Search Publications
A Spectroscopic Survey of Field Red Horizontal-branch Stars
Casetti-Dinescu, Dana I.; Afşar, Melike; Sneden, Christopher +3 more
A metallicity, chemical composition, and kinematic survey has been conducted for a sample of 340 candidate field red horizontal-branch (RHB) stars. Spectra with high resolution and high signal-to-noise ratio were gathered with the McDonald Observatory 2.7 m Tull and the Hobby-Eberly Telescope echelle spectrographs, and were used to determine effec…
The MURALES survey. I. A dual AGN in the radio galaxy 3C 459?
Marconi, A.; Capetti, A.; Gilli, R. +12 more
We observed the FR II radio galaxy 3C 459 (z = 0.22) with the MUSE spectrograph at the Very Large Telescope (VLT) as part of the MURALES project (a MUse RAdio Loud Emission line Snapshot survey). We detected diffuse nuclear emission and a filamentary ionized gas structure forming a one-sided, triangular-shaped region extending out to ∼80 kpc. The …
The Influence of Stellar Spin on Ignition of Thermonuclear Runaways
Galloway, Duncan K.; Kuulkers, Erik; Chenevez, Jérôme +8 more
Runaway thermonuclear burning of a layer of accumulated fuel on the surface of a compact star provides a brief but intense display of stellar nuclear processes. For neutron stars accreting from a binary companion, these events manifest as thermonuclear (type-I) X-ray bursts, and recur on typical timescales of hours to days. We measured the burst r…
A Gaia DR2 search for dwarf galaxies towards Fermi-LAT sources: implications for annihilating dark matter
Calore, Francesca; Ciucǎ, Ioana; Kawata, Daisuke +3 more
We make the first attempt to find dwarf galaxies in eight Fermi-LAT extended, unassociated, source fields using Gaia DR2. After probing previously unexplored heliocentric distances of d < 20 kpc with an extreme-deconvolution (XD) technique, we find no sign of a dwarf galaxy in any of these fields despite Gaia's excellent astrometric accuracy. O…
Pulse phase-resolved analysis of SMC X-3 during its 2016–2017 super-Eddington outburst
Weng, Shan-Shan; Ge, Ming-Yu; Zhao, Hai-Hui +2 more
The Be X-ray pulsar SMC X-3 underwent an extra long and ultraluminous giant outburst from 2016 August to 2017 March. The peak X-ray luminosity is up to
Testing statistical isotropy in cosmic microwave background polarization maps
Rath, Pranati K.; Samal, Pramoda Kumar; Panda, Srikanta +2 more
We apply our symmetry based Power tensor technique to test conformity of PLANCK Polarization maps with statistical isotropy. On a wide range of angular scales (l = 40 - 150), our preliminary analysis detects many statistically anisotropic multipoles in foreground cleaned full sky PLANCK polarization maps viz., COMMANDER and NILC. We also study the…
In-orbit performance and calibration of the Hard X-ray Imager onboard Hitomi (ASTRO-H)
Enoto, Teruaki; Yamaoka, Kazutaka; Fukazawa, Yasushi +38 more
The Hard X-ray Imager (HXI) onboard Hitomi (ASTRO-H) is an imaging spectrometer covering hard x-ray energies of 5 to 80 keV. Combined with the Hard X-ray Telescope, it enables imaging spectroscopy with an angular resolution of 1‧.7 half-power diameter, in a field of view of 9‧ × 9‧. The main imager is composed of f…
Compositional studies of Mare Moscoviense: New perspectives from Chandrayaan-1 VIS-NIR data
Bhatt, Megha; Mall, Urs; Bhardwaj, Anil +5 more
Moscoviense is one of the prominent mare-filled basin on the lunar far side holding key insights about volcanic activity on the far side. Here, we present spectral and elemental maps of mare Moscoviense, using the Moon Mineralogy Mapper (M3) and Infrared Spectrometer-2 (SIR-2) data-sets. The different mare units are mapped based on thei…
The two ultraluminous X-ray sources in the galaxy NGC 925
Mereghetti, S.; Wolter, A.; Esposito, P. +7 more
NGC 925 ULX-1 and ULX-2 are two ultraluminous X-ray sources (ULXs) in the galaxy NGC 925, at a distance of 8.5 Mpc. For the first time, we analysed high quality, simultaneous XMM-Newton and NuSTAR data of both sources. Although at a first glance ULX-1 resembles an intermediate mass black hole candidate (IMBH) because of its high X-ray luminosity […
Transport of Internetwork Magnetic Flux Elements in the Solar Photosphere
Rempel, Matthias; Bellot Rubio, Luis R.; Gošić, Milan +2 more
The motions of small-scale magnetic flux elements in the solar photosphere can provide some measure of the Lagrangian properties of the convective flow. Measurements of these motions have been critical in estimating the turbulent diffusion coefficient in flux-transport dynamo models and in determining the Alfvén wave excitation spectrum for corona…