Search Publications
Assessment of Phobos gravity field determination from both near polar and near equatorial orbital flyby data
Andert, T.; Li, F.; Yan, J. G. +5 more
The C20 and C22 coefficients of the Phobos gravity field are key parameters to constrain the internal structure of the Martian moon, but reliable observed values of these parameters are still missing. In this paper, we demonstrate, through a combination of forward and inverse modelling of simulated Doppler spacecraft tracking…
Narrow vs. broad-line Seyfert 1 galaxies: X-ray, optical, and mid-infrared AGN characteristics
Popović, Luka Č.; Lakićević, Maša; Kovačević-Dojčinović, Jelena
investigated narrow-line Seyfert 1 galaxies (NLS1s) at optical, mid-infrared (MIR), and X-ray wavelengths, comparing them to the broad-line active galactic nuclei (BLAGNs). We found that black hole mass, coronal line luminosities, X-ray hardness ratio and X-ray, and optical and MIR luminosities are higher for the BLAGNs than for NLS1s, while polic…
Hour time-scale QPOs in the X-ray and radio emission of LS I +61°303
Cimò, G.; Chernyakova, M.; Massi, M. +2 more
LS I +61°303 is an X-ray binary with a radio outburst every ∼27 d. Previous studies of the stellar system revealed radio microflares superimposed on the large radio outburst. We present here new radio observations of LS I +61°303 at 2.2 GHz with the Westerbork Synthesis Radio Telescope (WSRT). Using various timing analysis methods, we find signifi…
The character of the warm ionized medium
Geyer, Marisa; Walker, Mark A.
Herschel observations of far-infrared N+ emission lines have demonstrated that dense plasma, with n_ e∼ 30 cm^{-3}, is ubiquitous in the inner Galactic plane. By combining the information from Herschel with other tracers of ionized gas, we build a picture of this dense plasma. We adopt a collisional ionization model, so the analysis is …
A magnetic study of the δ Scuti variable HD 21190 and the close solar-type background star CPD -83°64B
Ilyin, I.; Niemczura, E.; Hubrig, S. +3 more
HD 21190 is a known δ Scuti star showing Ap star characteristics and a variability period of 3.6 h discovered by the Hipparcos mission. Using Gaia DR1 data for an astrometric analysis, it was recently suggested that HD 21190 forms a physical binary system with the companion CPD -83° 64B. An atmospheric chemical analysis based on High Accuracy Radi…
The role of external far-ultraviolet irradiation in the survival of astrophysical ices in Elias 29
Rocha, W. R. M.; Pilling, S.
The survival of astrophysical ices in star-forming regions depends on the suitability of temperature, density and radiation conditions. In this article, the role of the interstellar radiation field (ISRF) on ices in Elias 29 is addressed. This object is the most luminous protostar in the ρ Oph E molecular cloud and is surrounded by many young stel…
Multiconfiguration Dirac-Hartree-Fock calculations of energy levels and radiative rates of Fe VII
Li, Yang; Xu, Xiaokai; Li, Bowen +2 more
Detailed calculations are performed for 134 fine-structure levels of the 3p63d2, 3p63d4s, 3p53d3 and 3p63d4p configurations in Fe VII using the multiconfiguration Dirac-Hartree-Fock (MCDHF) and relativistic configuration interaction (RCI) methods. Important electron correlation effe…
A photometric study of globular clusters observed by the APOGEE survey
Masseron, Thomas; Monelli, Matteo; García-Hernández, D. A. +8 more
In this paper, we describe the photometric and spectroscopic properties of multiple populations in seven northern globular clusters. In this study, we employ precise ground-based photometry from the private collection of Stetson, space photometry from the Hubble Space Telescope (HST), literature abundances of Na and O, and Apache Point Observatory…
Decoupled black hole accretion and quenching: the relationship between BHAR, SFR and quenching in Milky Way- and Andromeda-mass progenitors since z = 2.5
Morrison, G.; Papovich, C.; Glazebrook, K. +13 more
We investigate the relationship between the black hole accretion rate (BHAR) and star formation rate (SFR) for Milky Way (MW) and Andromeda (M31)-mass progenitors from z = 0.2 to 2.5. We source galaxies from the Ks-band-selected ZFOURGE survey, which includes multiwavelength data spanning 0.3-160 µm. We use decomposition software …
A Hubble Space Telescope imaging study of four FeLoBAL quasar host galaxies
Vestergaard, M.; Fan, X.; Lawther, D.
We study the host galaxies of four Iron Low-Ionization Broad Absorption-line Quasars (FeLoBALs), using Hubble Space Telescope imaging data, investigating the possibility that they represent a transition between an obscured active galactic nucleus (AGN) and an ordinary optical quasar. In this scenario, the FeLoBALs represent the early stage of merg…