High-sensitivity maps of the large-scale structure of atomic hydrogen in the starburst dwarf galaxy NGC 1569 show evidence for an HI cloud with a mass of 7 · 10 6 M ⊙ , at a projected distance of 5 kpc from the parent galaxy. This cloud may be a condensation in a low-column-density HI halo or a companion galaxy/HI-cloud. NGC 1569 and its companion are connected by a low surface brightness HI br...

We discuss current progress and future plans for the general antiparticle spectrometer experiment (GAPS). GAPS detects antideuterons through the X-rays and pions emitted during the deexcitation of exotic atoms formed when the antideuterons are slowed down and stopped in targets. GAPS provides an exceptionally sensitive means to detect cosmic-ray antideuterons. Cosmic-ray antideuterons can provi...

We have observed near–IR H 2 line emission on large scales in the Galactic center. Paper I discussed our 400 pc long strip map and 50 pc map of the H 2 v = 1 → 0 S(1) line. In this paper, we present observations of the higher vibrational lines (H 2 v = 2 → 1 S(1) and v = 3 → 2 S(3)) at selected positions and conclude that strong far–UV radiations excites the H 2. We compare the H 2 v = 1 → 0 S(...

We propose that the UV/X-ray correlation observed in NGC 4151 by EXOSAT and IUE is due to reemission of the X-ray flux absorbed by cold clouds in the line of sight. This transmission model satisfies the energy balance, provides a good fit to the X-ray and UV data, and predicts no Compton reflection of X-rays (as observed). The correlation can alternatively be explained by reprocessing of X-rays...

This report outlines recent notable extra-galactic source observations by the CANGAROO-II 10-m telescope. Flux upper limits above ∼400 GeV were obtained from observations of the BL Lacertae object, PKS2155−304, in 2000 and 2001. Diffuse gamma-ray emission from the starburst galaxy NGC 253 was also detected at a high confidence level, and E>10 TeV gamma-rays were observed with 5.7 σ significance...