Surveys with Involvement
The group is part of some of the largest current and future 3D redshift surveys, as well as other major efforts using ground and space-based telescopes.
DESI will map 30 M galaxy and quasar spectra from 2021-2025; it is on schedule now and can take as many as 150,000 spectra a night! It will study a wide range of science topics, from dark energy, to gravity, to the neutrino mass, to galaxy physics.
Our group has helped observe for DESI, as well as leading several ongoing DESI projects. A particular focus is the Higher-Order Clustering (HOC) topical group, which ZS co-chairs and which focuses on using higher-order statistics. In the past, ZS has served on the Publications Board and as small-scale Clustering, Cross-Correlations, and Clusters (C3) working group co-chair. ZS is also part of a DESI secondary target project to get redshifts of ~15,000 high-z objects to improve calibration of photometric surveys to then be used for CMB cross-correlations.
Dr. Jiamin Hou also plays a major service role in DESI, in the past serving on the Early Career Scientists Committee, organizing research fora, and as a peer mentor, and currently serving as interim Clustering, Cross-Correlations, and Clusters (C3) working group co-chair and on the Publications Board.
DESI papers including group members
DESI Collaboration incl. Slepian, Hou, and Cahn, The Early Data Release of the Dark Energy Spectroscopic Instrument, in submission.
DESI Collaboration incl. Slepian, Hou, and Cahn, Validation of the Scientific Program for the Dark Energy Spectroscopic Instrument, in submission.
Allende-Prieto et al. incl. Slepian, GTC Follow-up Observations of Very Metal-Poor Star Candidates from DESI, ApJ.
Alam et al. incl. Slepian, Towards testing the theory of gravity with DESI: summary statistics, model predictions and future simulation requirements, JCAP.
NASA's Nancy Grace Roman Telescope will perform a large space-based survey of high-redshift galaxies using a grism. It will launch in May 2027.
ZS and Dr. Jiamin Hou are part of a Project Infrastructure Team (PIT) recently selected to produce the community infrastructure and do first analyses for the Galaxy Redshift Survey (GRS). Their focus will be on preparing for 3 and 4-Point Correlation Function, and their Fourier analog bispectrum and trispectrum, analyses, producing both CPU and GPU infrastructure to do so.
VISTA is a 4 m infrared telescope in Chile, and ZS is involved in projects to improve modeling of the Point-Spread Function and improve the search for young, embedded star clusters, along with UF Prof. Elizabeth Lada, Macquarie University Prof. Richard de Grijs, University of Potsdam Prof. Maria-Rosa Cioni, and led by Macquarie University/University of Potsdam PhD student Amy Miller. These projects harness data from the Vista Magellanic Cloud (VMC) survey.
Gran Telescopio Canarias (GTC), located at the Instituto de Astrofisica de Canarias (IAC) on Grand Canary in the Canary Islands, is the largest optical and near-infrared telescope in the world, at 10.7 m, and UF Astronomy is a 2.5% partner in it.
The group and collaborators has pursued time on the GTC almost every semester both through UF's proprietary time and through joint Spain-UF collaborative time. ZS has also served on the internal GTC Time Allocation Committee (TAC), including as chair, for multiple semesters.
Our projects include spectroscopic follow up of galaxies with photometric redshifts from WISE, with the ultimate aim of improving the redshift calibration of all of WISE to unlock its full potential in cross-correlation studies with the CMB. This is work in collaboration with Dr. Alex Krolewski and Dr. Krittapas Chanchaiworawit. We also have an ongoing program to follow up DESI Milky Way Survey stars that are candidates to be extremely metal-poor stars but need higher-resolution and higher S/N spectroscopic confirmation. This is in collaboration with Prof. Carlos Allende-Prieto (IAC) and Prof. Rana Ezzeddine (UF), and first results are here.