Search Publications
Determining mass limits around HD 163296 through SPHERE direct imaging data
Barbieri, M.; Rouan, D.; Henning, T. +33 more
HD 163296 is a Herbig Ae/Be star known to host a protoplanetary disc with a ringed structure. To explain the disc features, previous works proposed the presence of planets embedded into the disc. We have observed HD 163296 with the near-infrared (NIR) branch of SPHERE composed by IRDIS (InfraRed Dual-band Imager and Spectrograph) and IFS (integral…
Extreme resonance line profile variations in the ultraviolet spectra of NGC 1624-2: probing the giant magnetosphere of the most strongly magnetized known O-type star
Martins, F.; Owocki, S. P.; Wade, G. A. +12 more
In this paper, we present high-resolution HST/COS observations of the extreme magnetic O star NGC 1624-2. These represent the first ultraviolet spectra of this archetypal object. We examine the variability of its wind-sensitive resonance lines, comparing it to that of other known magnetic O stars. In particular, the observed variations in the prof…
On the observational behaviour of the highly polarized Type IIn supernova SN 2017hcc
Eswaraiah, Chakali; Pandey, S. B.; Kumar, Brajesh +10 more
We present the results based on photometric (Swift UVOT), broad-band polarimetric (V and Rbands) and optical spectroscopic observations of the Type IIn supernova (SN) 2017hcc. Our study is supplemented with spectropolarimetric data available in literature for this event. The post-peak light-curve evolution is slow (∼0.2 mag 100 d-1 in b…
The metal-rich halo tail extended in |z|: a characterization with Gaia DR2 and APOGEE
Beers, Timothy C.; Chiappini, Cristina; Recio-Blanco, Alejandra +12 more
We report an analysis of the metal-rich tail ([Fe/H] > -0.75) of stars located at distances from the Galactic plane up to |z| ∼ 10 kpc, observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). We examine the chemistry, kinematics, and dynamics of this metal-rich sample using chemical abundances and radial velocities prov…
Modelling accretion disc emission with generalized temperature profile and its effect on AGN spectral energy distribution
Jin, Chichuan; Yuan, Weimin; Liu, He-Yang +3 more
The broad-band spectral energy distribution (SED) of active galactic nuclei (AGNs) is investigated for a well-selected sample composed of 23 Seyfert 1 galaxies observed simultaneously in the optical/ultraviolet (UV) and X-ray bands with the Neil Gehrels Swift Observatory. The optical to UV continuum spectra are modelled, for the first time, with e…
Can intrinsic alignments of elongated low-mass galaxies be used to map the cosmic web at high redshift?
Ferguson, Henry C.; Giavalisco, Mauro; Koekemoer, Anton M. +13 more
Hubble Space Telescope observations show that low-mass (M_*=10^9-10^{10} M_{⊙ }) galaxies at high redshift (z = 1.0-2.5) tend to be elongated (prolate) rather than disky (oblate) or spheroidal. This is explained in zoom-in cosmological hydrodynamical simulations by the fact that these galaxies are forming in cosmic web filaments where accretion ha…
The distance, rotation, and physical parameters of ζ Pup
Howarth, Ian D.; van Leeuwen, Floor
We scrutinize the Hipparcos parallax for the bright O supergiant ζ Pup and confirm that the implied distance of 332 ± 11 pc appears to be reliable. We then review the implications for the star's physical parameters and the consequences for the interpretation of Pphot, the 1.78-d photometric period. The inferred mass, radius, and luminos…
Thermal balance and comparison of gas and dust properties of dense clumps in the Hi-GAL survey
Rygl, K. L. J.; Elia, D.; Schisano, E. +7 more
We present a comparative study of physical properties derived from gas and dust emission in a sample of 1068 dense Galactic clumps. The sources are selected from the cross-match of the Herschel Infrared Galactic Plane Survey with 16 catalogues of NH3 line emission in its lowest inversion (1,1) and (2,2) transitions. The sample covers a …
Distinguishing circumstellar from stellar photometric variability in Eta Carinae
Gull, T. R.; Corcoran, M. F.; Madura, T. I. +14 more
The interacting binary Eta Carinae remains one of the most enigmatic massive stars in our Galaxy despite over four centuries of observations. In this work, its light curve from the ultraviolet to the near-infrared is analysed using spatially resolved HST observations and intense monitoring at the La Plata Observatory, combined with previously publ…
Young massive clusters in the interacting LIRG Arp 299: evidence for the dependence of star cluster formation and evolution on environment
Väisänen, P.; Ryder, S. D.; Randriamanakoto, Z. +1 more
Archival WFC3/UVIS imaging of Arp 299 (NGC 3690E+ NGC 3690W) is retrieved to investigate the young massive cluster (YMC) population of this ongoing merger. We extract 2182 cluster candidates, including 1323 high confidence photometric sources. Multiband photometry is matched with Yggdrasil models to estimate the age, mass, and extinction of each c…