In this blogpost we introduce another batch of supporting papers released yesterday on April 11, just one week after releasing our cosmological results using BAO from galaxies and quasars and the Lyman-alpha forest.  Yesterday’s papers do not exhibit new results, but represent major stepping stones towards the cosmology results from the RSD (aka Full Shape) analysis we plan to release soon. They fall into the two categories:  DESI 2024 II: Sample definitions, characteristics, and two-point clustering statistics. DESI 2024 V: Analysis of the full-shape of two-point clustering statist ..read more

On April 4, DESI released a set of papers marking our first release of year one (Y1) results. This page contains summaries of our main results and a guide to the publications. The papers will be available on arXiv at 5pm PST on April 4, and until then are available here. Helpful links A press release containing a high-level overview of our main results: https://newscenter.lbl.gov/2024/04/04/desi-first-results-make-most-precise-measurement-of-expanding-universe/  A brief announcement on our webpage: https://www.desi.lbl.gov/2024/04/04/first-cosmology-results-from-desi-most-precise-measure ..read more

16 February 2024 BaoBan, DESI’s ambassador for Education and Public Outreach, made a recent appearance at the 85th Annual Tohono O’odham Nation Rodeo and Parade, featuring prominently in the parade entry from Kitt Peak National Observatory (KPNO). A coyote from the wilds of Arizona, BaoBan has previously appeared in comic strips and other DESI-related public engagement activities. The DESI project is being carried out at KPNO, which is located atop I’oligam Du’ag, in the homeland of the Tohono O’odham Nation. BaoBan greeted spectators at the 2024 Tohono O’odham Rodeo parade (Credit: M. Ed ..read more

Dillon Brout, Harvard University June 16, 2023 The universe (and especially Messier 101) never ceases to amaze us. Recently, a remarkable Type II supernova event unfolded in the nearby “Pinwheel galaxy” (M101), captivating astronomers worldwide. We are just 12 years removed from the famed supernova 2011fe residing in M101 and that sparked its own paradigm shift for studies of supernovae. The one that occurred this past week, dubbed SN2023ixf, promises to offer a wealth of new scientific insights due to its exceptional characteristics and close proximity. This presents a rare opportunity to del ..read more

The first public release of DESI data is now available! Taken during DESI’s Survey Validation phase, the Early Data Release (EDR) includes spectra and redshifts for 1.2 million galaxies and quasars, as well as observations of nearly half a million stars in our own Milky Way galaxy. The DESI Early Data Release by the numbers: Amount of data: 80 TB Exposures taken: 2,480 Redshifts collected: 1.2 million extragalactic (galaxies and quasars) Objects in the Milky Way imaged: 496,000 Quasars spotted: 90,000 Time spent observing: 6 months  Size compared to full DESI dataset: 2% Part of DE ..read more

The story behind creating and naming our favorite coyote. Samuel Brieden, The University of Edinburgh May 12, 2023 Welcome our new DESI ambassador for Education and Public Outreach (EPO), BaoBan! You might have met him already, when he was presenting our powerful focal plane (see a virtual tour through it here) or wishing a happy new year. From now on, BaoBan is assisting us with science communications, as long as he is in the mood. Although BaoBan is very attracted to the Mayall telescope, he shows up at Kitt Peak quite rarely because, like other wild coyotes, BaoBan spends most of his time h ..read more

January 18, 2023 The all-sky camera on the Mayall telescope were the DESI instrument is located provides a view of the entire sky above Kitt Peak National Observatory. This camera helps observers monitor weather conditions and visibility, and confirm when it is safe to open the dome above the telescope. While the skies above Kitt Peak are very often clear, that is not always the case, as shown below in a series of camera images from the night of September 23, 2022. The night began with clouds and rain, and for over an hour flashes of lightning lit up both the sky and the camera view. Finally ..read more

Even the smallest of correlations between galaxies and their environment can impact measurements on the largest scales. Claire Lamman, Harvard University September 9, 2022 Understanding the largest structures in the Universe and how they evolve is more convoluted than just mapping out the positions of galaxies. This is because galaxy characteristics are not random; they are tangled both with how we choose targets and the underlying cosmic structure that we’re measuring. Interpreting DESI data involves carefully separating these threads, making sure to leave no loose ends. An important idea to ..read more

David Sprayberry, NOIRLab August 25, 2022 After the Contreras Fire swept over part of Kitt Peak in June, July was devoted to restoring electrical power and water service to the mountaintop. We also carefully assessed every structure for safety, possible fire damage, and the extent of cleaning required. Currently electricity at the summit is provided solely by back-up generators (more on that later). Because the water system lost pressure during the power outage, it was necessary to flush it with chlorine and then fresh water from the storage tanks, and then have the water tested to ensure it m ..read more

Anand Raichoor and Christophe Yeche August 22, 2022 We are glad to announce the publication on arXiv on Friday, August 19, 2022 of eight papers from Year 1 Key Project 1 (Y1KP1). These papers describe: how the DESI Main Survey targets are selected, along with their photometric and main spectroscopic properties (MWS: Cooper et al. 2022, BGS: Hahn et al. 2022, LRG: Zhou et al. 2022, ELG: Raichoor et al. 2022; QSO: Chaussidon et al. 2022); the pipeline to process those targets for DESI observations (Myers et al. 2022); the building of redshift truth tables based on visual inspections (Lan et al ..read more