IFAE

About: IFAE is a other organization based out in Barcelona, Spain. It is known for research contribution in the topics: Large Hadron Collider & Galaxy. The organization has 664 authors who have published 1270 publications receiving 51097 citations. The organization is also known as: Instituto de Fisica de Altas Energias & IFAE.

MAGIC observations of MWC 656, the only known Be/BH system

Abstract: Context. MWC 656 has recently been established as the first observatio nally detected high-mass X-ray binary system containing a Be star and a black hole (BH). The system has been associated with a gamma-ray flaring event detected by the AGILE satellite in July 2010. Aims. Our aim is to evaluate if the MWC 656 gamma-ray emission extends to very high energy (VHE> 100 GeV) gamma rays. Methods. We have observed MWC 656 with the MAGIC telescopes for∼23 hours during two observation periods: between May and June 2012 and June 2013. During the last period, observations were performed contemporaneously with X-ray (XMM-Newton) and optical (STELLA) instruments. Results. We have not detected the MWC 656 binary system at TeV energies with the MAGIC Telescopes in either of the two campaigns carried out. Upper limits (ULs) to the integral flu x above 300 GeV have been set, as well as differential ULs at a level of ∼ 5% of the Crab Nebula flux. The results obtained from the MAGIC observations do not support persistent emission of very high energy gamma rays from this system at a level of 2.4% the Crab fl ux.

The PAU Survey: spectral features and galaxy clustering using simulated narrow-band photometry

Abstract: We present a mock catalogue for the Physics of the Accelerating Universe Survey (PAUS) and use it to quantify the competitiveness of narrow-band imaging for measuring spectral features and galaxy clustering. The mock agrees with observed number count and redshift distribution data. We demonstrate the importance of including emission lines in the narrow-band fluxes. We show that PAUCam has sufficient resolution to measure the strength of the 4000 A break to the nominal PAUS depth. We predict the evolution of a narrow-band luminosity function and show how this can be affected by the O II emission line. We introduce new rest-frame broad-bands (UV and blue) that can be derived directly from the narrow-band fluxes. We use these bands along with D4000 and redshift to define galaxy samples and provide predictions for galaxy clustering measurements. We show that systematic errors in the recovery of the projected clustering due to photometric redshift errors in PAUS are significantly smaller than the expected statistical errors. The galaxy clustering on two halo scales can be recovered quantitatively without correction, and all qualitative trends seen in the one halo term are recovered. In this analysis, mixing between samples reduces the expected contrast between the one halo clustering of red and blue galaxies and demonstrates the importance of a mock catalogue for interpreting galaxy clustering results. The mock catalogue is available on request at https://cosmohub.pic.es/home.

Measurement of ZZ production in the ℓℓνν final state with the ATLAS detector in pp collisions at √s = 13 TeV

Abstract: This paper presents a measurement of ZZ production with the ATLAS detector at the Large Hadron Collider. The measurement is carried out in the final state with two charged leptons and two neutrinos ...

Measuring linear and non-linear galaxy bias using counts-in-cells in the Dark Energy Survey Science Verification data

Abstract: Non-linear bias measurements require a great level of control of potential systematic effects in galaxy redshift surveys. Our goal is to demonstrate the viability of using Counts-in-Cells (CiC), a statistical measure of the galaxy distribution, as a competitive method to determine linear and higher-order galaxy bias and assess clustering systematics. We measure the galaxy bias by comparing the first four moments of the galaxy density distribution with those of the dark matter distribution. We use data from the MICE simulation to evaluate the performance of this method, and subsequently perform measurements on the public Science Verification (SV) data from the Dark Energy Survey (DES). We find that the linear bias obtained with CiC is consistent with measurements of the bias performed using galaxy-galaxy clustering, galaxy-galaxy lensing,CMB lensing, and shear+clustering measurements. Furthermore, we compute the projected (2D) non-linear bias using the expansion δ g =∑ 3 k=0 (b k /k!)δ k, finding a non-zero value for b 2 at the 3σ level. We also check a non-local bias model and show that the linear bias measurements are robust to the addition of new parameters. We compare our 2D results to the 3D prediction and find compatibility in the large scale regime (>30 Mpc h −1)