Search Publications

Testing modified gravity with wide binaries in Gaia DR2
DOI: 10.1093/mnras/stz1898 Bibcode: 2019MNRAS.488.4740P

Sutherland, Will; Pittordis, Charalambos

Several recent studies have shown that very wide binary stars can potentially provide an interesting test for modified-gravity theories which attempt to emulate dark matter; these systems should be almost Newtonian according to standard dark-matter theories, while the predictions for MOND-like theories are distinctly different, if the various obse…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 57
LoTSS/HETDEX: Optical quasars. I. Low-frequency radio properties of optically selected quasars
DOI: 10.1051/0004-6361/201833892 Bibcode: 2019A&A...622A..11G

Prandoni, I.; Callingham, J. R.; Shimwell, T. W. +17 more

The radio-loud/radio-quiet (RL/RQ) dichotomy in quasars is still an open question. Although it is thought that accretion onto supermassive black holes in the centre the host galaxies of quasars is responsible for some radio continuum emission, there is still a debate as to whether star formation or active galactic nuclei (AGN) activity dominate th…

2019 Astronomy and Astrophysics
Herschel 57
The Main Sequence at z ∼ 1.3 Contains a Sizable Fraction of Galaxies with Compact Star Formation Sizes: A New Population of Early Post-starbursts?
DOI: 10.3847/2041-8213/ab1f92 Bibcode: 2019ApJ...877L..23P

Daddi, E.; Elbaz, D.; Le Floc'h, E. +20 more

Atacama Large Millimeter/submillimeter Array (ALMA) measurements for 93 Herschel-selected galaxies at 1.1 ≤ z ≤ 1.7 in COSMOS reveal a sizable (>29%) population with compact star formation (SF) sizes, lying on average >×3.6 below the optical stellar mass (M )-size relation of disks. This sample widely spans the star-forming main …

2019 The Astrophysical Journal
Herschel 57
Flaring Activity of Proxima Centauri from TESS Observations: Quasiperiodic Oscillations during Flare Decay and Inferences on the Habitability of Proxima b
DOI: 10.3847/1538-4357/ab41f5 Bibcode: 2019ApJ...884..160V

Pál, András; Moór, Attila; Vida, Krisztián +3 more

We analyze the light curve of the M5.5 dwarf Proxima Centauri obtained by the Transiting Exoplanet Survey Satellite (TESS) in Sectors 11 and 12. In the ≈50 day long light curve we identified and analyzed 72 flare events. The flare rate was 1.49 events per day; in total, 7.2% of the observing time was classified as flaring. The estimated flare ener…

2019 The Astrophysical Journal
Gaia 57
A new, clean catalogue of extragalactic non-nuclear X-ray sources in nearby galaxies
DOI: 10.1093/mnras/sty3403 Bibcode: 2019MNRAS.483.5554E

Earnshaw, H. P.; Roberts, T. P.; Mateos, S. +2 more

We have created a new, clean catalogue of extragalactic non-nuclear X-ray sources by correlating the 3XMM-DR4 data release of the XMM-Newton Serendipitous Source Catalogue with the Third Reference Catalogue of Bright Galaxies and the Catalogue of Neighbouring Galaxies, using an improved version of the method presented in Walton et al. Our catalogu…

2019 Monthly Notices of the Royal Astronomical Society
XMM-Newton 57
Hunting Axion Dark Matter with Protoplanetary Disk Polarimetry
DOI: 10.1103/PhysRevLett.122.191101 Bibcode: 2019PhRvL.122s1101F

Tazaki, Ryo; Toma, Kenji; Fujita, Tomohiro

We find that the polarimetric observations of protoplanetary disks are useful to search for ultralight axion dark matter. Axion dark matter predicts the rotation of the linear polarization plane of propagating light, and protoplanetary disks are ideal targets to observe it. We show that a recent observation puts the tightest constraint on the axio…

2019 Physical Review Letters
Gaia 57
Detection of the nearest Jupiter analogue in radial velocity and astrometry data
DOI: 10.1093/mnras/stz2912 Bibcode: 2019MNRAS.490.5002F

Janson, Markus; Anglada-Escudé, Guillem; Feng, Fabo +4 more

The presence of Jupiter is crucial to the architecture of the Solar system and models underline this to be a generic feature of planetary systems. We find the detection of the difference between the position and motion recorded by the contemporary astrometric satellite Gaia and its precursor Hipparcos can be used to discover Jupiter-like planets. …

2019 Monthly Notices of the Royal Astronomical Society
Gaia Hipparcos 57
Star cluster catalogues for the LEGUS dwarf galaxies
DOI: 10.1093/mnras/stz331 Bibcode: 2019MNRAS.484.4897C

Schaerer, D.; Östlin, G.; Herrero, A. +62 more

We present the star cluster catalogues for 17 dwarf and irregular galaxies in the HST Treasury Program `Legacy ExtraGalactic UV Survey' (LEGUS). Cluster identification and photometry in this sub-sample are similar to that of the entire LEGUS sample, but special methods were developed to provide robust catalogues with accurate fluxes due to low clu…

2019 Monthly Notices of the Royal Astronomical Society
eHST 57
Contact binaries at the short period cut-off - I. Statistics and the first photometric investigations of 10 totally eclipsing systems
DOI: 10.1093/mnras/stz715 Bibcode: 2019MNRAS.485.4588L

Li, Kai; Xia, Qi-Qi; Gao, Xing +5 more

The period distribution of contact binaries exhibits a very sharp short period cut-off at 0.22 d. In order to provide valuable information on this short period limit, we observed 10 totally eclipsing contact binaries with orbital periods near this cut-off. By detailed analysis using the W-D code, we determined that two of these systems are A-subty…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 57
Assessing the effect of lens mass model in cosmological application with updated galaxy-scale strong gravitational lensing sample
DOI: 10.1093/mnras/stz1902 Bibcode: 2019MNRAS.488.3745C

Shu, Yiping; Cao, Xiaoyue; Chen, Yun +1 more

By comparing the dynamical and lensing masses of early-type lens galaxies, one can constrain both the cosmological parameters and the density profiles of galaxies. We explore the constraining power on cosmological parameters and the effect of the lens mass model in this method with 161 galaxy-scale strong lensing systems, which is currently the la…

2019 Monthly Notices of the Royal Astronomical Society
eHST 56