Ks-band (2.14 micron) imaging of southern massive star formation regions traced by methanol masers

We present deep, wide-field, Ks-band (2.14 micron) images towards 87 southern massive star formation regions traced by methanol maser emission. Using point-spread function fitting, we generate 2.14 micron point source catalogues towards each of the regions. For the regions between 10 degrees and 350 degrees galactic longitude and galactic latitude +/- 1 degree, we match the 2.14 micron sources with the GLIMPSE point source catalogue to generate a combined 2.14 to 8.0 micron point source catalogue. We provide this data for the astronomical community to utilise in studies of the stellar content of embedded clusters.Comment: Accepted PASA. Full version including figures available from http://www.cfa.harvard.edu/~slongmor/snl_iris2_withfigs.pd

Physical characterisation of southern massive star-forming regions using Parkes NH3_3 observations

We have undertaken a Parkes ammonia spectral line study, in the lowest two inversion transitions, of southern massive star formation regions, including young massive candidate protostars, with the aim of characterising the earliest stages of massive star formation. 138 sources from the submillimetre continuum emission studies of Hill et al., were found to have robust (1,1) detections, including two sources with two velocity components, and 102 in the (2,2) transition. We determine the ammonia line properties of the sources: linewidth, flux density, kinetic temperature, NH$_3$ column density and opacity, and revisit our SED modelling procedure to derive the mass for 52 of the sources. By combining the continuum emission information with ammonia observations we substantially constrain the physical properties of the high-mass clumps. There is clear complementarity between ammonia and continuum observations for derivations of physical parameters. The MM-only class, identified in the continuum studies of Hill et al., display smaller sizes, mass and velocity dispersion and/or turbulence than star-forming clumps, suggesting a quiescent prestellar stage and/or the formation of less massive stars.Comment: 20 pages, 9 Figures, 1 appendix (to appear in full online only, a sample appendix in the paper); 7 tables. Accepted by MNRA

Heart of Darkness: dust obscuration of the central stellar component in globular clusters younger than ~100Myr in multiple stellar population models

To explain the observed anomalies in stellar populations within globular clusters, many globular cluster formation theories require two independent episodes of star formation. A fundamental prediction of these models is that the clusters must accumulate large gas reservoirs as the raw material to form the second stellar generation. We show that young clusters containing the required gas reservoir should exhibit the following observational signatures: (i) a dip in the measured luminosity profile or an increase in measured reddening towards the cluster centre, with Av >10mag within a radius of a few pc; (ii) bright (sub)mm emission from dust grains; (iii) bright molecular line emission once the gas is dense enough to begin forming stars. Unless the IMF is anomalously skewed towards low-mass stars, the clusters should also show obvious signs of star formation via optical emission lines (e.g. H_alpha) after the stars have formed. These observational signatures should be readily observable towards any compact clusters (radii of a few pc) in the nearby Universe with masses > 10^6 Msun and ages <100Myr. This provides a straightforward way to directly test globular cluster formation models which predict large gas reservoirs are required to form the second stellar generation. The fact that no such observational evidence exists calls into question whether such a mechanism happens regularly for YMCs in galaxies within a few tens of Mpc

Third Eye

The artwork completed as a part of my thesis exhibition is grounded in an investigation into perception, vision, intuitive art making, and the bond experienced between twins. The work comes from a personal place because art making, for me, has always been about self-understanding. For that comprehension to be holistic and far-reaching, I seek to recognize the sentimental, phenomenal, and physical ties created by being a twin. This thesis exploration also creates an opportunity for the viewer to experience my visual inquiries into being a twin and my loss of eyesight. Seven years ago, I had a traumatic eye injury, which affected my lens and retina. The damage done was permanent, but it has given me a unique way of seeing the world. This new perception of double vision and blurriness is used as a language for art making, allowing my artwork to live in a place both real and unreal. Thus, this thesis paper endeavors to both share two personal experiences: the irreplaceable and rare bond experienced between twins, like myself, and my unique way of seeing the world

A unique role for Stat5 in recovery from acute anemia

The precise role of erythropoietin receptor–activated (EpoR-activated) Stat5 in the regulation of erythropoiesis remains unclear. In this issue of the JCI, Menon and colleagues present new experimental data that indicate a distinct role for Stat5 in the regulation of stress-induced erythropoiesis, such as during acute anemic states. A critical function for Stat5 is to promote cell survival, possibly through transcriptional induction of the antiapoptotic protein Bcl-x. In the present experimental system, erythropoietin-Stat5 signals did not induce Bcl-x expression but did induce oncostatin-M. Moreover, oncostatin-M was found to enhance survival of erythroid progenitors. This work differentiates between steady-state (or homeostatic) erythropoiesis and stress-induced erythropoiesis at the level of EpoR signaling

The New Disability Historiography: Introduction

Produced by Hawai'i University Affiliated Program on Disabilities, University of Hawai'i at Manoa, Honolulu, HI and Sawyer School of Management, Suffolk University, Boston, MA