Probing the bottom end of the IMF in orion with Gemini
IAU SYMP (2003) 63-66
Abstract:
We present very deep JHK imaging of the Trapezium Cluster obtained with Gemini South/Flamingos and Gemini North/Hokupa'a. These images probe the IMF down to similar to 2 M-Jup in a total area of similar to 8 arcmin(2). Several very faint new planetary mass candidates are detected and sources previously detected with UKIRT are verified. Photometry of 124 point sources in this field produces a Luminosity Function which. drops to zero at K=18.75. Allowing. for modest extinction this corresponds to a possible turn-down in the IMF near 5 Mjup. A minority of PMOs exhibit large K band excesses attributed to hot dust, confirming their extreme youth. Some of the faintest sources are associated with short trails of light of uncertain nature. These may provide a clue to the origin of PMOs, perhaps marking evacuated paths cleared by rapidly moving objects.The magnetic field in the central parsec
ASTRONOMISCHE NACHRICHTEN 324 (2003) 563-566
Optical-IR echelle spectroscopy of NGC 6302
Revista Mexicana de Astronomia y Astrofisica: Serie de Conferencias 12 (2002) 132-133
Abstract:
Echelle spectroscopy of [Si VI] 1.96 μm, [Mg VIII] 3.03 μm, and [Ar VI] 4.53 μm, using UKIRT+CGS4, shows the line pro les in PN NGC 6302 are singly peaked and unresolved even at R ∼ 20 000, with line widths less than 22 kms-1. A photoionized structure is evidenced by spatial and velocity stratification as a function of ionization potential. But a variety of models, with density and Te gradients, reproduce the spectrum equally well. Preliminary analysis of the 3000-10000 Å echellogram of NGC 6302, acquired at R ∼ 80 000 using VLT+UVES, confirms the stratified nebular structure, but yields intriguing results concerning the line profiles: [Ne V] 3426 Å is broader than [Ne IV] 4723 Å. These observations rule out the existence of an evacuated cavity, or hot bubble, at least on 1″ and 3 km s-1 scales. We do not confirm the broad wings in [Ne V] 3426 Å reported by Meaburn & Walsh (1980).UFTI: The 0.8-2.5μm fast track imager for the UK Infrared Telescope
Proceedings of SPIE - The International Society for Optical Engineering 4841:2 (2002) 901-912
Abstract:
In 1996, it was proposed to build a near-infrared imager for the 3.8-m UK Infrared Telescope in Hawaii, to exploit the 1024 pixel format detectors that were then becoming available. In order to achieve a fast delivery, the instrument was kept simple and existing designs were reused or modified where possible. UFTI was delivered within 2.5 years of the project start. The instrument is based around a 1k Rockwell Hawaii detector and a LSR Astrocam controller and uses the new Mauna Kea optimised J,H,K filter set along with I and Z broad-band filters and several narrow-band line filters. The instrument is cooled by a CTI cry-cooler, while the mechanisms are operated by cold, internal, Bergelahr stepping motors. On UKIRT it can be coupled to a Fabry-Perot etalon for tunable narrow-band imaging at K, or a waveplate for imaging polarimetry through 1-2.5μm; the cold analyser is a Barium Borate Wollaston prism. UFTI was designed to take full advantage of the good image quality delivered by UKIRT on conclusion of the upgrades programme, and has a fine scale of 0.09 arcsec/pixel. It is used within the UKIRT observatory environment and was the first instrument integrated into ORAC, the Observatory Reduction and Acquisition Control System. Results obtained during instrument characterisation in the lab and over the last 3 years on UKIRT are presented, along with performance figures. UFTI has now been used on UKIRT for several hundred nights, and aspects of instrument performance are discussed.A search for the infrared spectroscopic signature of hot Jupiter planets
Monthly Notices of the Royal Astronomical Society 336:2 (2002) 637-642