The volatile abundances in comet 17P/Holmes were measured on three dates (UT 2007 October 27.6 and 31.3 and November 2.3) using high-dispersion (λ/Δλ~2.5×104) infrared spectroscopy with NIRSPEC at the W. M. Keck Observatory and CSHELL at the NASA Infrared Telescope Facility. Compared to other comets, the relative gas production rates in the coma

We study the structural properties of the low surface brightness stellar hosts in blue compact galaxies by fitting a two-dimensional Sérsic law to their optical images. The accurate isolation of the starburst emission is an important strength of the method. It allows us to obtain more reliable structural parameters, especially when a Sérsic law is

We present the optical-to-submillimetre spectral energy distributions (SEDs) for 33 radio and mid-infrared (mid-IR) identified submillimetre galaxies discovered via the SHADES 850-μm SCUBA imaging in the Subaru-XMM Deep Field (SXDF). Optical data for the sources come from the SXDF and mid- and far-IR fluxes from SWIRE. We obtain photometric

We study the kinematics of the barred spiral galaxy NGC 6946 by investigating the velocity field from Hα Fabry-Perot observations, determine the pattern speed of the bar by using the Tremaine-Weinberg method, and find a main pattern speed of 21.7+4.0-0.8 km-1 s-1 kpc-1. Our data clearly suggest the presence of an additional pattern with a pattern

Surface brightness profiles for early type (S0-Sb) disks exhibit three main classes (Type I, II, and III). Type II profiles are more common in barred galaxies, and most of the time appear to be related to the bar's outer Lindblad resonance. Roughly half of barred galaxies in the field have Type II profiles, but almost none in the Virgo cluster do

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