Science Archives Publication System

Eccentric-Disk Models for the Nucleus of M31

DOI: 10.1086/378638 Bibcode: 2003ApJ...599..237P

Tremaine, Scott; Peiris, Hiranya V.

We construct dynamical models of the ``double'' nucleus of M31 in which the nucleus consists of an eccentric disk of stars orbiting a central black hole. The principal approximation in these models is that the disk stars travel in a Keplerian potential; i.e., we neglect the mass of the disk relative to the black hole. We consider both ``aligned'' …

2003 • The Astrophysical Journal

eHST 61

Mapping the Circumstellar Environment of T Tauri with Fluorescent H₂ Emission

DOI: 10.1086/379557 Bibcode: 2003AJ....126.3076W

Valenti, Jeff A.; Brown, Alexander; Walter, Frederick M. +6 more

We have obtained three long-slit, far-UV spectra of the pre-main-sequence system T Tauri. These Hubble Space Telescope STIS spectra show a strong and variable on-source spectrum composed of both fluoresced H₂ and stellar chromospheric lines. Extended H₂ emission is seen up to 10" from the T Tau system. The on-source and exten…

2003 • The Astronomical Journal

eHST 61

A Chandra X-Ray Study of the Dense Globular Cluster Terzan 5

DOI: 10.1086/375189 Bibcode: 2003ApJ...590..809H

Heinke, C. O.; Cohn, H. N.; Lugger, P. M. +3 more

We report a Chandra ACIS-I observation of the dense globular cluster Terzan 5. The previously known transient low-mass X-ray binary (LMXB) EXO 1745-248 in the cluster entered a rare high state during our 2000 August observation, complicating the analysis. Nevertheless, nine additional sources clearly associated with the cluster are also detected, …

2003 • The Astrophysical Journal

eHST 61

The Spiros imaging software for the Integral SPI spectrometer

DOI: 10.1051/0004-6361:20031260 Bibcode: 2003A&A...411L.123S

Connell, P.; Skinner, G.

A key tool in the package of software available for the analysis of data from the SPI spectrometer of Integral is the SPIROS system developed at the University of Birmingham. Although intended primarily for the analysis of point sources and for the extraction of spectral information, SPIROS has many additional capabilities. The software is describ…

2003 • Astronomy and Astrophysics

INTEGRAL 61

The Dust in Lyman Break Galaxies

DOI: 10.1086/368344 Bibcode: 2003ApJ...587..533V

Gordon, Karl D.; Witt, Adolf N.; Vijh, Uma P.

We present our analysis of UV attenuation by internal dust of a large sample (N=906 galaxies) of Lyman break galaxies (LBGs). Using spectral energy distributions (SEDs) from the PÉGASE galaxy spectral evolution model, we apply dust attenuation corrections to the G-R colors, using the Witt & Gordon models for radiative transfer in dusty galacti…

2003 • The Astrophysical Journal

eHST 61

Delayed Soft X-Ray Emission Lines in the Afterglow of GRB 030227

DOI: 10.1086/378790 Bibcode: 2003ApJ...595L..29W

Watson, D.; Reeves, J. N.; Pedersen, K. +2 more

Strong delayed X-ray line emission is detected in the afterglow of gamma-ray burst GRB 030227, appearing near the end of the XMM-Newton observation, nearly 20 hr after the burst. The observed flux in the lines, not simply the equivalent width, sharply increases from an undetectable level (<1.7×10^-14 ergs cm^-2 s^-1

2003 • The Astrophysical Journal

XMM-Newton 61

Deep Hubble Space Telescope Imaging of Sextans A. II. Cepheids and Distance

DOI: 10.1086/346279 Bibcode: 2003AJ....125.1261D

Dolphin, Andrew E.; Skillman, Evan D.; Saha, A. +6 more

We have identified 82 short-period variable stars in Sextans A from deep Wide Field Planetary Camera 2 observations. All the periodic variables appear to be short-period Cepheids, with periods as small as 0.8 days for fundamental mode Cepheids and 0.5 days for first-overtone Cepheids. These objects have been used, along with measurements of the re…

2003 • The Astronomical Journal

eHST 61

An extragalactic supernebula confined by gravity

DOI: 10.1038/nature01689 Bibcode: 2003Natur.423..621T

Larkin, J. E.; Turner, J. L.; Beck, S. C. +3 more

Little is known about the origins of globular clusters, which contain hundreds of thousands of stars in a volume only a few light years across. Radiation pressure and winds from luminous young stars should disperse the star-forming gas and disrupt the formation of the cluster. Globular clusters in our Galaxy cannot provide answers; they are billio…

2003 • Nature

eHST 61

The Solar Wind and Its Magnetic Sources at Sunspot Maximum

DOI: 10.1086/368302 Bibcode: 2003ApJ...587..818W

Sheeley, N. R., Jr.; Wang, Y. -M.

We use in situ measurements from the Advanced Composition Explorer and magnetograph data from the National Solar Observatory to relate the properties of the solar wind during 1998-2002 to its source region magnetic fields. The great bulk of the solar maximum wind is characterized by low proton speeds (v_p~420 km s^-1) and high …

2003 • The Astrophysical Journal

SOHO 61

The interferometric diameter and internal structure of Sirius A

DOI: 10.1051/0004-6361:20030994 Bibcode: 2003A&A...408..681K

Bordé, P.; Morel, P.; Kervella, P. +2 more

The interferometric observations of dwarf stars in the solar neighbourhood, combined with HIPPARCOS parallaxes provide very precise values of their linear diameters. In this paper, we report the direct measurement of the angular diameter of the bright star Sirius A with the VINCI/VLTI instrument. We obtain a uniform disk angular diameter of theta_…

2003 • Astronomy and Astrophysics

Hipparcos 60