Search Publications
Ultracool dwarf benchmarks with Gaia primaries
Gromadzki, M.; Caballero, J. A.; Montes, D. +14 more
We explore the potential of Gaia for the field of benchmark ultracool/brown dwarf companions, and present the results of an initial search for metal-rich/metal-poor systems. A simulated population of resolved ultracool dwarf companions to Gaia primary stars is generated and assessed. Of the order of ∼24 000 companions should be identifiable outsid…
The VLT-FLAMES Tarantula Survey. XXVII. Physical parameters of B-type main-sequence binary systems in the Tarantula nebula
Howarth, I. D.; Crowther, P. A.; Dufton, P. L. +14 more
A spectroscopic analysis has been undertaken for the B-type multiple systems (excluding those with supergiant primaries) in the VLT-FLAMES Tarantula Survey (VFTS). Projected rotational velocities, vesini, for the primaries have been estimated using a Fourier Transform technique and confirmed by fitting rotationally broadened profiles. A…
SXP 15.6: X-ray spectral and temporal properties of a newly discovered pulsar in the Small Magellanic Cloud
Haberl, F.; Zezas, A.; Antoniou, V. +1 more
We report on the X-ray spectral and temporal properties of the Be/X-ray binary system XMMU J004855.5-734946 located in the Small Magellanic Cloud. The system was monitored by Swift/XRT during a moderate outburst in 2016 July, while an unanticipated Chandra target of opportunity observation was triggered when the luminosity of the system was greate…
Follow-up of isolated neutron star candidates from the eROSITA survey
Motch, C.; Pires, A. M.; Schwope, A. D.
Peculiar groups of X-ray emitting isolated neutron stars, which include magnetars, the "magnificent seven", and central compact objects in supernova remnants, escape detection in standard pulsar surveys. Yet, they constitute a key element in understanding the neutron star evolution and phenomenology. Their use in population studies in the galactic…
The Local Spiral Arm in the LAMOST-Gaia Common Stars?
Zhang, Yong; Wu, Yue; Liu, Chao +7 more
Using the LAMOST-Gaia common stars, we demonstrate that the in-plane velocity fields for the nearby young stars are significantly different from those for the old ones. For the young stars, the probably perturbed velocities that are similar to the old population are mostly removed from the velocity maps in the X-Y plane. The residual velocity fiel…
A Very Large (θ E ≳ 40″) Strong Gravitational Lens Selected with the Sunyaev-Zel’dovich Effect: PLCK G287.0+32.9 (z = 0.38)
Koekemoer, Anton M.; Zitrin, Adi; Nonino, Mario +7 more
Since galaxy clusters sit at the high end of the mass function, the number of galaxy clusters both massive and concentrated enough to yield particularly large Einstein radii poses useful constraints on cosmological and structure formation models. To date, less than a handful of clusters are known to have Einstein radii exceeding ∼ 40\prime\pr…
A Multi-wavelength Analysis of Binary-AGN Candidate PSO J334.2028+01.4075
Gezari, Suvi; Gültekin, Kayhan; Runnoe, Jessie +4 more
We present an analysis of the first Chandra observation of PSO J334.2028+01.4075 (PSO J334), targeted as a binary-AGN candidate based on periodic variations of the optical flux. With no prior targeted X-ray coverage for PSO J334, our new 40 ks Chandra observation allows for the opportunity to differentiate between a single- or binary-AGN system, a…
Multiple kinematical populations in Vela OB2 from Gaia DR1 data
Randich, S.; Micela, G.; Jeffries, R. D. +3 more
Context. Recent results using radial-velocity measurements from the Gaia-ESO Survey have led to the discovery of multiple kinematic populations across the Vela OB2 association. We present here a proper-motion study of the same region.
Aims: Our aim is to test whether or not the radial-velocity populations have a counterpart in proper-motion s…
Uncrowding R 136 from VLT/SPHERE extreme adaptive optics
Avenhaus, H.; Robbe-Dubois, S.; Vakili, F. +12 more
This paper presents the sharpest near-IR images of the massive cluster R 136 to date, based on the extreme adaptive optics of the SPHERE focal instrument implemented on the ESO Very Large Telescope and operated in its IRDIS imaging mode.The crowded stellar population in the core of the R 136 starburst compact cluster remains still to be characteri…
Diffuse radio emission in MACS J0025.4-1222: the effect of a major merger on bulk separation of ICM components
Riseley, C. J.; Scaife, A. M. M.; Wise, M. W. +1 more
Context. Mergers of galaxy clusters are among the most energetic events in the Universe. These events have significant impact on the intra-cluster medium, depositing vast amounts of energy, often in the form of shocks, as well as heavily influencing the properties of the constituent galaxy population. Many clusters have been shown to host large-sc…