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Johan Comparat

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Related publications (49)

The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the Extended Baryon Oscillation Spectroscopic Survey and from the Second Phase of the Apache Point Observatory Galactic Evolution Experiment

Guillaume Blanc, Ghazaleh Erfanianfar, Johan Comparat, Amy Jones, Jean-Paul Richard Kneib, Yuguang Chen, Timothée Guy Olivier Delubac, Yu Liang, Anand Stéphane Raichoor, John Wilson, Hongyu Li, Cheng Zhao, Yuting Wang, Meng Yang, David Schlegel, Yue Shen, Cheng Li, Zheng Zheng, Jiayi Sun

2018

Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe

Guillaume Blanc, Johan Comparat, Amy Jones, Jean-Paul Richard Kneib, Timothée Guy Olivier Delubac, Chao Liu, Anand Stéphane Raichoor, John Wilson, Hongyu Li, Yuting Wang, Meng Yang, David Schlegel, Cheng Li, Zheng Zheng, Jiayi Sun

We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resoluti ...

2017

The SDSS-IV eBOSS: emission line galaxy catalogues at z approximate to 0.8 and study of systematic errors in the angular clustering

Johan Comparat, Xiaoqing Zhou, Jean-Paul Richard Kneib, Timothée Guy Olivier Delubac, Anand Stéphane Raichoor

We present two wide-field catalogues of photometrically selected emission line galaxies (ELGs) at z approximate to 0.8 covering about 2800 deg(2)over the south galactic cap. The catalogues were obtained using a Fisher discriminant technique described in a ...

Oxford Univ Press2017

VICS82: The VISTA-CFHT Stripe 82 Near-infrared Survey

Johan Comparat, Jean-Paul Richard Kneib

We present the VISTA-CFHT Stripe 82 (VICS82) survey: a near-infrared (J+K-s) survey covering 150 square degrees of the Sloan Digital Sky Survey (SDSS) equatorial Stripe 82 to an average depth of J = 21.9 AB mag and K-s = 21.4 AB mag (80% completeness limit ...

Iop Publishing Ltd2017

The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: final emission line galaxy target selection

Johan Comparat, Claudio Gorgoni, Jean-Paul Richard Kneib, Timothée Guy Olivier Delubac, Anand Stéphane Raichoor, Arjun Dey, David Schlegel, Yi Wang

We describe the algorithm used to select the emission line galaxy (ELG) sample at z similar to 0.85 for the extended Baryon Oscillation Spectroscopic Survey of the Sloan Digital Sky Survey IV, using photometric data from the DECam Legacy Survey. Our select ...

Oxford Univ Press2017

Photometric redshifts and clustering of emission line galaxies selected jointly by DES and eBOSS

Eduardo Sanchez, Johan Comparat, Jean-Paul Richard Kneib, Timothée Guy Olivier Delubac, Yi Zhang

We present the results of the first observations of the emission line galaxies (ELG) of the extended Baryon Oscillation Spectroscopic Survey. From the total 9000 targets, 4600 have been selected from the Dark Energy Survey (DES). In this subsample, the tot ...

Oxford Univ Press2017

The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point Observatory

Guillaume Blanc, Johan Comparat, Amy Jones, Pierre Laurent, Jean-Paul Richard Kneib, Yuguang Chen, Timothée Guy Olivier Delubac, Yu Liang, Chao Liu, Anand Stéphane Raichoor, John Wilson, Cheng Zhao, Yuting Wang, Meng Yang, Michael James Henry Smith, David Schlegel, Ginevra Favole, Cheng Li, Zheng Zheng, Yang Gao, Jiayi Sun, Chen Li

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in 2014 July. It pursues three core programs: the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2), Mapping Nearby Galaxies at APO (MaNGA), and the Extend ...

Iop Publishing Ltd2017

Clustering of quasars in SDSS-IV eBOSS: study of potential systematics and bias determination

Johan Comparat, Pierre Laurent, Jean-Paul Richard Kneib

We study the first year of the eBOSS quasar sample in the redshift range 0.9 < z < 2.2 which includes 68,772 homogeneously selected quasars. We show that the main source of systematics in the evaluation of the correlation function arises from inhomogeneiti ...

Iop Publishing Ltd2017

The Mass-Concentration Relation and the Stellar-to-halo Mass Ratio in the CFHT Stripe 82 Survey

Johan Comparat, Jean-Paul Richard Kneib, Huanyuan Shan

We present a new measurement of the mass-concentration relation and the stellar-to-halo mass ratio over the halo-mass range 5 x 10(12) to 2 x 10(14) M circle dot. To achieve this, we use weak lensing measurements from the Canada-France-Hawaii Telescope Str ...

Iop Publishing Ltd2017

The Sdss-Iv Extended Baryon Oscillation Spectroscopic Survey: Overview And Early Data

Johan Comparat, Pierre Laurent, Jean-Paul Richard Kneib, Timothée Guy Olivier Delubac, Yu Liang, Anand Stéphane Raichoor, Cheng Zhao, Yuting Wang, David Schlegel, Cheng Li, Zheng Zheng

In a six-year program started in 2014 July, the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) will conduct novel cosmological observations using the BOSS spectrograph at Apache Point Observatory. These observations will be conducted simultaneous ...

Iop Publishing Ltd2016

The extended Baryon Oscillation Spectroscopic Survey: a cosmological forecast

Johan Comparat, Jean-Paul Richard Kneib, Timothée Guy Olivier Delubac, Yuting Wang, Hanyu Zhang

We present a science forecast for the extended Baryon Oscillation Spectroscopic Survey (eBOSS) survey. Focusing on discrete tracers, we forecast the expected accuracy of the baryonic acoustic oscillation (BAO), the redshift-space distortion (RSD) measureme ...

Oxford Univ Press2016

The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: selecting emission line galaxies using the Fisher discriminant

Johan Comparat, Xiaoqing Zhou, Jean-Paul Richard Kneib, Timothée Guy Olivier Delubac, Jian Wang, Anand Stéphane Raichoor, Zhe Jiang

We present a new selection technique of producing spectroscopic target catalogues for massive spectroscopic surveys for cosmology. This work was conducted in the context of the extended Baryon Oscillation Spectroscopic Survey (eBOSS), which will use simila ...

Edp Sciences S A2016

Clustering properties of g-selected galaxies at z similar to 0.8

Johan Comparat, Jean-Paul Richard Kneib, Timothée Guy Olivier Delubac, David Schlegel, Ginevra Favole

Current and future large redshift surveys, as the Sloan Digital Sky Survey IV extended Baryon Oscillation Spectroscopic Survey (SDSS-IV/eBOSS) or the Dark Energy Spectroscopic Instrument (DESI), will use emission-line galaxies (ELGs) to probe cosmological ...

Wiley-Blackwell2016

The evolution of the [O II], H beta and [O III] emission line luminosity functions over the last nine billions years

Johan Richard, Johan Comparat, Jeffrey Newman, Jean-Paul Richard Kneib, Timothée Guy Olivier Delubac, Anand Stéphane Raichoor

Emission line galaxies are one of the main tracers of the large-scale structure to be targeted by the next-generation dark energy surveys. To provide a better understanding of the properties and statistics of these galaxies, we have collected spectroscopic ...

Oxford Univ Press2016

MultiDarkLens Simulations: weak lensing light-cones and data base presentation

Johan Comparat, Jean-Paul Richard Kneib, Huanyuan Shan

In this paper we present a large data base of weak lensing light cones constructed using different snapshots from the Big MultiDark simulation (BigMDPL). The ray-tracing through different multiple plane has been performed with the GLAMER code accounting bo ...

Oxford Univ Press2016

SDSS-IV eBOSS emission-line galaxy pilot survey

Eduardo Sanchez, Johan Comparat, Jean-Paul Richard Kneib, Zhirui Xu, Timothée Guy Olivier Delubac, Yi Zhang, Anand Stéphane Raichoor, David Schlegel

The Sloan Digital Sky Survey IV extended Baryonic Oscillation Spectroscopic Survey (SDSS-IV/eBOSS) will observe 195 000 emission-line galaxies (ELGs) to measure the baryonic acoustic oscillation (BAO) standard ruler at redshift 0.9. To test different ELG s ...

Edp Sciences S A2016

The Sdss-Iv Extended Baryon Oscillation Spectroscopic Survey: Luminous Red Galaxy Target Selection

Johan Comparat, Jean-Paul Richard Kneib, Timothée Guy Olivier Delubac, David Schlegel

We describe the algorithm used to select the luminous red galaxy (LRG) sample for the extended Baryon Oscillation Spectroscopic Survey (eBOSS) of the Sloan Digital Sky Survey IV (SDSS-IV) using photometric data from both the SDSS and the Wide-field Infrare ...

Iop Publishing Ltd2016

NEAR-ULTRAVIOLET SPECTROSCOPY OF STAR-FORMING GALAXIES FROM eBOSS: SIGNATURES OF UBIQUITOUS GALACTIC-SCALE OUTFLOWS (vol 815, 48, 2015)

Johan Comparat, Jeffrey Newman, Jean-Paul Richard Kneib, Timothée Guy Olivier Delubac, Anand Stéphane Raichoor

Iop Publishing Ltd2016

Cosmological implications of baryon acoustic oscillation measurements

Johan Comparat, Jean-Paul Richard Kneib, Timothée Guy Olivier Delubac, David Schlegel

We derive constraints on cosmological parameters and tests of dark energy models from the combination of baryon acoustic oscillation (BAO) measurements with cosmic microwave background (CMB) data and a recent reanalysis of Type Ia supernova (SN) data. In p ...

American Physical Society2015

Spectroscopic needs for imaging dark energy experiments

Johan Comparat, Jean-Paul Richard Kneib, Anja Von der Linden

Ongoing and near-future imaging-based dark energy experiments are critically dependent upon photometric redshifts (a.k.a. photo-z's): i.e., estimates of the redshifts of objects based only on flux information obtained through broad filters. Higher-quality, ...

Elsevier2015

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