TRANSCEND: Cosmology and astrophysics from a census of the transient Universe
Lead Research Organisation:
QUEEN'S UNIVERSITY BELFAST
Abstract
Explosive transients are uniquely powerful probes for understanding the evolution of the Universe at all scales. Through leadership in revolutionary new time-domain sky surveys, we will unleash the power of transients to tackle three key science questions with far-reaching implications: What is the nature of dark energy? How do stars live, die and enrich their environments with chemical elements? How do massive black holes form and grow and together with galaxies? We will answer these fundamental questions by collecting and analysing the largest spectroscopic data set of transients ever obtained. We will provide unprecedented statistical samples of all known types of explosions, as well as the first samples of extreme outliers or completely new classes.
Next year, the Rubin Observatory’s Legacy Survey of Space and Time (LSST) will come online. This will discover millions of transients, far beyond what has been possible with past or current surveys, providing an unprecedented opportunity. But to realise this scientific potential necessitates a step change in our approach to follow-up observations. We are leading the Time Domain Extragalactic Survey (TiDES), using multiplexed spectroscopy with the 4-metre ESO Multi-Object Spectroscopic Telescope (4MOST). Through TiDES, we will deliver a world-leading new approach to transient science by systematically obtaining spectra of >30,000 transients and >200,000 host galaxies over 5 years. This will be not just the largest transient dataset ever obtained (by a factor of ~5), but also has much higher spectral resolution (by a factor ~10) and far greater homogeneity (and therefore statistical power and control of selection biases) than any previous transient experiment.
The unrivalled spectroscopy from TiDES is critical to understanding the LSST transient population and the far-reaching physics that they probe. No other survey can achieve such systematic, extensive spectroscopic data; in fact TiDES is the only program planned to systematically follow up LSST transients and their hosts. Spectra are essential to robustly classify transients and to identify the completely new types of events lurking in LSST. They encode fundamental properties and chemical compositions, and hence the underlying physics and the contribution to galactic enrichment. Only spectra can provide accurate redshifts required to measure physical luminosities from LSST photometry.
We have put together a focused team of UK transient astronomers, combining some of the leading early career faculty in the field with experienced global leaders. We have extensive expertise in survey operations and simulations, transient classification and characterisation, supernova and black hole astrophysics, and state-of-the-art supernova cosmology. Such an ambitious program is only possible by combining our skills, and we have designed an efficient work flow to maximise science outcomes and complementarity between work packages. RIAs will lead the science exploitation of our survey, and we have developed an effective plan to train this next generation of transient astronomers. Our plan will allow the UK to lead globally in this very high profile science area, and could not be more timely: due to the time-critical nature of obtaining spectra of transients before they fade, this project must run in parallel with LSST.
Next year, the Rubin Observatory’s Legacy Survey of Space and Time (LSST) will come online. This will discover millions of transients, far beyond what has been possible with past or current surveys, providing an unprecedented opportunity. But to realise this scientific potential necessitates a step change in our approach to follow-up observations. We are leading the Time Domain Extragalactic Survey (TiDES), using multiplexed spectroscopy with the 4-metre ESO Multi-Object Spectroscopic Telescope (4MOST). Through TiDES, we will deliver a world-leading new approach to transient science by systematically obtaining spectra of >30,000 transients and >200,000 host galaxies over 5 years. This will be not just the largest transient dataset ever obtained (by a factor of ~5), but also has much higher spectral resolution (by a factor ~10) and far greater homogeneity (and therefore statistical power and control of selection biases) than any previous transient experiment.
The unrivalled spectroscopy from TiDES is critical to understanding the LSST transient population and the far-reaching physics that they probe. No other survey can achieve such systematic, extensive spectroscopic data; in fact TiDES is the only program planned to systematically follow up LSST transients and their hosts. Spectra are essential to robustly classify transients and to identify the completely new types of events lurking in LSST. They encode fundamental properties and chemical compositions, and hence the underlying physics and the contribution to galactic enrichment. Only spectra can provide accurate redshifts required to measure physical luminosities from LSST photometry.
We have put together a focused team of UK transient astronomers, combining some of the leading early career faculty in the field with experienced global leaders. We have extensive expertise in survey operations and simulations, transient classification and characterisation, supernova and black hole astrophysics, and state-of-the-art supernova cosmology. Such an ambitious program is only possible by combining our skills, and we have designed an efficient work flow to maximise science outcomes and complementarity between work packages. RIAs will lead the science exploitation of our survey, and we have developed an effective plan to train this next generation of transient astronomers. Our plan will allow the UK to lead globally in this very high profile science area, and could not be more timely: due to the time-critical nature of obtaining spectra of transients before they fade, this project must run in parallel with LSST.