Présidents de session
Science talks: Euclid + 4MOST
- Julien Peloton (CNRS-IJCLab)
- Cyrille Doux (LPSC)
Science talks: Supernovae
- Benjamin Racine (CPPM/IN2P3/CNRS)
Science talks: Clusters
- Cyrille Doux (LPSC)
Science talks: AuxTel activities
- Il n'a pas de président de session pour ce bloc
Science talks: Commissioning and calibration
- Nicoleta Pauna (LPC)
Science talks: Weak lensing and large-scale structure
- Céline Combet (LPSC)
- Cyrille Doux (LPSC)
Science talks: Fink
- Johan BREGEON (IN2P3 LSPC)
-
William Gillard (CPPM - Université Aix-Marseille)13/12/2023 16:00
-
Johan Richard (CRAL)13/12/2023 16:30
-
Alexandre Boucaud (APC / IN2P3)13/12/2023 17:00
Reproducibility is a very important topic in today's research world.
With the upcoming wealth of data and amount of code needed to process it, using an adequate set of tools is key to help you and your colleagues ensure the produced results will be reproducible, or at least keep track of how they were achieved. This is what MLOps intends to do.In this presentation I will define what are...
Go to contribution page -
joseph chevalier (IJCLab - A2C)13/12/2023 17:20
In the interest of improving photo-z estimation with template fitting methods, data from observations with FORS2 has been used to generate templates to be used in LEPHARE-like code. An in-house estimator enables access to the whole posterior distribution of redshift and aims to help us understand how to generate / select the best templates, and how to extract the closest point-estimate to the...
Go to contribution page -
Manon Ramel (LPSC / IN2P3)13/12/2023 17:40
Upcoming deep optical surveys such as the Vera C. Rubin Observatory Legacy Survey of Space and Time will scan the sky to unprecedented depths and detect billions of galaxies. This amount of detections will however cause the apparent superposition of galaxies on the images, called blending, and generate a new systematic error due to the confusion of sources. As consequences, the measurements of...
Go to contribution page -
Florian Ruppin (IP2I Lyon)14/12/2023 09:00
Understanding the impact of astrophysical environment on type Ia supernovae (SNe Ia) properties is crucial to minimize systematic uncertainties in cosmological analyses based on this probe. We investigated the dependence of the SN Ia SALT2.4 light-curve stretch on the distance from their nearest galaxy cluster to study a potential effect of the intracluster medium (ICM) environment on SNe Ia...
Go to contribution page -
Bruno Sanchez (CPPM - CNRS)14/12/2023 09:20
-
Damiano Rosselli (CPPM)14/12/2023 09:40
Analyzing the distribution of peculiar velocities for a sample of objects enable us to measure the growth-rate of cosmic structure ($f\sigma_8$), which is directly linked to the theory of gravity assumed in the cosmological model. In this work we measure peculiar velocities of SNeIa by comparing their estimated distances with redshifts. We recover the SNeIa peculiar velocities through the...
Go to contribution page -
Constantin Payerne (LPSC (IN2P3))14/12/2023 10:00
Cosmological parameters can be inferred from the measurement of cluster abundance in the unbinned regime. The standard unbinned likelihood is based on Poisson statistics and does not include the Super-Sample Covariance (SSC), assumed to be negligible, arising from the fluctuation and clustering of the underlying matter density field. In this talk, I present a formalism to account for SSC in...
Go to contribution page -
Rance Solomon (LAPP)14/12/2023 10:20
The Cluster Finder Comparison Project is aimed at building a pipeline for consolidating, validating, and comparing various cluster finder algorithms on the cosmoDC2 and DC2 simulated catalogs. This project not only gives a better understanding of how the different cluster finder algorithms perform but also provides consistent metric estimations like purity and completeness which is to be used...
Go to contribution page -
Dr Michel Aguena (APC)14/12/2023 10:40
The abundance of galaxy clusters is a powerful probe for cosmology, especially on large optical surveys where hundreds of thousands can be detected. One of the main techniques that allows us to evaluate the large number of composing galaxies at a low cost is the photometric estimation of redshifts, i. e. photo-zs. Here we intend to evaluate the propagation of the uncertainties of photozs on...
Go to contribution page -
thibault guillemin (LAPP)14/12/2023 14:00
-
marc moniez (LAL-IN2P3)14/12/2023 14:20
En septembre dernier, de nouveaux éléments optiques ont été installés et testés pour la spectroscopie sur AuxTel. Je discuterai des améliorations attendues à la suite de ces modifications, et montrerai les premiers résultats.
Last September, new optical elements were installed and tested for spectroscopy on AuxTel. I will discuss the improvements expected as a result of these...
Go to contribution page -
Dr Sylvie Dagoret (IJCLab)15/12/2023 09:00
Our aim is to extract SED templates from spectral and photometric data observed at high redshift to update the database of SED templates used for the PhotoZ SED Template fitting.
At present, we have a set of 550 spectra observed on the Fors2 instrument of the UT1 telescope at the VLT by astronomer Edmond Giraud (LUMP, Eric Nuss and J. Cohen-Tanugi) at an average redshift of 0.3.
These...
Go to contribution page -
Martin Rodriguez Monroy (IJCLab)15/12/2023 09:20
Nous travaillons sur une technique d’estimation des compensations de couleur par objet basées sur des observations spectroscopiques avec le télescope auxiliaire (AuxTel) à appliquer à la photométrie de LSST. Cette méthode se basera sur la comparaison des couleurs obtenues à partir de spectres standards lors de la traversée d'une atmosphère standard et lors de la traversée d'atmosphères...
Go to contribution page -
Kélian SOMMER (LUPM/IN2P3)15/12/2023 09:40
With the upcoming Legacy Survey of Space and Time, the number of observed type Ia supernovae is expected to substantially increase, leading to a reduction in statistical uncertainties and thus placing flux calibration as the predominant source of uncertainty in constraining the dark energy equation of state parameter w.
Atmosphere is one of the last remaining sources of systematic...
Go to contribution page -
Thierry Souverin15/12/2023 10:00
The number of type Ia supernova observations will see significant growth within the next decade, especially thanks to the Legacy Survey of Space and Time undertaken by the Vera Rubin Observatory in Chile. With this improvement, statistical uncertainties will decrease and flux calibration will become the main uncertainty for the characterization of dark energy. The StarDICE experiment proposes...
Go to contribution page -
Jérémy Neveu (LPNHE), thibault guillemin (LAPP)15/12/2023 10:20
-
Enya Van den Abeele (LPNHE)15/12/2023 11:00
Shear estimation began in 1995 with the KSB proposal, which essentially consists of using a combination of the second moments of the observed image of the galaxy and the PSF. Numerous other methods have been proposed over the years, and in most cases, the measurements derived from these methods have to be corrected using simulations, and therefore depend on the assumptions of these...
Go to contribution page -
Anna Niemiec (LPNHE)15/12/2023 11:20
I will present the weak lensing analysis of the 6 very massive and complex Frontier Field clusters, using the BUFFALO HST observations, and I will discuss how the different measuring and modeling assumptions impact their mass estimation.
Go to contribution page -
Calum Murray (APC , University of Paris)15/12/2023 11:40
We look for signatures of the Hu-Sawicki f (R) modified gravity theory, proposed to explain the observed accelerated expansion of the
Go to contribution page
universe; in observations of the galaxy distribution, the cosmic microwave background (CMB), and gravitational lensing of the CMB.
We study constraints obtained by using observations of only the CMB primary anisotropies, before adding the galaxy power... -
Sofia Bisero (GEPI, Observatoire de Paris, Université PSL, CNRS)15/12/2023 14:00
Gravitational wave (GW) multi-messenger (MM) observations of binary neutron star systems mergers (BNSs) are extremely challenging. With current GW interferometers, BNS detection rates are low. This will significantly improve with next generation gravitational wave interferometers, such as the Einstein Telescope (ET). These latter will detect thousands of BNS beyond the Local Universe,...
Go to contribution page -
Maria Pruzhinskaya (LPC)15/12/2023 14:20
The detection of new astronomical sources is one of the most anticipated outcomes of the next generation of large-scale sky surveys. Experiments such as the Vera Rubin Observatory Legacy Survey of Space and Time are expected to continuously monitor large areas of the sky with remarkable deliberation, which will undoubtedly lead to the detection of unforeseen astrophysical phenomena. At the...
Go to contribution page -
Marina Masson (LPSC)15/12/2023 14:40
Gamma-Ray Bursts (GRBs) are among the most energetic phenomena in the Universe. Viewed off-axis, this emission has a negligible gamma-ray flux and is hence called ”GRB orphan afterglow” (OA). To identify OAs in Rubin LSST data, we plan to use the characteristic features of their light curves which depends on several parameters defined by the chosen model, here the forward shock model...
Go to contribution page -
Roman Le Montagner15/12/2023 15:00
The upcoming Vera C. Rubin Observatory with its deep and wide survey of the sky will revolutionize the time domain astronomy. Compared to current sky surveys such as the Zwicky Transient Facility (ZTF), the Rubin Observatory will provide a volume of transient and variable objects at least ten times larger, reaching ten million transient alerts per night. To overcome this challenge, the Fink...
Go to contribution page -
Roman Le Montagner
With the advent of large-scale astronomical surveys, such as the Zwicky Transient Facility (ZTF) and the forthcoming Vera
Go to contribution page
C. Rubin Observatory's Legacy Survey of Space and Time (LSST), the number of alerts generated by transient, variable, and moving
astronomical objects are snowballing, reaching millions of alerts per night. This talk will present Fink-FAT, a third-party module dedicated to... -
Cyrille Doux (LPSC)