudes not accessible to the Voyager cameras and new measurements of southern-latitude wind velocities determined during the 1986 Voyager encounter. Images acquired with the Keck 10-me…

2001 • Icarus

eHST 48

The Abundances of Solid N₂ and Gaseous CO₂ in Interstellar Dense Molecular Clouds

DOI: 10.1086/319023 Bibcode: 2001ApJ...548..836S

Allamandola, L. J.; Sandford, S. A.; Bernstein, M. P. +2 more

We present 2338-2322 cm^-1 (4.277-4.307 µm) infrared spectra of a number of N₂-containing mixed molecular ices and demonstrate that the strength of the infrared ``forbidden'' band due to the NN stretch near 2328 cm^-1 (4.295 µm) is extremely sensitive to the composition of the ice. The strength of the 232…

2001 • The Astrophysical Journal

ISO 48

Interferometric Astrometry with Hubble Space Telescope Fine Guidance Sensor 3: The Parallax of the Cataclysmic Variable TV Columbae

DOI: 10.1086/323047 Bibcode: 2001ApJ...560..907M

McArthur, B. E.; Benedict, G. F.; Franz, O. G. +14 more

TV Col is a 13th magnitude intermediate polar cataclysmic variable with multiple periods found in the light curves. Past estimates predicted a distance of 400 pc to greater than 500 pc. Recently completed Hubble Space Telescope fine guidance sensor interferometric observations allow us to determine the first trigonometric parallax to TV Col. This …

2001 • The Astrophysical Journal

Hipparcos eHST 48

A Search for Early Optical Emission from Short- and Long-Duration Gamma-Ray Bursts

DOI: 10.1086/321719 Bibcode: 2001ApJ...554L.159K

Hurley, Kevin; McKay, Tim; Kehoe, Robert +16 more

Gamma-ray bursts of short duration may harbor vital clues to the range of phenomena producing bursts. However, recent progress from the observation of optical counterparts has not benefited the study of short bursts. We have searched for early optical emission from six gamma-ray bursts using the telephoto array on the Robotic Optical Transient Sea…

2001 • The Astrophysical Journal

Ulysses 48

Comparison of source detection procedures for XMM-Newton images

DOI: 10.1051/0004-6361:20010264 Bibcode: 2001A&A...370..689V

Valtchanov, I.; Pierre, M.; Gastaud, R.

Procedures based on current methods to detect sources in X-ray images are applied to simulated XMM-Newton images. All significant instrumental effects are taken into account, and two kinds of sources are considered - unresolved sources represented by the telescope PSF and extended ones represented by a beta -profile model. Different sets of test c…

2001 • Astronomy and Astrophysics

XMM-Newton 48

The MACHO Project Hubble Space Telescope Follow-Up: Preliminary Results on the Location of the Large Magellanic Cloud Microlensing Source Stars

DOI: 10.1086/320554 Bibcode: 2001ApJ...552..582A

Alcock, C.; Allsman, R. A.; Alves, D. R. +21 more

We attempt to determine whether the MACHO microlensing source stars are drawn from the average population of the LMC or from a population behind the LMC by examining the Hubble Space Telescope (HST) color-magnitude diagram (CMD) of microlensing source stars. We present WFPC2 HST photometry of eight MACHO microlensing source stars and the surroundi…

2001 • The Astrophysical Journal

eHST 48