Search Publications
First gas-phase metallicity gradients of 0.1 ≲ z ≲ 0.8 galaxies with MUSE
Finley, Hayley; Carton, David; Brinchmann, Jarle +8 more
Galaxies at low-redshift typically possess negative gas-phase metallicity gradients (centres more metal-rich than their outskirts), whereas it is not uncommon to observe positive metallicity gradients in higher-redshift galaxies (z ≳ 0.6). Bridging these epochs, we present gas-phase metallicity gradients of 84 star-forming galaxies between 0.08 &l…
Super-Eddington accretion on to the neutron star NGC 7793 P13: Broad-band X-ray spectroscopy and ultraluminous X-ray sources
Harrison, F. A.; Ptak, A.; Stern, D. +8 more
We present a detailed, broad-band X-ray spectral analysis of the ultraluminous X-ray source (ULX) pulsar NGC 7793 P13, a known super-Eddington source, utilizing data from the XMM-Newton, NuSTAR and Chandra observatories. The broad-band XMM-Newton+NuSTAR spectrum of P13 is qualitatively similar to the rest of the ULX sample with broad-band coverage…
Investigation of the inner structures around HD 169142 with VLT/SPHERE
Rouan, D.; Ménard, F.; Quanz, S. P. +47 more
We present observations of the Herbig Ae star HD 169142 with the VLT/SPHERE instruments InfraRed Dual-band Imager and Spectrograph (IRDIS) (K1K2 and H2H3 bands) and the Integral Field Spectrograph (IFS) (Y, J and H bands). We detect several bright blobs at ∼180 mas separation from the star, and a faint arc-like structure in the IFS data. Our refer…
The age-velocity dispersion relation of the Galactic discs from LAMOST-Gaia data
Liu, Chao; Yu, Jincheng
We present the age-velocity dispersion relation (AVR) in three dimensions in the solar neighbourhood using 3564 commonly observed sub-giant/red giant branch stars selected from The Large Sky Area Multi-Object Fiber Spectroscopic Telescope, which gives the age and radial velocity, and Gaia, which measures the distance and proper motion. The stars a…
The Chandra COSMOS Legacy Survey: Compton thick AGN at high redshift
Vignali, C.; Gilli, R.; Comastri, A. +8 more
The existence of a large population of Compton thick (CT; NH > 1024 cm-2) active galactic nuclei (AGN) is a key ingredient of most cosmic X-ray background synthesis models. However, direct identification of these sources, especially at high redshift, is difficult due to flux suppression and complex spectral shap…
Extended main sequence turnoffs in open clusters as seen by Gaia - I. NGC 2818 and the role of stellar rotation
Cabrera-Ziri, I.; Usher, C.; Bastian, N. +5 more
We present an analysis of the relatively low mass (∼2400 M⊙), ∼800 Myr, Galactic open cluster, NGC 2818, using Gaia DR2 results combined with VLT/FLAMES spectroscopy. Using Gaia DR2 proper motions and parallax measurements, we are able to select a clean sample of cluster members. This cluster displays a clear extended main sequence turn…
Planck's view on the spectrum of the Sunyaev-Zeldovich effect
Bertoldi, Frank; Chluba, Jens; Basu, Kaustuv +1 more
We present a detailed analysis of the stacked frequency spectrum of a large sample of galaxy clusters using Planck data, together with auxiliary data from the AKARI and IRAS missions. Our primary goal is to search for the imprint of relativistic corrections to the thermal Sunyaev-Zeldovich effect (tSZ) spectrum, which allow to measure the temperat…
The role of galaxies and AGN in reionizing the IGM - I. Keck spectroscopy of 5 < z < 7 galaxies in the QSO field J1148+5251
Stark, Daniel P.; Ellis, Richard S.; Bosman, Sarah E. I. +7 more
We introduce a new method for determining the influence of galaxies and active galactic nuclei (AGN) on the intergalactic medium (IGM) at high redshift and illustrate its potential via a first application to the field of the z = 6.42 QSO J1148+5251. Correlating spatial positions Lyman break galaxies (LBGs) with the Lyman alpha forest seen in the s…
Age-resolved chemistry of red giants in the solar neighbourhood
Bovy, Jo; Majewski, Steven R.; Feuillet, Diane K. +7 more
In the age of high-resolution spectroscopic stellar surveys of the Milky Way, the number of stars with detailed abundances of multiple elements is rapidly increasing. These elemental abundances are directly influenced by the evolutionary history of the Galaxy, but this can be difficult to interpret without an absolute timeline of the abundance enr…
LLAMA: normal star formation efficiencies of molecular gas in the centres of luminous Seyfert galaxies
Lutz, D.; Genzel, R.; Sturm, E. +23 more
Using new Atacama Pathfinder Experiment and James Clerk Maxwell Telescope spectroscopy of the CO 2→1 line, we undertake a controlled study of cold molecular gas in moderately luminous (Lbol = 1043-44.5 erg s-1) active galactic nuclei (AGN) and inactive galaxies from the Luminous Local AGN with Matched Analogs (LLAM…