Spectroscopy of planetary mass brown dwarfs in Orion
Monthly Notices of the Royal Astronomical Society: Letters 373:1 (2006)
Abstract:
We report the results of near infrared spectroscopy of 11 luminosity-selected candidate planetary mass objects (PMOs) in the Trapezium Cluster with Gemini South/Gemini Near-Infrared Spectrograph and Gemini North/Near-Infrared Imager. Six have spectral types ≥M9, in agreement with expectations for PMOs. Two have slightly earlier types, and three are much earlier types which are probably field stars. Four of the six sources with types ≥M9 have pseudo-continuum profiles which confirm them as low gravity cluster members. The gravity status of the other cool dwarfs is less clear but these remain candidate PMOs. The derived number fraction of PMOs with M = 3 - 15 MJup is 1-14 per cent, these broad limits reflecting the uncertainty in source ages. However, the number fraction with M < 20 MJup is at least 5 per cent. These detections add significantly to the body of evidence that a planetary mass population is produced by the star formation process. © 2006 The Authors. Journal compilation © 2006 RAS.Mid-infrared, spatially resolved spectroscopy of the nucleus of the Circinus galaxy
Monthly Notices of the Royal Astronomical Society 367 (2006) 1689-1698
Radio and infrared recombination studies of the southern massive star forming region G333.6-0.2
Monthly Notices of the Royal Astronomical Society 368:4 (2006) 1843-1855
Abstract:
We present high spatial resolution radio and near-infrared hydrogen recombination line observations of the southern massive star forming region G333.6-0.2. The 3.4-cm continuum peak is found slightly offset from the infrared (IR) source. The H90α spectra show for the first time a double-peak profile at some positions. The complex velocity structure may be accounted for by champagne outflows, which may also explain the offset between the radio and IR sources. The 2.17-μm Brγ image and H90α map are combined to construct an extinction map which shows a trend probably set by the blister nature of the H ii region. The total number of Lyman continuum photons in the central 50-arcsec is estimated to be equivalent to that emitted by up to 19 O7V stars. © 2006 RAS.High-resolution mid-infrared observations of AGN
SPITZER SPACE TELESCOPE: NEW VIEWS OF THE COSMOS 357 (2006) 263-+
Mid-infrared, spatially resolved spectroscopy of the nucleus of the Circinus galaxy
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 367:4 (2006) 1689-1698