Rubin Observatory is a discovery machine, with the capability to identify exotic astrophysical transients faster than any existing observatory. 3% of the LSST has been allocated for Target of Opportunity observations, which includes an observatory response to gravitational wave events, high energy neutrinos, potentially-hazardous asteroids, and other astrophysical phenomena. Target of...
Accurate modeling of precipitable water vapor (PWV) variations is essential to meet Rubin Observatory’s photometric precision requirements, particularly in the Y band. Simulations with getObsAtmo and rubin_sim show that achieving photometric errors below 1, 5, and 10 mmag corresponds respectively to statistical PWV uncertainties of ΔPWVₛₜₐₜ < 0.03, 0.1, and 0.5 mm.
PWV measurements...
The Auxiliary telescope (AuxTel) of the Rubin Observatory is a spectrometer that precisely characterizes the atmosphere during LSST observation. Observing standard stars and comparing the resulting spectra with out-of-atmosphere CALSPEC spectra gives the whole atmospheric transmission curve. This procedure is performed with a forward modeling software called Spectractor, which is implemented...
Je propose une présentation pour la session parallèle CBP. Je parlerai des différentes versions du CBP qui ont été construites parallèlement à celui de Rubin, pour mettre en lumière leurs résultats, leurs avantages et inconvénients, ainsi que les leçons apprises qui font écho aux travaux sur le CBP Rubin.
Realistic transient simulations are essential to interpret the observations of surveys such as LSST.
I will present skysurvey, a Python library developed in the cosmological team in Lyon, that simulates astrophysical transients, and in particular Type Ia supernovae, for any survey, including LSST. skysurvey aims to combine computational efficiency, ease of use, and physical realism and...
The Halo Mass Function (HMF) is a parametric function that allows to describe the distribution of halos masses given a cosmology and the redshift. It is thus widely used in cluster analyses to extract cosmological parameters like sigma_8 and Omega_M from the observation of clusters. Many different HMF exist in the literature with different parameterizations as a function of redshift and...
Galaxy clusters are among the most powerful probes of cosmology, providing key insights into the growth of structure and the nature of dark energy. However, translating cluster observations into robust cosmological constraints remains challenging, primarily due to uncertainties in mass calibration and systematic effects. Upcoming surveys such as the Rubin Observatory’s LSST and Euclid will...
I will present the Centre Pierre Binétruy, located on the campus at UC Berkeley and working closely with Stanford and SLAC. The Center's role is to facilitate collaborations between French researchers and researchers in the Bay Area: UC Berkeley, LBNL, Stanford, SLAC. We have funds to support travel and can host short- and long-term visitors. One of our flagship projects is Rubin/LSST.
I will give an overview of the last activities of the Fink broker, and describe the status of processing Rubin alerts.
The early light curves of supernovae provide critical insights into the properties of their progenitor systems and, in some cases, play an essential role in our understanding of the evolution of the Universe. With the advent of wide-field surveys such as the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST), large samples of early supernova light curves will become available,...
The LSST will provide an excellent opportunity to study a wide range of fast transients and to better understand the diverse physical mechanisms driving explosive astrophysical events. During the first month of my PhD, I conducted research aimed at distinguishing rapid explosive transients and performed systematic scans using the Skyportal platform and the private ZTF alert stream. These same...
Tidal disruption events (TDEs) refer to the destruction of a star by the tidal forces around a black hole, leading to outbursts that can last for months. Although modern optical time-domain surveys have substantially expanded the known TDE sample, these events remain rare. Further increasing the sample is crucial for advancing our understanding of the underlying physics, making TDE discovery a...
The Ellis and Baldwin formula provides a model-independant way to measure our own velocity with respect to matter at large scale. However, this measurement doesn't coincide with the same measurement with respect to the CMB, which puts into question the existence of the Cosmological Rest Frame [Secrest et al. 2021]. I will explain how LSST will provide an extremely useful data set to work on...
Weak gravitational lensing maps contain rich, non-Gaussian information that standard two-point statistics miss. Full-field inference tackles this by forward-modeling the entire map—evolving initial conditions through structure formation and observational effects—and using the maps themselves to learn about cosmology, without compressing to summary statistics.
In this talk, I will...
Cosmological research in the era of deep, wide-area surveys such as Euclid and Rubin/LSST benefits greatly from combining datasets collected with different instruments. However, the large volume of data makes analysis increasingly challenging. To address this, we developed a package based on the Variational Autoencoder (VAE) architecture that enables compact representations of spectroscopic...
Dark matter subhalos with masses from 10⁶ to 10⁹ solar masses are mostly invisible, but could impact the structure of stellar streams observed by LSST. Presentation on how LSST systematics could impact density fluctuations measurements in stellar streams, used to set dark matter constrains.
I will present the plans to deploy the computing infrastructure in support of Rubin science at IN2P3. I will also describe the tests that we intend to perform on the short term to validate and improve the model.
