Multi-messenger studies based on LSST observations
Advisor: Michael Prouza or Asen Christov (IP CAS)
Funding: Fully funded
Website: https://www.fzu.cz/en/oddeleni/department-of-astroparticle-physics/research-subjects/lsst-large-synoptic-survey-telescope

The Large Synoptic Survey Telescope (LSST) [1], to start operations in 2022, is in many ways a novel telescope, promising to advance various aspects of our knowledge of the universe. The defining approach of the project is to regularly collect images of the sky (on a daily basis) and build a comprehensive set of data for all the objects in the field of view. The LSST data-sets will provide an opportunity for diverse series of analyses focused on a particular class of objects or processes, such as AGNs, tidal disruption events, GRBs and other transients. A great attention is paid to learning about dark matter and dark energy from measurements of week lensing, large scale structures or type Ia Supernovae.

A recent discovery by the IceCube collaboration linked a blazar TXS 0506+056 to a high energy neutrino emission [2,3]- a discovery made possible only due to the multi-messenger approach - combining neutrino observations with gamma-ray measurements by Fermi LAT and MAGIC. Within the angular resolution of the Icecube neutrinos there will be many objects resolved by LSST, only some of them will be considered possible source of neutrinos. It is of interest to study whether some of them show a particular type of behavior - for instance coincident change in activity or spectrum - and the relation to Fermi LAT measurements. Tidal disruption events are one of the proposed candidates for cosmic ray acceleration [4,5,6] - correlation study of such events identified by LSST with neutrinos can shed light on these phenomena.

A laboratory for development and testing optical sensors for astronomy was recently established at the FZU - Institute of Physics of the Czech Academy of Sciences. We collaborate closely with LSST and other projects, such as Pierre Auger Observatory and CTA. We follow the progress of instrumentation manufactures like Andor, Moravian instruments, Hamamatsu and others, testing their products or prototypes to check the performance and give feedback on how to improve the hardware or firmware.

We primarily offer an experimentally focused PhD student position. The candidate will work on characterization and developments of CCD and CMOS sensors/cameras for astronomy in our laboratory, including a type of CCD sensor used in LSST. Part of the work will be developing the laboratory itself, improving the experimental techniques and making new types of measurements possible, developing the control and data acquisition software. The experience gained while working with optical sensors, learning about the effects which affect the images, will be put to use within the LSST collaborations. The immediate contribution would be within the Instrumental Effects Working Group, helping to understand and calibrate the LSST observations. The detailed knowledge of the LSST data will be then an advantage for an analysis focused on multi-messenger studies combining it with IceCube and Fermi LAT public data.

An alternative, more theoretically focused work and PhD topic within the Dark Energy Science Collaboration (DESC) might be also identified. Our recent involvement in this respect was based on the simulations of modified gravities, and also related to the contribution to the Core Cosmological Library (CCL).

[1] LSST collaboration, LSST: from Science Drivers to Reference Design and Anticipated Data Products, Astrophys.J. 873 (2019) no.2, 111
[2] Multimessenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922A, Science 13 Jul 2018: Vol. 361, Issue 6398, eaat1378, DOI: 10.1126/science.aat1378
[3] Neutrino emission from the direction of the blazar TXS 0506+056 prior to the IceCube-170922A alert, Science 13 Jul 2018: Vol. 361, Issue 6398, pp. 147-151, DOI: 10.1126/science.aat2890
[4] Search for Neutrinos from Populations of Optical Transients, R Stein (for the IceCube Collaboration), arXiv preprint arXiv:1908.08547, 2019
[5] Neutrino Emissions from Tidal Disruption Remnants, K Hayasaki, R Yamazaki - arXiv preprint arXiv:1908.10882, 2019
[6] High energy neutrinos from the tidal disruption of stars, C. Lunardini and W. Winter, Phys. Rev. D 95, 123001