Reflections on Building and then Teaching in a HyFlex Classroom at Allard Hall

How to teach in a pandemic? This is the question we were forced to answer over the course of a weekend in March when UBC’s physical campus closed and in-person teaching was no longer possible. The pivot to the world of online teaching was abrupt and reactive; there simply wasn’t time to do anything other than keep courses going as best we could, with technology and techniques we were learning as we taught

ALMA observations of 99 GHz free-free and H40α\alpha line emission from star formation in the centre of NGC 253

We present Atacama Large Millimeter/submillimeter Array observations of 99.02 GHz free-free and H40$\alpha$ emission from the centre of the nearby starburst galaxy NGC 253. We calculate electron temperatures of 3700-4500 K for the photoionized gas, which agrees with previous measurements. We measure a photoionizing photon production rate of $(3.2\pm0.2)\times10^{53}$ s$^{-1}$ and a star formation rate of $1.73\pm0.12$ M$_\odot$ yr$^{-1}$ within the central 20$\times$10 arcsec, which fall within the broad range of measurements from previous millimetre and radio observations but which are better constrained. We also demonstrate that the dust opacities are ~3 dex higher than inferred from previous near-infrared data, which illustrates the benefits of using millimetre star formation tracers in very dusty sources.Comment: 5 pages, 3 figures, accepted for publication in MNRAS Letter

Deep ALMA imaging of the merger NGC1614 - Is CO tracing a massive inflow of non-starforming gas?

Observations of the molecular gas over scales of 0.5 to several kpc provide crucial information on how gas moves through galaxies, especially in mergers and interacting systems, where it ultimately reaches the galaxy center, accumulates, and feeds nuclear activity. Studying the processes involved in the gas transport is an important step forward to understand galaxy evolution. 12CO, 13CO and C18O1-0 high-sensitivity ALMA observations were used to assess properties of the large-scale molecular gas reservoir and its connection to the circumnuclear molecular ring in NGC1614. The role of excitation and abundances were studied in this context. Spatial distributions of the 12CO and 13CO emission show significant differences. 12CO traces the large-scale molecular gas reservoir, associated with a dust lane that harbors infalling gas. 13CO emission is - for the first time - detected in the large-scale dust lane. Its emission peaks between dust lane and circumnuclear molecular ring. A 12CO-to-13CO1-0 intensity ratio map shows high values in the ring region (~30) typical for the centers of luminous galaxy mergers and even more extreme values in the dust lane (>45). This drop in ratio is consistent with molecular gas in the dust lane being in a diffuse, unbound state while being funneled towards the nucleus. We find a high 16O-to-18O abundance ratio in the starburst region (>900), typical of quiescent disk gas - by now, the starburst is expected to have enriched the nuclear ISM in 18O relative to 16O. The massive inflow of gas may be partially responsible for the low 18O/16O abundance since it will dilute the starburst enrichment with unprocessed gas from greater radii. The 12CO-to-13CO abundance is consistent with this scenario. It suggests that the nucleus of NGC1614 is in a transient phase of evolution where starburst and nuclear growth are fuelled by returning gas from the minor merger event.Comment: 10 pages, 9 figures, accepted for publication in A&

Exploring factors influencing the use of an eHealth intervention for families of children with hearing loss: An application of the COM-B model

BACKGROUND: Prior to developing a successful eHealth intervention, it is important that we explore stakeholders’ capacity to adapt to eHealth. OBJECTIVE: To explore what factors influence the use eHealth services from the perspectives of families of children with hearing loss and professionals who support families as they transition into early intervention. METHODS: A qualitative study incorporating semi-structured in-depth interviews was conducted with families (n = 17) and professionals (n = 11). Interview topic guides were developed based on the COM-B model of behaviour change to explore barriers and facilitators related to capability, opportunity, and motivation. RESULTS: The COM-B model captured several factors that may influence the use eHealth interventions for families of children with hearing loss. The capability factors included computer literacy and familiarity with social media. The opportunity factors were access to online resources, reliable Internet, and affordable equipment. Professionals’ and families’ preferences and a culture of face-to-face services were also identified as barriers for using eHealth. The motivation factors included families’ and professionals’ confidence in using technology and beliefs that there were benefits (e.g., saving travel) associated with using eHealth services. In contrast, beliefs that eHealth may be difficult to set up and not able to replace in-person communication identified as barriers to families and professionals adopting eHealth interventions. CONCLUSION: Findings of this study indicated that implementation of an eHealth intervention could be facilitated by addressing the barriers in stakeholders’ capabilities, opportunities (e.g., equipment and social support), and motivation (e.g., negative beliefs about eHealth) before developing eHealth services

Deep Space Network information system architecture study

The purpose of this article is to describe an architecture for the Deep Space Network (DSN) information system in the years 2000-2010 and to provide guidelines for its evolution during the 1990s. The study scope is defined to be from the front-end areas at the antennas to the end users (spacecraft teams, principal investigators, archival storage systems, and non-NASA partners). The architectural vision provides guidance for major DSN implementation efforts during the next decade. A strong motivation for the study is an expected dramatic improvement in information-systems technologies, such as the following: computer processing, automation technology (including knowledge-based systems), networking and data transport, software and hardware engineering, and human-interface technology. The proposed Ground Information System has the following major features: unified architecture from the front-end area to the end user; open-systems standards to achieve interoperability; DSN production of level 0 data; delivery of level 0 data from the Deep Space Communications Complex, if desired; dedicated telemetry processors for each receiver; security against unauthorized access and errors; and highly automated monitor and control

Tests of star formation metrics in the low metallicity galaxy NGC 5253 using ALMA observations of H30α\alpha line emission

We use Atacama Large Millimeter/submillimeter Array (ALMA) observations of H30$\alpha$ (231.90 GHz) emission from the low metallicity dwarf galaxy NGC 5253 to measure the star formation rate (SFR) within the galaxy and to test the reliability of SFRs derived from other commonly-used metrics. The H30$\alpha$ emission, which originates mainly from the central starburst, yields a photoionizing photon production rate of (1.9$\pm$0.3)$\times$10$^{52}$ s$^{-1}$ and an SFR of 0.087$\pm$0.013 M$_\odot$ yr$^{-1}$ based on conversions that account for the low metallicity of the galaxy and for stellar rotation. Among the other star formation metrics we examined, the SFR calculated from the total infrared flux was statistically equivalent to the values from the H30$\alpha$ data. The SFR based on previously-published versions of the H$\alpha$ flux that were extinction corrected using Pa$\alpha$ and Pa$\beta$ lines were lower than but also statistically similar to the H30$\alpha$ value. The mid-infrared (22 $\mu$m) flux density and the composite star formation tracer based on H$\alpha$ and mid-infrared emission give SFRs that were significantly higher because the dust emission appears unusually hot compared to typical spiral galaxies. Conversely, the 70 and 160 $\mu$m flux densities yielded SFR lower than the H30$\alpha$ value, although the SFRs from the 70 $\mu$m and H30$\alpha$ data were within 1-2$\sigma$ of each other. While further analysis on a broader range of galaxies are needed, these results are instructive of the best and worst methods to use when measuring SFR in low metallicity dwarf galaxies like NGC 5253.Comment: 14 pages, 5 figures, accepted for publication in MNRA

Discovery of a bright radio transient in M82: a new radio supernova?

In this Letter, we report the discovery of a new bright radio transient in M82. Using the Very Large Array, we observed the nuclear region of M82 at several epochs at 22 GHz and detected a new bright radio source in this galaxy's central region. We find a flux density for this flaring source that is ~300 times larger than upper limits determined in previous observations. The flare must have started between 2007 October 29 and 2008 March 24. Over the last year, the flux density of this new source has decreased from ~100 mJy to ~11 mJy. The lightcurve (based on only three data points) can be fitted better with an exponential decay than with a power law. Based on the current data we cannot identify the nature of this transient source. However, a new radio supernova seems to be the most natural explanation. With it's flux density of more than 100 mJy, it is at least 1.5 times brighter than SN1993J in M81 at the peak of its lightcurve at 22 GHz.Comment: accepted Astronomy & Astrophysics, 4 pages, 3 figures, final version & corrected abstract, also available at http://www.mpifr-bonn.mpg.de/staff/abrunthaler/pub.shtm

Two exhibitions of photographs

An exhibition of photographs held at the Fine Arts Gallery in 197

Deep observations of the Super-CLASS super-cluster at 325 MHz with the GMRT: the low-frequency source catalogue

We present the results of 325 MHz GMRT observations of a super-cluster field, known to contain five Abell clusters at redshift $z \sim 0.2$. We achieve a nominal sensitivity of $34\,\mu$Jy beam$^{-1}$ toward the phase centre. We compile a catalogue of 3257 sources with flux densities in the range $183\,\mu\rm{Jy}\,-\,1.5\,\rm{Jy}$ within the entire $\sim 6.5$ square degree field of view. Subsequently, we use available survey data at other frequencies to derive the spectral index distribution for a sub-sample of these sources, recovering two distinct populations -- a dominant population which exhibit spectral index trends typical of steep-spectrum synchrotron emission, and a smaller population of sources with typically flat or rising spectra. We identify a number of sources with ultra-steep spectra or rising spectra for further analysis, finding two candidate high-redshift radio galaxies and three gigahertz-peaked-spectrum radio sources. Finally, we derive the Euclidean-normalised differential source counts using the catalogue compiled in this work, for sources with flux densities in excess of $223 \, \mu$Jy. Our differential source counts are consistent with both previous observations at this frequency and models of the low-frequency source population. These represent the deepest source counts yet derived at 325 MHz. Our source counts exhibit the well-known flattening at mJy flux densities, consistent with an emerging population of star-forming galaxies; we also find marginal evidence of a downturn at flux densities below $308 \, \mu$Jy, a feature so far only seen at 1.4 GHz.Comment: 25 pages, 18 figures, 10 tables. Accepted for publication in MNRA