#dark-energy-survey — Public Fediverse posts

NOIRLab image of the week

The Cosmic Steering Wheel NGC 1269

Credit: Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA; Image processing: R. Colombari & M. Zamani (NSF NOIRLab)

https://noirlab.edu/public/images/iotw2608a/

#NOIRLab #NGC1269 #galaxy #galaxies #astrodon #astrophysics #astronomy #science #photography #DarkEnergySurvey

Dark Energy Survey Year Y6 Results Day!

This morning’s arXiv announcement contained a number of papers related to the Dark Energy Survey Y6 analysis. There is also a Zoom webinar later today at 10.30 Central Time (16.30 GMT’; 13.30 in Greeland). Details can be found here.

You can find links to and abstracts of all the papers here, but I thought it would be useful to provide arXiv links to the latest batch here.

• arXiv:2601.14559 Dark Energy Survey Year 6 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing – this is the key summary paper.
• arXiv:2601.14484 Dark Energy Survey Year 6 Results: MagLim++ Lens Sample Selection and Measurements of Galaxy Clustering
• arXiv:2601.14864 Dark Energy Survey: DESI-Independent Angular BAO Measurement
• arXiv:2601.15175 Dark Energy Survey Year 6 Results: Galaxy-galaxy lensing
• arXiv:2601.14833 Dark Energy Survey Year 6 Results: Magnification modeling and its impact on galaxy clustering and galaxy-galaxy lensing cosmology
• arXiv:2601.14859 Dark Energy Survey Year 6 Results: Weak Lensing and Galaxy Clustering Cosmological Analysis Framework

A number of DES Y6 papers already published – including several in the Open Journal of Astrophysics – are listed here.

I’ll just highlight a couple of points from the first paper listed above, which uses the now standard “3x2pt” analysis, which combines three complementary two-point correlation functions: cosmic shear; galaxy-galaxy lensing and galaxy clustering. The abstract of this paper is as follows:

A notable result is contained in the last sentence. The simplest interpretation of dark energy is that it is a cosmological constant (usually called Λ) which – as explained here – corresponds to a perfect fluid with an equation-of-state p=wρc2 with w=-1. In this case the effective mass density  ρ of the dark energy remains constant as the universe expands. To parametrise departures from this constant behaviour, cosmologists have replaced this form with the form w(a)=w0+wa(1-a) where a(t) is the cosmic scale factor. A cosmological constant Λ would correspond to a point (w0=-1, wa=0) in the plane defined by these parameters, but the only requirement for dark energy to result in cosmic acceleration is that w<-1/3, not that w=-1. Results last year from DESI suggested a value of w0 different from -1, but DES does not.

I thought I’d add one of the cosmological contraint plots:

The results look qualitatively similar to previous plots but the contours have shifted a bit.

#Cosmology #DarkEnergy #DarkEnergySpectroscopicInstrument #DarkEnergySurvey #DES #DESYear6 #DESI

Dark Energy Survey - implications for cosmological expansion models from the final DES Baryon Acoustic Oscillation and Supernova data: https://arxiv.org/abs/2503.06712 -> Latest #DarkEnergySurvey Data Suggest Possible Variations in Dark Energy Over Time: https://noirlab.edu/public/news/noirlab2513/ - DES spots potential inconsistencies in the standard model of cosmology, supporting a theory of evolving dark energy that could alter the foundations of physics (this is *not* the same study as the DESI stories just out).

[Einstein's theory and #observation data] Researchers have compared #DarkEnergySurvey data with predictions from Einstein's theory of #GeneralRelativity ... and discovered some #incompatibility ...

“We have discovered that very far in the past, 6 and 7 billion years ago, the depth of the #GravitationalSinks is completely compatible with Einstein's predictions. On the other hand, in the period closer to today, 3.5 and 5 billion years ago, they are a little shallower than predicted by Einstein”, reveals Isaac Tutusaus, assistant astronomer at IRAP / Université Paul Sabatier Toulouse III.

Is the slowdown in the growth of gravitational sinks linked to the acceleration of the #expansion of our #Universe? The answer will undoubtedly be found in a few years' time, thanks to more numerous and more precise data from the @ec_euclid mission.

Details+: https://www.irap.omp.eu/en/2024/11/einsteins-equations-collide-with-the-mysteries-of-the-universe/

[Théorie d'#Einstein et données d'#observation] Des chercheurs ont comparé les données du #DarkEnergySurvey aux prévisions de la théorie de la #relativité générale d'Einstein ... et découvert une certaine #incompatibilité ...

« Nous avons découvert que très loin dans le passé, il y a 6 et 7 milliards d’années, la profondeur des #PuitsGravitationnels est complètement compatible avec les prédictions d’Einstein. En revanche, dans la période plus proche d’aujourd’hui, il y a 3,5 et 5 milliards d’années, ils sont un peu moins profonds que prédit par Einstein », révèle Isaac Tutusaus, astronome adjoint à l'IRAP / Université Paul Sabatier Toulouse III.

Le ralentissement de la croissance de puits gravitationnels est-elle liée à l'accélération de l' #expansion de notre #Univers ? La réponse sans doute dans quelques années, grâce aux données plus nombreuses et plus précises de la mission @ec_euclid

Infos+ : https://www.irap.omp.eu/2024/11/les-equations-deinstein-se-heurtent-aux-mysteres-de-lunivers/

The Dark Energy Survey - Cosmology Results with ∼1500 New High-redshift Type Ia Supernovae Using the Full 5 yr Data Set: https://iopscience.iop.org/article/10.3847/2041-8213/ad6f9f -> Testing Cosmology with the #DarkEnergySurvey Five-Year Supernova Dataset: https://aasnova.org/2024/10/29/testing-cosmology-with-the-dark-energy-survey-five-year-supernova-dataset/

Dark Energy Survey - a 2.1% measurement of the angular Baryonic Acoustic Oscillation scale at redshift zeff=0.85 from the final dataset: https://arxiv.org/abs/2402.10696 -> New measurement of cosmic distances in the #DarkEnergySurvey gives clues about the nature of dark energy: https://news.fnal.gov/2024/02/new-measurement-of-cosmic-distances-in-the-dark-energy-survey-gives-clues-about-the-nature-of-dark-energy/

The #DarkEnergySurvey - Cosmology Results With ~1500 New High-redshift Type Ia Supernovae Using The Full 5-year Dataset: https://arxiv.org/abs/2401.02929 -> Dark Energy Survey Publishes Definitive Results from Largest, Deepest, Most Uniform Supernova Sample: https://noirlab.edu/public/news/noirlab2401/ and https://www.ucl.ac.uk/news/2024/jan/new-research-improves-understanding-expansion-universe - Dark Energy Camera at NOIRLab’s CTIO provides unique insights into the acceleration of the Universe.

"The powerful camera built for the Dark Energy Survey has taken more than 1 million photos from its perch in Chile. Here are some of the best."

https://www.symmetrymagazine.org/article/15-spectacular-photos-from-the-dark-energy-camera

#Telescopes #Space #Astronomy #Images #DarkEnergySurvey