Search Publications
Can power spectrum observations rule out slow-roll inflation?
Lewis, Antony; Vieira, J. P. P.; Byrnes, Christian T.
The spectral index of scalar perturbations is an important observable that allows us to learn about inflationary physics. In particular, a detection of a significant deviation from a constant spectral index could enable us to rule out the simplest class of inflation models. We investigate whether future observations could rule out canonical single…
A photometric study of globular clusters observed by the APOGEE survey
Masseron, Thomas; Monelli, Matteo; García-Hernández, D. A. +8 more
In this paper, we describe the photometric and spectroscopic properties of multiple populations in seven northern globular clusters. In this study, we employ precise ground-based photometry from the private collection of Stetson, space photometry from the Hubble Space Telescope (HST), literature abundances of Na and O, and Apache Point Observatory…
A Systematic Solution to Multi-Instrument Coregistration of High-Resolution Planetary Images to an Orthorectified Baseline
Muller, Jan-Peter; Sidiropoulos, Panagiotis
First Observation of Lion Roar Emission in Saturn's Magnetosheath
Gurnett, D. A.; Hospodarsky, G. B.; Kurth, W. S. +3 more
We present an observation of intense emissions in Saturn's magnetosheath as detected by the Cassini spacecraft. The emissions are observed in the dawn sector (magnetic local time ∼06:45) of the magnetosheath over a time period of 11 h before the spacecraft crossed the bow shock and entered the unshocked solar wind. They are found to be narrow-band…
Comparing experts and novices in Martian surface feature change detection and identification
Muller, Jan-Peter; Sidiropoulos, Panagiotis; Bamford, Steven +4 more
Change detection in satellite images is a key concern of the Earth Observation field for environmental and climate change monitoring. Satellite images also provide important clues to both the past and present surface conditions of other planets, which cannot be validated on the ground. With the volume of satellite imagery continuing to grow, the i…
Retrieval of H2O abundance in Titan's stratosphere: A (re)analysis of CIRS/Cassini and PACS/Herschel observations
Lellouch, E.; Irwin, P. G. J.; Teanby, N. A. +6 more
Since its first measurement 20 years ago by the Infrared Space Observatory (ISO), the water (H2O) mole fraction in Titan's stratosphere remains uncertain due to large differences between the determinations from available measurements. More particularly, the recent measurements made from the Herschel observatory (PACS and HIFI) estimated…
Internal gravity, self-energy, and disruption of comets and asteroids
Korycansky, D. G.; Dobrovolskis, Anthony R.
The internal gravity and self-gravitational energy of a comet, asteroid, or small moon have applications to their geophysics, including their formation, evolution, cratering, and disruption, the stresses and strains inside such objects, sample return, eventual asteroid mining, and planetary defense strategies for potentially hazardous objects. Thi…
Decoupled black hole accretion and quenching: the relationship between BHAR, SFR and quenching in Milky Way- and Andromeda-mass progenitors since z = 2.5
Morrison, G.; Papovich, C.; Glazebrook, K. +13 more
We investigate the relationship between the black hole accretion rate (BHAR) and star formation rate (SFR) for Milky Way (MW) and Andromeda (M31)-mass progenitors from z = 0.2 to 2.5. We source galaxies from the Ks-band-selected ZFOURGE survey, which includes multiwavelength data spanning 0.3-160 µm. We use decomposition software …
The Lyman Alpha Reference Sample. IX. Revelations from deep surface photometry
Cannon, John M.; Hayes, Matthew; Östlin, Göran +7 more
Context. The Lyman α Reference Sample (LARS) of 14 star-forming galaxies offers a wealth of insight into the workings of these local analogs to high-redshift star-forming galaxies. The sample has been well-studied in terms of Lyα and other emission line properties, such as H I mass, gas kinematics, and morphology.
Aims: We analyze deep surfac…
X-Ray Spectral Properties of Seyfert I Galaxy LEDA 168563
Fabian, Andrew C.; Tsuruta, Sachiko; Liebmann, Andrew C. +2 more
Interesting among possible mechanisms responsible for X-ray emission from active galactic nuclei (AGNs) is ionized relativistic reflection (IRR). Since it arises close to the central black hole it can test strong gravity. Its characteristic features include a high energy Compton hump, a broad Fe Kα line, and a soft excess. Therefore, using the Swi…