New Anglo-Australian Telescope near-infrared and Swedish-ESO Submillimetre Telescope CO obJ p 2 r 1 servations are combined with existing Infrared Space Observatory mid-infrared and Australia Telescope Compact Array centimeter radio continuum observations to examine the protostellar content of the Bok globule BHR 71. Together with observations of Herbig-Haro objects, these data show the followi...

We report here the discovery of a 30 ′′-chain of embedded Herbig-Haro (HH) objects in the ρ Ophiuchi dark cloud. These HH objects were first detected during a deep KS-band observation (completeness magnitude for point source∼19) made with NTT/SOFI. We confirm their nature with follow-up observations made with H2 v=1–0 S(1) narrow-band filter. We argue that they belong to two different jets eman...

The near infrared (1-2 μm) and the thermal infrared (3-25 μm) trace many of the environments in which masers are thought to reside, including shocks, outflows, accretion disks, and the dense medium near protostars. After a number of recent surveys it has been found that there is a higher detection rate of mid-IR emission towards masers than cm radio continuum emission from UC HII regions, and t...

When interstellar clouds collapse to form new stars and planets, the surrounding gas and dust become part of the infalling envelopes and rotating disks, thus providing the basic material from which new solar systems are formed. Instrumentation to probe the chemistry in low-mass star-forming regions has only recently become available. The results of a systematic program to study the abundances i...

We now begin to trace the journey towards a star. How long does this take? The answer is surprisingly short: a good many clouds already contain new stars and these stars tend to be young. The typical cloud cannot spend long, if any time at all, in a dormant state. The first challenge is to accumulate gas into a molecular cloud. One dilemma is to decide what occurred first: the production of the...

Over 5 years of daily hard X-ray (.20 keV) monitoring of the 2 minute accretion-powered pulsar GX 114 with the Compton Gamma Ray ObservatoryyBATSE large-area detectors has found nearly continuous rapid spin-down, interrupted by a bright 200 day spin-up episode. During spin-down, the torque becomes more negative as the luminosity increases (assuming that the 20–60 keV pulsed flux traces bolometr...

We report the discovery of a nearby, embedded cluster of young stellar objects, associated filamentary infrared dark cloud, and 4.5 mm shock emission knots from outflows detected in Spitzer IRAC mid-infrared imaging of the Serpens-Aquila Rift obtained as part of the Spitzer Gould Belt Legacy Survey. We also present radial velocity measurements of the region from molecular line observations obta...

Massive protostars evolve from hot cores to ultra-compact H II regions and eventually form classical H II regions; however, details of this evolution are far from understood. A few years ago, a new class of exceptionally small and dense objects, so-called hyper-compact H II regions, was discovered. They are believed to represent a transitional stage in early massive stellar evolution. Thus, the...

Over five years of daily hard X-ray (>20 keV) monitoring of the 2 min accretion-powered pulsar GX 1+4 with the Compton Gamma Ray Observatory/BATSE large-area detectors has found nearly continuous rapid spin-down, interrupted by a bright 200-d spin-up episode. During spin-down, the torque becomes more negative as the luminosity increases (assuming that the 20– 60 keV pulsed flux traces bolometri...