Emily Curtis

PhD Research

Overview

My PhD thesis involved using HARP (the Heterodyne Array Receiver Project, see also my technical pages), an array spectrograph built in the Cavendish Astrophysics Group for the James Clerk Maxwell Telescope (JCMT) for a wide-field survey of star formation. In addition, I undertook various small instrumentation projects, helping to commission HARP on the telescope and working on the upgrade of a JCMT receiver for use as part of the eSMA.

The survey

Most of my thesis was analysing spectral-line observations, undertaken with HARP in the ¹²CO, ¹³CO and C¹⁸O J=3-2 rotational transitions, towards the Perseus molecular cloud. Perseus is one of the closest regions of clustered, low-mass star formation (d~250 pc), allowing us to probe the details of star formation models in a relatively turbulent environment. These data represented some of the largest and highest-quality datasets in this higher J transition recorded at the time. For an overview of the survey see Curtis, Richer & Buckle (2010).

The analysis

So far, I have undertaken a wide-ranging analysis on these data, including:

Exploring the kinematics of star-forming cores, looking at their linewidths, gravitational and rotational properties (Curtis & Richer, 2010);
Identifying clumps of emission in three-dimensions and exploring their corresponding properties (Curtis 2009, Chapter 7);
Constructing radiative transfer models of idealised star-forming cores to predict the line strengths observed (Curtis 2009, Chapter 8);
Identifying and exploring the properties of high-velocity outflows, noted in all the regions observed (Curtis et al. 2010)

JCMT Gould Belt Legacy Survey

I am actively involved in the JCMT Gould Belt Survey (GBS), undertaking the HARP Science Verification for the survey and am leading the data taking and analysis for the first continuum observations. The GBS aims to map all of the nearby regions of star formation (less than 500 pc from the Sun) with SCUBA-2, a new continuum receiver for the JCMT. From these large-scale observations, we intended to identify thousands of starless and protostellar cores, from which we would select the brightest to map with HARP in CO and its isotopologues (like my thesis work). Unfortunately, SCUBA-2 was a little late, so we started without it, using HARP to map medium-sized regions in the already known bright regions. Five first-look data papers examining the HARP data towards Orion A (Buckle et al.), Orion B (Buckle et al. 2010), Taurus (Davis et al. 2010), Ophiuchus (White et al.) and Serpens (Graves et al. 2010) have been published or are imminent. For further details see the survey description paper (Ward-Thompson et al. 2007).

Structure analysis

One of the primary drives for my PhD was gathering a high-quality dataset with which to test quantitatively predictions from star formation models. In collaboration with Jane Buckle and others, I have started to look at the different structure scalings in my Perseus and other GBS data for comparison with those seen in numerical simulations.