Search Publications
Our Galaxy's youngest disc
Li, Chengdong; Binney, James
We investigate the structure of our Galaxy's young stellar disc by fitting the distribution functions (DFs) of a new family to 5D Gaia data for a sample of $47\, 000$ OB stars. Tests of the fitting procedure show that the young disc's DF would be strongly constrained by Gaia data if the distribution of Galactic dust were accurately known. The DF t…
Magnetic field topology, chemical spot distributions, and photometric variability of the Ap star φ Draconis
Neiner, C.; Kochukhov, O.; Papakonstantinou, N.
The primary component of the multiple star φ Dra is one of the brightest magnetic chemically peculiar stars in the northern sky. Here, we report results of a comprehensive study of the rotational photometric variability, binarity, magnetic field geometry, and surface chemical spot structure for this star. We derived a precise photometric rotationa…
The pre-He white dwarfs in eclipsing binaries - IV. WASP 1814+48 with multiperiodic pulsations
Hong, Kyeongsoo; Lee, Jae Woo; Park, Jang-Ho +1 more
For the EL CVn candidate 1SWASPJ181417.43+481117.0 (WASP 1814+48), we secured the first spectroscopic observations between 2015 April and 2021 March. Using the echelle spectra, the radial velocities (RVs) of the primary star were measured with its atmospheric parameters of Teff, 1 = 7770 ± 130 K and $v$1sin i = 47 ± 6 km s
The X-ray spectral-timing contribution of the stellar wind in the hard state of Cyg X-1
Wilms, J.; Uttley, P.; De Marco, B. +6 more
The clumpy stellar wind from the companion star in high-mass X-ray binaries causes variable, partial absorption of the emission from the X-ray source. We studied XMM-Newton observations from a 7.22 d long monitoring campaign, in order to constrain the effects of the stellar wind on the short-time-scale X-ray spectral-timing properties of Cygnus X-…
An edge-on orbit for the eccentric long-period planet HR 5183 b
Vanderburg, Andrew; Pearce, Logan A.; Venner, Alexander
The long-period giant planet HR 5183 b has one of the most extreme orbits among exoplanets known to date, and represents a test for models of their dynamical evolution. In this work, we use Hipparcos-Gaia astrometry to measure the orbital inclination of this planet for the first time and find $i=89.9^{+13.3\circ }_{-13.5}$, fully consistent with e…
New evidences in IRDC G333.73 + 0.37: colliding filamentary clouds, hub-filament system, and embedded cores
Dewangan, L. K.
To unravel the star formation process, we present a multi-scale and multi-wavelength study of the filamentary infrared dark cloud (IRDC) G333.73 + 0.37, which hosts previously known two H II regions located at its center. Each H II region is associated with a mid-infrared source, and is excited by a massive OB star. Two filamentary structures and …
SOFIA/HAWC+ observations of the Crab Nebula: dust properties from polarized emission
Pattle, Kate; Kirchschlager, Florian; De Looze, Ilse +14 more
Supernova remnants (SNRs) are well-recognized dust producers, but their net dust production rate remains elusive due to uncertainties in grain properties that propagate into observed dust mass uncertainties, and determine how efficiently these grains are processed by reverse shocks. In this paper, we present a detection of polarized dust emission …
Albedo variegation on Comet 67P/Churyumov-Gerasimenko
Buratti, Bonnie J.; Hicks, Michael D.; Davidsson, Björn J. R.
We here study the level of albedo variegation on the nucleus of Comet 67P/Churyumov-Gerasimenko. This is done by fitting the parameters of a standard photometric phase function model to disc-average radiance factor data in images acquired by the Rosetta/OSIRIS Narrow Angle Camera in the orange filter. Local discrepancies between the observed radia…
Impact of bar resonances in the velocity-space distribution of the solar neighbourhood stars in a self-consistent N-body Galactic disc simulation
Fujii, Michiko S.; Portegies Zwart, Simon; Baba, Junichi +3 more
The velocity-space distribution of the solar neighbourhood stars shows complex substructures. Most of the previous studies use static potentials to investigate their origins. Instead we use a self-consistent N-body model of the Milky Way, whose potential is asymmetric and evolves with time. In this paper, we quantitatively evaluate the similaritie…
Redshift space three-point correlation function of IGM at z < 0.48
Srianand, Raghunathan; Gaikwad, Prakash; Maitra, Soumak +1 more
Ly α forest decomposed into Voigt profile components allows us to study clustering properties of the intergalactic-medium and its dependence on various physical quantities. Here, we report the first detections of probability excess of low-z (i.e z < 0.48) Ly α absorber triplets over redshift-space scale of r∥ ≤ 8 pMpc (Mpc in physica…