Search Publications
The very faint hard state of the persistent neutron star X-ray binary SLX 1737-282 near the Galactic Centre
Haberl, F.; Ponti, G.; De Marco, B. +2 more
We report on a detailed study of the spectral and temporal properties of the neutron star low-mass X-ray binary SLX 1737-282, which is located only ∼1° away from Sgr A*. The system is expected to have a short orbital period, even within the ultracompact regime, given its persistent nature at low X-ray luminosities and the long duration thermonucle…
Interstellar polarization and extinction towards the young open cluster NGC 1502
Paunzen, E.; Topasna, G. A.; Kaltcheva, N. T.
Aims: NGC 1502 is located at the periphery of the Cam OB1 association and probably within the Orion Spur, with published distance estimates varying between 0.7 and 1.5 kpc. We combine new polarimetric observations and existing uvbyβ and UBV photometries to provide new estimates of the cluster's parameters.
Methods: We present new multi-w…
A high dust emissivity index β for a CO-faint galaxy in a filamentary Lyα nebula at z = 3.1
Hayes, Matthew; Kohno, Kotaro; Tanaka, Ichi +15 more
We present CO J = 4-3 line and 3 mm dust continuum observations of a 100 kpc-scale filamentary Lyα nebula (SSA22 LAB18) at z = 3.1 using the Atacama Large Millimeter/submillimeter Array (ALMA). We detected the CO J = 4-3 line at a systemic zCO = 3.093 ± 0.001 at 11 σ from one of the ALMA continuum sources associated with the Lyα filamen…
Non-equilibrium ionization by a periodic electron beam. II. Synthetic Si IV and O IV transition region spectra
Dudík, Jaroslav; Dzifčáková, Elena
Context. Transition region (TR) spectra typically show the Si IV 1402.8 Å line to be enhanced by a factor of 5 or more compared to the neighboring O IV 1401.2 Å, contrary to predictions of ionization equilibrium models and the Maxwellian distribution of particle energies. Non-equilibrium effects in TR spectra are therefore expected.
Aims: To …
A Spatially Resolved Study of X-Ray Properties in Superbubble 30 Dor C with XMM-Newton
Matsumoto, Hironori; Fukui, Yasuo; Sano, Hidetoshi +4 more
We carry out a spatially resolved spectral analysis with a physical scale of ∼10 pc in X-ray for the superbubble 30 Dor C, which has the largest diameter of ∼80 pc and the brightest non-thermal emission in superbubbles, for the first time. We aim at investigating spatial variation of the physical properties of non-thermal emission as detected in s…
A Correction for IUE UV Flux Distributions from Comparisons with CALSPEC
Bianchi, Luciana; Bohlin, Ralph C.
A collection of spectral energy distributions (SEDs) is available in the Hubble Space Telescope (HST) CALSPEC database that is based on calculated model atmospheres for pure hydrogen white dwarfs (WDs). A much larger set (∼100,000) of UV SEDs covering the range (1150-3350 Å) with somewhat lower quality are available in the IUE database. IUE low-di…
Spectroastrometric Study of Ro-vibrational CO Emission from the Herbig Ae Star HD 179218 with ISHELL on the NASA Infrared Telescope Facility
Najita, Joan R.; Brittain, Sean D.; Carr, John S.
We present analysis of commissioning M-band data acquired with the infrared echelle spectrograph (iSHELL) on NASA’s Infrared Telescope Facility. In this paper we describe the delivered performance of the instrument for these M-band observations and the data reduction process. The feasibility of using iSHELL for spectro-astrometry is tested on the …
Infrared colours and inferred masses of metal-poor giant stars in the Kepler field
Schlaufman, Kevin C.; Kennedy, G. M.; Casey, A. R. +1 more
Intrinsically luminous giant stars in the Milky Way are the only potential volume-complete tracers of the distant disc, bulge, and halo. The chemical abundances of metal-poor giants also reflect the compositions of the earliest star-forming regions, providing the initial conditions for the chemical evolution of the Galaxy. However, the intrinsic r…
Observational status of Tachyon Natural Inflation and reheating
Nozari, Kourosh; Rashidi, Narges; Grøn, Øyvind
We study observational viability of Natural Inflation with a tachyon field as inflaton. By obtaining the main perturbation parameters in this model, we perform a numerical analysis on the parameter space of the model and in confrontation with 68% and 95% CL regions of Planck2015 data. By adopting a warped background geometry, we find some new cons…
The Star Formation Reference Survey - II. Activity demographics and host-galaxy properties for infrared-selected galaxies
Zezas, A.; Ashby, M. L. N.; Willner, S. P. +1 more
We present activity demographics and host-galaxy properties of infrared-selected galaxies in the local Universe, using the representative Star Formation Reference Survey (SFRS). Our classification scheme is based on a combination of optical emission-line diagrams (BPT) and infrared (IR)-colour diagnostics. Using the weights assigned to the SFRS ga…