Publications

Here’s a comprehensive list of all work published by members of the DES Collaboration, with arXiv links to all papers.

THE ELECTROMAGNETIC COUNTERPART OF THE BINARY NEUTRON STAR MERGER LIGO/VIRGO GW170817. I. DISCOVERY OF THE OPTICAL COUNTERPART USING THE DARK ENERGY CAMERA

This is the first paper of the series describing results of our followup observations of GW170817 using DECam. We present observations that led to our independent discovery of the optical source and we establish its association with GW170817 by showing that none of the 1500 other sources found within the event localization region could plausibly be associated with the event. We monitored the source for over two weeks and provide the lightcurve data as a machine-readable file in this link. Detailed modeling of the source is performed in a companion paper (Cowperthwaite et al. 2017). A measurement of the Hubble constant, the first utilizing a gravitational wave event as a standard siren measurement of distance, is enabled by this work (LVC, et al. 2017). A study of the event’s host galaxy (Palmese et al. 2017) and of the probability of detecting more of these sources in past and future surveys (Scolnic et al. 2017) also resulted from this program which is featured in an overview paper of all followup programs (LVC, et al. 2017).

THE ELECTROMAGNETIC COUNTERPART OF THE BINARY NEUTRON STAR MERGER LIGO/VIRGO GW170817. II. UV, OPTICAL, AND NEAR-IR LIGHT CURVES AND COMPARISON TO KILONOVA MODELS

This paper presents photometry of the optical/NIR counterpart to GW170817 using data from DECam, the Hubble Space Telescope, and Gemini-South. We model these data finding that they are consistent with the emission expected for an r-process powered kilonova. The inferred ejecta mass is consistent with the suggestion that neutron star mergers are a dominant site of r-process production in the Universe.

THE MULTI-MESSENGER DISCOVERY AND OBSERVATION OF A BINARY NEUTRON STAR MERGER

This paper announces the first multi-messenger observations of a binary neutron star merger, which was detected in gravitational waves, as a short gamma-ray burst, and as an electromagnetic transient. The optical observations identified the source as in the galaxy NGC 4993, which LIGO/Virgo determined is at a distance of 40 Mpc from the gravitational-wave signal. The multi-band light curves and spectra are consistent with a kilonova explosion produced by the neutron star merger.

A GRAVITATIONAL-WAVE STANDARD SIREN MEASUREMENT OF THE HUBBLE CONSTANT

This paper presents the first standard siren measurement of the Hubble constant. The gravitational wave measurement of GW170817 provides a direct estimate of the distance to the source, without the use any sort of distance ladder. Instead, the distance is calibrated by the theory of general relativity. The identification of the host galaxy, NGC 4993, allows a completely independent measurement of the redshift of the source. By combining these two quantities, we determine a value for the Hubble constant. This value, while consistent with existing measurements, is a completely novel and independent way to measure this crucially important cosmological quantity.

HOW MANY KILONOVAE CAN BE FOUND IN PAST, PRESENT, AND FUTURE SURVEY DATASETS?

In this paper, we attempt to answer the question “How many kilonovae (KNe) can be found in past, present and future datasets?” We use the DES-GW light-curve and an estimate of the rate, and detailed simulations of 11 different surveys, to predict KN discovery numbers for each survey. While we find that it is not highly likely more than a couple KNe can be found in past datasets, we predict that tens of KNe can be found in future datasets, and some of these KNe may be even at higher redshift than the sensitivity of future GW experiments.

Dark Energy Survey Year 1 Results: The Impact of Galaxy Neighbours on Weak Lensing Cosmology with IM3SHAPE

This paper uses simulated DES Y1 images to explore the impact of neighboring galaxies on galaxy shape measurements with im3shape and thereby on cosmology constraints from weak lensing cosmic shear. For more information, contact Simon Samuroff ([email protected]).

Dark Energy Survey Year 1 Results: Multi-Probe Methodology and Simulated Likelihood Analyses

This paper presents the methodology for combining the 3 measurements used in DES Y1 to derive cosmological constraints: galaxy clustering, galaxy-galaxy lensing, and cosmic shear. For more information, please contact Elisabeth Krause ([email protected]) or Tim Eifler ([email protected]).

Dark Energy Survey Year 1 Results: Cosmological Constraints from Cosmic Shear

This paper presents the most significant detection of weak gravitational lensing cosmic shear in a galaxy survey to date, using shapes of 26 million galaxies in 4 redshift bins, and derives constraints on cosmological parameters therefrom. This is one of the 3 measurements used in “Cosmological Constraints from Galaxy Clustering and Weak Lensing.” For more information, please contact Michael Troxel ([email protected]).

Dark Energy Survey Year 1 Results: Photometric Data Set for Cosmology

The Year 1 Gold catalog includes measurements of 137 million objects (galaxies and stars) in 5 filters (grizY) over 1800 square degrees of the sky. These data underlie many of the Year 1 cosmology results. For more information, contact Alex Drlica-Wagner ([email protected]).