Search Publications
An application of an optimal statistic for characterizing relative orientations
Martin, P. G.; Poidevin, F.; Hill, Ryley +5 more
We present the projected Rayleigh statistic (PRS), a modification of the classic Rayleigh statistic, as a test for non-uniform relative orientation between two pseudo-vector fields. In the application here, this gives an effective way of investigating whether polarization pseudo-vectors (spin-2 quantities) are preferentially parallel or perpendicu…
COSMOGRAIL. XVII. Time delays for the quadruply imaged quasar PG 1115+080
Magain, P.; Kim, S.; Frieman, J. +24 more
We present time-delay estimates for the quadruply imaged quasar PG 1115+080. Our results are based on almost daily observations for seven months at the ESO MPIA 2.2 m telescope at La Silla Observatory, reaching a signal-to-noise ratio of about 1000 per quasar image. In addition, we re-analyze existing light curves from the literature that we compl…
A catalog of polychromatic bulge-disc decompositions of ∼17.600 galaxies in CANDELS
Barro, Guillermo; Pérez-González, Pablo G.; Kocevski, Dale D. +20 more
Understanding how bulges grow in galaxies is a critical step towards unveiling the link between galaxy morphology and star-formation. To do so, it is necessary to decompose large sample of galaxies at different epochs into their main components (bulges and discs). This is particularly challenging, especially at high redshifts, where galaxies are p…
Spatially unresolved SED fitting can underestimate galaxy masses: a solution to the missing mass problem
Sawicki, Marcin; Sorba, Robert
We perform spatially resolved, pixel-by-pixel Spectral Energy Distribution (SED) fitting on galaxies up to z ∼ 2.5 in the Hubble eXtreme Deep Field (XDF). Comparing stellar mass estimates from spatially resolved and spatially unresolved photometry we find that unresolved masses can be systematically underestimated by factors of up to 5. The ratio …
Do current cosmological observations rule out all covariant Galileons?
Peirone, Simone; Frusciante, Noemi; Hu, Bin +2 more
We revisit the cosmology of covariant Galileon gravity in view of the most recent cosmological data sets, including weak lensing. As a higher derivative theory, covariant Galileon models do not have a Λ CDM limit and predict a very different structure formation pattern compared with the standard Λ CDM scenario. Previous cosmological analyses sugge…
The Spectrum of the Universe
Hill, Ryley; Masui, Kiyoshi W.; Scott, Douglas
The cosmic background (CB) radiation, encompassing the sum of emission from all sources outside our own Milky Way galaxy across the entire electromagnetic spectrum, is a fundamental phenomenon in observational cosmology. Many experiments have been conceived to measure it (or its constituents) since the extragalactic Universe was first discovered; …
Characterizing Accreting Double White Dwarf Binaries with the Laser Interferometer Space Antenna and Gaia
Larson, Shane L.; Breivik, Katelyn; Kremer, Kyle +3 more
We demonstrate a method to fully characterize mass-transferring double white dwarf (DWD) systems with a helium-rich (He) white dwarf (WD) donor based on the mass-radius (M-R) relationship for He WDs. Using a simulated Galactic population of DWDs, we show that donor and accretor masses can be inferred for up to ∼60 systems observed by both Laser In…
Gaia 17bpi: An FU Ori-type Outburst
Naylor, Tim; Mainzer, Amy K.; Hillenbrand, Lynne A. +7 more
We report on the source Gaia 17bpi and identify it as a new, ongoing FU Ori-type outburst, associated with a young stellar object. The optical light curve from Gaia exhibited a 3.5 mag rise with the source appearing to plateau in mid-/late 2018. Mid-infrared observations from NEOWISE also show a >3 mag rise that occurred in two stages, with the…
Larger Mutual Inclinations for the Shortest-period Planets
Winn, Joshua N.; Dai, Fei; Masuda, Kento
The Kepler mission revealed a population of compact multiple-planet systems with orbital periods shorter than a year, and occasionally even shorter than a day. By analyzing a sample of 102 Kepler and K2 multiple-planet systems, we measure the minimum difference ΔI between the orbital inclinations, as a function of the orbital distance of the inner…
Two-halo term in stacked thermal Sunyaev-Zel'dovich measurements: Implications for self-similarity
Hill, J. Colin; Jain, Bhuvnesh; Greco, Johnny P. +2 more
The relation between the mass and integrated electron pressure of galaxy group and cluster halos can be probed by stacking maps of the thermal Sunyaev-Zel'dovich (tSZ) effect. Perhaps surprisingly, recent observational results have indicated that the scaling relation between integrated pressure and mass follows the prediction of simple, self-simil…