Search Publications
XMM-Newton observations of the cluster of galaxies Abell 496. Measurements of the elemental abundances in the intracluster medium
Kaastra, J. S.; Molendi, S.; Ferrigno, C. +2 more
The results from XMM-Newton observations of the relaxed cluster of galaxies Abell 496 are presented. The spatially-resolved X-ray spectra taken by the European Photon Imaging Cameras show a temperature drop and a Fe abundance increase in the intra-cluster medium (ICM) towards the cD galaxy at the cluster center. The abundances of Si and S also sho…
The X-ray spectrum of the supernova remnant 1E 0102.2-7219
Behar, E.; Kahn, S. M.; den Herder, J. W. +2 more
In this letter we present the soft X-ray (5-35 Å) spectrum of the supernova remnant (SNR)
Numerical simulations of weak lensing measurements
Refregier, Alexandre; Ellis, Richard S.; Clowe, Douglas +1 more
Weak gravitational lensing induces distortions on the images of background galaxies, and thus provides a direct measure of mass fluctuations in the Universe. The distortion signature from large-scale structure has recently been detected by several groups for the first time, opening promising prospects for the near future. Since the distortions ind…
M Dwarfs from Hubble Space Telescope Star Counts. IV.
Gould, Andrew; Salim, Samir; Bahcall, John N. +2 more
We study a sample of about 1400 disk M dwarfs that are found in 148 fields observed with the Wide Field Camera 2 (WFC2) on the Hubble Space Telescope and 162 fields observed with pre-repair Planetary Camera 1 (PC1), of which 95 of the WFC2 fields are newly analyzed. The method of maximum likelihood is applied to derive the luminosity function and …
Modeling the Interstellar Medium of Low Surface Brightness Galaxies: Constraining Internal Extinction, Disk Color Gradients, and Intrinsic Rotation Curve Shapes
Wood, Kenneth; Matthews, L. D.
We use a combination of three-dimensional Monte Carlo radiative transfer techniques and multiwavelength (BRHK, Hα) imaging data to investigate the nature of the interstellar medium (ISM) in the edge-on, low surface brightness (LSB) galaxy UGC 7321. Using realistic models that incorporate multiple scattering effects and clumping of the stars and th…
Global physical conditions of the interstellar medium in nearby galaxies
Onaka, T.; Roellig, T. L.; Negishi, T. +1 more
Far-infrared spectra (43-197 mu m) of 34 nearby galaxies obtained by the Long Wavelength Spectrometer (LWS) aboard the Infrared Space Observatory (ISO) were analyzed to investigate the general properties of interstellar matter in galaxies. The present sample includes not only normal galaxies but also starbursts and active galactic nuclei (AGNs). F…
Near-Infrared Imaging and [O I] Spectroscopy of IC 443 using Two Micron All Sky Survey and Infrared Space Observatory
Reach, W. T.; Rho, Jeonghee; Jarrett, T. H. +1 more
We present near-infrared J (1.25 µm), H (1.65 µm), and Ks (2.17 µm) imaging of the entire supernova remnant IC 443 from the Two Micron All Sky Survey (2MASS), and Infrared Space Observatory (ISO) LWS observations of [O I] for 11 positions in the northeast. Near-infrared emission from IC 443 was detected in all three ba…
Structural Properties of Massive Young Clusters
Maíz-Apellániz, Jesús
We have retrieved multicolor WFPC2/Hubble Space Telescope data from the STScI archive for 27 nearby massive (>~3×104 Msolar) young (<20 Myr) star clusters (MYCs). The data represents the most complete sample of clearly resolved MYCs to date. We have analyzed their structural properties and have found that they can be cl…
Hubble Space Telescope Images of Stephan's Quintet: Star Cluster Formation in a Compact Group Environment
Charlton, Jane C.; Whitmore, Bradley C.; Gallagher, Sarah C. +2 more
Analysis of Hubble Space Telescope Wide Field Planetary Camera 2 images of Stephan's Quintet, Hickson Compact Group 92, yielded 115 candidate star clusters (with V-I<1.5). Unlike in merger remnants, the cluster candidates in Stephan's Quintet are not clustered in the inner regions of the galaxies; they are spread over the debris and surrounding…
New Photometry for the Intermediate-Age Large Magellanic Cloud Globular Cluster NGC 2121 and the Nature of the LMC Age Gap
Rich, R. Michael; Shara, Michael M.; Zurek, David
We report new photometry for the cluster NGC 2121 in the Large Magellanic Cloud, which shows a prominent hydrogen core exhaustion gap at the turnoff and a descending subgiant branch reminiscent of Galactic open clusters. We achieve an excellent fit using the Girardi isochrones, finding an age of 3.2+/-0.5 Gyr, with [Fe/H]=-0.6+/-0.2. The isochrone…