Rubin-LSST

Abstract:

We present results from an ongoing investigation using the Kilo Degree Survey (KiDS) on the VLT Survey Telescope (VST) to provide a census of ultra-compact massive galaxies (UCMGs), defined as galaxies with stellar masses M* > 8 × 1010M⊙ and effective radii Re < 1.5 kpc. UCMGs, which are expected to have undergone very few merger events, provide a unique view on the accretion history of the most massive galaxies in the Universe. Over an effective sky area of nearly 330 deg2, we select UCMG candidates from KiDS multicolour images, which provide high quality structural parameters, photometric redshifts, and stellar masses. Our sample of ~1000 photometrically selected UCMGs at z < 0.5 represents the largest sample of UCMG candidates assembled to date over the largest sky area. In this paper, we present the first effort to obtain their redshifts using different facilities, starting with first results for 28 candidates with redshifts z < 0.5, obtained at NTT and TNG telescopes.We confirmed, as bona fide UCMGs, 19 out of the 28 candidates with new redshifts. A further 46 UCMG candidates are confirmed with literature spectroscopic redshifts (35 at z < 0.5), bringing the final cumulative sample of spectroscopically confirmed lower-z UCMGs to 54 galaxies, which is the largest sample at redshifts below 0.5. We use these spectroscopic redshifts to quantify systematic errors in our photometric selection, and use these to correct our UCMG number counts. We finally compare the results to independent data sets and simulations.

Abstract:

A combined measurement of differential and inclusive total cross sections of Higgs boson production is performed using 36.1 fb−1 of 13 TeV proton–proton collision data produced by the LHC and recorded by the ATLAS detector in 2015 and 2016. Cross sections are obtained from measured H→γγ and H→ZZ⁎→4ℓ event yields, which are combined taking into account detector efficiencies, resolution, acceptances and branching fractions. The total Higgs boson production cross section is measured to be 57.0−5.9+6.0 (stat.) −3.3+4.0 (syst.) pb, in agreement with the Standard Model prediction. Differential cross-section measurements are presented for the Higgs boson transverse momentum distribution, Higgs boson rapidity, number of jets produced together with the Higgs boson, and the transverse momentum of the leading jet. The results from the two decay channels are found to be compatible, and their combination agrees with the Standard Model predictions.

Abstract:

JINGLE is a new JCMT legacy survey designed to systematically study the cold interstellar medium of galaxies in the local Universe. As part of the survey we perform 850 µm continuum measurements with SCUBA-2 for a representative sample of 193 Herschel-selected galaxies with M* > 109 M⊙, as well as integrated CO(2–1) line fluxes with RxA3m for a subset of 90 of these galaxies. The sample is selected from fields covered by the Herschel-ATLAS survey that are also targeted by the MaNGA optical integral-field spectroscopic survey. The new JCMT observations combined with the multiwavelength ancillary data will allow for the robust characterization of the properties of dust in the nearby Universe, and the benchmarking of scaling relations between dust, gas, and global galaxy properties. In this paper we give an overview of the survey objectives and details about the sample selection and JCMT observations, present a consistent 30-band UV-to-FIR photometric catalogue with derived properties, and introduce the JINGLE Main Data Release. Science highlights include the non-linearity of the relation between 850 µm luminosity and CO line luminosity (log LCO(2–1) =  1.372 logL850–1.376), and the serendipitous discovery of candidate z > 6 galaxies.

Abstract:

A search for the decay of the Standard Model Higgs boson into a bb¯ pair when produced in association with a W or Z boson is performed with the ATLAS detector. The data, corresponding to an integrated luminosity of 79.8fb−1 were collected in proton–proton collisions during Run 2 of the Large Hadron Collider at a centre-of-mass energy of 13TeV. For a Higgs boson mass of 125GeV, an excess of events over the expected background from other Standard Model processes is found with an observed (expected) significance of 4.9 (4.3) standard deviations. A combination with the results from other searches in Run 1 and in Run 2 for the Higgs boson in the bb¯ decay mode is performed, which yields an observed (expected) significance of 5.4 (5.5) standard deviations, thus providing direct observation of the Higgs boson decay into b-quarks. The ratio of the measured event yield for a Higgs boson decaying into bb¯ to the Standard Model expectation is 1.01±0.12(stat.)−0.15+0.16(syst.). Additionally, a combination of Run 2 results searching for the Higgs boson produced in association with a vector boson yields an observed (expected) significance of 5.3 (4.8) standard deviations.