Search Publications
Abundant molecular gas in the intergalactic medium of Stephan's Quintet
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 …
High-Resolution Mid-Infrared Morphology of Cygnus A
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…
Hubble Space Telescope Wide Field Planetary Camera 2 observations of hyperluminous infrared galaxies
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…
Study of the Per OB2 star forming complex. II. Structure and kinematics
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…
Clues about the star formation history of the M31 disc from WFPC2 photometry
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 …
Energetics of Explosive Events Observed with SUMER
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…
The Spatial Distribution of the Far-Infrared Emission in NGC 253
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…
Multiple Light Echoes from SN 1993J
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…
A photoionization model of the compact H II region G29.96-0.02
Morisset, C.; Schaerer, D.; Cox, P. +5 more
We present a detailed photoionization model of G29.96-0.02 (hereafter G29.96), one of the brightest Galactic Ultra Compact H Ii (UCHII) regions in the Galaxy. This source has been observed extensively at radio and infrared wavelengths. The most recent data include a complete ISO (SWS and LWS) spectrum, which displays a remarkable richness in atomi…
Non-radial pulsation, rotation and outburst in the Be star omega Orionis from the MuSiCoS 1998 campaign
Stahl, O.; Kaper, L.; Smartt, S. J. +26 more