Showing papers by "European Southern Observatory published in 2020"
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National Radio Astronomy Observatory1, University of Manitoba2, Cornell University3, United States Naval Research Laboratory4, Space Telescope Science Institute5, University of Toronto6, Saint Anselm College7, California Institute of Technology8, University of California, Berkeley9, Max Planck Society10, Drexel University11, University of Alberta12, University of Minnesota13, University of Cape Town14, University of the Western Cape15, Universidad de Guanajuato16, Harvard University17, University of Bristol18, Academia Sinica Institute of Astronomy and Astrophysics19, Pennsylvania State University20, University of Iowa21, West Virginia University22, University of Colorado Boulder23, Newcastle University24, Leiden University25, Hebrew University of Jerusalem26, University of Washington27, University of Oxford28, Smithsonian Institution29, University of Illinois at Urbana–Champaign30, National Autonomous University of Mexico31, Spanish National Research Council32, European Southern Observatory33, University of Hamburg34, INAF35
TL;DR: The Very Large Array Sky Survey (VLASS) as discussed by the authors is a synoptic, all-sky radio sky survey with a unique combination of high angular resolution (≈2.5"), sensitivity (a 1σ goal of 70 μJy/beam in the coadded data), full linear Stokes polarimetry, time domain coverage, and wide bandwidth (2-4 GHz).
Abstract: The Very Large Array Sky Survey (VLASS) is a synoptic, all-sky radio sky survey with a unique combination of high angular resolution (≈2.5\"), sensitivity (a 1σ goal of 70 μJy/beam in the coadded data), full linear Stokes polarimetry, time domain coverage, and wide bandwidth (2-4 GHz). The first observations began in September 2017, and observing for the survey will finish in 2024. VLASS will use approximately 5500 hours of time on the Karl G. Jansky Very Large Array (VLA) to cover the whole sky visible to the VLA (Declination > −40∘), a total of 33,885 deg^2. The data will be taken in three epochs to allow the discovery of variable and transient radio sources. The survey is designed to engage radio astronomy experts, multi-wavelength astronomers, and citizen scientists alike. By utilizing an \"on the fly\" interferometry mode, the observing overheads are much reduced compared to a conventional pointed survey. In this paper, we present the science case and observational strategy for the survey, and also results from early survey observations.
288 citations
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European Southern Observatory1, University of Lisbon2, Max Planck Society3, University of Grenoble4, CERN5, University of Paris6, Leiden University7, University of Colorado Boulder8, University of Cologne9, University of Porto10, University of California, Berkeley11, University of Cambridge12, Weizmann Institute of Science13
TL;DR: In this article, the first detection of the GR Schwarzschild precession (SP) in S2's orbit was reported, which is a kink between the pre-and post-pericentre directions of motion ≈±1 year around pericentre passage.
Abstract: The star S2 orbiting the compact radio source Sgr A* is a precision probe of the gravitational field around the closest massive black hole (candidate). Over the last 2.7 decades we have monitored the star’s radial velocity and motion on the sky, mainly with the SINFONI and NACO adaptive optics (AO) instruments on the ESO VLT, and since 2017, with the four-telescope interferometric beam combiner instrument GRAVITY. In this Letter we report the first detection of the General Relativity (GR) Schwarzschild Precession (SP) in S2’s orbit. Owing to its highly elliptical orbit (e = 0.88), S2’s SP is mainly a kink between the pre-and post-pericentre directions of motion ≈±1 year around pericentre passage, relative to the corresponding Kepler orbit. The superb 2017−2019 astrometry of GRAVITY defines the pericentre passage and outgoing direction. The incoming direction is anchored by 118 NACO-AO measurements of S2’s position in the infrared reference frame, with an additional 75 direct measurements of the S2-Sgr A* separation during bright states (“flares”) of Sgr A*. Our 14-parameter model fits for the distance, central mass, the position and motion of the reference frame of the AO astrometry relative to the mass, the six parameters of the orbit, as well as a dimensionless parameter f SP for the SP (f SP = 0 for Newton and 1 for GR). From data up to the end of 2019 we robustly detect the SP of S2, δ ϕ ≈ 12′ per orbital period. From posterior fitting and MCMC Bayesian analysis with different weighting schemes and bootstrapping we find f SP = 1.10 ± 0.19. The S2 data are fully consistent with GR. Any extended mass inside S2’s orbit cannot exceed ≈0.1% of the central mass. Any compact third mass inside the central arcsecond must be less than about 1000 M ⊙ .
284 citations
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Heidelberg University1, Max Planck Society2, Liverpool John Moores University3, Australian National University4, Hoffmann-La Roche5, University of Toulouse6, Ohio State University7, Ghent University8, University of Paris9, University of Chile10, European Southern Observatory11, University of Alberta12, University of Bonn13, Carnegie Institution for Science14, École normale supérieure de Lyon15, California Institute of Technology16, ASTRON17
TL;DR: German Research Foundation (DFG) and the European Research Council (ERC) as mentioned in this paper proposed a joint research cooperation scheme with the French National Cosmology et Galaxies (PNCG) of the Centre national de la recherche scientifique/Institut national de physique nucleaire et de physique des particules (IN2P3) of France.
Abstract: German Research Foundation (DFG)
KR4801/1-1
German Research Foundation (DFG)
KR4801/2-1
European Research Council (ERC)
714907
Australia-Germany Joint Research Cooperation Scheme (UA-DAAD)
57387355
Australian Research Council
FT140101202
Programme National 'Physique et Chimie du Milieu Interstellaire' (PCMI) of the Centre national de la recherche scientifique/Institut national des sciences de l'Univers (CNRS/INSU)
Institut de Chimie/Institut de Physique (INC/INP)
French Atomic Energy Commission
Centre National D'etudes Spatiales
Programme National Cosmology et Galaxies (PNCG) of CNRS/INSU
INP
Institut national de physique nucleaire et de physique des particules (IN2P3)
French Atomic Energy Commission
Centre National D'etudes Spatiales
European Research Council (ERC)
694343
726384
National Science Foundation (NSF)
1615105
1615109
1653300
National Aeronautics and Space Administration (NASA) Astrophysics Data Analysis Program (ADAP)
NNX16AF48G
NNX17AF39G
Natural Sciences and Engineering Research Council of Canada
RGPIN-2017-03987
Fondo de Fomento al Desarrollo Cientifico y Tecnologico of the Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT/FONDECYT), Programa de Iniciacion, Folio
11150220
German Research Foundation (DFG)
SFB 881
Germany's Excellence Strategy (Heidelberg STRUCTURES Excellence Cluster)
EXC-2181/1-390900948
German Research Foundation (DFG)
KR4598/2-1
MINECO/FEDER
AYA2016-79006-P
MCIU/AEI/FEDER
PGC2018-094671-B-I00
Centre National de la Recherche Scientifique (CNRS)
Max Planck Society
IGN (Spain)
184 citations
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TL;DR: In this article, the authors report the discovery of a luminous quasar, J1007+2115 at 7.515$ (Pōniuā'ena), from a wide-field reionization-era quasar survey.
Abstract: We report the discovery of a luminous quasar, J1007+2115 at $z=7.515$ (\"Pōniuā'ena\"), from our wide-field reionization-era quasar survey. J1007+2115 is the second quasar now known at $z>7.5$, deep into the reionization epoch. The quasar is powered by a $(1.5\\pm0.2)\\times10^9$ $M_{\\odot}$ supermassive black hole (SMBH), based on its broad MgII emission-line profile from Gemini and Keck near-IR spectroscopy. The SMBH in J1007+2115 is twice as massive as that in quasar J1342+0928 at $z=7.54$, the current quasar redshift record holder. The existence of such a massive SMBH just 700 million years after the Big Bang significantly challenges models of the earliest SMBH growth. Model assumptions of Eddington-limited accretion and a radiative efficiency of 0.1 require a seed black hole of $\\gtrsim 10^{4}$ $M_{\\odot}$ at $z=30$. This requirement suggests either a massive black hole seed as a result of direct collapse or earlier periods of rapid black hole growth with hyper-Eddington accretion and/or a low radiative efficiency. We measure the damping wing signature imprinted by neutral hydrogen absorption in the intergalactic medium (IGM) on J1007+2115's Ly$\\alpha$ line profile, and find that it is weaker than that of J1342+0928 and two other $z\\gtrsim7$ quasars. We estimate an IGM volume-averaged neutral fraction $\\langle x\\rm_{HI}\\rangle=0.39^{+0.22}_{-0.13}$. This range of values suggests a patchy reionization history toward different IGM sightlines. We detect the 158 $\\mu$m [C II] emission line in J1007+2115 with ALMA; this line centroid yields a systemic redshift of $z=7.5149\\pm0.0004$ and indicates a star formation rate of $\\sim210$ $M_{\\odot}$ yr$^{-1}$ in its host galaxy.
182 citations
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University of California, Los Angeles1, University of Copenhagen2, Fermilab3, École Polytechnique Fédérale de Lausanne4, University of Chicago5, University of Liège6, European Southern Observatory7, University of California, Davis8, Inter-University Centre for Astronomy and Astrophysics9, Andrés Bello National University10, University of Cambridge11, University of Tokyo12, University of Wisconsin-Madison13, University College London14, University of Pennsylvania15, SLAC National Accelerator Laboratory16, University of Illinois at Urbana–Champaign17, IFAE18, Spanish National Research Council19, INAF20, Indian Institute of Technology, Hyderabad21, Ludwig Maximilian University of Munich22, University of Michigan23, Autonomous University of Madrid24, Santa Cruz Institute for Particle Physics25, Ohio State University26, Smithsonian Institution27, University of Arizona28, University of São Paulo29, Texas A&M University30, Princeton University31, University of Sussex32, Universidade Federal do Rio Grande do Sul33, Duke University34, University of Southampton35, Brandeis University36, Oak Ridge National Laboratory37
TL;DR: In this paper, a blind time-delay cosmographic analysis for the lens system DES J0408−5354 is presented, which combines the measured time delays, line-of-sight central velocity dispersion of the deflector, and statistically constrained external convergence with the lens models to estimate two cosmological distances.
Abstract: We present a blind time-delay cosmographic analysis for the lens system DES J0408−5354. This system is extraordinary for the presence of two sets of multiple images at different redshifts, which provide the opportunity to obtain more information at the cost of increased modelling complexity with respect to previously analysed systems. We perform detailed modelling of the mass distribution for this lens system using three band Hubble Space Telescope imaging. We combine the measured time delays, line-of-sight central velocity dispersion of the deflector, and statistically constrained external convergence with our lens models to estimate two cosmological distances. We measure the ‘effective’ time-delay distance corresponding to the redshifts of the deflector and the lensed quasar DeffΔt=3382+146−115 Mpc and the angular diameter distance to the deflector Dd = 1711+376−280 Mpc, with covariance between the two distances. From these constraints on the cosmological distances, we infer the Hubble constant H0= 74.2+2.7−3.0 km s−1 Mpc−1 assuming a flat ΛCDM cosmology and a uniform prior for Ωm as Ωm∼U(0.05,0.5). This measurement gives the most precise constraint on H0 to date from a single lens. Our measurement is consistent with that obtained from the previous sample of six lenses analysed by the H0 Lenses in COSMOGRAIL’s Wellspring (H0LiCOW) collaboration. It is also consistent with measurements of H0 based on the local distance ladder, reinforcing the tension with the inference from early Universe probes, for example, with 2.2σ discrepancy from the cosmic microwave background measurement.
174 citations
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TL;DR: In this article, the authors describe the data reduction pipeline of the MUSE integral field spectrograph operated at the ESO Paranal Observatory, and demonstrate that the pipeline provides dataacubes ready for scientific analysis.
Abstract: The processing of raw data from modern astronomical instruments is often carried out nowadays using dedicated software, known as pipelines, largely run in automated operation. In this paper we describe the data reduction pipeline of the Multi Unit Spectroscopic Explorer (MUSE) integral field spectrograph operated at the ESO Paranal Observatory. This spectrograph is a complex machine: it records data of 1152 separate spatial elements on detectors in its 24 integral field units. Efficiently handling such data requires sophisticated software with a high degree of automation and parallelization. We describe the algorithms of all processing steps that operate on calibrations and science data in detail, and explain how the raw science data is transformed into calibrated datacubes. We finally check the quality of selected procedures and output data products, and demonstrate that the pipeline provides datacubes ready for scientific analysis.
156 citations
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Durham University1, University of Nottingham2, University of Western Australia3, Australian National University4, University of the Western Cape5, University of Leicester6, Dalhousie University7, European Southern Observatory8, University of Hertfordshire9, University of Edinburgh10, University of Hawaii11, University College London12, Leiden University13, University of British Columbia14, University of Manchester15, Max Planck Society16, Lancaster University17
TL;DR: In this paper, the physical properties of a large, homogeneously selected sample of ALMA-located sub-mm galaxies (SMGs) detected in the SCUBA-2 CLS 850-$\mu$m map of the UKIDSS/UDS field were analyzed.
Abstract: We analyse the physical properties of a large, homogeneously selected sample of ALMA-located sub-mm galaxies (SMGs) detected in the SCUBA-2 CLS 850-$\mu$m map of the UKIDSS/UDS field. This survey, AS2UDS, identified 707 SMGs across the ~1 sq.deg. field, including ~17 per cent which are undetected in the optical/near-infrared to $K$>~25.7 mag. We interpret the UV-to-radio data using a physically motivated model, MAGPHYS and determine a median photometric redshift of z=2.61+-0.08, with a 68th percentile range of z=1.8-3.4 and just ~6 per cent at z>4. The redshift distribution is well fit by a model combining evolution of the gas fraction in halos with the growth of halo mass past a threshold of ~4x10$^{12}$M$_\odot$, thus SMGs may represent the highly efficient collapse of gas-rich massive halos. Our survey provides a sample of the most massive, dusty galaxies at z>~1, with median dust and stellar masses of $M_d$=(6.8+-0.3)x10$^{8}$M$_\odot$ (thus, gas masses of ~10$^{11}$M$_\odot$) and $M_\ast=$(1.26+-0.05)x10$^{11}$M$_\odot$. These galaxies have gas fractions of $f_{gas}=$0.41+-0.02 with depletion timescales of ~150Myr. The gas mass function evolution at high masses is consistent with constraints at lower masses from blind CO-surveys, with an increase to z~2-3 and then a decline at higher redshifts. The space density and masses of SMGs suggests that almost all galaxies with $M_\ast$>~2x10$^{11}$M$_\odot$ have passed through an SMG-like phase. We find no evolution in dust temperature at a constant far-infrared luminosity across z~1.5-4. We show that SMGs appear to behave as simple homologous systems in the far-infrared, having properties consistent with a centrally illuminated starburst. Our study provides strong support for an evolutionary link between the active, gas-rich SMG population at z>1 and the formation of massive, bulge-dominated galaxies across the history of the Universe.
144 citations
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California Institute of Technology1, University of Cambridge2, University of Copenhagen3, University of Padua4, University of Tokyo5, Paul Sabatier University6, University of Geneva7, University of La Serena8, University of Antofagasta9, University of Bologna10, Space Telescope Science Institute11, Waseda University12, National Institutes of Natural Sciences, Japan13, Valparaiso University14, University of California, Davis15, University of Florida16, Max Planck Society17, Cornell University18, European Southern Observatory19, Leiden University20, University of Massachusetts Amherst21
TL;DR: The ALMA-ALPINE [CII] survey (A2C2S) aims at characterizing the properties of a sample of normal star-forming galaxies (SFGs).
Abstract: The ALMA-ALPINE [CII] survey (A2C2S) aims at characterizing the properties of a sample of normal star-forming galaxies (SFGs). ALPINE, the ALMA Large Program to INvestigate 118 galaxies observed in the [CII]-158$\mu$m line and far Infrared (FIR) continuum emission in the period of rapid mass assembly, right after HI reionization ended, at redshifts 4
140 citations
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École Polytechnique Fédérale de Lausanne1, University of California, Los Angeles2, Technische Universität München3, Max Planck Society4, Academia Sinica Institute of Astronomy and Astrophysics5, Stanford University6, University of California, Davis7, University of Tokyo8, Niels Bohr Institute9, University of Cambridge10, Fermilab11, University of Portsmouth12, Kapteyn Astronomical Institute13, Valparaiso University14, Leiden University15, European Southern Observatory16, INAF17
TL;DR: In this article, the authors investigate three potential sources: stellar kinematics, 2- line-of-sight effects, and 3- the deflector mass model and find no evidence of bias or errors larger than the current statistical uncertainties reported by TDCOSMO.
Abstract: Time-delay cosmography of lensed quasars has achieved 2.4% precision on the measurement of the Hubble constant, H0. As part of an ongoing effort to uncover and control systematic uncertainties, we investigate three potential sources: 1- stellar kinematics, 2- line-of-sight effects, and 3- the deflector mass model. To meet this goal in a quantitative way, we reproduced the H0LiCOW/SHARP/STRIDES (hereafter TDCOSMO) procedures on a set of real and simulated data, and we find the following. First, stellar kinematics cannot be a dominant source of error or bias since we find that a systematic change of 10% of measured velocity dispersion leads to only a 0.7% shift on H0 from the seven lenses analyzed by TDCOSMO. Second, we find no bias to arise from incorrect estimation of the line-of-sight effects. Third, we show that elliptical composite (stars + dark matter halo), power-law, and cored power-law mass profiles have the flexibility to yield a broad range in H0 values. However, the TDCOSMO procedures that model the data with both composite and power-law mass profiles are informative. If the models agree, as we observe in real systems owing to the "bulge-halo" conspiracy, H0 is recovered precisely and accurately by both models. If the two models disagree, as in the case of some pathological models illustrated here, the TDCOSMO procedure either discriminates between them through the goodness of fit, or it accounts for the discrepancy in the final error bars provided by the analysis. This conclusion is consistent with a reanalysis of six of the TDCOSMO (real) lenses: the composite model yields H0 = 74.0-1.8+1.7 km s-1 Mpc-1, while the power-law model yields 74.2-1.6+1.6 km s-1 Mpc-1. In conclusion, we find no evidence of bias or errors larger than the current statistical uncertainties reported by TDCOSMO.
139 citations
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Australia Telescope National Facility1, University of Sydney2, University of Western Australia3, INAF4, Royal Military College of Canada5, Swinburne University of Technology6, European Southern Observatory7, Aix-Marseille University8, University of the Western Cape9, Australian National University10, University of Lyon11, Liverpool John Moores University12, University of Cape Town13, ASTRON14, Kapteyn Astronomical Institute15, Commonwealth Scientific and Industrial Research Organisation16, University of New Mexico17, University of Louisville18, University of Queensland19, University of Newcastle20, Spanish National Research Council21, Rhodes University22, Ruhr University Bochum23, Russian Academy of Sciences24, Macquarie University25, Sejong University26, Columbia University27, Peking University28, University of Wisconsin-Madison29, Max Planck Society30
TL;DR: The Widefield ASKAP L-band Legacy All-sky Blind Survey (wallaby) as discussed by the authors is a next-generation survey of neutral hydrogen (H i) in the Local Universe, which uses the widefield, high-resolution capability of the Australian Square Kilometer Array Pathfinder (ASKAP), a radio interferometer consisting of 36 dishes equipped with Phased-Array Feeds.
Abstract: The Widefield ASKAP L-band Legacy All-sky Blind surveY (wallaby) is a next-generation survey of neutral hydrogen (H i) in the Local Universe. It uses the widefield, high-resolution capability of the Australian Square Kilometer Array Pathfinder (ASKAP), a radio interferometer consisting of 36 \times12-m dishes equipped with Phased-Array Feeds (PAFs), located in an extremely radio-quiet zone in Western Australia. wallaby aims to survey three-quarters of the sky (-90^{\circ} < \delta< +30^{\circ}) to a redshift of z \lesssim0.26, and generate spectral line image cubes at ∼30 arcsec resolution and ∼1.6 mJy beam$^{−1}$ per 4 km s$^{−1}$ channel sensitivity. ASKAP’s instantaneous field of view at 1.4 GHz, delivered by the PAF’s 36 beams, is about 30 sq deg. At an integrated signal-to-noise ratio of five, wallaby is expected to detect around half a million galaxies with a mean redshift of z \sim0.05 (∼200 Mpc). The scientific goals of wallaby include: (a) a census of gas-rich galaxies in the vicinity of the Local Group; (b) a study of the H i properties of galaxies, groups and clusters, in particular the influence of the environment on galaxy evolution; and (c) the refinement of cosmological parameters using the spatial and redshift distribution of low-bias gas-rich galaxies. For context we provide an overview of recent and planned large-scale H i surveys. Combined with existing and new multi-wavelength sky surveys, wallaby will enable an exciting new generation of panchromatic studies of the Local Universe. — First results from the wallaby pilot survey are revealed, with initial data products publicly available in the CSIRO ASKAP Science Data Archive (CASDA).
131 citations
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TL;DR: Absorption lines of iron in the dayside atmosphere of an ultrahot giant exoplanet disappear after travelling across the nightside, showing that the iron has condensed during its travel.
Abstract: Ultrahot giant exoplanets receive thousands of times Earth’s insolation1,2. Their high-temperature atmospheres (greater than 2,000 kelvin) are ideal laboratories for studying extreme planetary climates and chemistry3–5. Daysides are predicted to be cloud-free, dominated by atomic species6 and much hotter than nightsides5,7,8. Atoms are expected to recombine into molecules over the nightside9, resulting in different day and night chemistries. Although metallic elements and a large temperature contrast have been observed10–14, no chemical gradient has been measured across the surface of such an exoplanet. Different atmospheric chemistry between the day-to-night (‘evening’) and night-to-day (‘morning’) terminators could, however, be revealed as an asymmetric absorption signature during transit4,7,15. Here we report the detection of an asymmetric atmospheric signature in the ultrahot exoplanet WASP-76b. We spectrally and temporally resolve this signature using a combination of high-dispersion spectroscopy with a large photon-collecting area. The absorption signal, attributed to neutral iron, is blueshifted by −11 ± 0.7 kilometres per second on the trailing limb, which can be explained by a combination of planetary rotation and wind blowing from the hot dayside16. In contrast, no signal arises from the nightside close to the morning terminator, showing that atomic iron is not absorbing starlight there. We conclude that iron must therefore condense during its journey across the nightside. Absorption lines of iron in the dayside atmosphere of an ultrahot giant exoplanet disappear after travelling across the nightside, showing that the iron has condensed during its travel.
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Humboldt University of Berlin1, Lawrence Berkeley National Laboratory2, Yale University3, University of California, Berkeley4, University of Southampton5, Stockholm University6, Max Planck Society7, University of California, Santa Barbara8, Las Cumbres Observatory Global Telescope Network9, Tsinghua University10, Space Telescope Science Institute11, Institute for the Physics and Mathematics of the Universe12, European Southern Observatory13
TL;DR: In this article, a large sample of nearby Type Ia supernovae (SN Ia) is classified into those that are located in predominantly younger or older environments, based on the specific star formation rate measured within a projected distance of 1 kpc from each SN location.
Abstract: As part of an on-going effort to identify, understand and correct for astrophysics biases in the standardization of Type Ia supernovae (SN Ia) for cosmology, we have statistically classified a large sample of nearby SNe Ia into those that are located in predominantly younger or older environments. This classification is based on the specific star formation rate measured within a projected distance of 1 kpc from each SN location (LsSFR). This is an important refinement compared to using the local star formation rate directly, as it provides a normalization for relative numbers of available SN progenitors and is more robust against extinction by dust. We find that the SNe Ia in predominantly younger environments are ΔY = 0.163 ± 0.029 mag (5.7σ) fainter than those in predominantly older environments after conventional light-curve standardization. This is the strongest standardized SN Ia brightness systematic connected to the host-galaxy environment measured to date. The well-established step in standardized brightnesses between SNe Ia in hosts with lower or higher total stellar masses is smaller, at ΔM = 0.119 ± 0.032 mag (4.5σ), for the same set of SNe Ia. When fit simultaneously, the environment-age offset remains very significant, with ΔY = 0.129 ± 0.032 mag (4.0σ), while the global stellar mass step is reduced to ΔM = 0.064 ± 0.029 mag (2.2σ). Thus, approximately 70% of the variance from the stellar mass step is due to an underlying dependence on environment-based progenitor age. Also, we verify that using the local star formation rate alone is not as powerful as LsSFR at sorting SNe Ia into brighter and fainter subsets. Standardization that only uses the SNe Ia in younger environments reduces the total dispersion from 0.142 ± 0.008 mag to 0.120 ± 0.010 mag. We show that as environment-ages evolve with redshift, a strong bias, especially on the measurement of the derivative of the dark energy equation of state, can develop. Fortunately, data that measure and correct for this effect using our local specific star formation rate indicator, are likely to be available for many next-generation SN Ia cosmology experiments.
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National Radio Astronomy Observatory1, University of Toledo2, Spanish National Research Council3, University of Texas at Austin4, Leiden University5, California Institute of Technology6, University of Concepción7, University of Oklahoma8, Space Telescope Science Institute9, Chalmers University of Technology10, University of Illinois at Urbana–Champaign11, University of Virginia12, Harvard University13, Northwestern University14, State University of New York at Fredonia15, University of Cambridge16, University of Arizona17, Western Washington University18, European Southern Observatory19, University of Chile20, Max Planck Society21, University of Rochester22
TL;DR: In this article, the authors conducted a survey of 328 protostars in the Orion molecular clouds with the Atacama Large Millimeter/submillimeter Array at 0.87 mm at a resolution of ∼0.08 (32 au).
Abstract: We have conducted a survey of 328 protostars in the Orion molecular clouds with the Atacama Large Millimeter/submillimeter Array at 0.87 mm at a resolution of ∼0.″1 (40 au), including observations with the Very Large Array at 9 mm toward 148 protostars at a resolution of ∼0.″08 (32 au). This is the largest multiwavelength survey of protostars at this resolution by an order of magnitude. We use the dust continuum emission at 0.87 and 9 mm to measure the dust disk radii and masses toward the Class 0, Class I, and flat-spectrum protostars, characterizing the evolution of these disk properties in the protostellar phase. The mean dust disk radii for the Class 0, Class I, and flat-spectrum protostars are 44.9-3.4+5.8, 37.0-3.0+4.9, and 28.5-2.3+3.7 au, respectively, and the mean protostellar dust disk masses are 25.9-4.0+7.7, 14.9-2.2+3.8, 11.6-1.9+3.5 M⊙, respectively. The decrease in dust disk masses is expected from disk evolution and accretion, but the decrease in disk radii may point to the initial conditions of star formation not leading to the systematic growth of disk radii or that radial drift is keeping the dust disk sizes small. At least 146 protostellar disks (35% of 379 detected 0.87 mm continuum sources plus 42 nondetections) have disk radii greater than 50 au in our sample. These properties are not found to vary significantly between different regions within Orion. The protostellar dust disk mass distributions are systematically larger than those of Class II disks by a factor of >4, providing evidence that the cores of giant planets may need to at least begin their formation during the protostellar phase.
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TL;DR: In this article, the authors presented general hard X-ray (KX) and optical (KO) corrections, computed by combining several AGN samples spanning the widest (about 7 dex) luminosity range ever used for this type of studies.
Abstract: Context. The AGN bolometric correction is a key element for understanding black hole (BH) demographics and computing accurate BH accretion histories from AGN luminosities. However, current estimates still differ from each other by up to a factor of two to three, and rely on extrapolations at the lowest and highest luminosities. Aims. Here we revisit this fundamental question by presenting general hard X-ray (KX) and optical (KO) bolometric corrections, computed by combining several AGN samples spanning the widest (about 7 dex) luminosity range ever used for this type of studies. Methods. We analysed a total of ∼1000 type 1 and type 2 AGN for which we performed a dedicated SED-fitting. Results. We provide a bolometric correction separately for type 1 and type 2 AGN; the two bolometric corrections agree in the overlapping luminosity range. Based on this we computed for the first time a universal bolometric correction for the whole AGN sample (both type 1 and type 2). We found that KX is fairly constant at log(LBOL/L⊙) < 11, while it increases up to about one order of magnitude at log(LBOL/L⊙) ∼ 14.5. A similar increasing trend has been observed when its dependence on either the Eddington ratio or the BH mass is considered, while no dependence on redshift up to z ∼ 3.5 has been found. In contrast, the optical bolometric correction appears to be fairly constant (i.e. KO ∼ 5) regardless of the independent variable. We also verified that our bolometric corrections correctly predict the AGN bolometric luminosity functions. According to this analysis, our bolometric corrections can be applied to the whole AGN population in a wide range of luminosity and redshift.
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TL;DR: In this article, the authors used Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 (1.1-1.3 mm) continuum observations of embedded disks in the Perseus star-forming region together with Very Large Array (VLA) Ka -band (9 mm) data to provide a robust estimate of dust disk masses from the flux densities measured in the image plane.
Abstract: Context. Recent years have seen building evidence that planet formation starts early, in the first ~0.5 Myr. Studying the dust masses available in young disks enables us to understand the origin of planetary systems given that mature disks are lacking the solid material necessary to reproduce the observed exoplanetary systems, especially the massive ones.Aims. We aim to determine if disks in the embedded stage of star formation contain enough dust to explain the solid content of the most massive exoplanets.Methods. We use Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 (1.1–1.3 mm) continuum observations of embedded disks in the Perseus star-forming region together with Very Large Array (VLA) Ka -band (9 mm) data to provide a robust estimate of dust disk masses from the flux densities measured in the image plane.Results. We find a strong linear correlation between the ALMA and VLA fluxes, demonstrating that emission at both wavelengths is dominated by dust emission. For a subsample of optically thin sources, we find a median spectral index of 2.5 from which we derive the dust opacity index β = 0.5, suggesting significant dust growth. Comparison with ALMA surveys of Orion shows that the Class I dust disk mass distribution between the two regions is similar, but that the Class 0 disks are more massive in Perseus than those in Orion. Using the DIANA opacity model including large grains, with a dust opacity value of κ 9 mm = 0.28 cm2 g−1 , the median dust masses of the embedded disks in Perseus are 158 M ⊕ for Class 0 and 52 M ⊕ for Class I from the VLA fluxes. The lower limits on the median masses from ALMA fluxes are 47 M ⊕ and 12 M ⊕ for Class 0 and Class I, respectively, obtained using the maximum dust opacity value κ 1.3 mm = 2.3 cm2 g−1 . The dust masses of young Class 0 and I disks are larger by at least a factor of ten and three, respectively, compared with dust masses inferred for Class II disks in Lupus and other regions.Conclusions. The dust masses of Class 0 and I disks in Perseus derived from the VLA data are high enough to produce the observed exoplanet systems with efficiencies acceptable by planet formation models: the solid content in observed giant exoplanets can be explained if planet formation starts in Class 0 phase with an efficiency of ~15%. A higher efficiency of ~30% is necessary if the planet formation is set to start in Class I disks.
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TL;DR: The first volume-limited sample of cataclysmic variables (CVs), selected using the accurate parallaxes provided by the second data release (DR2) of the European Space Agency Gaia space mission, was presented in this paper.
Abstract: We present the first volume-limited sample of cataclysmic variables (CVs), selected using the accurate parallaxes provided by the second data release (DR2) of the European Space Agency Gaia space mission. The sample is composed of 42 CVs within 150 pc, including two new systems discovered using the Gaia data, and is (77±10) per cent complete. We use this sample to study the intrinsic properties of the Galactic CV population. In particular, the CV space density we derive, ρ=(4.8+0.6−0.8)×10−6pc−3, is lower than that predicted by most binary population synthesis studies. We also find a low fraction of period bounce CVs, seven per cent, and an average white dwarf mass of ⟨MWD⟩=(0.83±0.17)M⊙. Both findings confirm previous results, ruling out the presence of observational biases affecting these measurements, as has been suggested in the past. The observed fraction of period bounce CVs falls well below theoretical predictions, by at least a factor of five, and remains one of the open problems in the current understanding of CV evolution. Conversely, the average white dwarf mass supports the presence of additional mechanisms of angular momentum loss that have been accounted for in the latest evolutionary models. The fraction of magnetic CVs in the 150 pc sample is remarkably high at 36 per cent. This is in striking contrast with the absence of magnetic white dwarfs in the detached population of CV progenitors, and underlines that the evolution of magnetic systems has to be included in the next generation of population models.
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Aix-Marseille University1, INAF2, Université Paris-Saclay3, University of Edinburgh4, Max Planck Society5, University of Tübingen6, University of Bern7, University of Lyon8, University of Grenoble9, Centre national de la recherche scientifique10, ETH Zurich11, University of Paris12, University of Geneva13, European Southern Observatory14, Goddard Space Flight Center15, Institut de recherche pour le développement16
TL;DR: In this paper, the authors present an initial statistical analysis for a subsample of 150 stars that are representative of the full SHINE sample, and use a MCMC tool to compare their observations to two different types of models.
Abstract: The SHINE project is a 500-star survey performed with SPHERE on the VLT for the purpose of directly detecting new substellar companions and understanding their formation and early evolution. Here we present an initial statistical analysis for a subsample of 150 stars that are representative of the full SHINE sample. Our goal is to constrain the frequency of substellar companions with masses between 1 and 75 MJup and semimajor axes between 5 and 300 au. We adopt detection limits as a function of angular separation from the survey data for all stars converted into mass and projected orbital separation using the BEX-COND-hot evolutionary tracks and known distance to each system. Based on the results obtained for each star and on the 13 detections in the sample, we use a MCMC tool to compare our observations to two different types of models. The first is a parametric model based on observational constraints, and the second type are numerical models that combine advanced core accretion and gravitational instability planet population synthesis. Using the parametric model, we show that the frequencies of systems with at least one substellar companion are $23.0_{-9.7}^{+13.5}\%$, $5.8_{-2.8}^{+4.7}\%$, and $12.6_{-7.1}^{+12.9}\%$ for BA, FGK, and M stars, respectively. We also demonstrate that a planet-like formation pathway probably dominates the mass range from 1-75 MJup for companions around BA stars, while for M dwarfs, brown dwarf binaries dominate detections. In contrast, a combination of binary star-like and planet-like formation is required to best fit the observations for FGK stars. Using our population model and restricting our sample to FGK stars, we derive a frequency of $5.7_{-2.8}^{+3.8}\%$, consistent with predictions from the parametric model. More generally, the frequency values that we derive are in excellent agreement with values obtained in previous studies.
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Leiden University1, Max Planck Society2, ETH Zurich3, European Southern Observatory4, Aix-Marseille University5, Russian Academy of Sciences6, University of Cambridge7, University of Bern8, University of Tübingen9, Ludwig Maximilian University of Munich10, Instituto Superior Técnico11, University of Porto12, University College Dublin13, Space Telescope Science Institute14, University of Michigan15, University of Exeter16, University of Liège17, California Institute of Technology18, Diego Portales University19
TL;DR: In this article, the atmospheric properties of the directly imaged planet HR 8799e with a free retrieval approach were constrained using radiative transfer code petitRADTRANS for generating the spectra.
Abstract: Context. Clouds are ubiquitous in exoplanet atmospheres and they represent a challenge for the model interpretation of their spectra. When generating a large number of model spectra, complex cloud models often prove too costly numerically, whereas more efficient models may be overly simplified.
Aims: We aim to constrain the atmospheric properties of the directly imaged planet HR 8799e with a free retrieval approach.
Methods: We used our radiative transfer code petitRADTRANS for generating the spectra, which we coupled to the PyMultiNest tool. We added the effect of multiple scattering which is important for treating clouds. Two cloud model parameterizations are tested: the first incorporates the mixing and settling of condensates, the second simply parameterizes the functional form of the opacity.
Results: In mock retrievals, using an inadequate cloud model may result in atmospheres that are more isothermal and less cloudy than the input. Applying our framework on observations of HR 8799e made with the GPI, SPHERE, and GRAVITY, we find a cloudy atmosphere governed by disequilibrium chemistry, confirming previous analyses. We retrieve that C/O = 0.60-0.08+0.07. Other models have not yet produced a well constrained C/O value for this planet. The retrieved C/O values of both cloud models are consistent, while leading to different atmospheric structures: either cloudy or more isothermal and less cloudy. Fitting the observations with the self-consistent Exo-REM model leads to comparable results, without constraining C/O.
Conclusions: With data from the most sensitive instruments, retrieval analyses of directly imaged planets are possible. The inferred C/O ratio of HR 8799e is independent of the cloud model and thus appears to be a robust. This C/O is consistent with stellar, which could indicate that the HR 8799e formed outside the CO2 or CO iceline. As it is the innermost planet of the system, this constraint could apply to all HR 8799 planets.
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Leiden University1, Diego Portales University2, Max Planck Society3, National Radio Astronomy Observatory4, University of Cambridge5, Durham University6, University of Western Australia7, European Southern Observatory8, Swinburne University of Technology9, Atacama Large Millimeter Submillimeter Array10, Institut d'Astrophysique de Paris11, Hiroshima University12, University of Copenhagen13, University of Geneva14, Cornell University15
TL;DR: In this paper, the Atacama Large Millimeter/submillimeter Array (ALMA) Spectroscopic Survey in the Hubble Ultra-Deep Field (ASPECS) large program was used to probe dust-enshrouded star formation from 1362 Lyman-break galaxies spanning the redshift range z = 1.5−10 (to ~7−28 M ⊙ yr−1 at 4σ over the entire range).
Abstract: We make use of sensitive (9.3 μJy beam−1 rms) 1.2 mm continuum observations from the Atacama Large Millimeter/submillimeter Array (ALMA) Spectroscopic Survey in the Hubble Ultra-Deep Field (ASPECS) large program to probe dust-enshrouded star formation from 1362 Lyman-break galaxies spanning the redshift range z = 1.5–10 (to ~7–28 M ⊙ yr−1 at 4σ over the entire range). We find that the fraction of ALMA-detected galaxies in our z = 1.5–10 samples increases steeply with stellar mass, with the detection fraction rising from 0% at 109.0 M ⊙ to ${85}_{-18}^{+9}$% at >1010 M ⊙. Moreover, on stacking all 1253 low-mass ( ${10}^{9.5}\,{M}_{\odot }$ and an SMC-like relation at lower masses. Using stellar mass and β measurements for z ~ 2 galaxies over the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, we derive a new empirical relation between β and stellar mass and then use this correlation to show that our IRX–β and IRX–stellar mass relations are consistent with each other. We then use these constraints to express the IRX as a bivariate function of β and stellar mass. Finally, we present updated estimates of star formation rate density determinations at z > 3, leveraging present improvements in the measured IRX and recent probes of ultraluminous far-IR galaxies at z > 2.
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TL;DR: In this article, a VLT/X-Shooter spectroscopy of the Lyman continuum (LyC) emitting galaxy Ion2 at z = 3.2121 was presented.
Abstract: We present a VLT/X-Shooter spectroscopy of the Lyman continuum (LyC) emitting galaxy Ion2 at z = 3.2121 and compare it to that of the recently discovered strongly lensed LyC emitter at z = 2.37, known as the Sunburst arc. Three main results emerge from the X-Shooter spectrum: (a) the Ly α has three distinct peaks with the central one at the systemic redshift, indicating a ionized tunnel through which both Ly α and LyC radiation escape; (b) the large O32 oxygen index ([O III] λλ4959, 5007/[O II] λλ3727, 3729) of 9.18+−118232 is compatible to those measured in local (z ∼0.4) LyC leakers; (c) there are narrow nebular high-ionization metal lines with σv 20), suggests that this exceptional object is a gravitationally bound star cluster observed at a cosmological distance, with a stellar mass M ≲ 107 M☉ and an effective radius smaller than 20 pc. Intriguingly, sources like Sunburst but without lensing magnification might appear as Ion2-like galaxies, in which unresolved massive star clusters dominate the ultraviolet emission. This work supports the idea that dense young star clusters can contribute to the ionization of the IGM through holes created by stellar feedback.
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University of Geneva1, University of Bern2, Lund University3, INAF4, University of Amsterdam5, Katholieke Universiteit Leuven6, University of St Andrews7, ETH Zurich8, University College London9, Catholic University of the Most Holy Conception10, University of Warwick11, European Southern Observatory12, Spanish National Research Council13, University of La Laguna14, University of Padua15, University of Grenoble16
TL;DR: In this article, the authors applied the cross-correlation technique and direct differential spectroscopy to search for sodium and other neutral and ionised atoms, TiO, VO, and SH in high-resolution transit spectra obtained with the HARPS spectrograph.
Abstract: Context. WASP-121 b is a hot Jupiter that was recently found to possess rich emission (day side) and transmission (limb) spectra, suggestive of the presence of a multitude of chemical species in the atmosphere. Aims. We survey the transmission spectrum of WASP-121 b for line-absorption by metals and molecules at high spectral resolution and elaborate on existing interpretations of the optical transmission spectrum observed with the Hubble Space Telescope (HST). Methods. We applied the cross-correlation technique and direct differential spectroscopy to search for sodium and other neutral and ionised atoms, TiO, VO, and SH in high-resolution transit spectra obtained with the HARPS spectrograph. We injected models assuming chemical and hydrostatic equilibrium with a varying temperature and composition to enable model comparison, and employed two bootstrap methods to test the robustness of our detections. Results. We detect neutral Mg, Na, Ca, Cr, Fe, Ni, and V, which we predict exists in equilibrium with a significant quantity of VO, supporting earlier observations by HST/WFC3. Non-detections of Ti and TiO support the hypothesis that Ti is depleted via a cold-trap mechanism, as has been proposed in the literature. Atomic line depths are under-predicted by hydrostatic models by a factor of 1.5 to 8, confirming recent findings that the atmosphere is extended. We predict the existence of significant concentrations of gas-phase TiO2, VO2, and TiS, which could be important absorbers at optical and near-IR wavelengths in hot Jupiter atmospheres. However, accurate line-list data are not currently available for them. We find no evidence for absorption by SH and find that inflated atomic lines can plausibly explain the slope of the transmission spectrum observed in the near-ultraviolet with HST. The Na I D lines are significantly broadened (FWHM ∼50 to 70 km s-1) and show a difference in their respective depths of ~15 scale heights, which is not expected from isothermal hydrostatic theory. If this asymmetry is of astrophysical origin, it may indicate that Na I forms an optically thin envelope, reminiscent of the Na I cloud surrounding Jupiter, or that it is hydrodynamically outflowing.
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TL;DR: In this paper, the authors show that the H I mass density of the universe is well determined to redshifts z ~ 5 and shows minor evolution with time, showing that the relationship between stars, gas, and metals in galaxies is a critical component of understanding the cosmic baryon cycle.
Abstract: Characterizing the relationship between stars, gas, and metals in galaxies is a critical component of understanding the cosmic baryon cycle. We compile contemporary censuses of the baryons in collapsed structures, their chemical make-up and dust content. We show that: The H I mass density of the Universe is well determined to redshifts z ~ 5 and shows minor evolution with time. New observations of molecular hydrogen reveal its evolution mirrors that of the global star formation rate density. The constant cosmic molecular gas depletion timescale points to a universal relationship between gas reservoirs and star formation. The metal mass density in cold gas ($T 2.5. At lower redshifts, the contributors to the total amount of metals are more diverse; at z < 1, most of the observed metals are bound in stars. Overall there is little evidence for a "missing metals problem" in modern censuses. We characterize the dust content of neutral gas over cosmic time, finding the dust-to-gas and dust-to-metals ratios fall with decreasing metallicity. We calculate the cosmological dust mass density in the neutral gas up to z ~ 5. There is good agreement between multiple tracers of the dust content of the Universe.
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University of Paris1, University of Cambridge2, European Southern Observatory3, Max Planck Society4, Leiden University5, California Institute of Technology6, University of Lisbon7, University of Grenoble8, University of Cologne9, Dublin Institute for Advanced Studies10, University of California, Berkeley11, University of Liège12, Space Telescope Science Institute13
TL;DR: In this paper, the authors used the GRAVITY instrument with the four 8.2 m telescopes of the Very Large Telescope Interferometer (VLIW) to obtain K-band spectro-interferometric data on β Pictoris b.
Abstract: Context. β Pictoris is arguably one of the most studied stellar systems outside of our own. Some 30 yr of observations have revealed a highly-structured circumstellar disk, with rings, belts, and a giant planet: β Pictoris b. However very little is known about how this system came into being.Aims. Our objective is to estimate the C/O ratio in the atmosphere of β Pictoris b and obtain an estimate of the dynamical mass of the planet, as well as to refine its orbital parameters using high-precision astrometry.Methods. We used the GRAVITY instrument with the four 8.2 m telescopes of the Very Large Telescope Interferometer to obtain K -band spectro-interferometric data on β Pic b. We extracted a medium resolution (R = 500) K -band spectrum of the planet and a high-precision astrometric position. We estimated the planetary C/O ratio using two different approaches (forward modeling and free retrieval) from two different codes (ExoREM and petitRADTRANS, respectively). Finally, we used a simplified model of two formation scenarios (gravitational collapse and core-accretion) to determine which can best explain the measured C/O ratio.Results. Our new astrometry disfavors a circular orbit for β Pic b ( ). Combined with previous results and with HIPPARCOS/Gaia measurements, this astrometry points to a planet mass of M = 12.7 ± 2.2 M Jup . This value is compatible with the mass derived with the free-retrieval code petitRADTRANS using spectral data only. The forward modeling and free-retrieval approches yield very similar results regarding the atmosphere of β Pic b. In particular, the C/O ratios derived with the two codes are identical (0.43 ± 0.05 vs. ). We argue that if the stellar C/O in β Pic is Solar, then this combination of a very high mass and a low C/O ratio for the planet suggests a formation through core-accretion, with strong planetesimal enrichment.
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TL;DR: In this paper, the authors measured a volume-averaged neutral hydrogen fraction at a quasar DES J025216.8 within 68% (95%) confidence intervals when marginalizing over quasar lifetimes of $10^3\le t_{\rm Q}10^8$ yr.
Abstract: Luminous $z\ge7$ quasars provide direct probes of the evolution of supermassive black holes (SMBHs) and the intergalactic medium (IGM) during the epoch of reionization (EoR). The Ly$\alpha$ damping wing absorption imprinted by neutral hydrogen in the IGM can be detected in a single EoR quasar spectrum, allowing the measurement of the IGM neutral fraction towards that line of sight. However, damping wing features have only been detected in two $z>7$ quasars in previous studies. In this paper, we present new high quality optical and near-infrared spectroscopy of the $z=7.00$ quasar DES J025216.64--050331.8 obtained with Keck/NIRES and Gemini/GMOS. By using the MgII single-epoch virial method, we find that it hosts a $\rm (1.39\pm0.16) \times10^{9} ~M_\odot$ SMBH accreting at an Eddington ratio of $\lambda_{\rm Edd}=0.7\pm0.1$, consistent with the values seen in other luminous $z\sim 7$ quasars. Furthermore, the Ly$\alpha$ region of the spectrum exhibits a strong damping wing absorption feature. The lack of associated metal absorption in the quasar spectrum indicates that this absorption is imprinted by a neutral IGM. Using a state-of-the-art model developed by Davies et al., we measure a volume-averaged neutral hydrogen fraction at $z=7$ of $\langle x_{\rm HI} \rangle = 0.70^{+0.20}_{-0.23} (^{+0.28}_{-0.48})$ within 68% (95%) confidence intervals when marginalizing over quasar lifetimes of $10^3\le t_{\rm Q}\le10^8$ yr. This is the highest IGM neutral fraction yet measured using reionization-era quasar spectra.
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TL;DR: In this paper, a joint Markov chain Monte Carlo analysis on the time series of the RV and full width half maximum of the cross-correlation function was performed to disentangle activity-induced and planetary-induced signals.
Abstract: Context. The discovery of Proxima b marked one of the most important milestones in exoplanetary science in recent years. Yet the limited precision of the available radial velocity data and the difficulty in modelling the stellar activity calls for a confirmation of the Earth-mass planet.Aims. We aim to confirm the presence of Proxima b using independent measurements obtained with the new ESPRESSO spectrograph, and refine the planetary parameters taking advantage of its improved precision.Methods. We analysed 63 spectroscopic ESPRESSO observations of Proxima (Gl 551) taken during 2019. We obtained radial velocity measurements with a typical radial velocity photon noise of 26 cm s−1 . We combined these data with archival spectroscopic observations and newly obtained photometric measurements to model the stellar activity signals and disentangle them from planetary signals in the radial velocity (RV) data. We ran a joint Markov chain Monte Carlo analysis on the time series of the RV and full width half maximum of the cross-correlation function to model the planetary and stellar signals present in the data, applying Gaussian process regression to deal with the stellar activity signals.Results. We confirm the presence of Proxima b independently in the ESPRESSO data and in the combined ESPRESSO+ HARPS+UVES dataset. The ESPRESSO data on its own shows Proxima b at a period of 11.218 ± 0.029 days, with a minimum mass of 1.29 ± 0.13 M ⊕ . In the combined dataset we measure a period of 11.18427 ± 0.00070 days with a minimum mass of 1.173 ± 0.086 M ⊕ . We get a clear measurement of the stellar rotation period (87 ± 12 d) and its induced RV signal, but no evidence of stellar activity as a potential cause for the 11.2 days signal. We find some evidence for the presence of a second short-period signal, at 5.15 days with a semi-amplitude of only 40 cm s−1 . If caused by a planetary companion, it would correspond to a minimum mass of 0.29 ± 0.08 M ⊕ . We find that forthe case of Proxima, the full width half maximum of the cross-correlation function can be used as a proxy for the brightness changes and that its gradient with time can be used to successfully detrend the RV data from part of the influence of stellar activity. The activity-induced RV signal in the ESPRESSO data shows a trend in amplitude towards redder wavelengths. Velocities measured using the red end of the spectrograph are less affected by activity, suggesting that the stellar activity is spot dominated. This could be used to create differential RVs that are activity dominated and can be used to disentangle activity-induced and planetary-induced signals. The data collected excludes the presence of extra companions with masses above 0.6 M ⊕ at periods shorter than 50 days.
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TL;DR: The data reduction pipeline of the Multi Unit Spectroscopic Explorer (MUSE) integral field spectrograph operated at ESO's Paranal observatory is described and how the raw science data gets transformed into calibrated datacubes is explained.
Abstract: Processing of raw data from modern astronomical instruments is nowadays often carried out using dedicated software, so-called "pipelines" which are largely run in automated operation. In this paper we describe the data reduction pipeline of the Multi Unit Spectroscopic Explorer (MUSE) integral field spectrograph operated at ESO's Paranal observatory. This spectrograph is a complex machine: it records data of 1152 separate spatial elements on detectors in its 24 integral field units. Efficiently handling such data requires sophisticated software, a high degree of automation and parallelization. We describe the algorithms of all processing steps that operate on calibrations and science data in detail, and explain how the raw science data gets transformed into calibrated datacubes. We finally check the quality of selected procedures and output data products, and demonstrate that the pipeline provides datacubes ready for scientific analysis.
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TL;DR: In this article, optical spectroscopy for the transiting ultra-hot Jupiter WASP-121b was presented, which is on a nearly polar (obliquity ψ North = 88.1 ± 0.25° or ψ South = 91.11 ± 0.20°) orbit, and exclude a high differential rotation for its fast-rotating (P ) can be explained by the rotation of the tidally locked planet.
Abstract: Ultra-hot Jupiters offer interesting prospects for expanding our theories on dynamical evolution and the properties of extremely irradiated atmospheres. In this context, we present the analysis of new optical spectroscopy for the transiting ultra-hot Jupiter WASP-121b. We first refine the orbital properties of WASP-121b, which is on a nearly polar (obliquity ψ North = 88.1 ± 0.25° or ψ South = 91.11 ± 0.20°) orbit, and exclude a high differential rotation for its fast-rotating (P ) can be explained by the rotation of the tidally locked planet. Its blueshift (−5.2 ± 0.5 km s−1 ) could trace strong winds from the dayside to the nightside, or the anisotropic expansion of the planetary thermosphere.
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TL;DR: In this paper, a study of the [CII] 158micron line and underlying far-infrared (FIR) continuum emission of 27 quasar host galaxies at z~6, traced by the Atacama Large Millimeter/submillimeter Array at a spatial resolution of ~1 physical kpc.
Abstract: We present a study of the [CII] 158micron line and underlying far-infrared (FIR) continuum emission of 27 quasar host galaxies at z~6, traced by the Atacama Large Millimeter/submillimeter Array at a spatial resolution of ~1 physical kpc. The [CII] emission in the bright, central regions of the quasars have sizes of 1.0-4.8kpc. The dust continuum emission is typically more compact than [CII]. We find that 13/27 quasars (approximately one-half) have companion galaxies in the field, at projected separations of 3-90kpc. The position of dust emission and the Gaia-corrected positions of the central accreting black holes are cospatial (typical offsets 6 quasar hosts reside. Some outliers with offsets of ~500pc can be linked to disturbed morphologies, most likely due to ongoing or recent mergers. We find no correlation between the central brightness of the FIR emission and the bolometric luminosity of the accreting black hole. The FIR-derived star-formation rate densities (SFRDs) in the host galaxies peak at the galaxies' centers, at typical values between 100 and 1000 M_sun/yr/kpc^2. These values are below the Eddington limit for star formation, but similar to those found in local ultraluminous infrared galaxies. The SFRDs drop toward larger radii by an order of magnitude. Likewise, the [CII]/FIR luminosity ratios of the quasar hosts are lowest in their centers (few x10^-4) and increase by a factor of a few toward the galaxies' outskirts, consistent with resolved studies of lower-redshift sources.
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TL;DR: In this paper, the authors describe the observations and resultant galaxy cluster catalog from the 2770 deg2 SPTpol Extended Cluster Survey (SPT-ECS), and associate SZ-selected clusters, from both SPT-ECS and the SPT SZ survey, with clusters from the DES redMaPPer sample, and find an offset distribution between the SZ center and central galaxy in general agreement with previous work, though with a larger fraction of clusters with significant offsets.
Abstract: We describe the observations and resultant galaxy cluster catalog from the 2770 deg2 SPTpol Extended Cluster Survey (SPT-ECS). Clusters are identified via the Sunyaev-Zel'dovich (SZ) effect and confirmed with a combination of archival and targeted follow-up data, making particular use of data from the Dark Energy Survey (DES). With incomplete follow-up we have confirmed as clusters 244 of 266 candidates at a detection significance ξ ≥ 5 and an additional 204 systems at 4 4 threshold, and 10% of their measured SZ flux. We associate SZ-selected clusters, from both SPT-ECS and the SPT-SZ survey, with clusters from the DES redMaPPer sample, and we find an offset distribution between the SZ center and central galaxy in general agreement with previous work, though with a larger fraction of clusters with significant offsets. Adopting a fixed Planck-like cosmology, we measure the optical richness-SZ mass (l - M) relation and find it to be 28% shallower than that from a weak-lensing analysis of the DES data-a difference significant at the 4σ level-with the relations intersecting at λ = 60. The SPT-ECS cluster sample will be particularly useful for studying the evolution of massive clusters and, in combination with DES lensing observations and the SPT-SZ cluster sample, will be an important component of future cosmological analyses.
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Max Planck Society1, Ghent University2, University of Alberta3, Ohio State University4, European Southern Observatory5, École normale supérieure de Lyon6, Heidelberg University7, University of Western Australia8, Australian National University9, University of Toulouse10, Hoffmann-La Roche11, University of Bonn12, Carnegie Institution for Science13, University of Chile14, University of Paris15
TL;DR: The European Research Council (ERC) and the Natural Sciences and Engineering Research Council of Canada (NERC) as mentioned in this paper proposed the European Horizon 2020 research and innovation program (EH2020).
Abstract: European Research Council (ERC)
694343
Natural Sciences and Engineering Research Council of Canada
RGPIN-201703987
German Research Foundation (DFG)
KR4801/1-1
German Research Foundation (DFG)
KR4801/2-1
European Research Council (ERC)
714907
German Research Foundation (DFG)
SFB 881
138713538
EXC 2181/1-390900948
Programme National "Physique et Chimie du Milieu Interstellaire" (PCMI) of CNRS/INSU
INC/INP - CEA
Centre National D'etudes Spatiales
Programme National Cosmology and Galaxies (PNCG) of CNRS/INSU
INP
IN2P3
French Atomic Energy Commission
European Union's Horizon 2020 research and innovation program
726384