Search Publications
The incidence of X-ray selected AGN in nearby galaxies
Birchall, Keir L.; Watson, M. G.; Aird, J. +1 more
We present the identification and analysis of an unbiased sample of active galactic nuclei (AGN) that lie within the local galaxy population. Using the MPA-JHU catalogue (based on SDSS DR8) and 3XMM DR7 we define a parent sample of 25 949 local galaxies (z ≤ 0.33). After confirming that there was strictly no AGN light contaminating stellar mass an…
New constraints on anisotropic expansion from supernovae Type Ia
van Dyk, D. A.; Hudson, M. J.; Trotta, R. +2 more
We re-examine the contentious question of constraints on anisotropic expansion from Type Ia supernovae (SNIa) in the light of a novel determination of peculiar velocities, which are crucial to test isotropy with SNe out to distances ⪝200h-1 Mpc. We re-analyse the Joint Light-Curve Analysis (JLA) Supernovae (SNe) data, improving on previ…
H α morphologies of star clusters in 16 LEGUS galaxies: Constraints on H II region evolution time-scales
Boquien, M.; Calzetti, D.; Adamo, A. +14 more
The analysis of star cluster ages in tandem with the morphology of their H II regions can provide insight into the processes that clear a cluster's natal gas, as well as the accuracy of cluster ages and dust reddening derived from Spectral Energy Distribution (SED) fitting. We classify 3757 star clusters in 16 nearby galaxies according to their H …
The Magellanic Edges Survey - II. Formation of the LMC's northern arm
Da Costa, G. S.; Belokurov, V.; Koposov, S. E. +3 more
The highly-substructured outskirts of the Magellanic Clouds provide ideal locations for studying the complex interaction history between both Clouds and the Milky Way (MW). In this paper, we investigate the origin of a >20° long arm-like feature in the northern outskirts of the Large Magellanic Cloud (LMC) using data from the Magellanic Edges S…
Star-spots and magnetism: testing the activity paradigm in the Pleiades and M67
Pinsonneault, Marc H.; Cao, Lyra
We measure star-spot filling fractions for 240 stars in the Pleiades and M67 open star clusters using APOGEE high-resolution H-band spectra. For this work, we developed a modified spectroscopic pipeline which solves for star-spot filling fraction and star-spot temperature contrast. We exclude binary stars, finding that the large majority of binari…
Milky Way mass with K giants and BHB stars using LAMOST, SDSS/SEGUE, and Gaia: 3D spherical Jeans equation and tracer mass estimator
Bird, Sarah A.; Zhao, Gang; Tian, Hai-Jun +8 more
We measure the enclosed Milky Way mass profile to Galactocentric distances of ~70 and ~50 kpc using the smooth, diffuse stellar halo samples of Bird et al. The samples are Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and Sloan Digital Sky Survey/Sloan Extension for Galactic Understanding and Exploration (SDSS/SEGUE) K giants …
Detecting low-mass haloes with strong gravitational lensing I: the effect of data quality and lensing configuration
White, Simon D. M.; Fassnacht, Christopher D.; Rizzo, Francesca +5 more
This paper aims to quantify how the lowest halo mass that can be detected with galaxy-galaxy strong gravitational lensing depends on the quality of the observations and the characteristics of the observed lens systems. Using simulated data, we measure the lowest detectable NFW mass at each location of the lens plane, in the form of detailed sensit…
The extreme properties of the nearby hyper-Eddington accreting active galactic nucleus in IRAS 04416+1215
Ho, Luis C.; Ricci, Claudio; Tombesi, Francesco +6 more
The physical properties of the accretion flow and of the X-ray emitting plasma, in supermassive black holes accreting at extreme Eddington rates, are still very unclear. Here we present the analysis of simultaneous XMM-Newton and NuSTAR observations of the hyper-Eddington Seyfert 1 galaxy IRAS 04416+1215, carried out in 2020. The main goal of thes…
TOI-530b: a giant planet transiting an M-dwarf detected by TESS
Barclay, Thomas; Latham, David W.; Bedell, Megan +46 more
We report the discovery of TOI-530b, a transiting Saturn-like planet around an M0.5V dwarf, delivered by the Transiting Exoplanet Survey Satellite (TESS). The host star is located at a distance of 147.7 ± 0.6 pc with a radius of R* = 0.54 ± 0.03 R⊙ and a mass of M* = 0.53 ± 0.02 M⊙. We verify the planeta…
3D hydrodynamic simulations for the formation of the Local Group satellite planes
Famaey, Benoit; Kroupa, Pavel; Ibata, Rodrigo +5 more
The existence of mutually correlated thin and rotating planes of satellite galaxies around both the Milky Way (MW) and Andromeda (M31) calls for an explanation. Previous work in Milgromian dynamics (MOND) indicated that a past MW-M31 encounter might have led to the formation of these satellite planes. We perform the first-ever hydrodynamical MOND …