Search Publications
Evidence for a Massive Warm-Hot Circumgalactic Medium around NGC 3221
Nicastro, Fabrizio; Mathur, Smita; Gupta, Anjali +3 more
We report a 3.4σ detection of the warm-hot, massive, extended circumgalactic medium (CGM) around an L ⋆ star-forming spiral galaxy NGC 3221, using deep Suzaku observations. The temperature of the gas is 106.1 K, comparable to that of the Milky Way CGM. The spatial extent of the gas is at least 150 kpc. For a β-model of densit…
Linear bias forecasts for emission line cosmological surveys
Merson, Alexander; Smith, Alex; Benson, Andrew +2 more
We forecast the linear bias for Hα-emitting galaxies at high redshift. To simulate a Euclid-like and a WFIRST-like survey, we place galaxies into a large-volume dark matter halo lightcone by sampling a library of luminosity-dependent halo occupation distributions (HODs), which is constructed using a physically motivated galaxy formation model. We …
A Gaia view of the two OB associations Cygnus OB2 and Carina OB1: the signature of their formation process
Lim, Beomdu; Nazé, Yaël; Gosset, Eric +1 more
OB associations are the prime star-forming sites in galaxies. However, the detailed formation process of such stellar systems still remains a mystery. In this context, identifying the presence of substructures may help in tracing the footprints of their formation process. Here, we present a kinematic study of the two massive OB associations Cygnus…
The compact multiple system HIP 41431
Molnár, L.; Latham, D. W.; Tokovinin, A. +4 more
The nearby (50 pc) K7V dwarf HIP 41431 (EPIC 212096658) is a compact three-tier hierarchy. Three K7V stars with similar masses, from 0.61 to 0.63 solar, make a triple-lined spectroscopic system where the inner binary with a period of 2.9 d is eclipsing, and the outer companion on a 59-d orbit exerts strong dynamical influence revealed by the eclip…
K2-290: a warm Jupiter and a mini-Neptune in a triple-star system
Kuzuhara, M.; Alonso, R.; Deeg, H. +41 more
We report the discovery of two transiting planets orbiting K2-290 (EPIC 249624646), a bright (V = 11.11) late F-type star residing in a triple-star system. It was observed during Campaign 15 of the K2 mission, and in order to confirm and characterize the system, follow-up spectroscopy and AO imaging were carried out using the FIES, HARPS, HARPS-N,…
Long-term evolutions of the cyclotron line energies in Her X-1, Vela X-1, and Cen X-3 as observed with Swift/BAT
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…
Solar wind charge exchange in cometary atmospheres. III. Results from the Rosetta mission to comet 67P/Churyumov-Gerasimenko
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…
Possible Evidence for Cosmic-Ray Acceleration in the Type Ia SNR RCW 86: Spatial Correlation between TeV Gamma-Rays and Interstellar Atomic Protons
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…
Milky Way Tomography with the SkyMapper Southern Survey. I. Atmospheric Parameters and Distances of One Million Red Giants
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 …
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
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…