Search Publications
Calibration of the MACHO Photometry Database
Alcock, C.; Allsman, R. A.; Alves, D. R. +22 more
The MACHO Project is a microlensing survey that monitors the brightnesses of ~60 million stars in the Large Magellanic Cloud (LMC), Small Magellanic Cloud, and Galactic bulge. Our database presently contains about 80 billion photometric measurements, a significant fraction of all astronomical photometry. We describe the calibration of MACHO two-co…
Hubble Space Telescope Space Telescope Imaging Spectrograph Coronagraphic Imaging of the Herbig AE Star AB Aurigae
Bruhweiler, F. C.; Lindler, Don J.; Boggess, A. +5 more
We present the first broadband, coronagraphic Hubble Space Telescope images of the bright, optically visible, isolated Herbig Ae star AB Aurigae. The Space Telescope Imaging Spectrograph (STIS) images reveal extended circumstellar nebulosity (r~1300 AU) covering the region of the millimeter continuum and CO disk. The structure is observed in the d…
FIRBACK. I. A deep survey at 175 microns with ISO, preliminary results
Aussel, H.; Elbaz, D.; Cesarsky, C. +10 more
FIRBACK is a deep survey conducted with the ISOPHOT instrument aboard the Infrared Space Observatory (ISO) at an effective wavelength of 175 mu m. We present here results we have obtained on the first field, the so-called Marano1 which covers around 0.25 square degree. We find that the source density for objects with a flux above 200 mJy exceeds t…
The Magnitude-Size Relation of Galaxies out to z~1
Illingworth, Garth D.; Gebhardt, Karl; Faber, S. M. +6 more
As part of the Deep Extragalactic Evolutionary Probe (DEEP) survey, a sample of 190 field galaxies (I814<=23.5) in the ``Groth Survey Strip'' has been used to analyze the magnitude-size relation over the range 0.1<z<1.1. The survey is statistically complete to this magnitude limit. All galaxies have photometric structural param…
Observations and Implications of the Star Formation History of the Large Magellanic Cloud
Cole, Andrew A.; Ballester, Gilda E.; Crisp, David +14 more
We present derivations of star formation histories based on color-magnitude diagrams of three fields in the LMC from HST/WFPC2 observations. One field is located in the LMC bar and the other two are in the outer disk. We find that a significant component of stars older than 4 Gyr is required to match the observed color-magnitude diagrams. Models w…
The Globular Cluster System in the Inner Region of M87
Kundu, Arunav; Whitmore, Bradley C.; Sparks, William B. +3 more
We have identified 1057 globular cluster candidates in a WFPC2 image of the inner region of M87. The globular cluster luminosity function (GCLF) can be well fitted by a Gaussian profile with a mean value of m0V=23.67+/-0.07 mag and σ=1.39+/-0.06 mag. The GCLF in five radial bins is found to be statistically the same at all po…
Modeling W44 as a Supernova Remnant in a Density Gradient with a Partially Formed Dense Shell and Thermal Conduction in the Hot Interior. I. The Analytical Model
Smith, Randall K.; Shelton, R. L.; Maciejewski, Witold +4 more
We show that many observations of W44, a supernova remnant in the Galactic plane at a distance of about 2500 pc, are remarkably consistent with the simplest realistic model. The model remnant is evolving in a smooth ambient medium of fairly high density, about 6 cm-3 on average, with a substantial density gradient. At the observed time …
Observations of a Propagating Disturbance in TRACE
Thompson, B. J.; Wills-Davey, M. J.
TRACE observations from 13 June 1998 in 171 and 195 Å wavelengths show a propagating disturbance, initiated near the origin of a C-class flare. The wave moves through and disrupts diffuse, overarching coronal loops. Only these overlying structures are affected by the wave; lower-lying coronal structures are unperturbed. The front does not appear i…
A Reanalysis of the Ultraviolet Extinction from Interstellar Dust in the Large Magellanic Cloud
Gordon, Karl D.; Clayton, Geoffrey C.; Misselt, K. A.
We have reanalyzed the Large Magellanic Cloud's (LMC) ultraviolet (UV) extinction using data from the IUE final archive. Our new analysis takes advantage of the improved signal-to-noise ratio of the IUE NEWSIPS reduction, the exclusion of stars with very low reddening, the careful selection of well-matched comparison stars, and an analysis of the …
Mid-Infrared and Optical Spectroscopy of Ultraluminous Infrared Galaxies: A Comparison
Lutz, D.; Genzel, R.; Veilleux, S.
New tools from Infrared Space Observatory (ISO) mid-infrared spectroscopy have recently become available to determine the power sources of dust-obscured ultraluminous infrared galaxies (ULIRGs). We compare ISO classifications--starburst or active galactic nucleus (AGN)--with classifications from optical spectroscopy and with optical/near-infrared …