Search Publications

Long-term evolutions of the cyclotron line energies in Her X-1, Vela X-1, and Cen X-3 as observed with Swift/BAT
DOI: 10.1093/mnras/stz264 Bibcode: 2019MNRAS.484.3797J

Santangelo, A.; Ducci, L.; Zhang, S. +3 more

We study the long-term evolution of the centroid energy of cyclotron lines - often referered to as cyclotron resonance scattering features (CRSFs) - in Her X-1, Vela X-1, and Cen X-3, using survey observations of the Burst Alert Telescope onboard Swift. We find a significant decrease of the fundamental CRSF energy in Her X-1 and the first harmonic…

2019 Monthly Notices of the Royal Astronomical Society
INTEGRAL 25
Solar wind charge exchange in cometary atmospheres. III. Results from the Rosetta mission to comet 67P/Churyumov-Gerasimenko
DOI: 10.1051/0004-6361/201834881 Bibcode: 2019A&A...630A..37S

Alho, Markku; Simon Wedlund, Cyril; Nilsson, Hans +12 more

Context. Solar wind charge-changing reactions are of paramount importance to the physico-chemistry of the atmosphere of a comet. The ESA/Rosetta mission to comet 67P/Churyumov-Gerasimenko (67P) provides a unique opportunity to study charge-changing processes in situ.
Aims: To understand the role of these reactions in the evolution of the sola…

2019 Astronomy and Astrophysics
Rosetta 25
Possible Evidence for Cosmic-Ray Acceleration in the Type Ia SNR RCW 86: Spatial Correlation between TeV Gamma-Rays and Interstellar Atomic Protons
DOI: 10.3847/1538-4357/ab108f Bibcode: 2019ApJ...876...37S

Rowell, G.; Fukui, Y.; Mitsuishi, I. +13 more

We present a detailed morphological study of TeV gamma-rays, synchrotron radiation, and interstellar gas in the young Type Ia supernova remnant (SNR) RCW 86. We find that the interstellar atomic gas shows good spatial correlation with the gamma-rays, indicating that the TeV gamma-rays from RCW 86 are likely predominantly of hadronic origin. In con…

2019 The Astrophysical Journal
XMM-Newton 25
Milky Way Tomography with the SkyMapper Southern Survey. I. Atmospheric Parameters and Distances of One Million Red Giants
DOI: 10.3847/1538-4365/ab1f72 Bibcode: 2019ApJS..243....7H

Wolf, C.; Wang, H. -F.; Huang, Y. +7 more

Accurate determinations of atmospheric parameters (effective temperature T eff, surface gravity log g, and metallicity [Fe/H]) and distances for large complete samples are of vital importance for various Galactic studies. We have developed a photometric method to select red giant stars and estimate their atmospheric parameters from the …

2019 The Astrophysical Journal Supplement Series
Gaia 25
The W UMa binaries USNO-A2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac: light curve solutions and global parameters based on Gaia distances
DOI: 10.1088/1674-4527/19/1/14 Bibcode: 2019RAA....19...14K

Popov, Velimir A.; Petrov, Nikola I.; Kjurkchieva, Diana P. +1 more

We present photometric observations in Sloan filters g‧, i‧ of the eclipsing W UMa stars USNO-A2.0 1350-17365531, V471 Cas, V479 Lac and V560 Lac. The sinusoidal-like O - C diagram of V471 Cas indicates the presence of a third body with mass 0.12 M (a red dwarf) at distance 897 R . The O - C diagram of V479 Lac reveals a p…

2019 Research in Astronomy and Astrophysics
Gaia 25
Precise radial velocities of giant stars. XII. Evidence against the proposed planet Aldebaran b
DOI: 10.1051/0004-6361/201834028 Bibcode: 2019A&A...625A..22R

Trifonov, Trifon; Stock, Stephan; Reffert, Sabine +2 more

Context. Radial-velocity variations of the K giant star Aldebaran (α Tau) were first reported in the early 1990s. After subsequent analyses, the radial-velocity variability with a period of ∼629 d has recently been interpreted as caused by a planet of several Jovian masses.
Aims: We want to further investigate the hypothesis of an extrasolar …

2019 Astronomy and Astrophysics
Gaia 25
Dust-to-gas Ratio Resurgence in Circumstellar Disks Due to the Formation of Giant Planets: The Case of HD 163296
DOI: 10.3847/1538-4357/ab18f5 Bibcode: 2019ApJ...877...50T

Marzari, F.; Testi, L.; Polychroni, D. +1 more

The amount of dust present in circumstellar disks is expected to steadily decrease with age due to the growth from µm-sized particles to planetesimals and planets. Mature circumstellar disks, however, can be observed to contain significant amounts of dust and possess high dust-to-gas ratios. Using HD 163296 as our case study, we explore how …

2019 The Astrophysical Journal
Gaia 25
Seismic modelling of early B-type pulsators observed by BRITE - I. θ Ophiuchi
DOI: 10.1093/mnras/stz639 Bibcode: 2019MNRAS.485.3544W

Moffat, Anthony F. J.; Pablo, Herbert; Walczak, Przemysław +8 more

We analyse time-series observations from the BRITE-Constellation of the well-known β Cephei type star θ Ophiuchi. Seven previously known frequencies were confirmed and 19 new frequency peaks were detected. In particular, high-order g modes, typical for the SPB (Slowly Pulsating B-type star) pulsators, are uncovered. These low-frequency modes are a…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 25
A search for gravitationally lensed quasars and quasar pairs in Pan-STARRS1: spectroscopy and sources of shear in the diamond 2M1134-2103
DOI: 10.1093/mnras/stz1142 Bibcode: 2019MNRAS.486.4987R

Fassnacht, Christopher D.; Chen, Geoff C. -F.; Nelson, George J. +4 more

We present results of a systematic search for gravitationally lensed quasars in Pan-STARRS1. Our final sample of candidates comprises of 91 systems, not including 25 rediscovered lensed quasars and quasar pairs. In the absence of spectroscopy to verify the lensing nature of the candidates, the main sources of contaminants are likely to be quasar p…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 25
Cassini-VIMS observations of Saturn's main rings: II. A spectrophotometric study by means of Monte Carlo ray-tracing and Hapke's theory
DOI: 10.1016/j.icarus.2018.07.010 Bibcode: 2019Icar..317..242C

Clark, R. N.; Nicholson, P. D.; D'Aversa, E. +9 more

This work is the second in a series of manuscripts devoted to the investigation of the spectrophotometric properties of Saturn's rings from Cassini-VIMS (Visible and Infrared Mapping Spectrometer) observations. The dataset used for this analysis is represented by ten radial spectrograms of the rings which have been derived in Filacchione et al. (2…

2019 Icarus
Cassini 25