M. Soares-Santos
A5064135000- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Cosmology and Gravitation Theories
- Pulsars and Gravitational Waves Research
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Adaptive optics and wavefront sensing
- Astrophysical Phenomena and Observations
- CCD and CMOS Imaging Sensors
- Geophysics and Gravity Measurements
- Dark Matter and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Astrophysics and Star Formation Studies
- Remote Sensing in Agriculture
- Astro and Planetary Science
- Gaussian Processes and Bayesian Inference
- Calibration and Measurement Techniques
- Impact of Light on Environment and Health
- Statistical and numerical algorithms
- Advanced Image Processing Techniques
- Planetary Science and Exploration
- History and Developments in Astronomy
- Advanced Vision and Imaging
University of Michigan–Ann Arbor
2020-2024
Valongo Observatory
2021-2024
National Observatory
2021-2024
University of Zurich
2024
Lancaster University
2024
Centre National de la Recherche Scientifique
2024
American Public University System
2024
Oak Ridge National Laboratory
2024
Michigan United
2022-2024
Aix-Marseille Université
2024
We present UV, optical, and NIR photometry of the first electromagnetic counterpart to a gravitational wave source from Advanced LIGO/Virgo, binary neutron star merger GW170817. Our data set extends discovery optical at $0.47$ days $18.5$ post-merger, includes observations with Dark Energy Camera (DECam), Gemini-South/FLAMINGOS-2 (GS/F2), {\it Hubble Space Telescope} ({\it HST}). The spectral energy distribution (SED) inferred this $0.6$ is well described by blackbody model $T\approx 8300$...
Abstract We present the Dark Energy Camera (DECam) discovery of optical counterpart first binary neutron star merger detected through gravitational-wave emission, GW170817. Our observations commenced 10.5 hr post-merger, as soon localization region became accessible from Chile. imaged 70 deg 2 in i and z bands, covering 93% initial integrated probability, to a depth necessary identify likely counterparts (e.g., kilonova). At 11.4 post-merger we bright transient located nucleus NGC 4993 at...
We report the discovery of eight new ultra-faint dwarf galaxy candidates in second year optical imaging data from Dark Energy Survey (DES). Six these are detected at high confidence, while two lower-confidence identified regions non-uniform survey coverage. The stellar systems found by three independent automated search techniques and as overdensities stars, consistent with isochrone luminosity function an old metal-poor simple population. faint (Mv > -4.7 mag) span a range physical sizes...
We report the discovery of eight new Milky Way companions in optical imaging data collected during first year Dark Energy Survey (DES). Each system is identified as a statistically significant over-density individual stars consistent with expected isochrone and luminosity function an old metal-poor stellar population. The objects span wide range absolute magnitudes (MV from to ), physical sizes (), heliocentric distances (). Based on low surface brightnesses, large sizes, and/or...
We report the discovery of rising X-ray emission from binary neutron star (BNS) merger event GW170817. This is first detection a gravitational-wave source. Observations acquired with Chandra Observatory (CXO) at t~2.3 days post reveal no significant emission, L_x<=3.2x10^38 erg/s (isotropic-equivalent). Continued monitoring revealed presence an source that brightened time, reaching L_x\sim 9x10^39 ~15.1 merger. interpret these findings in context isotropic and collimated relativistic...
ABSTRACT We search for excess γ -ray emission coincident with the positions of confirmed and candidate Milky Way satellite galaxies using six years data from Fermi Large Area Telescope (LAT). Our sample 45 stellar systems includes 28 kinematically dark-matter-dominated dwarf spheroidal (dSphs) 17 recently discovered that have photometric characteristics consistent population known dSphs. For each these targets, relative predicted flux due to dark matter annihilation is taken kinematic...
We present Very Large Array (VLA) and Atacama Millimeter/sub-millimeter ALMA radio observations of GW\,170817, the first Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo gravitational wave (GW) event from a binary neutron star merger GW with an electromagnetic (EM) counterpart. Our data include following discovery optical transient at both centimeter ($13.7$ hours post merger) millimeter ($2.41$ days bands. detect faint emission 6 GHz 19.47 39.23 after merger, but not in...
We present a near-infrared spectral sequence of the electromagnetic counterpart to binary neutron star merger GW170817 detected by Advanced LIGO/Virgo. Our dataset comprises seven epochs J+H spectra taken with FLAMINGOS-2 on Gemini-South between 1.5 and 10.5 days after merger. In initial epoch, spectrum is dominated smooth blue continuum due high-velocity, lanthanide-poor kilonova component. Starting following night, all subsequent instead show features that are similar those predicted in...
ABSTRACT We describe updates to the redMaPPer algorithm, a photometric red-sequence cluster finder specifically designed for large surveys. The updated algorithm is applied of Science Verification (SV) data from Dark Energy Survey (DES), and Sloan Digital Sky (SDSS) DR8 set. DES SV catalog locally volume limited contains 786 clusters with richness (roughly equivalent ) . consists 26,311 , sharply increasing threshold as function redshift performance both catalogs shown be excellent,...
We combine Dark Energy Survey Year 1 clustering and weak lensing data with Baryon Acoustic Oscillations (BAO) Big Bang Nucleosynthesis (BBN) experiments to constrain the Hubble constant. Assuming a flat $\Lambda$CDM model minimal neutrino mass ($\sum m_\nu = 0.06$ eV) we find $H_0=67.2^{+1.2}_{-1.0}$ km/s/Mpc (68% CL). This result is completely independent of constant measurements based on distance ladder, Cosmic Microwave Background (CMB) anisotropies (both temperature polarization), strong...
Abstract We present optical and ultraviolet spectra of the first electromagnetic counterpart to a gravitational-wave (GW) source, binary neutron star merger GW170817. Spectra were obtained nightly between 1.5 9.5 days post-merger, using Southern Astrophysical Research Magellan telescopes; UV spectrum was with Hubble Space Telescope at 5.5 days. Our data reveal rapidly fading blue component ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>T</mml:mi>...
We describe the creation, content, and validation of Dark Energy Survey (DES) internal year-one cosmology data set, Y1A1 GOLD, in support upcoming cosmological analyses. The GOLD set is assembled from multiple epochs DES imaging consists calibrated photometric zeropoints, object catalogs, ancillary products - e.g., maps survey depth observing conditions, star-galaxy classification, redshift estimates that are necessary for accurate wide-area catalog ~137 million objects detected coadded...
We perform a comprehensive study of Milky Way (MW) satellite galaxies to constrain the fundamental properties dark matter (DM). This analysis fully incorporates inhomogeneities in spatial distribution and detectability MW satellites marginalizes over uncertainties mapping between DM halos, system, disruption subhalos by disk. Our results are consistent with cold, collisionless paradigm yield strongest cosmological constraints date on particle models warm, interacting, fuzzy matter. At 95%...
We present an improved measurement of the Hubble constant (H_0) using 'inverse distance ladder' method, which adds information from 207 Type Ia supernovae (SNe Ia) Dark Energy Survey (DES) at redshift 0.018 < z 0.85 to existing measurements 122 low (z 0.07) SNe (Low-z) and Baryon Acoustic Oscillations (BAOs). Whereas traditional H_0 with use a ladder parallax Cepheid variable stars, inverse relies on absolute BAOs calibrate intrinsic magnitude Ia. find = 67.8 +/- 1.3 km s-1 Mpc-1...
We constrain the mass–richness scaling relation of redMaPPer galaxy clusters identified in Dark Energy Survey Year 1 data using weak gravitational lensing. split into 4 × 3 bins richness λ and redshift |$z$| for ≥ 20 0.2 ≤ 0.65 measure mean masses these their stacked lensing signal. By modelling as 〈M200m|λ, |$z$|〉 = M0(λ/40)F((1 + |$z$|)/1.35)G, we normalization at 5.0 per cent level, finding M0 [3.081 ± 0.075(stat) 0.133(sys)] · 1014 M⊙ 40 0.35. The recovered index is F 1.356 0.051 (stat)...
We present two galaxy shape catalogues from the Dark Energy Survey Year 1 data set, covering 1500 square degrees with a median redshift of $0.59$. The cover main fields: Stripe 82, and an area overlapping South Pole Telescope survey region. describe our analysis process in particular measurement using independent shear pipelines, METACALIBRATION IM3SHAPE. catalogue uses Gaussian model innovative internal calibration scheme, was applied to $riz$-bands, yielding 34.8M objects. IM3SHAPE...
We present constraints on extensions of the minimal cosmological models dominated by dark matter and energy, $\Lambda$CDM $w$CDM, using a combined analysis galaxy clustering weak gravitational lensing from first-year data Dark Energy Survey (DES Y1) in combination with external data. consider four energy-dominated scenarios: 1) nonzero curvature $\Omega_k$, 2) number relativistic species $N_{\rm eff}$ different standard value 3.046, 3) time-varying equation-of-state energy described...
ABSTRACT We present a blind time-delay cosmographic analysis for the lens system DES J0408−5354. This is extraordinary presence of two sets multiple images at different redshifts, which provide opportunity to obtain more information cost increased modelling complexity with respect previously analysed systems. perform detailed mass distribution this using three band Hubble Space Telescope imaging. combine measured time delays, line-of-sight central velocity dispersion deflector, and...
We introduce redMaGiC, an automated algorithm for selecting Luminous Red Galaxies (LRGs). The was specifically developed to minimize photometric redshift uncertainties in large-scale structure studies. redMaGiC achieves this by self-training the color-cuts necessary produce a luminosity-thresholded LRG sample of constant comoving density. demonstrate that photozs are very nearly as accurate best machine-learning based methods, yet they require minimal spectroscopic training, do not suffer...
We present weak lensing shear catalogues for 139 square degrees of data taken during the Science Verification (SV) time new Dark Energy Camera (DECam) being used Survey (DES). describe our object selection, point spread function estimation and measurement procedures using two independent pipelines, im3shape ngmix, which produce 2.12 million 3.44 galaxies, respectively. detail a set null tests measurements find that they pass requirements systematic errors at level necessary science...
The population of Milky Way (MW) satellites contains the faintest known galaxies and thus provides essential insight into galaxy formation dark matter microphysics. Here we combine a model galaxy--halo connection with newly derived observational selection functions based on searches for in photometric surveys over nearly entire high Galactic latitude sky. In particular, use cosmological zoom-in simulations MW-like halos that include realistic Large Magellanic Cloud (LMC) analogs to fit...
ABSTRACT We present and characterize the galaxy shape catalogue from first 3 yr of Dark Energy Survey (DES) observations, over an effective area 4143 deg2 southern sky. describe our data analysis process self-calibrating shear measurement pipeline metacalibration, which builds improves upon used in DES Year 1 several aspects. The weak-lensing consists 100 204 026 galaxies, measured riz bands, resulting a weighted source number density neff = 5.59 gal arcmin−2 corresponding noise σe 0.261....
Determining the distribution of redshifts galaxies observed by wide-field photometric experiments like Dark Energy Survey is an essential component to mapping matter density field with gravitational lensing. In this work we describe methods used assign individual weak lensing source from Year 3 Weak Lensing Source Catalogue four tomographic bins and estimate redshift distributions in these bins. As first application data, validate that assumptions made apply DES Y3 develop a full treatment...
Abstract A system of 5020 robotic fiber positioners was installed in 2019 on the Mayall Telescope, at Kitt Peak National Observatory. The robots automatically retarget their optical fibers every 10–20 minutes, each to a precision several microns, with reconfiguration time fewer than 2 minutes. Over next 5 yr, they will enable newly constructed Dark Energy Spectroscopic Instrument (DESI) measure spectra 35 million galaxies and quasars. DESI produce largest 3D map universe date expansion...
We present angular diameter measurements obtained by measuring the position of Baryon Acoustic Oscillations (BAO) in an optimised sample galaxies from first three years Dark Energy Survey data (DES Y3). The consists 7 million distributed over a footprint 4100 deg$^2$ with $0.6 < z_{\rm photo} 1.1$ and typical redshift uncertainty $0.03(1+z)$. selection is same as BAO measurement year DES data, but analysis presented here uses times area, extends to higher makes number improvements, including...