Science Archives Publication System

Spectral analysis of the sdO K 648, the exciting star of the planetary nebula Ps 1 in the globular cluster M 15 (NGC 7078)

DOI: 10.1051/0004-6361:20011535 Bibcode: 2002A&A...381.1007R

Rauch, T.; Werner, K.; Heber, U.

We present a spectral analysis of the sdO central star K 648 based on medium-resolution optical and high-resolution UV spectra. The photospheric parameters are determined by means of state-of-the-art NLTE model atmosphere techniques. We found T_eff = 39 +/- 2 and log g = 3.9 +/- 0.2. The helium (\ratiow{He}{H}{0.08}) a…

2002 • Astronomy and Astrophysics

IUE eHST 42

Physical Structure of the Proto-Planetary Nebula CRL 618. I. Optical Long-Slit Spectroscopy and Imaging

DOI: 10.1086/342316 Bibcode: 2002ApJ...578..269S

Sahai, R.; Sánchez Contreras, C.; Gil de Paz, A.

In this paper we present optical long-slit spectroscopy and imaging of the proto-planetary nebula CRL 618. The optical lobes of CRL 618 consist of shock-excited gas, which emits many recombination and forbidden lines, and dust, which scatters light from the innermost regions. From the analysis of the scattered Hα emission, we derive a nebular incl…

2002 • The Astrophysical Journal

eHST 42

Abundant molecular gas in the intergalactic medium of Stephan's Quintet

DOI: 10.1051/0004-6361:20021232 Bibcode: 2002A&A...394..823L

Duc, P. -A.; Braine, J.; Charmandaris, V. +3 more

Stephan's Quintet (SQ) is a system consisting of at least four interacting galaxies which is well known for its complex dynamical and star formation history. It possesses a rich intergalactic medium (IGM), where hydrogen clouds, both atomic and molecular, associated with two starbursts (refered to as SQ A and B) have been found. In order to study …

2002 • Astronomy and Astrophysics

ISO 42

High-Resolution Mid-Infrared Morphology of Cygnus A

DOI: 10.1086/338071 Bibcode: 2002ApJ...566..675R

Tadhunter, Clive N.; Radomski, James T.; Packham, Christopher +2 more

We present subarcsecond-resolution mid-infrared images at 10.8 and 18.2 µm of Cyg A. These images were obtained with the University of Florida mid-IR camera/spectrometer OSCIR at the Keck II 10 m telescope. Our data show extended mid-IR emission primarily to the east of the nucleus with a possible western extension detected after image decon…

2002 • The Astrophysical Journal

eHST 41

Hubble Space Telescope Wide Field Planetary Camera 2 observations of hyperluminous infrared galaxies

DOI: 10.1046/j.1365-8711.2002.04991.x Bibcode: 2002MNRAS.329..605F

Farrah, D.; Verma, A.; Rowan-Robinson, M. +2 more

We present Hubble Space Telescope Wide Field Planetary Camera 2 I-band imaging for a sample of nine hyperluminous infrared galaxies (HLIRGs) spanning a redshift range 0.45<z<1.34. Three of the sample have morphologies showing evidence for interactions and six are quasi-stellar objects (QSOs). Host galaxies in the QSOs are detected reliably o…

2002 • Monthly Notices of the Royal Astronomical Society

eHST 41

Study of the Per OB2 star forming complex. II. Structure and kinematics

DOI: 10.1051/0004-6361:20020418 Bibcode: 2002A&A...387..117B

Scholz, R. -D.; Piskunov, A. E.; Kharchenko, N. V. +2 more

The study of a sky area with a 20 degree diameter centered on the nearby association Per OB2 has been carried out on the basis of the ``Compiled Catalogue of Astronomical Data in the Per OB2 Field'' presented in a previous paper. The catalogue contains about 30 000 stars with accurate proper motions in the Hipparcos system as well as magnitudes su…

2002 • Astronomy and Astrophysics

Hipparcos 41

Clues about the star formation history of the M31 disc from WFPC2 photometry

DOI: 10.1046/j.1365-8711.2002.05088.x Bibcode: 2002MNRAS.331..293W

Williams, Benjamin F.

Over the past several years, the Hubble Space Telescope (HST) has acquired many broad-band images of various regions in the M31 disc. I have obtained 27 such fields from the HST data archive in order to produce colour-magnitude diagrams (CMDs) of the stellar populations contained within these areas of the disc. I have attempted to reproduce these …

2002 • Monthly Notices of the Royal Astronomical Society

eHST 41

Energetics of Explosive Events Observed with SUMER

DOI: 10.1086/324714 Bibcode: 2002ApJ...565.1298W

Winebarger, Amy R.; Warren, Harry P.; Mariska, John T. +1 more

Observations of solar chromosphere-corona transition region plasma show evidence of small-scale, short-lived dynamic phenomena characterized by significant nonthermal broadening and asymmetry in the wings of spectral line profiles. These impulsive mass motions (explosive events) are thought to be the product of magnetic reconnection and to be simi…

2002 • The Astrophysical Journal

SOHO 41

The Spatial Distribution of the Far-Infrared Emission in NGC 253

DOI: 10.1086/341109 Bibcode: 2002ApJ...574..709M

Pérez García, A. M.; Acosta-Pulido, J. A.; Melo, V. P. +2 more

We study the far-infrared emission properties of the nearby starburst galaxy NGC 253 based on IRAS maps and an ISOPHOT map at 180 µm. Based on the analysis of the light profiles, we have been able to identify three main structural components: an unresolved nuclear component, an exponential disk, and a kiloparsec-scale bar. In addition, we al…

2002 • The Astrophysical Journal

ISO 41

Multiple Light Echoes from SN 1993J

DOI: 10.1086/346016 Bibcode: 2002ApJ...581L..97S

Crotts, Arlin P. S.; Sugerman, Ben E. K.

Using the technique of point-spread function-matched image subtraction, we have analyzed archival Hubble Space Telescope (HST) Wide Field Planetary Camera 2 data to reveal details of at least two light echo structures, including some unknown before now, around SN 1993J in the galaxy M81. In particular, we see one partial sheet of material 81 pc in…

2002 • The Astrophysical Journal

eHST 41