Search Publications
Neutral carbon and highly excited CO in a massive star-forming main sequence galaxy at z = 2.2
Daddi, Emanuele; Aravena, Manuel; Decarli, Roberto +5 more
We used the Plateau De Bure Interferometer to observe multiple CO and neutral carbon transitions in a z = 2.2 main sequence disk galaxy, BX610. Our observation of CO(7-6), CO(4-3), and both far-infrared (FIR) [CI] lines complements previous observations of Hα and low-J CO, and reveals a galaxy that is vigorously forming stars with UV fields (Log(G…
The water line emission and ortho-to-para ratio in the Orion Bar photon-dominated region
Le Petit, F.; Roueff, E.; Lis, D. C. +2 more
Context. The ortho-to-para ratio (OPR) of water in the interstellar medium (ISM) is often assumed to be related to the formation temperature of water molecules, making it a potentially interesting tracer of the thermal history of interstellar gas.
Aims: A very low OPR of 0.1-0.5 was previously reported in the Orion Bar photon-dominated region…
Stellar populations of galaxies in the ALHAMBRA survey up to z ∼ 1. IV. Properties of quiescent galaxies on the stellar mass-size plane
Cenarro, A. J.; López-Sanjuan, C.; Perea, J. +7 more
Aims: We perform a comprehensive study of the stellar population properties (formation epoch, age, metallicity, and extinction) of quiescent galaxies as a function of size and stellar mass to constrain the physical mechanism governing the stellar mass assembly and the likely evolutive scenarios that explain their growth in size.
Methods:…
The blue straggler population of the old open cluster Berkeley 17
Chen, W. P.; Beccari, Giacomo; Vaidya, Kaushar +1 more
Context. Blue straggler stars (BSSs) are observed in Galactic globular clusters and old open clusters. The radial distribution of BSSs has been used to diagnose the dynamical evolution of globular clusters. For the first time, with a reliable sample of BSSs identified with Gaia DR2, we conduct such an analysis for an open cluster.
Aims: We ai…
Comparative study of photo-produced ionosphere in the close environment of comets
Galand, M.; Beth, A.; Heritier, K. L.
Context. The Giotto and Rosetta missions gave us the unique opportunity of probing the close environment of cometary ionospheres of 1P/Halley (1P) and 67P/Churyumov-Gerasimenko (67P). The plasma conditions encountered at these two comets were very different from each other, which mainly stem from the different heliocentric distances, which drive p…
Influence of inelastic collisions with hydrogen atoms on the non-local thermodynamic equilibrium line formation for Fe I and Fe II in the 1D model atmospheres of late-type stars
Yakovleva, S. A.; Belyaev, A. K.; Sitnova, T. +1 more
Context. Iron plays a crucial role in studies of late-type stars. In their atmospheres, neutral iron is the minority species, and lines of Fe I are subject to the departures from local thermodynamic equilibrium (LTE). In contrast, one believes that LTE is a realistic approximation for Fe II lines. The main source of the uncertainties in the non-LT…
ARGOS at the LBT. Binocular laser guided ground-layer adaptive optics
Genzel, R.; Quirrenbach, A.; Beckmann, U. +48 more
Having completed its commissioning phase, the Advanced Rayleigh guided Ground-layer adaptive Optics System (ARGOS) facility is coming online for scientific observations at the Large Binocular Telescope (LBT). With six Rayleigh laser guide stars in two constellations and the corresponding wavefront sensing, ARGOS corrects the ground-layer distortio…
The TeV-emitting radio galaxy 3C 264. VLBI kinematics and SED modeling
Vignali, C.; Grandi, P.; Boccardi, B. +5 more
Context. In March 2018, the detection by VERITAS of very-high-energy emission (VHE > 100 GeV) from 3C 264 was reported. This is the sixth, and second most distant, radio galaxy ever detected in the TeV regime.
Aims: In this article we present a radio and X-ray analysis of the jet in 3C 264. We determine the main physical parameters of the …
Constraints on positron annihilation kinematics in the inner Galaxy
Diehl, Roland; Siegert, Thomas; Panther, Fiona H. +4 more
Context. The annihilation of cosmic positrons with electrons in the interstellar medium results in the strongest persistent γ-ray line signal in the sky. For the past 50 yr, this 511 keV emission - predominantly from the galactic bulge region and from a low surface-brightness disk - has puzzled observers and theoreticians. A key issue for understa…
Molecular gas in radio galaxies in dense megaparsec-scale environments at z = 0.4-2.6
Castignani, G.; De Zotti, G.; Benoist, C. +4 more
Context. Low luminosity radio galaxies (LLRGs) typically reside in dense megaparsec-scale environments and are often associated with brightest cluster galaxies (BCGs). They are an excellent tool to study the evolution of molecular gas reservoirs in giant ellipticals, even close to the active galactic nucleus.
Aims: We investigate the role of …